------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ E L A B -- -- -- -- B o d y -- -- -- -- Copyright (C) 1997-2018, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Checks; use Checks; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Ch11; use Exp_Ch11; with Exp_Tss; use Exp_Tss; with Exp_Util; use Exp_Util; with Expander; use Expander; with Lib; use Lib; with Lib.Load; use Lib.Load; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Cat; use Sem_Cat; with Sem_Ch7; use Sem_Ch7; with Sem_Ch8; use Sem_Ch8; with Sem_Prag; use Sem_Prag; with Sem_Util; use Sem_Util; with Sinfo; use Sinfo; with Sinput; use Sinput; with Snames; use Snames; with Stand; use Stand; with Table; with Tbuild; use Tbuild; with Uintp; use Uintp; with Uname; use Uname; with GNAT.HTable; use GNAT.HTable; package body Sem_Elab is ----------------------------------------- -- Access-before-elaboration mechanism -- ----------------------------------------- -- The access-before-elaboration (ABE) mechanism implemented in this unit -- has the following objectives: -- -- * Diagnose at compile-time or install run-time checks to prevent ABE -- access to data and behaviour. -- -- The high-level idea is to accurately diagnose ABE issues within a -- single unit because the ABE mechanism can inspect the whole unit. -- As soon as the elaboration graph extends to an external unit, the -- diagnostics stop because the body of the unit may not be available. -- Due to control and data flow, the ABE mechanism cannot accurately -- determine whether a particular scenario will be elaborated or not. -- Conditional ABE checks are therefore used to verify the elaboration -- status of a local and external target at run time. -- -- * Supply elaboration dependencies for a unit to binde -- -- The ABE mechanism registers each outgoing elaboration edge for the -- main unit in its ALI file. GNATbind and binde can then reconstruct -- the full elaboration graph and determine the proper elaboration -- order for all units in the compilation. -- -- The ABE mechanism supports three models of elaboration: -- -- * Dynamic model - This is the most permissive of the three models. -- When the dynamic model is in effect, the mechanism performs very -- little diagnostics and generates run-time checks to detect ABE -- issues. The behaviour of this model is identical to that specified -- by the Ada RM. This model is enabled with switch -gnatE. -- -- * Static model - This is the middle ground of the three models. When -- the static model is in effect, the mechanism diagnoses and installs -- run-time checks to detect ABE issues in the main unit. In addition, -- the mechanism generates implicit Elaborate or Elaborate_All pragmas -- to ensure the prior elaboration of withed units. The model employs -- textual order, with clause context, and elaboration-related source -- pragmas. This is the default model. -- -- * SPARK model - This is the most conservative of the three models and -- impelements the semantics defined in SPARK RM 7.7. The SPARK model -- is in effect only when a context resides in a SPARK_Mode On region, -- otherwise the mechanism falls back to one of the previous models. -- -- The ABE mechanism consists of a "recording" phase and a "processing" -- phase. ----------------- -- Terminology -- ----------------- -- * ABE - An attempt to activate, call, or instantiate a scenario which -- has not been fully elaborated. -- -- * Bridge target - A type of target. A bridge target is a link between -- scenarios. It is usually a byproduct of expansion and does not have -- any direct ABE ramifications. -- -- * Call marker - A special node used to indicate the presence of a call -- in the tree in case expansion transforms or eliminates the original -- call. N_Call_Marker nodes do not have static and run-time semantics. -- -- * Conditional ABE - A type of ABE. A conditional ABE occurs when the -- elaboration or invocation of a target by a scenario within the main -- unit causes an ABE, but does not cause an ABE for another scenarios -- within the main unit. -- -- * Declaration level - A type of enclosing level. A scenario or target is -- at the declaration level when it appears within the declarations of a -- block statement, entry body, subprogram body, or task body, ignoring -- enclosing packages. -- -- * Early call region - A section of code which ends at a subprogram body -- and starts from the nearest non-preelaborable construct which precedes -- the subprogram body. The early call region extends from a package body -- to a package spec when the spec carries pragma Elaborate_Body. -- -- * Generic library level - A type of enclosing level. A scenario or -- target is at the generic library level if it appears in a generic -- package library unit, ignoring enclosing packages. -- -- * Guaranteed ABE - A type of ABE. A guaranteed ABE occurs when the -- elaboration or invocation of a target by all scenarios within the -- main unit causes an ABE. -- -- * Instantiation library level - A type of enclosing level. A scenario -- or target is at the instantiation library level if it appears in an -- instantiation library unit, ignoring enclosing packages. -- -- * Library level - A type of enclosing level. A scenario or target is at -- the library level if it appears in a package library unit, ignoring -- enclosng packages. -- -- * Non-library-level encapsulator - A construct that cannot be elaborated -- on its own and requires elaboration by a top-level scenario. -- -- * Scenario - A construct or context which may be elaborated or executed -- by elaboration code. The scenarios recognized by the ABE mechanism are -- as follows: -- -- - '[Unrestricted_]Access of entries, operators, and subprograms -- -- - Assignments to variables -- -- - Calls to entries, operators, and subprograms -- -- - Derived type declarations -- -- - Instantiations -- -- - Pragma Refined_State -- -- - Reads of variables -- -- - Task activation -- -- * Target - A construct referenced by a scenario. The targets recognized -- by the ABE mechanism are as follows: -- -- - For '[Unrestricted_]Access of entries, operators, and subprograms, -- the target is the entry, operator, or subprogram. -- -- - For assignments to variables, the target is the variable -- -- - For calls, the target is the entry, operator, or subprogram -- -- - For derived type declarations, the target is the derived type -- -- - For instantiations, the target is the generic template -- -- - For pragma Refined_State, the targets are the constituents -- -- - For reads of variables, the target is the variable -- -- - For task activation, the target is the task body -- -- * Top-level scenario - A scenario which appears in a non-generic main -- unit. Depending on the elaboration model is in effect, the following -- addotional restrictions apply: -- -- - Dynamic model - No restrictions -- -- - SPARK model - Falls back to either the dynamic or static model -- -- - Static model - The scenario must be at the library level --------------------- -- Recording phase -- --------------------- -- The Recording phase coincides with the analysis/resolution phase of the -- compiler. It has the following objectives: -- -- * Record all top-level scenarios for examination by the Processing -- phase. -- -- Saving only a certain number of nodes improves the performance of -- the ABE mechanism. This eliminates the need to examine the whole -- tree in a separate pass. -- -- * Record certain SPARK scenarios which are not necessarily executable -- during elaboration, but still require elaboration-related checks. -- -- Saving only a certain number of nodes improves the performance of -- the ABE mechanism. This eliminates the need to examine the whole -- tree in a separate pass. -- -- * Detect and diagnose calls in preelaborable or pure units, including -- generic bodies. -- -- This diagnostic is carried out during the Recording phase because it -- does not need the heavy recursive traversal done by the Processing -- phase. -- -- * Detect and diagnose guaranteed ABEs caused by instantiations, -- calls, and task activation. -- -- The issues detected by the ABE mechanism are reported as warnings -- because they do not violate Ada semantics. Forward instantiations -- may thus reach gigi, however gigi cannot handle certain kinds of -- premature instantiations and may crash. To avoid this limitation, -- the ABE mechanism must identify forward instantiations as early as -- possible and suppress their bodies. Calls and task activations are -- included in this category for completeness. ---------------------- -- Processing phase -- ---------------------- -- The Processing phase is a separate pass which starts after instantiating -- and/or inlining of bodies, but before the removal of Ghost code. It has -- the following objectives: -- -- * Examine all top-level scenarios saved during the Recording phase -- -- The top-level scenarios act as roots for depth-first traversal of -- the call/instantiation/task activation graph. The traversal stops -- when an outgoing edge leaves the main unit. -- -- * Examine all SPARK scenarios saved during the Recording phase -- -- * Depending on the elaboration model in effect, perform the following -- actions: -- -- - Dynamic model - Install run-time conditional ABE checks. -- -- - SPARK model - Enforce the SPARK elaboration rules -- -- - Static model - Diagnose conditional ABEs, install run-time -- conditional ABE checks, and guarantee the elaboration of -- external units. -- -- * Examine nested scenarios -- -- Nested scenarios discovered during the depth-first traversal are -- in turn subjected to the same actions outlined above and examined -- for the next level of nested scenarios. ------------------ -- Architecture -- ------------------ -- Analysis/Resolution -- | -- +- Build_Call_Marker -- | -- +- Build_Variable_Reference_Marker -- | -- +- | -------------------- Recording phase ---------------------------+ -- | v | -- | Record_Elaboration_Scenario | -- | | | -- | +--> Check_Preelaborated_Call | -- | | | -- | +--> Process_Guaranteed_ABE | -- | | | | -- | | +--> Process_Guaranteed_ABE_Activation | -- | | | | -- | | +--> Process_Guaranteed_ABE_Call | -- | | | | -- | | +--> Process_Guaranteed_ABE_Instantiation | -- | | | -- +- | ----------------------------------------------------------------+ -- | -- | -- +--> SPARK_Scenarios -- | +-----------+-----------+ .. +-----------+ -- | | Scenario1 | Scenario2 | .. | ScenarioN | -- | +-----------+-----------+ .. +-----------+ -- | -- +--> Top_Level_Scenarios -- | +-----------+-----------+ .. +-----------+ -- | | Scenario1 | Scenario2 | .. | ScenarioN | -- | +-----------+-----------+ .. +-----------+ -- | -- End of Compilation -- | -- +- | --------------------- Processing phase -------------------------+ -- | v | -- | Check_Elaboration_Scenarios | -- | | | -- | +--> Check_SPARK_Scenario | -- | | | | -- | | +--> Check_SPARK_Derived_Type | -- | | | | -- | | +--> Check_SPARK_Instantiation | -- | | | | -- | | +--> Check_SPARK_Refined_State_Pragma | -- | | | -- | +--> Process_Conditional_ABE <---------------------------+ | -- | | | | -- | +--> Process_Conditional_ABE_Access Is_Suitable_Scenario | -- | | ^ | -- | +--> Process_Conditional_ABE_Activation | | -- | | | | | -- | | +-----------------------------+ | | -- | | | | | -- | +--> Process_Conditional_ABE_Call +--------> Traverse_Body | -- | | | | | -- | | +-----------------------------+ | -- | | | -- | +--> Process_Conditional_ABE_Instantiation | -- | | | -- | +--> Process_Conditional_ABE_Variable_Assignment | -- | | | -- | +--> Process_Conditional_ABE_Variable_Reference | -- | | -- +--------------------------------------------------------------------+ ---------------------- -- Important points -- ---------------------- -- The Processing phase starts after the analysis, resolution, expansion -- phase has completed. As a result, no current semantic information is -- available. The scope stack is empty, global flags such as In_Instance -- or Inside_A_Generic become useless. To remedy this, the ABE mechanism -- must either save or recompute semantic information. -- Expansion heavily transforms calls and to some extent instantiations. To -- remedy this, the ABE mechanism generates N_Call_Marker nodes in order to -- capture the target and relevant attributes of the original call. -- The diagnostics of the ABE mechanism depend on accurate source locations -- to determine the spacial relation of nodes. ----------------------------------------- -- Suppression of elaboration warnings -- ----------------------------------------- -- Elaboration warnings along multiple traversal paths rooted at a scenario -- are suppressed when the scenario has elaboration warnings suppressed. -- -- Root scenario -- | -- +-- Child scenario 1 -- | | -- | +-- Grandchild scenario 1 -- | | -- | +-- Grandchild scenario N -- | -- +-- Child scenario N -- -- If the root scenario has elaboration warnings suppressed, then all its -- child, grandchild, etc. scenarios will have their elaboration warnings -- suppressed. -- -- In addition to switch -gnatwL, pragma Warnings may be used to suppress -- elaboration-related warnings when used in the following manner: -- -- pragma Warnings ("L"); -- -- -- -- pragma Warnings (Off, target); -- -- pragma Warnings (Off); -- -- -- * To suppress elaboration warnings for '[Unrestricted_]Access of -- entries, operators, and subprograms, either: -- -- - Suppress the entry, operator, or subprogram, or -- - Suppress the attribute, or -- - Use switch -gnatw.f -- -- * To suppress elaboration warnings for calls to entries, operators, -- and subprograms, either: -- -- - Suppress the entry, operator, or subprogram, or -- - Suppress the call -- -- * To suppress elaboration warnings for instantiations, suppress the -- instantiation. -- -- * To suppress elaboration warnings for task activations, either: -- -- - Suppress the task object, or -- - Suppress the task type, or -- - Suppress the activation call -------------- -- Switches -- -------------- -- The following switches may be used to control the behavior of the ABE -- mechanism. -- -- -gnatd_a stop elaboration checks on accept or select statement -- -- The ABE mechanism stops the traversal of a task body when it -- encounters an accept or a select statement. This behavior is -- equivalent to restriction No_Entry_Calls_In_Elaboration_Code, -- but without penalizing actual entry calls during elaboration. -- -- -gnatd_e ignore entry calls and requeue statements for elaboration -- -- The ABE mechanism does not generate N_Call_Marker nodes for -- protected or task entry calls as well as requeue statements. -- As a result, the calls and requeues are not recorded or -- processed. -- -- -gnatdE elaboration checks on predefined units -- -- The ABE mechanism considers scenarios which appear in internal -- units (Ada, GNAT, Interfaces, System). -- -- -gnatd.G ignore calls through generic formal parameters for elaboration -- -- The ABE mechanism does not generate N_Call_Marker nodes for -- calls which occur in expanded instances, and invoke generic -- actual subprograms through generic formal subprograms. As a -- result, the calls are not recorded or processed. -- -- -gnatd_i ignore activations and calls to instances for elaboration -- -- The ABE mechanism ignores calls and task activations when they -- target a subprogram or task type defined an external instance. -- As a result, the calls and task activations are not processed. -- -- -gnatdL ignore external calls from instances for elaboration -- -- The ABE mechanism does not generate N_Call_Marker nodes for -- calls which occur in expanded instances, do not invoke generic -- actual subprograms through formal subprograms, and the target -- is external to the instance. As a result, the calls are not -- recorded or processed. -- -- -gnatd.o conservative elaboration order for indirect calls -- -- The ABE mechanism treats '[Unrestricted_]Access of an entry, -- operator, or subprogram as an immediate invocation of the -- target. As a result, it performs ABE checks and diagnostics on -- the immediate call. -- -- -gnatd_p ignore assertion pragmas for elaboration -- -- The ABE mechanism does not generate N_Call_Marker nodes for -- calls to subprograms which verify the run-time semantics of -- the following assertion pragmas: -- -- Default_Initial_Condition -- Initial_Condition -- Invariant -- Invariant'Class -- Post -- Post'Class -- Postcondition -- Type_Invariant -- Type_Invariant_Class -- -- As a result, the assertion expressions of the pragmas are not -- processed. -- -- -gnatd_s stop elaboration checks on synchronous suspension -- -- The ABE mechanism stops the traversal of a task body when it -- encounters a call to one of the following routines: -- -- Ada.Synchronous_Barriers.Wait_For_Release -- Ada.Synchronous_Task_Control.Suspend_Until_True -- -- -gnatd.U ignore indirect calls for static elaboration -- -- The ABE mechanism does not consider '[Unrestricted_]Access of -- entries, operators, and subprograms. As a result, the scenarios -- are not recorder or processed. -- -- -gnatd.v enforce SPARK elaboration rules in SPARK code -- -- The ABE mechanism applies some of the SPARK elaboration rules -- defined in the SPARK reference manual, chapter 7.7. Note that -- certain rules are always enforced, regardless of whether the -- switch is active. -- -- -gnatd.y disable implicit pragma Elaborate_All on task bodies -- -- The ABE mechanism does not generate implicit Elaborate_All when -- the need for the pragma came from a task body. -- -- -gnatE dynamic elaboration checking mode enabled -- -- The ABE mechanism assumes that any scenario is elaborated or -- invoked by elaboration code. The ABE mechanism performs very -- little diagnostics and generates condintional ABE checks to -- detect ABE issues at run-time. -- -- -gnatel turn on info messages on generated Elaborate[_All] pragmas -- -- The ABE mechanism produces information messages on generated -- implicit Elabote[_All] pragmas along with traceback showing -- why the pragma was generated. In addition, the ABE mechanism -- produces information messages for each scenario elaborated or -- invoked by elaboration code. -- -- -gnateL turn off info messages on generated Elaborate[_All] pragmas -- -- The complementary switch for -gnatel. -- -- -gnatH legacy elaboration checking mode enabled -- -- When this switch is in effect, the pre-18.x ABE model becomes -- the defacto ABE model. This ammounts to cutting off all entry -- points into the new ABE mechanism, and giving full control to -- the old ABE mechanism. -- -- -gnatJ permissive elaboration checking mode enabled -- -- This switch activates the following switches: -- -- -gnatd_a -- -gnatd_e -- -gnatd.G -- -gnatd_i -- -gnatdL -- -gnatd_p -- -gnatd_s -- -gnatd.U -- -gnatd.y -- -- IMPORTANT: The behavior of the ABE mechanism becomes more -- permissive at the cost of accurate diagnostics and runtime -- ABE checks. -- -- -gnatw.f turn on warnings for suspicious Subp'Access -- -- The ABE mechanism treats '[Unrestricted_]Access of an entry, -- operator, or subprogram as a pseudo invocation of the target. -- As a result, it performs ABE diagnostics on the pseudo call. -- -- -gnatw.F turn off warnings for suspicious Subp'Access -- -- The complementary switch for -gnatw.f. -- -- -gnatwl turn on warnings for elaboration problems -- -- The ABE mechanism produces warnings on detected ABEs along with -- a traceback showing the graph of the ABE. -- -- -gnatwL turn off warnings for elaboration problems -- -- The complementary switch for -gnatwl. --------------------------- -- Adding a new scenario -- --------------------------- -- The following steps describe how to add a new elaboration scenario and -- preserve the existing architecture. Note that not all of the steps may -- need to be carried out. -- -- 1) Update predicate Is_Scenario -- -- 2) Add predicate Is_Suitable_xxx. Include a call to it in predicate -- Is_Suitable_Scenario. -- -- 3) Update routine Record_Elaboration_Scenario -- -- 4) Add routine Process_Conditional_ABE_xxx. Include a call to it in -- routine Process_Conditional_ABE. -- -- 5) Add routine Process_Guaranteed_ABE_xxx. Include a call to it in -- routine Process_Guaranteed_ABE. -- -- 6) Add routine Check_SPARK_xxx. Include a call to it in routine -- Check_SPARK_Scenario. -- -- 7) Add routine Info_xxx. Include a call to it in routine -- Process_Conditional_ABE_xxx. -- -- 8) Add routine Output_xxx. Include a call to it in routine -- Output_Active_Scenarios. -- -- 9) Add routine Extract_xxx_Attributes -- -- 10) Update routine Is_Potential_Scenario ------------------------- -- Adding a new target -- ------------------------- -- The following steps describe how to add a new elaboration target and -- preserve the existing architecture. Note that not all of the steps may -- need to be carried out. -- -- 1) Add predicate Is_xxx. -- -- 2) Update the following predicates -- -- Is_Ada_Semantic_Target -- Is_Assertion_Pragma_Target -- Is_Bridge_Target -- Is_SPARK_Semantic_Target -- -- If necessary, create a new category. -- -- 3) Update the appropriate Info_xxx routine. -- -- 4) Update the appropriate Output_xxx routine. -- -- 5) Update routine Extract_Target_Attributes. If necessary, create a -- new Extract_xxx routine. -------------------------- -- Debugging ABE issues -- -------------------------- -- * If the issue involves a call, ensure that the call is eligible for ABE -- processing and receives a corresponding call marker. The routines of -- interest are -- -- Build_Call_Marker -- Record_Elaboration_Scenario -- * If the issue involves an arbitrary scenario, ensure that the scenario -- is either recorded, or is successfully recognized while traversing a -- body. The routines of interest are -- -- Record_Elaboration_Scenario -- Process_Conditional_ABE -- Process_Guaranteed_ABE -- Traverse_Body -- * If the issue involves a circularity in the elaboration order, examine -- the ALI files and look for the following encodings next to units: -- -- E indicates a source Elaborate -- -- EA indicates a source Elaborate_All -- -- AD indicates an implicit Elaborate_All -- -- ED indicates an implicit Elaborate -- -- If possible, compare these encodings with those generated by the old -- ABE mechanism. The routines of interest are -- -- Ensure_Prior_Elaboration ---------------- -- Attributes -- ---------------- -- To minimize the amount of code within routines, the ABE mechanism relies -- on "attribute" records to capture relevant information for a scenario or -- a target. -- The following type captures relevant attributes which pertain to a call type Call_Attributes is record Elab_Checks_OK : Boolean; -- This flag is set when the call has elaboration checks enabled Elab_Warnings_OK : Boolean; -- This flag is set when the call has elaboration warnings elabled From_Source : Boolean; -- This flag is set when the call comes from source Ghost_Mode_Ignore : Boolean; -- This flag is set when the call appears in a region subject to pragma -- Ghost with policy Ignore. In_Declarations : Boolean; -- This flag is set when the call appears at the declaration level Is_Dispatching : Boolean; -- This flag is set when the call is dispatching SPARK_Mode_On : Boolean; -- This flag is set when the call appears in a region subject to pragma -- SPARK_Mode with value On. end record; -- The following type captures relevant attributes which pertain to the -- prior elaboration of a unit. This type is coupled together with a unit -- to form a key -> value relationship. type Elaboration_Attributes is record Source_Pragma : Node_Id; -- This attribute denotes a source Elaborate or Elaborate_All pragma -- which guarantees the prior elaboration of some unit with respect -- to the main unit. The pragma may come from the following contexts: -- * The main unit -- * The spec of the main unit (if applicable) -- * Any parent spec of the main unit (if applicable) -- * Any parent subunit of the main unit (if applicable) -- The attribute remains Empty if no such pragma is available. Source -- pragmas play a role in satisfying SPARK elaboration requirements. With_Clause : Node_Id; -- This attribute denotes an internally generated or source with clause -- for some unit withed by the main unit. With clauses carry flags which -- represent implicit Elaborate or Elaborate_All pragmas. These clauses -- play a role in supplying the elaboration dependencies to binde. end record; No_Elaboration_Attributes : constant Elaboration_Attributes := (Source_Pragma => Empty, With_Clause => Empty); -- The following type captures relevant attributes which pertain to an -- instantiation. type Instantiation_Attributes is record Elab_Checks_OK : Boolean; -- This flag is set when the instantiation has elaboration checks -- enabled. Elab_Warnings_OK : Boolean; -- This flag is set when the instantiation has elaboration warnings -- enabled. Ghost_Mode_Ignore : Boolean; -- This flag is set when the instantiation appears in a region subject -- to pragma Ghost with policy ignore, or starts one such region. In_Declarations : Boolean; -- This flag is set when the instantiation appears at the declaration -- level. SPARK_Mode_On : Boolean; -- This flag is set when the instantiation appears in a region subject -- to pragma SPARK_Mode with value On, or starts one such region. end record; -- The following type captures relevant attributes which pertain to the -- state of the Processing phase. type Processing_Attributes is record Suppress_Implicit_Pragmas : Boolean; -- This flag is set when the Processing phase must not generate any -- implicit Elaborate[_All] pragmas. Suppress_Warnings : Boolean; -- This flag is set when the Processing phase must not emit any warnings -- on elaboration problems. Within_Initial_Condition : Boolean; -- This flag is set when the Processing phase is currently examining a -- scenario which was reached from an initial condition procedure. Within_Instance : Boolean; -- This flag is set when the Processing phase is currently examining a -- scenario which was reached from a scenario defined in an instance. Within_Partial_Finalization : Boolean; -- This flag is set when the Processing phase is currently examining a -- scenario which was reached from a partial finalization procedure. Within_Task_Body : Boolean; -- This flag is set when the Processing phase is currently examining a -- scenario which was reached from a task body. end record; Initial_State : constant Processing_Attributes := (Suppress_Implicit_Pragmas => False, Suppress_Warnings => False, Within_Initial_Condition => False, Within_Instance => False, Within_Partial_Finalization => False, Within_Task_Body => False); -- The following type captures relevant attributes which pertain to a -- target. type Target_Attributes is record Elab_Checks_OK : Boolean; -- This flag is set when the target has elaboration checks enabled Elab_Warnings_OK : Boolean; -- This flag is set when the target has elaboration warnings enabled From_Source : Boolean; -- This flag is set when the target comes from source Ghost_Mode_Ignore : Boolean; -- This flag is set when the target appears in a region subject to -- pragma Ghost with policy ignore, or starts one such region. SPARK_Mode_On : Boolean; -- This flag is set when the target appears in a region subject to -- pragma SPARK_Mode with value On, or starts one such region. Spec_Decl : Node_Id; -- This attribute denotes the declaration of Spec_Id Unit_Id : Entity_Id; -- This attribute denotes the top unit where Spec_Id resides -- The semantics of the following attributes depend on the target Body_Barf : Node_Id; Body_Decl : Node_Id; Spec_Id : Entity_Id; -- The target is a generic package or a subprogram -- -- * Body_Barf - Empty -- -- * Body_Decl - This attribute denotes the generic or subprogram -- body. -- -- * Spec_Id - This attribute denotes the entity of the generic -- package or subprogram. -- The target is a protected entry -- -- * Body_Barf - This attribute denotes the body of the barrier -- function if expansion took place, otherwise it is Empty. -- -- * Body_Decl - This attribute denotes the body of the procedure -- which emulates the entry if expansion took place, otherwise it -- denotes the body of the protected entry. -- -- * Spec_Id - This attribute denotes the entity of the procedure -- which emulates the entry if expansion took place, otherwise it -- denotes the protected entry. -- The target is a protected subprogram -- -- * Body_Barf - Empty -- -- * Body_Decl - This attribute denotes the body of the protected or -- unprotected version of the protected subprogram if expansion took -- place, otherwise it denotes the body of the protected subprogram. -- -- * Spec_Id - This attribute denotes the entity of the protected or -- unprotected version of the protected subprogram if expansion took -- place, otherwise it is the entity of the protected subprogram. -- The target is a task entry -- -- * Body_Barf - Empty -- -- * Body_Decl - This attribute denotes the body of the procedure -- which emulates the task body if expansion took place, otherwise -- it denotes the body of the task type. -- -- * Spec_Id - This attribute denotes the entity of the procedure -- which emulates the task body if expansion took place, otherwise -- it denotes the entity of the task type. end record; -- The following type captures relevant attributes which pertain to a task -- type. type Task_Attributes is record Body_Decl : Node_Id; -- This attribute denotes the declaration of the procedure body which -- emulates the behaviour of the task body. Elab_Checks_OK : Boolean; -- This flag is set when the task type has elaboration checks enabled Elab_Warnings_OK : Boolean; -- This flag is set when the task type has elaboration warnings enabled Ghost_Mode_Ignore : Boolean; -- This flag is set when the task type appears in a region subject to -- pragma Ghost with policy ignore, or starts one such region. SPARK_Mode_On : Boolean; -- This flag is set when the task type appears in a region subject to -- pragma SPARK_Mode with value On, or starts one such region. Spec_Id : Entity_Id; -- This attribute denotes the entity of the initial declaration of the -- procedure body which emulates the behaviour of the task body. Task_Decl : Node_Id; -- This attribute denotes the declaration of the task type Unit_Id : Entity_Id; -- This attribute denotes the entity of the compilation unit where the -- task type resides. end record; -- The following type captures relevant attributes which pertain to a -- variable. type Variable_Attributes is record Unit_Id : Entity_Id; -- This attribute denotes the entity of the compilation unit where the -- variable resides. end record; --------------------- -- Data structures -- --------------------- -- The ABE mechanism employs lists and hash tables to store information -- pertaining to scenarios and targets, as well as the Processing phase. -- The need for data structures comes partly from the size limitation of -- nodes. Note that the use of hash tables is conservative and operations -- are carried out only when a particular hash table has at least one key -- value pair (see xxx_In_Use flags). -- The following table stores the early call regions of subprogram bodies Early_Call_Regions_Max : constant := 101; type Early_Call_Regions_Index is range 0 .. Early_Call_Regions_Max - 1; function Early_Call_Regions_Hash (Key : Entity_Id) return Early_Call_Regions_Index; -- Obtain the hash value of entity Key Early_Call_Regions_In_Use : Boolean := False; -- This flag determines whether table Early_Call_Regions contains at least -- least one key/value pair. Early_Call_Regions_No_Element : constant Node_Id := Empty; package Early_Call_Regions is new Simple_HTable (Header_Num => Early_Call_Regions_Index, Element => Node_Id, No_Element => Early_Call_Regions_No_Element, Key => Entity_Id, Hash => Early_Call_Regions_Hash, Equal => "="); -- The following table stores the elaboration status of all units withed by -- the main unit. Elaboration_Statuses_Max : constant := 1009; type Elaboration_Statuses_Index is range 0 .. Elaboration_Statuses_Max - 1; function Elaboration_Statuses_Hash (Key : Entity_Id) return Elaboration_Statuses_Index; -- Obtain the hash value of entity Key Elaboration_Statuses_In_Use : Boolean := False; -- This flag flag determines whether table Elaboration_Statuses contains at -- least one key/value pair. Elaboration_Statuses_No_Element : constant Elaboration_Attributes := No_Elaboration_Attributes; package Elaboration_Statuses is new Simple_HTable (Header_Num => Elaboration_Statuses_Index, Element => Elaboration_Attributes, No_Element => Elaboration_Statuses_No_Element, Key => Entity_Id, Hash => Elaboration_Statuses_Hash, Equal => "="); -- The following table stores a status flag for each SPARK scenario saved -- in table SPARK_Scenarios. Recorded_SPARK_Scenarios_Max : constant := 127; type Recorded_SPARK_Scenarios_Index is range 0 .. Recorded_SPARK_Scenarios_Max - 1; function Recorded_SPARK_Scenarios_Hash (Key : Node_Id) return Recorded_SPARK_Scenarios_Index; -- Obtain the hash value of Key Recorded_SPARK_Scenarios_In_Use : Boolean := False; -- This flag flag determines whether table Recorded_SPARK_Scenarios -- contains at least one key/value pair. Recorded_SPARK_Scenarios_No_Element : constant Boolean := False; package Recorded_SPARK_Scenarios is new Simple_HTable (Header_Num => Recorded_SPARK_Scenarios_Index, Element => Boolean, No_Element => Recorded_SPARK_Scenarios_No_Element, Key => Node_Id, Hash => Recorded_SPARK_Scenarios_Hash, Equal => "="); -- The following table stores a status flag for each top-level scenario -- recorded in table Top_Level_Scenarios. Recorded_Top_Level_Scenarios_Max : constant := 503; type Recorded_Top_Level_Scenarios_Index is range 0 .. Recorded_Top_Level_Scenarios_Max - 1; function Recorded_Top_Level_Scenarios_Hash (Key : Node_Id) return Recorded_Top_Level_Scenarios_Index; -- Obtain the hash value of entity Key Recorded_Top_Level_Scenarios_In_Use : Boolean := False; -- This flag flag determines whether table Recorded_Top_Level_Scenarios -- contains at least one key/value pair. Recorded_Top_Level_Scenarios_No_Element : constant Boolean := False; package Recorded_Top_Level_Scenarios is new Simple_HTable (Header_Num => Recorded_Top_Level_Scenarios_Index, Element => Boolean, No_Element => Recorded_Top_Level_Scenarios_No_Element, Key => Node_Id, Hash => Recorded_Top_Level_Scenarios_Hash, Equal => "="); -- The following table stores all active scenarios in a recursive traversal -- starting from a top-level scenario. This table must be maintained in a -- FIFO fashion. package Scenario_Stack is new Table.Table (Table_Component_Type => Node_Id, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 50, Table_Increment => 100, Table_Name => "Scenario_Stack"); -- The following table stores SPARK scenarios which are not necessarily -- executable during elaboration, but still require elaboration-related -- checks. package SPARK_Scenarios is new Table.Table (Table_Component_Type => Node_Id, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 50, Table_Increment => 100, Table_Name => "SPARK_Scenarios"); -- The following table stores all top-level scenario saved during the -- Recording phase. The contents of this table act as traversal roots -- later in the Processing phase. This table must be maintained in a -- LIFO fashion. package Top_Level_Scenarios is new Table.Table (Table_Component_Type => Node_Id, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 1000, Table_Increment => 100, Table_Name => "Top_Level_Scenarios"); -- The following table stores the bodies of all eligible scenarios visited -- during a traversal starting from a top-level scenario. The contents of -- this table must be reset upon each new traversal. Visited_Bodies_Max : constant := 511; type Visited_Bodies_Index is range 0 .. Visited_Bodies_Max - 1; function Visited_Bodies_Hash (Key : Node_Id) return Visited_Bodies_Index; -- Obtain the hash value of node Key Visited_Bodies_In_Use : Boolean := False; -- This flag determines whether table Visited_Bodies contains at least one -- key/value pair. Visited_Bodies_No_Element : constant Boolean := False; package Visited_Bodies is new Simple_HTable (Header_Num => Visited_Bodies_Index, Element => Boolean, No_Element => Visited_Bodies_No_Element, Key => Node_Id, Hash => Visited_Bodies_Hash, Equal => "="); ----------------------- -- Local subprograms -- ----------------------- -- Multiple local subprograms are utilized to lower the semantic complexity -- of the Recording and Processing phase. procedure Check_Preelaborated_Call (Call : Node_Id); pragma Inline (Check_Preelaborated_Call); -- Verify that entry, operator, or subprogram call Call does not appear at -- the library level of a preelaborated unit. procedure Check_SPARK_Derived_Type (Typ_Decl : Node_Id); pragma Inline (Check_SPARK_Derived_Type); -- Verify that the freeze node of a derived type denoted by declaration -- Typ_Decl is within the early call region of each overriding primitive -- body that belongs to the derived type (SPARK RM 7.7(8)). procedure Check_SPARK_Instantiation (Exp_Inst : Node_Id); pragma Inline (Check_SPARK_Instantiation); -- Verify that expanded instance Exp_Inst does not precede the generic body -- it instantiates (SPARK RM 7.7(6)). procedure Check_SPARK_Model_In_Effect (N : Node_Id); pragma Inline (Check_SPARK_Model_In_Effect); -- Determine whether a suitable elaboration model is currently in effect -- for verifying the SPARK rules of scenario N. Emit a warning if this is -- not the case. procedure Check_SPARK_Scenario (N : Node_Id); pragma Inline (Check_SPARK_Scenario); -- Top-level dispatcher for verifying SPARK scenarios which are not always -- executable during elaboration but still need elaboration-related checks. procedure Check_SPARK_Refined_State_Pragma (N : Node_Id); pragma Inline (Check_SPARK_Refined_State_Pragma); -- Verify that each constituent of Refined_State pragma N which belongs to -- an abstract state mentioned in pragma Initializes has prior elaboration -- with respect to the main unit (SPARK RM 7.7.1(7)). function Compilation_Unit (Unit_Id : Entity_Id) return Node_Id; pragma Inline (Compilation_Unit); -- Return the N_Compilation_Unit node of unit Unit_Id function Early_Call_Region (Body_Id : Entity_Id) return Node_Id; pragma Inline (Early_Call_Region); -- Return the early call region associated with entry or subprogram body -- Body_Id. IMPORTANT: This routine does not find the early call region. -- To compute it, use routine Find_Early_Call_Region. procedure Elab_Msg_NE (Msg : String; N : Node_Id; Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean); pragma Inline (Elab_Msg_NE); -- Wrapper around Error_Msg_NE. Emit message Msg concerning arbitrary node -- N and entity. If flag Info_Msg is set, the routine emits an information -- message, otherwise it emits an error. If flag In_SPARK is set, then -- string " in SPARK" is added to the end of the message. function Elaboration_Status (Unit_Id : Entity_Id) return Elaboration_Attributes; pragma Inline (Elaboration_Status); -- Return the set of elaboration attributes associated with unit Unit_Id procedure Ensure_Prior_Elaboration (N : Node_Id; Unit_Id : Entity_Id; Prag_Nam : Name_Id; State : Processing_Attributes); -- Guarantee the elaboration of unit Unit_Id with respect to the main unit -- by installing pragma Elaborate or Elaborate_All denoted by Prag_Nam. N -- denotes the related scenario. State denotes the current state of the -- Processing phase. procedure Ensure_Prior_Elaboration_Dynamic (N : Node_Id; Unit_Id : Entity_Id; Prag_Nam : Name_Id); -- Guarantee the elaboration of unit Unit_Id with respect to the main unit -- by suggesting the use of Elaborate[_All] with name Prag_Nam. N denotes -- the related scenario. procedure Ensure_Prior_Elaboration_Static (N : Node_Id; Unit_Id : Entity_Id; Prag_Nam : Name_Id); -- Guarantee the elaboration of unit Unit_Id with respect to the main unit -- by installing an implicit Elaborate[_All] pragma with name Prag_Nam. N -- denotes the related scenario. function Extract_Assignment_Name (Asmt : Node_Id) return Node_Id; pragma Inline (Extract_Assignment_Name); -- Obtain the Name attribute of assignment statement Asmt procedure Extract_Call_Attributes (Call : Node_Id; Target_Id : out Entity_Id; Attrs : out Call_Attributes); pragma Inline (Extract_Call_Attributes); -- Obtain attributes Attrs associated with call Call. Target_Id is the -- entity of the call target. function Extract_Call_Name (Call : Node_Id) return Node_Id; pragma Inline (Extract_Call_Name); -- Obtain the Name attribute of entry or subprogram call Call procedure Extract_Instance_Attributes (Exp_Inst : Node_Id; Inst_Body : out Node_Id; Inst_Decl : out Node_Id); pragma Inline (Extract_Instance_Attributes); -- Obtain body Inst_Body and spec Inst_Decl of expanded instance Exp_Inst procedure Extract_Instantiation_Attributes (Exp_Inst : Node_Id; Inst : out Node_Id; Inst_Id : out Entity_Id; Gen_Id : out Entity_Id; Attrs : out Instantiation_Attributes); pragma Inline (Extract_Instantiation_Attributes); -- Obtain attributes Attrs associated with expanded instantiation Exp_Inst. -- Inst is the instantiation. Inst_Id is the entity of the instance. Gen_Id -- is the entity of the generic unit being instantiated. procedure Extract_Target_Attributes (Target_Id : Entity_Id; Attrs : out Target_Attributes); -- Obtain attributes Attrs associated with an entry, package, or subprogram -- denoted by Target_Id. procedure Extract_Task_Attributes (Typ : Entity_Id; Attrs : out Task_Attributes); pragma Inline (Extract_Task_Attributes); -- Obtain attributes Attrs associated with task type Typ procedure Extract_Variable_Reference_Attributes (Ref : Node_Id; Var_Id : out Entity_Id; Attrs : out Variable_Attributes); pragma Inline (Extract_Variable_Reference_Attributes); -- Obtain attributes Attrs associated with reference Ref that mentions -- variable Var_Id. function Find_Code_Unit (N : Node_Or_Entity_Id) return Entity_Id; pragma Inline (Find_Code_Unit); -- Return the code unit which contains arbitrary node or entity N. This -- is the unit of the file which physically contains the related construct -- denoted by N except when N is within an instantiation. In that case the -- unit is that of the top-level instantiation. function Find_Early_Call_Region (Body_Decl : Node_Id; Assume_Elab_Body : Boolean := False; Skip_Memoization : Boolean := False) return Node_Id; -- Find the start of the early call region which belongs to subprogram body -- Body_Decl as defined in SPARK RM 7.7. The behavior of the routine is to -- find the early call region, memoize it, and return it, but this behavior -- can be altered. Flag Assume_Elab_Body should be set when a package spec -- may lack pragma Elaborate_Body, but the routine must still examine that -- spec. Flag Skip_Memoization should be set when the routine must avoid -- memoizing the region. procedure Find_Elaborated_Units; -- Populate table Elaboration_Statuses with all units which have prior -- elaboration with respect to the main unit. function Find_Enclosing_Instance (N : Node_Id) return Node_Id; pragma Inline (Find_Enclosing_Instance); -- Find the declaration or body of the nearest expanded instance which -- encloses arbitrary node N. Return Empty if no such instance exists. function Find_Top_Unit (N : Node_Or_Entity_Id) return Entity_Id; pragma Inline (Find_Top_Unit); -- Return the top unit which contains arbitrary node or entity N. The unit -- is obtained by logically unwinding instantiations and subunits when N -- resides within one. function Find_Unit_Entity (N : Node_Id) return Entity_Id; pragma Inline (Find_Unit_Entity); -- Return the entity of unit N function First_Formal_Type (Subp_Id : Entity_Id) return Entity_Id; pragma Inline (First_Formal_Type); -- Return the type of subprogram Subp_Id's first formal parameter. If the -- subprogram lacks formal parameters, return Empty. function Has_Body (Pack_Decl : Node_Id) return Boolean; -- Determine whether package declaration Pack_Decl has a corresponding body -- or would eventually have one. function Has_Prior_Elaboration (Unit_Id : Entity_Id; Context_OK : Boolean := False; Elab_Body_OK : Boolean := False; Same_Unit_OK : Boolean := False) return Boolean; pragma Inline (Has_Prior_Elaboration); -- Determine whether unit Unit_Id is elaborated prior to the main unit. -- If flag Context_OK is set, the routine considers the following case -- as valid prior elaboration: -- -- * Unit_Id is in the elaboration context of the main unit -- -- If flag Elab_Body_OK is set, the routine considers the following case -- as valid prior elaboration: -- -- * Unit_Id has pragma Elaborate_Body and is not the main unit -- -- If flag Same_Unit_OK is set, the routine considers the following cases -- as valid prior elaboration: -- -- * Unit_Id is the main unit -- -- * Unit_Id denotes the spec of the main unit body function In_External_Instance (N : Node_Id; Target_Decl : Node_Id) return Boolean; pragma Inline (In_External_Instance); -- Determine whether a target desctibed by its declaration Target_Decl -- resides in a package instance which is external to scenario N. function In_Main_Context (N : Node_Id) return Boolean; pragma Inline (In_Main_Context); -- Determine whether arbitrary node N appears within the main compilation -- unit. function In_Same_Context (N1 : Node_Id; N2 : Node_Id; Nested_OK : Boolean := False) return Boolean; -- Determine whether two arbitrary nodes N1 and N2 appear within the same -- context ignoring enclosing library levels. Nested_OK should be set when -- the context of N1 can enclose that of N2. function In_Task_Body (N : Node_Id) return Boolean; pragma Inline (In_Task_Body); -- Determine whether arbitrary node N appears within a task body procedure Info_Call (Call : Node_Id; Target_Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean); -- Output information concerning call Call which invokes target Target_Id. -- If flag Info_Msg is set, the routine emits an information message, -- otherwise it emits an error. If flag In_SPARK is set, then the string -- " in SPARK" is added to the end of the message. procedure Info_Instantiation (Inst : Node_Id; Gen_Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean); pragma Inline (Info_Instantiation); -- Output information concerning instantiation Inst which instantiates -- generic unit Gen_Id. If flag Info_Msg is set, the routine emits an -- information message, otherwise it emits an error. If flag In_SPARK -- is set, then string " in SPARK" is added to the end of the message. procedure Info_Variable_Reference (Ref : Node_Id; Var_Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean); pragma Inline (Info_Variable_Reference); -- Output information concerning reference Ref which mentions variable -- Var_Id. If flag Info_Msg is set, the routine emits an information -- message, otherwise it emits an error. If flag In_SPARK is set, then -- string " in SPARK" is added to the end of the message. function Insertion_Node (N : Node_Id; Ins_Nod : Node_Id) return Node_Id; pragma Inline (Insertion_Node); -- Obtain the proper insertion node of an ABE check or failure for scenario -- N and candidate insertion node Ins_Nod. procedure Install_ABE_Check (N : Node_Id; Id : Entity_Id; Ins_Nod : Node_Id); -- Insert a run-time ABE check for elaboration scenario N which verifies -- whether arbitrary entity Id is elaborated. The check in inserted prior -- to node Ins_Nod. procedure Install_ABE_Check (N : Node_Id; Target_Id : Entity_Id; Target_Decl : Node_Id; Target_Body : Node_Id; Ins_Nod : Node_Id); -- Insert a run-time ABE check for elaboration scenario N which verifies -- whether target Target_Id with initial declaration Target_Decl and body -- Target_Body is elaborated. The check is inserted prior to node Ins_Nod. procedure Install_ABE_Failure (N : Node_Id; Ins_Nod : Node_Id); -- Insert a Program_Error concerning a guaranteed ABE for elaboration -- scenario N. The failure is inserted prior to node Node_Id. function Is_Accept_Alternative_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Accept_Alternative_Proc); -- Determine whether arbitrary entity Id denotes an internally generated -- procedure which encapsulates the statements of an accept alternative. function Is_Activation_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Activation_Proc); -- Determine whether arbitrary entity Id denotes a runtime procedure in -- charge with activating tasks. function Is_Ada_Semantic_Target (Id : Entity_Id) return Boolean; pragma Inline (Is_Ada_Semantic_Target); -- Determine whether arbitrary entity Id denodes a source or internally -- generated subprogram which emulates Ada semantics. function Is_Assertion_Pragma_Target (Id : Entity_Id) return Boolean; pragma Inline (Is_Assertion_Pragma_Target); -- Determine whether arbitrary entity Id denotes a procedure which varifies -- the run-time semantics of an assertion pragma. function Is_Bodiless_Subprogram (Subp_Id : Entity_Id) return Boolean; pragma Inline (Is_Bodiless_Subprogram); -- Determine whether subprogram Subp_Id will never have a body function Is_Controlled_Proc (Subp_Id : Entity_Id; Subp_Nam : Name_Id) return Boolean; pragma Inline (Is_Controlled_Proc); -- Determine whether subprogram Subp_Id denotes controlled type primitives -- Adjust, Finalize, or Initialize as denoted by name Subp_Nam. function Is_Default_Initial_Condition_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Default_Initial_Condition_Proc); -- Determine whether arbitrary entity Id denotes internally generated -- routine Default_Initial_Condition. function Is_Finalizer_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Finalizer_Proc); -- Determine whether arbitrary entity Id denotes internally generated -- routine _Finalizer. function Is_Guaranteed_ABE (N : Node_Id; Target_Decl : Node_Id; Target_Body : Node_Id) return Boolean; pragma Inline (Is_Guaranteed_ABE); -- Determine whether scenario N with a target described by its initial -- declaration Target_Decl and body Target_Decl results in a guaranteed -- ABE. function Is_Initial_Condition_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Initial_Condition_Proc); -- Determine whether arbitrary entity Id denotes internally generated -- routine Initial_Condition. function Is_Initialized (Obj_Decl : Node_Id) return Boolean; pragma Inline (Is_Initialized); -- Determine whether object declaration Obj_Decl is initialized function Is_Invariant_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Invariant_Proc); -- Determine whether arbitrary entity Id denotes an invariant procedure function Is_Non_Library_Level_Encapsulator (N : Node_Id) return Boolean; pragma Inline (Is_Non_Library_Level_Encapsulator); -- Determine whether arbitrary node N is a non-library encapsulator function Is_Partial_Invariant_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Partial_Invariant_Proc); -- Determine whether arbitrary entity Id denotes a partial invariant -- procedure. function Is_Postconditions_Proc (Id : Entity_Id) return Boolean; pragma Inline (Is_Postconditions_Proc); -- Determine whether arbitrary entity Id denotes internally generated -- routine _Postconditions. function Is_Preelaborated_Unit (Id : Entity_Id) return Boolean; pragma Inline (Is_Preelaborated_Unit); -- Determine whether arbitrary entity Id denotes a unit which is subject to -- one of the following pragmas: -- -- * Preelaborable -- * Pure -- * Remote_Call_Interface -- * Remote_Types -- * Shared_Passive function Is_Protected_Entry (Id : Entity_Id) return Boolean; pragma Inline (Is_Protected_Entry); -- Determine whether arbitrary entity Id denotes a protected entry function Is_Protected_Subp (Id : Entity_Id) return Boolean; pragma Inline (Is_Protected_Subp); -- Determine whether entity Id denotes a protected subprogram function Is_Protected_Body_Subp (Id : Entity_Id) return Boolean; pragma Inline (Is_Protected_Body_Subp); -- Determine whether entity Id denotes the protected or unprotected version -- of a protected subprogram. function Is_Recorded_SPARK_Scenario (N : Node_Id) return Boolean; pragma Inline (Is_Recorded_SPARK_Scenario); -- Determine whether arbitrary node N is a recorded SPARK scenario which -- appears in table SPARK_Scenarios. function Is_Recorded_Top_Level_Scenario (N : Node_Id) return Boolean; pragma Inline (Is_Recorded_Top_Level_Scenario); -- Determine whether arbitrary node N is a recorded top-level scenario -- which appears in table Top_Level_Scenarios. function Is_Safe_Activation (Call : Node_Id; Task_Decl : Node_Id) return Boolean; pragma Inline (Is_Safe_Activation); -- Determine whether call Call which activates a task object described by -- declaration Task_Decl is always ABE-safe. function Is_Safe_Call (Call : Node_Id; Target_Attrs : Target_Attributes) return Boolean; pragma Inline (Is_Safe_Call); -- Determine whether call Call which invokes a target described by -- attributes Target_Attrs is always ABE-safe. function Is_Safe_Instantiation (Inst : Node_Id; Gen_Attrs : Target_Attributes) return Boolean; pragma Inline (Is_Safe_Instantiation); -- Determine whether instance Inst which instantiates a generic unit -- described by attributes Gen_Attrs is always ABE-safe. function Is_Same_Unit (Unit_1 : Entity_Id; Unit_2 : Entity_Id) return Boolean; pragma Inline (Is_Same_Unit); -- Determine whether entities Unit_1 and Unit_2 denote the same unit function Is_Scenario (N : Node_Id) return Boolean; pragma Inline (Is_Scenario); -- Determine whether attribute node N denotes a scenario. The scenario may -- not necessarily be eligible for ABE processing. function Is_SPARK_Semantic_Target (Id : Entity_Id) return Boolean; pragma Inline (Is_SPARK_Semantic_Target); -- Determine whether arbitrary entity Id nodes a source or internally -- generated subprogram which emulates SPARK semantics. function Is_Suitable_Access (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Access); -- Determine whether arbitrary node N denotes a suitable attribute for ABE -- processing. function Is_Suitable_Call (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Call); -- Determine whether arbitrary node N denotes a suitable call for ABE -- processing. function Is_Suitable_Instantiation (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Instantiation); -- Determine whether arbitrary node N is a suitable instantiation for ABE -- processing. function Is_Suitable_Scenario (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Scenario); -- Determine whether arbitrary node N is a suitable scenario for ABE -- processing. function Is_Suitable_SPARK_Derived_Type (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_SPARK_Derived_Type); -- Determine whether arbitrary node N denotes a suitable derived type -- declaration for ABE processing using the SPARK rules. function Is_Suitable_SPARK_Instantiation (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_SPARK_Instantiation); -- Determine whether arbitrary node N denotes a suitable instantiation for -- ABE processing using the SPARK rules. function Is_Suitable_SPARK_Refined_State_Pragma (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_SPARK_Refined_State_Pragma); -- Determine whether arbitrary node N denotes a suitable Refined_State -- pragma for ABE processing using the SPARK rules. function Is_Suitable_Variable_Assignment (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Variable_Assignment); -- Determine whether arbitrary node N denotes a suitable assignment for ABE -- processing. function Is_Suitable_Variable_Reference (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Variable_Reference); -- Determine whether arbitrary node N is a suitable variable reference for -- ABE processing. function Is_Synchronous_Suspension_Call (N : Node_Id) return Boolean; pragma Inline (Is_Synchronous_Suspension_Call); -- Determine whether arbitrary node N denotes a call to one the following -- routines: -- -- Ada.Synchronous_Barriers.Wait_For_Release -- Ada.Synchronous_Task_Control.Suspend_Until_True function Is_Task_Entry (Id : Entity_Id) return Boolean; pragma Inline (Is_Task_Entry); -- Determine whether arbitrary entity Id denotes a task entry function Is_Up_Level_Target (Target_Decl : Node_Id) return Boolean; pragma Inline (Is_Up_Level_Target); -- Determine whether the current root resides at the declaration level. If -- this is the case, determine whether a target described by declaration -- Target_Decl is within a context which encloses the current root or is in -- a different unit. function Is_Visited_Body (Body_Decl : Node_Id) return Boolean; pragma Inline (Is_Visited_Body); -- Determine whether subprogram body Body_Decl is already visited during a -- recursive traversal started from a top-level scenario. procedure Meet_Elaboration_Requirement (N : Node_Id; Target_Id : Entity_Id; Req_Nam : Name_Id); -- Determine whether elaboration requirement Req_Nam for scenario N with -- target Target_Id is met by the context of the main unit using the SPARK -- rules. Req_Nam must denote either Elaborate or Elaborate_All. Emit an -- error if this is not the case. function Non_Private_View (Typ : Entity_Id) return Entity_Id; pragma Inline (Non_Private_View); -- Return the full view of private type Typ if available, otherwise return -- type Typ. procedure Output_Active_Scenarios (Error_Nod : Node_Id); -- Output the contents of the active scenario stack from earliest to latest -- to supplement an earlier error emitted for node Error_Nod. procedure Pop_Active_Scenario (N : Node_Id); pragma Inline (Pop_Active_Scenario); -- Pop the top of the scenario stack. A check is made to ensure that the -- scenario being removed is the same as N. generic with procedure Process_Single_Activation (Call : Node_Id; Call_Attrs : Call_Attributes; Obj_Id : Entity_Id; Task_Attrs : Task_Attributes; State : Processing_Attributes); -- Perform ABE checks and diagnostics for task activation call Call -- which activates task Obj_Id. Call_Attrs are the attributes of the -- activation call. Task_Attrs are the attributes of the task type. -- State is the current state of the Processing phase. procedure Process_Activation_Generic (Call : Node_Id; Call_Attrs : Call_Attributes; State : Processing_Attributes); -- Perform ABE checks and diagnostics for activation call Call by invoking -- routine Process_Single_Activation on each task object being activated. -- Call_Attrs are the attributes of the activation call. State is the -- current state of the Processing phase. procedure Process_Conditional_ABE (N : Node_Id; State : Processing_Attributes := Initial_State); -- Top-level dispatcher for processing of various elaboration scenarios. -- Perform conditional ABE checks and diagnostics for scenario N. State -- is the current state of the Processing phase. procedure Process_Conditional_ABE_Access (Attr : Node_Id; State : Processing_Attributes); -- Perform ABE checks and diagnostics for 'Access to entry, operator, or -- subprogram denoted by Attr. State is the current state of the Processing -- phase. procedure Process_Conditional_ABE_Activation_Impl (Call : Node_Id; Call_Attrs : Call_Attributes; Obj_Id : Entity_Id; Task_Attrs : Task_Attributes; State : Processing_Attributes); -- Perform common conditional ABE checks and diagnostics for call Call -- which activates task Obj_Id ignoring the Ada or SPARK rules. Call_Attrs -- are the attributes of the activation call. Task_Attrs are the attributes -- of the task type. State is the current state of the Processing phase. procedure Process_Conditional_ABE_Call (Call : Node_Id; Call_Attrs : Call_Attributes; Target_Id : Entity_Id; State : Processing_Attributes); -- Top-level dispatcher for processing of calls. Perform ABE checks and -- diagnostics for call Call which invokes target Target_Id. Call_Attrs -- are the attributes of the call. State is the current state of the -- Processing phase. procedure Process_Conditional_ABE_Call_Ada (Call : Node_Id; Call_Attrs : Call_Attributes; Target_Id : Entity_Id; Target_Attrs : Target_Attributes; State : Processing_Attributes); -- Perform ABE checks and diagnostics for call Call which invokes target -- Target_Id using the Ada rules. Call_Attrs are the attributes of the -- call. Target_Attrs are attributes of the target. State is the current -- state of the Processing phase. procedure Process_Conditional_ABE_Call_SPARK (Call : Node_Id; Target_Id : Entity_Id; Target_Attrs : Target_Attributes; State : Processing_Attributes); -- Perform ABE checks and diagnostics for call Call which invokes target -- Target_Id using the SPARK rules. Target_Attrs denotes the attributes of -- the target. State is the current state of the Processing phase. procedure Process_Conditional_ABE_Instantiation (Exp_Inst : Node_Id; State : Processing_Attributes); -- Top-level dispatcher for processing of instantiations. Perform ABE -- checks and diagnostics for expanded instantiation Exp_Inst. State is -- the current state of the Processing phase. procedure Process_Conditional_ABE_Instantiation_Ada (Exp_Inst : Node_Id; Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Gen_Id : Entity_Id; Gen_Attrs : Target_Attributes; State : Processing_Attributes); -- Perform ABE checks and diagnostics for expanded instantiation Exp_Inst -- of generic Gen_Id using the Ada rules. Inst is the instantiation node. -- Inst_Attrs are the attributes of the instance. Gen_Attrs denotes the -- attributes of the generic. State is the current state of the Processing -- phase. procedure Process_Conditional_ABE_Instantiation_SPARK (Inst : Node_Id; Gen_Id : Entity_Id; Gen_Attrs : Target_Attributes; State : Processing_Attributes); -- Perform ABE checks and diagnostics for instantiation Inst of generic -- Gen_Id using the SPARK rules. Gen_Attrs denotes the attributes of the -- generic. State is the current state of the Processing phase. procedure Process_Conditional_ABE_Variable_Assignment (Asmt : Node_Id); -- Top-level dispatcher for processing of variable assignments. Perform ABE -- checks and diagnostics for assignment statement Asmt. procedure Process_Conditional_ABE_Variable_Assignment_Ada (Asmt : Node_Id; Var_Id : Entity_Id); -- Perform ABE checks and diagnostics for assignment statement Asmt that -- updates the value of variable Var_Id using the Ada rules. procedure Process_Conditional_ABE_Variable_Assignment_SPARK (Asmt : Node_Id; Var_Id : Entity_Id); -- Perform ABE checks and diagnostics for assignment statement Asmt that -- updates the value of variable Var_Id using the SPARK rules. procedure Process_Conditional_ABE_Variable_Reference (Ref : Node_Id); -- Top-level dispatcher for processing of variable references. Perform ABE -- checks and diagnostics for variable reference Ref. procedure Process_Conditional_ABE_Variable_Reference_Read (Ref : Node_Id; Var_Id : Entity_Id; Attrs : Variable_Attributes); -- Perform ABE checks and diagnostics for reference Ref described by its -- attributes Attrs, that reads variable Var_Id. procedure Process_Guaranteed_ABE (N : Node_Id); -- Top-level dispatcher for processing of scenarios which result in a -- guaranteed ABE. procedure Process_Guaranteed_ABE_Activation_Impl (Call : Node_Id; Call_Attrs : Call_Attributes; Obj_Id : Entity_Id; Task_Attrs : Task_Attributes; State : Processing_Attributes); -- Perform common guaranteed ABE checks and diagnostics for call Call which -- activates task Obj_Id ignoring the Ada or SPARK rules. Call_Attrs are -- the attributes of the activation call. Task_Attrs are the attributes of -- the task type. State is provided for compatibility and is not used. procedure Process_Guaranteed_ABE_Call (Call : Node_Id; Call_Attrs : Call_Attributes; Target_Id : Entity_Id); -- Perform common guaranteed ABE checks and diagnostics for call Call which -- invokes target Target_Id ignoring the Ada or SPARK rules. Call_Attrs are -- the attributes of the call. procedure Process_Guaranteed_ABE_Instantiation (Exp_Inst : Node_Id); -- Perform common guaranteed ABE checks and diagnostics for expanded -- instantiation Exp_Inst of generic Gen_Id ignoring the Ada or SPARK -- rules. procedure Push_Active_Scenario (N : Node_Id); pragma Inline (Push_Active_Scenario); -- Push scenario N on top of the scenario stack procedure Record_SPARK_Elaboration_Scenario (N : Node_Id); pragma Inline (Record_SPARK_Elaboration_Scenario); -- Save SPARK scenario N in table SPARK_Scenarios for later processing procedure Reset_Visited_Bodies; pragma Inline (Reset_Visited_Bodies); -- Clear the contents of table Visited_Bodies function Root_Scenario return Node_Id; pragma Inline (Root_Scenario); -- Return the top-level scenario which started a recursive search for other -- scenarios. It is assumed that there is a valid top-level scenario on the -- active scenario stack. procedure Set_Early_Call_Region (Body_Id : Entity_Id; Start : Node_Id); pragma Inline (Set_Early_Call_Region); -- Associate an early call region with begins at construct Start with entry -- or subprogram body Body_Id. procedure Set_Elaboration_Status (Unit_Id : Entity_Id; Val : Elaboration_Attributes); pragma Inline (Set_Elaboration_Status); -- Associate an set of elaboration attributes with unit Unit_Id procedure Set_Is_Recorded_SPARK_Scenario (N : Node_Id; Val : Boolean := True); pragma Inline (Set_Is_Recorded_SPARK_Scenario); -- Mark scenario N as being recorded in table SPARK_Scenarios procedure Set_Is_Recorded_Top_Level_Scenario (N : Node_Id; Val : Boolean := True); pragma Inline (Set_Is_Recorded_Top_Level_Scenario); -- Mark scenario N as being recorded in table Top_Level_Scenarios procedure Set_Is_Visited_Body (Subp_Body : Node_Id); pragma Inline (Set_Is_Visited_Body); -- Mark subprogram body Subp_Body as being visited during a recursive -- traversal started from a top-level scenario. function Static_Elaboration_Checks return Boolean; pragma Inline (Static_Elaboration_Checks); -- Determine whether the static model is in effect procedure Traverse_Body (N : Node_Id; State : Processing_Attributes); -- Inspect the declarative and statement lists of subprogram body N for -- suitable elaboration scenarios and process them. State is the current -- state of the Processing phase. function Unit_Entity (Unit_Id : Entity_Id) return Entity_Id; pragma Inline (Unit_Entity); -- Return the entity of the initial declaration for unit Unit_Id procedure Update_Elaboration_Scenario (New_N : Node_Id; Old_N : Node_Id); pragma Inline (Update_Elaboration_Scenario); -- Update all relevant internal data structures when scenario Old_N is -- transformed into scenario New_N by Atree.Rewrite. ----------------------- -- Build_Call_Marker -- ----------------------- procedure Build_Call_Marker (N : Node_Id) is function In_External_Context (Call : Node_Id; Target_Attrs : Target_Attributes) return Boolean; pragma Inline (In_External_Context); -- Determine whether a target described by attributes Target_Attrs is -- external to call Call which must reside within an instance. function In_Premature_Context (Call : Node_Id) return Boolean; -- Determine whether call Call appears within a premature context function Is_Bridge_Target (Id : Entity_Id) return Boolean; pragma Inline (Is_Bridge_Target); -- Determine whether arbitrary entity Id denotes a bridge target function Is_Default_Expression (Call : Node_Id) return Boolean; pragma Inline (Is_Default_Expression); -- Determine whether call Call acts as the expression of a defaulted -- parameter within a source call. function Is_Generic_Formal_Subp (Subp_Id : Entity_Id) return Boolean; pragma Inline (Is_Generic_Formal_Subp); -- Determine whether subprogram Subp_Id denotes a generic formal -- subprogram which appears in the "prologue" of an instantiation. ------------------------- -- In_External_Context -- ------------------------- function In_External_Context (Call : Node_Id; Target_Attrs : Target_Attributes) return Boolean is Inst : Node_Id; Inst_Body : Node_Id; Inst_Decl : Node_Id; begin -- Performance note: parent traversal Inst := Find_Enclosing_Instance (Call); -- The call appears within an instance if Present (Inst) then -- The call comes from the main unit and the target does not if In_Extended_Main_Code_Unit (Call) and then not In_Extended_Main_Code_Unit (Target_Attrs.Spec_Decl) then return True; -- Otherwise the target declaration must not appear within the -- instance spec or body. else Extract_Instance_Attributes (Exp_Inst => Inst, Inst_Decl => Inst_Decl, Inst_Body => Inst_Body); -- Performance note: parent traversal return not In_Subtree (N => Target_Attrs.Spec_Decl, Root1 => Inst_Decl, Root2 => Inst_Body); end if; end if; return False; end In_External_Context; -------------------------- -- In_Premature_Context -- -------------------------- function In_Premature_Context (Call : Node_Id) return Boolean is Par : Node_Id; begin -- Climb the parent chain looking for premature contexts Par := Parent (Call); while Present (Par) loop -- Aspect specifications and generic associations are premature -- contexts because nested calls has not been relocated to their -- final context. if Nkind_In (Par, N_Aspect_Specification, N_Generic_Association) then return True; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); end loop; return False; end In_Premature_Context; ---------------------- -- Is_Bridge_Target -- ---------------------- function Is_Bridge_Target (Id : Entity_Id) return Boolean is begin return Is_Accept_Alternative_Proc (Id) or else Is_Finalizer_Proc (Id) or else Is_Partial_Invariant_Proc (Id) or else Is_Postconditions_Proc (Id) or else Is_TSS (Id, TSS_Deep_Adjust) or else Is_TSS (Id, TSS_Deep_Finalize) or else Is_TSS (Id, TSS_Deep_Initialize); end Is_Bridge_Target; --------------------------- -- Is_Default_Expression -- --------------------------- function Is_Default_Expression (Call : Node_Id) return Boolean is Outer_Call : constant Node_Id := Parent (Call); Outer_Nam : Node_Id; begin -- To qualify, the node must appear immediately within a source call -- which invokes a source target. if Nkind_In (Outer_Call, N_Entry_Call_Statement, N_Function_Call, N_Procedure_Call_Statement) and then Comes_From_Source (Outer_Call) then Outer_Nam := Extract_Call_Name (Outer_Call); return Is_Entity_Name (Outer_Nam) and then Present (Entity (Outer_Nam)) and then Is_Subprogram_Or_Entry (Entity (Outer_Nam)) and then Comes_From_Source (Entity (Outer_Nam)); end if; return False; end Is_Default_Expression; ---------------------------- -- Is_Generic_Formal_Subp -- ---------------------------- function Is_Generic_Formal_Subp (Subp_Id : Entity_Id) return Boolean is Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id); Context : constant Node_Id := Parent (Subp_Decl); begin -- To qualify, the subprogram must rename a generic actual subprogram -- where the enclosing context is an instantiation. return Nkind (Subp_Decl) = N_Subprogram_Renaming_Declaration and then not Comes_From_Source (Subp_Decl) and then Nkind_In (Context, N_Function_Specification, N_Package_Specification, N_Procedure_Specification) and then Present (Generic_Parent (Context)); end Is_Generic_Formal_Subp; -- Local variables Call_Attrs : Call_Attributes; Call_Nam : Node_Id; Marker : Node_Id; Target_Attrs : Target_Attributes; Target_Id : Entity_Id; -- Start of processing for Build_Call_Marker begin -- Nothing to do when switch -gnatH (legacy elaboration checking mode -- enabled) is in effect because the legacy ABE mechanism does not need -- to carry out this action. if Legacy_Elaboration_Checks then return; -- Nothing to do for ASIS because ABE checks and diagnostics are not -- performed in this mode. elsif ASIS_Mode then return; -- Nothing to do when the call is being preanalyzed as the marker will -- be inserted in the wrong place. elsif Preanalysis_Active then return; -- Nothing to do when the input does not denote a call or a requeue elsif not Nkind_In (N, N_Entry_Call_Statement, N_Function_Call, N_Procedure_Call_Statement, N_Requeue_Statement) then return; -- Nothing to do when the input denotes entry call or requeue statement, -- and switch -gnatd_e (ignore entry calls and requeue statements for -- elaboration) is in effect. elsif Debug_Flag_Underscore_E and then Nkind_In (N, N_Entry_Call_Statement, N_Requeue_Statement) then return; end if; Call_Nam := Extract_Call_Name (N); -- Nothing to do when the call is erroneous or left in a bad state if not (Is_Entity_Name (Call_Nam) and then Present (Entity (Call_Nam)) and then Is_Subprogram_Or_Entry (Entity (Call_Nam))) then return; -- Nothing to do when the call invokes a generic formal subprogram and -- switch -gnatd.G (ignore calls through generic formal parameters for -- elaboration) is in effect. This check must be performed with the -- direct target of the call to avoid the side effects of mapping -- actuals to formals using renamings. elsif Debug_Flag_Dot_GG and then Is_Generic_Formal_Subp (Entity (Call_Nam)) then return; -- Nothing to do when the call is analyzed/resolved too early within an -- intermediate context. This check is saved for last because it incurs -- a performance penalty. -- Performance note: parent traversal elsif In_Premature_Context (N) then return; end if; Extract_Call_Attributes (Call => N, Target_Id => Target_Id, Attrs => Call_Attrs); Extract_Target_Attributes (Target_Id => Target_Id, Attrs => Target_Attrs); -- Nothing to do when the call appears within the expanded spec or -- body of an instantiated generic, the call does not invoke a generic -- formal subprogram, the target is external to the instance, and switch -- -gnatdL (ignore external calls from instances for elaboration) is in -- effect. if Debug_Flag_LL and then not Is_Generic_Formal_Subp (Entity (Call_Nam)) -- Performance note: parent traversal and then In_External_Context (Call => N, Target_Attrs => Target_Attrs) then return; -- Nothing to do when the call invokes an assertion pragma procedure -- and switch -gnatd_p (ignore assertion pragmas for elaboration) is -- in effect. elsif Debug_Flag_Underscore_P and then Is_Assertion_Pragma_Target (Target_Id) then return; -- Source calls to source targets are always considered because they -- reflect the original call graph. elsif Target_Attrs.From_Source and then Call_Attrs.From_Source then null; -- A call to a source function which acts as the default expression in -- another call requires special detection. elsif Target_Attrs.From_Source and then Nkind (N) = N_Function_Call and then Is_Default_Expression (N) then null; -- The target emulates Ada semantics elsif Is_Ada_Semantic_Target (Target_Id) then null; -- The target acts as a link between scenarios elsif Is_Bridge_Target (Target_Id) then null; -- The target emulates SPARK semantics elsif Is_SPARK_Semantic_Target (Target_Id) then null; -- Otherwise the call is not suitable for ABE processing. This prevents -- the generation of call markers which will never play a role in ABE -- diagnostics. else return; end if; -- At this point it is known that the call will play some role in ABE -- checks and diagnostics. Create a corresponding call marker in case -- the original call is heavily transformed by expansion later on. Marker := Make_Call_Marker (Sloc (N)); -- Inherit the attributes of the original call Set_Target (Marker, Target_Id); Set_Is_Declaration_Level_Node (Marker, Call_Attrs.In_Declarations); Set_Is_Dispatching_Call (Marker, Call_Attrs.Is_Dispatching); Set_Is_Elaboration_Checks_OK_Node (Marker, Call_Attrs.Elab_Checks_OK); Set_Is_Elaboration_Warnings_OK_Node (Marker, Call_Attrs.Elab_Warnings_OK); Set_Is_Ignored_Ghost_Node (Marker, Call_Attrs.Ghost_Mode_Ignore); Set_Is_Source_Call (Marker, Call_Attrs.From_Source); Set_Is_SPARK_Mode_On_Node (Marker, Call_Attrs.SPARK_Mode_On); -- The marker is inserted prior to the original call. This placement has -- several desirable effects: -- 1) The marker appears in the same context, in close proximity to -- the call. -- -- -- 2) Inserting the marker prior to the call ensures that an ABE check -- will take effect prior to the call. -- -- -- -- 3) The above two properties are preserved even when the call is a -- function which is subsequently relocated in order to capture its -- result. Note that if the call is relocated to a new context, the -- relocated call will receive a marker of its own. -- -- -- Temp : ... := Func_Call ...; -- ... Temp ... -- The insertion must take place even when the call does not occur in -- the main unit to keep the tree symmetric. This ensures that internal -- name serialization is consistent in case the call marker causes the -- tree to transform in some way. Insert_Action (N, Marker); -- The marker becomes the "corresponding" scenario for the call. Save -- the marker for later processing by the ABE phase. Record_Elaboration_Scenario (Marker); end Build_Call_Marker; ------------------------------------- -- Build_Variable_Reference_Marker -- ------------------------------------- procedure Build_Variable_Reference_Marker (N : Node_Id; Read : Boolean; Write : Boolean) is Marker : Node_Id; Var_Attrs : Variable_Attributes; Var_Id : Entity_Id; begin Extract_Variable_Reference_Attributes (Ref => N, Var_Id => Var_Id, Attrs => Var_Attrs); Marker := Make_Variable_Reference_Marker (Sloc (N)); -- Inherit the attributes of the original variable reference Set_Target (Marker, Var_Id); Set_Is_Read (Marker, Read); Set_Is_Write (Marker, Write); -- The marker is inserted prior to the original variable reference. The -- insertion must take place even when the reference does not occur in -- the main unit to keep the tree symmetric. This ensures that internal -- name serialization is consistent in case the variable marker causes -- the tree to transform in some way. Insert_Action (N, Marker); -- The marker becomes the "corresponding" scenario for the reference. -- Save the marker for later processing for the ABE phase. Record_Elaboration_Scenario (Marker); end Build_Variable_Reference_Marker; --------------------------------- -- Check_Elaboration_Scenarios -- --------------------------------- procedure Check_Elaboration_Scenarios is begin -- Nothing to do when switch -gnatH (legacy elaboration checking mode -- enabled) is in effect because the legacy ABE mechanism does not need -- to carry out this action. if Legacy_Elaboration_Checks then return; -- Nothing to do for ASIS because ABE checks and diagnostics are not -- performed in this mode. elsif ASIS_Mode then return; end if; -- Restore the original elaboration model which was in effect when the -- scenarios were first recorded. The model may be specified by pragma -- Elaboration_Checks which appears on the initial declaration of the -- main unit. Install_Elaboration_Model (Unit_Entity (Cunit_Entity (Main_Unit))); -- Examine the context of the main unit and record all units with prior -- elaboration with respect to it. Find_Elaborated_Units; -- Examine each top-level scenario saved during the Recording phase for -- conditional ABEs and perform various actions depending on the model -- in effect. The table of visited bodies is created for each new top- -- level scenario. for Index in Top_Level_Scenarios.First .. Top_Level_Scenarios.Last loop Reset_Visited_Bodies; Process_Conditional_ABE (Top_Level_Scenarios.Table (Index)); end loop; -- Examine each SPARK scenario saved during the Recording phase which -- is not necessarily executable during elaboration, but still requires -- elaboration-related checks. for Index in SPARK_Scenarios.First .. SPARK_Scenarios.Last loop Check_SPARK_Scenario (SPARK_Scenarios.Table (Index)); end loop; end Check_Elaboration_Scenarios; ------------------------------ -- Check_Preelaborated_Call -- ------------------------------ procedure Check_Preelaborated_Call (Call : Node_Id) is function In_Preelaborated_Context (N : Node_Id) return Boolean; -- Determine whether arbitrary node appears in a preelaborated context ------------------------------ -- In_Preelaborated_Context -- ------------------------------ function In_Preelaborated_Context (N : Node_Id) return Boolean is Body_Id : constant Entity_Id := Find_Code_Unit (N); Spec_Id : constant Entity_Id := Unique_Entity (Body_Id); begin -- The node appears within a package body whose corresponding spec is -- subject to pragma Remote_Call_Interface or Remote_Types. This does -- not result in a preelaborated context because the package body may -- be on another machine. if Ekind (Body_Id) = E_Package_Body and then Ekind_In (Spec_Id, E_Generic_Package, E_Package) and then (Is_Remote_Call_Interface (Spec_Id) or else Is_Remote_Types (Spec_Id)) then return False; -- Otherwise the node appears within a preelaborated context when the -- associated unit is preelaborated. else return Is_Preelaborated_Unit (Spec_Id); end if; end In_Preelaborated_Context; -- Local variables Call_Attrs : Call_Attributes; Level : Enclosing_Level_Kind; Target_Id : Entity_Id; -- Start of processing for Check_Preelaborated_Call begin Extract_Call_Attributes (Call => Call, Target_Id => Target_Id, Attrs => Call_Attrs); -- Nothing to do when the call is internally generated because it is -- assumed that it will never violate preelaboration. if not Call_Attrs.From_Source then return; end if; -- Performance note: parent traversal Level := Find_Enclosing_Level (Call); -- Library-level calls are always considered because they are part of -- the associated unit's elaboration actions. if Level in Library_Level then null; -- Calls at the library level of a generic package body must be checked -- because they would render an instantiation illegal if the template is -- marked as preelaborated. Note that this does not apply to calls at -- the library level of a generic package spec. elsif Level = Generic_Package_Body then null; -- Otherwise the call does not appear at the proper level and must not -- be considered for this check. else return; end if; -- The call appears within a preelaborated unit. Emit a warning only for -- internal uses, otherwise this is an error. if In_Preelaborated_Context (Call) then Error_Msg_Warn := GNAT_Mode; Error_Msg_N ("< FNode, Body_Decl => Body_Decl, Error_Nod => Typ_Decl); raise Stop_Check; end if; end Check_Overriding_Primitive; -------------------------- -- Freeze_Node_Location -- -------------------------- function Freeze_Node_Location (FNode : Node_Id) return Source_Ptr is Context : constant Node_Id := Parent (FNode); Loc : constant Source_Ptr := Sloc (FNode); Prv_Decls : List_Id; Vis_Decls : List_Id; begin -- In general, the source location of the freeze node is as close as -- possible to the real freeze point, except when the freeze node is -- at the "bottom" of a package spec. if Nkind (Context) = N_Package_Specification then Prv_Decls := Private_Declarations (Context); Vis_Decls := Visible_Declarations (Context); -- The freeze node appears in the private declarations of the -- package. if Present (Prv_Decls) and then List_Containing (FNode) = Prv_Decls then null; -- The freeze node appears in the visible declarations of the -- package and there are no private declarations. elsif Present (Vis_Decls) and then List_Containing (FNode) = Vis_Decls and then (No (Prv_Decls) or else Is_Empty_List (Prv_Decls)) then null; -- Otherwise the freeze node is not in the "last" declarative list -- of the package. Use the existing source location of the freeze -- node. else return Loc; end if; -- The freeze node appears at the "bottom" of the package when it -- is in the "last" declarative list and is either the last in the -- list or is followed by internal constructs only. In that case -- the more appropriate source location is that of the package end -- label. if not Precedes_Source_Construct (FNode) then return Sloc (End_Label (Context)); end if; end if; return Loc; end Freeze_Node_Location; ------------------------------- -- Precedes_Source_Construct -- ------------------------------- function Precedes_Source_Construct (N : Node_Id) return Boolean is Decl : Node_Id; begin Decl := Next (N); while Present (Decl) loop if Comes_From_Source (Decl) then return True; -- A generated body for a source expression function is treated as -- a source construct. elsif Nkind (Decl) = N_Subprogram_Body and then Was_Expression_Function (Decl) and then Comes_From_Source (Original_Node (Decl)) then return True; end if; Next (Decl); end loop; return False; end Precedes_Source_Construct; ---------------------------- -- Suggest_Elaborate_Body -- ---------------------------- procedure Suggest_Elaborate_Body (N : Node_Id; Body_Decl : Node_Id; Error_Nod : Node_Id) is Unt : constant Node_Id := Unit (Cunit (Main_Unit)); Region : Node_Id; begin -- The suggestion applies only when the subprogram body resides in a -- compilation package body, and a pragma Elaborate_Body would allow -- for the node to appear in the early call region of the subprogram -- body. This implies that all code from the subprogram body up to -- the node is preelaborable. if Nkind (Unt) = N_Package_Body then -- Find the start of the early call region again assuming that the -- package spec has pragma Elaborate_Body. Note that the internal -- data structures are intentionally not updated because this is a -- speculative search. Region := Find_Early_Call_Region (Body_Decl => Body_Decl, Assume_Elab_Body => True, Skip_Memoization => True); -- If the node appears within the early call region, assuming that -- the package spec carries pragma Elaborate_Body, then it is safe -- to suggest the pragma. if Earlier_In_Extended_Unit (Region, N) then Error_Msg_Name_1 := Name_Elaborate_Body; Error_Msg_NE ("\consider adding pragma % in spec of unit &", Error_Nod, Defining_Entity (Unt)); end if; end if; end Suggest_Elaborate_Body; -- Local variables FNode : constant Node_Id := Freeze_Node (Typ); Prims : constant Elist_Id := Direct_Primitive_Operations (Typ); Prim_Elmt : Elmt_Id; -- Start of processing for Check_SPARK_Derived_Type begin -- A type should have its freeze node set by the time SPARK scenarios -- are being verified. pragma Assert (Present (FNode)); -- Verify that the freeze node of the derived type is within the early -- call region of each overriding primitive body (SPARK RM 7.7(8)). if Present (Prims) then Prim_Elmt := First_Elmt (Prims); while Present (Prim_Elmt) loop Check_Overriding_Primitive (Prim => Node (Prim_Elmt), FNode => FNode); Next_Elmt (Prim_Elmt); end loop; end if; exception when Stop_Check => null; end Check_SPARK_Derived_Type; ------------------------------- -- Check_SPARK_Instantiation -- ------------------------------- procedure Check_SPARK_Instantiation (Exp_Inst : Node_Id) is Gen_Attrs : Target_Attributes; Gen_Id : Entity_Id; Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Inst_Id : Entity_Id; begin Extract_Instantiation_Attributes (Exp_Inst => Exp_Inst, Inst => Inst, Inst_Id => Inst_Id, Gen_Id => Gen_Id, Attrs => Inst_Attrs); Extract_Target_Attributes (Gen_Id, Gen_Attrs); -- The instantiation and the generic body are both in the main unit if Present (Gen_Attrs.Body_Decl) and then In_Extended_Main_Code_Unit (Gen_Attrs.Body_Decl) -- If the instantiation appears prior to the generic body, then the -- instantiation is illegal (SPARK RM 7.7(6)). -- IMPORTANT: This check must always be performed even when -gnatd.v -- (enforce SPARK elaboration rules in SPARK code) is not specified -- because the rule prevents use-before-declaration of objects that -- may precede the generic body. and then Earlier_In_Extended_Unit (Inst, Gen_Attrs.Body_Decl) then Error_Msg_NE ("cannot instantiate & before body seen", Inst, Gen_Id); end if; end Check_SPARK_Instantiation; --------------------------------- -- Check_SPARK_Model_In_Effect -- --------------------------------- SPARK_Model_Warning_Posted : Boolean := False; -- This flag prevents the same SPARK model-related warning from being -- emitted multiple times. procedure Check_SPARK_Model_In_Effect (N : Node_Id) is begin -- Do not emit the warning multiple times as this creates useless noise if SPARK_Model_Warning_Posted then null; -- SPARK rule verification requires the "strict" static model elsif Static_Elaboration_Checks and not Relaxed_Elaboration_Checks then null; -- Any other combination of models does not guarantee the absence of ABE -- problems for SPARK rule verification purposes. Note that there is no -- need to check for the legacy ABE mechanism because the legacy code -- has its own orthogonal processing for SPARK rules. else SPARK_Model_Warning_Posted := True; Error_Msg_N ("??SPARK elaboration checks require static elaboration model", N); if Dynamic_Elaboration_Checks then Error_Msg_N ("\dynamic elaboration model is in effect", N); else pragma Assert (Relaxed_Elaboration_Checks); Error_Msg_N ("\relaxed elaboration model is in effect", N); end if; end if; end Check_SPARK_Model_In_Effect; -------------------------- -- Check_SPARK_Scenario -- -------------------------- procedure Check_SPARK_Scenario (N : Node_Id) is begin -- Ensure that a suitable elaboration model is in effect for SPARK rule -- verification. Check_SPARK_Model_In_Effect (N); -- Add the current scenario to the stack of active scenarios Push_Active_Scenario (N); if Is_Suitable_SPARK_Derived_Type (N) then Check_SPARK_Derived_Type (N); elsif Is_Suitable_SPARK_Instantiation (N) then Check_SPARK_Instantiation (N); elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then Check_SPARK_Refined_State_Pragma (N); end if; -- Remove the current scenario from the stack of active scenarios once -- all ABE diagnostics and checks have been performed. Pop_Active_Scenario (N); end Check_SPARK_Scenario; -------------------------------------- -- Check_SPARK_Refined_State_Pragma -- -------------------------------------- procedure Check_SPARK_Refined_State_Pragma (N : Node_Id) is -- NOTE: The routines within Check_SPARK_Refined_State_Pragma are -- intentionally unnested to avoid deep indentation of code. procedure Check_SPARK_Constituent (Constit_Id : Entity_Id); pragma Inline (Check_SPARK_Constituent); -- Ensure that a single constituent Constit_Id is elaborated prior to -- the main unit. procedure Check_SPARK_Constituents (Constits : Elist_Id); pragma Inline (Check_SPARK_Constituents); -- Ensure that all constituents found in list Constits are elaborated -- prior to the main unit. procedure Check_SPARK_Initialized_State (State : Node_Id); pragma Inline (Check_SPARK_Initialized_State); -- Ensure that the constituents of single abstract state State are -- elaborated prior to the main unit. procedure Check_SPARK_Initialized_States (Pack_Id : Entity_Id); pragma Inline (Check_SPARK_Initialized_States); -- Ensure that the constituents of all abstract states which appear in -- the Initializes pragma of package Pack_Id are elaborated prior to the -- main unit. ----------------------------- -- Check_SPARK_Constituent -- ----------------------------- procedure Check_SPARK_Constituent (Constit_Id : Entity_Id) is Prag : Node_Id; begin -- Nothing to do for "null" constituents if Nkind (Constit_Id) = N_Null then return; -- Nothing to do for illegal constituents elsif Error_Posted (Constit_Id) then return; end if; Prag := SPARK_Pragma (Constit_Id); -- The check applies only when the constituent is subject to pragma -- SPARK_Mode On. if Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On then -- An external constituent of an abstract state which appears in -- the Initializes pragma of a package spec imposes an Elaborate -- requirement on the context of the main unit. Determine whether -- the context has a pragma strong enough to meet the requirement. -- IMPORTANT: This check is performed only when -gnatd.v (enforce -- SPARK elaboration rules in SPARK code) is in effect because the -- static model can ensure the prior elaboration of the unit which -- contains a constituent by installing implicit Elaborate pragma. if Debug_Flag_Dot_V then Meet_Elaboration_Requirement (N => N, Target_Id => Constit_Id, Req_Nam => Name_Elaborate); -- Otherwise ensure that the unit with the external constituent is -- elaborated prior to the main unit. else Ensure_Prior_Elaboration (N => N, Unit_Id => Find_Top_Unit (Constit_Id), Prag_Nam => Name_Elaborate, State => Initial_State); end if; end if; end Check_SPARK_Constituent; ------------------------------ -- Check_SPARK_Constituents -- ------------------------------ procedure Check_SPARK_Constituents (Constits : Elist_Id) is Constit_Elmt : Elmt_Id; begin if Present (Constits) then Constit_Elmt := First_Elmt (Constits); while Present (Constit_Elmt) loop Check_SPARK_Constituent (Node (Constit_Elmt)); Next_Elmt (Constit_Elmt); end loop; end if; end Check_SPARK_Constituents; ----------------------------------- -- Check_SPARK_Initialized_State -- ----------------------------------- procedure Check_SPARK_Initialized_State (State : Node_Id) is Prag : Node_Id; State_Id : Entity_Id; begin -- Nothing to do for "null" initialization items if Nkind (State) = N_Null then return; -- Nothing to do for illegal states elsif Error_Posted (State) then return; end if; State_Id := Entity_Of (State); -- Sanitize the state if No (State_Id) then return; elsif Error_Posted (State_Id) then return; elsif Ekind (State_Id) /= E_Abstract_State then return; end if; -- The check is performed only when the abstract state is subject to -- SPARK_Mode On. Prag := SPARK_Pragma (State_Id); if Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On then Check_SPARK_Constituents (Refinement_Constituents (State_Id)); end if; end Check_SPARK_Initialized_State; ------------------------------------ -- Check_SPARK_Initialized_States -- ------------------------------------ procedure Check_SPARK_Initialized_States (Pack_Id : Entity_Id) is Prag : constant Node_Id := Get_Pragma (Pack_Id, Pragma_Initializes); Init : Node_Id; Inits : Node_Id; begin if Present (Prag) then Inits := Expression (Get_Argument (Prag, Pack_Id)); -- Avoid processing a "null" initialization list. The only other -- alternative is an aggregate. if Nkind (Inits) = N_Aggregate then -- The initialization items appear in list form: -- -- (state1, state2) if Present (Expressions (Inits)) then Init := First (Expressions (Inits)); while Present (Init) loop Check_SPARK_Initialized_State (Init); Next (Init); end loop; end if; -- The initialization items appear in associated form: -- -- (state1 => item1, -- state2 => (item2, item3)) if Present (Component_Associations (Inits)) then Init := First (Component_Associations (Inits)); while Present (Init) loop Check_SPARK_Initialized_State (Init); Next (Init); end loop; end if; end if; end if; end Check_SPARK_Initialized_States; -- Local variables Pack_Body : constant Node_Id := Find_Related_Package_Or_Body (N); -- Start of processing for Check_SPARK_Refined_State_Pragma begin -- Pragma Refined_State must be associated with a package body pragma Assert (Present (Pack_Body) and then Nkind (Pack_Body) = N_Package_Body); -- Verify that each external contitunent of an abstract state mentioned -- in pragma Initializes is properly elaborated. Check_SPARK_Initialized_States (Unique_Defining_Entity (Pack_Body)); end Check_SPARK_Refined_State_Pragma; ---------------------- -- Compilation_Unit -- ---------------------- function Compilation_Unit (Unit_Id : Entity_Id) return Node_Id is Comp_Unit : Node_Id; begin Comp_Unit := Parent (Unit_Id); -- Handle the case where a concurrent subunit is rewritten as a null -- statement due to expansion activities. if Nkind (Comp_Unit) = N_Null_Statement and then Nkind_In (Original_Node (Comp_Unit), N_Protected_Body, N_Task_Body) then Comp_Unit := Parent (Comp_Unit); pragma Assert (Nkind (Comp_Unit) = N_Subunit); -- Otherwise use the declaration node of the unit else Comp_Unit := Parent (Unit_Declaration_Node (Unit_Id)); end if; -- Handle the case where a subprogram instantiation which acts as a -- compilation unit is expanded into an anonymous package that wraps -- the instantiated subprogram. if Nkind (Comp_Unit) = N_Package_Specification and then Nkind_In (Original_Node (Parent (Comp_Unit)), N_Function_Instantiation, N_Procedure_Instantiation) then Comp_Unit := Parent (Parent (Comp_Unit)); -- Handle the case where the compilation unit is a subunit elsif Nkind (Comp_Unit) = N_Subunit then Comp_Unit := Parent (Comp_Unit); end if; pragma Assert (Nkind (Comp_Unit) = N_Compilation_Unit); return Comp_Unit; end Compilation_Unit; ----------------------- -- Early_Call_Region -- ----------------------- function Early_Call_Region (Body_Id : Entity_Id) return Node_Id is begin pragma Assert (Ekind_In (Body_Id, E_Entry, E_Entry_Family, E_Function, E_Procedure, E_Subprogram_Body)); if Early_Call_Regions_In_Use then return Early_Call_Regions.Get (Body_Id); end if; return Early_Call_Regions_No_Element; end Early_Call_Region; ----------------------------- -- Early_Call_Regions_Hash -- ----------------------------- function Early_Call_Regions_Hash (Key : Entity_Id) return Early_Call_Regions_Index is begin return Early_Call_Regions_Index (Key mod Early_Call_Regions_Max); end Early_Call_Regions_Hash; ----------------- -- Elab_Msg_NE -- ----------------- procedure Elab_Msg_NE (Msg : String; N : Node_Id; Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean) is function Prefix return String; -- Obtain the prefix of the message function Suffix return String; -- Obtain the suffix of the message ------------ -- Prefix -- ------------ function Prefix return String is begin if Info_Msg then return "info: "; else return ""; end if; end Prefix; ------------ -- Suffix -- ------------ function Suffix return String is begin if In_SPARK then return " in SPARK"; else return ""; end if; end Suffix; -- Start of processing for Elab_Msg_NE begin Error_Msg_NE (Prefix & Msg & Suffix, N, Id); end Elab_Msg_NE; ------------------------ -- Elaboration_Status -- ------------------------ function Elaboration_Status (Unit_Id : Entity_Id) return Elaboration_Attributes is begin if Elaboration_Statuses_In_Use then return Elaboration_Statuses.Get (Unit_Id); end if; return Elaboration_Statuses_No_Element; end Elaboration_Status; ------------------------------- -- Elaboration_Statuses_Hash -- ------------------------------- function Elaboration_Statuses_Hash (Key : Entity_Id) return Elaboration_Statuses_Index is begin return Elaboration_Statuses_Index (Key mod Elaboration_Statuses_Max); end Elaboration_Statuses_Hash; ------------------------------ -- Ensure_Prior_Elaboration -- ------------------------------ procedure Ensure_Prior_Elaboration (N : Node_Id; Unit_Id : Entity_Id; Prag_Nam : Name_Id; State : Processing_Attributes) is begin pragma Assert (Nam_In (Prag_Nam, Name_Elaborate, Name_Elaborate_All)); -- Nothing to do when the caller has suppressed the generation of -- implicit Elaborate[_All] pragmas. if State.Suppress_Implicit_Pragmas then return; -- Nothing to do when the need for prior elaboration came from a partial -- finalization routine which occurs in an initialization context. This -- behaviour parallels that of the old ABE mechanism. elsif State.Within_Partial_Finalization then return; -- Nothing to do when the need for prior elaboration came from a task -- body and switch -gnatd.y (disable implicit pragma Elaborate_All on -- task bodies) is in effect. elsif Debug_Flag_Dot_Y and then State.Within_Task_Body then return; -- Nothing to do when the unit is elaborated prior to the main unit. -- This check must also consider the following cases: -- * No check is made against the context of the main unit because this -- is specific to the elaboration model in effect and requires custom -- handling (see Ensure_xxx_Prior_Elaboration). -- * Unit_Id is subject to pragma Elaborate_Body. An implicit pragma -- Elaborate[_All] MUST be generated even though Unit_Id is always -- elaborated prior to the main unit. This is a conservative strategy -- which ensures that other units withed by Unit_Id will not lead to -- an ABE. -- package A is package body A is -- procedure ABE; procedure ABE is ... end ABE; -- end A; end A; -- with A; -- package B is package body B is -- pragma Elaborate_Body; procedure Proc is -- begin -- procedure Proc; A.ABE; -- package B; end Proc; -- end B; -- with B; -- package C is package body C is -- ... ... -- end C; begin -- B.Proc; -- end C; -- In the example above, the elaboration of C invokes B.Proc. B is -- subject to pragma Elaborate_Body. If no pragma Elaborate[_All] is -- generated for B in C, then the following elaboratio order will lead -- to an ABE: -- spec of A elaborated -- spec of B elaborated -- body of B elaborated -- spec of C elaborated -- body of C elaborated <-- calls B.Proc which calls A.ABE -- body of A elaborated <-- problem -- The generation of an implicit pragma Elaborate_All (B) ensures that -- the elaboration order mechanism will not pick the above order. -- An implicit Elaborate is NOT generated when the unit is subject to -- Elaborate_Body because both pragmas have the exact same effect. -- * Unit_Id is the main unit. An implicit pragma Elaborate[_All] MUST -- NOT be generated in this case because a unit cannot depend on its -- own elaboration. This case is therefore treated as valid prior -- elaboration. elsif Has_Prior_Elaboration (Unit_Id => Unit_Id, Same_Unit_OK => True, Elab_Body_OK => Prag_Nam = Name_Elaborate) then return; -- Suggest the use of pragma Prag_Nam when the dynamic model is in -- effect. elsif Dynamic_Elaboration_Checks then Ensure_Prior_Elaboration_Dynamic (N => N, Unit_Id => Unit_Id, Prag_Nam => Prag_Nam); -- Install an implicit pragma Prag_Nam when the static model is in -- effect. else pragma Assert (Static_Elaboration_Checks); Ensure_Prior_Elaboration_Static (N => N, Unit_Id => Unit_Id, Prag_Nam => Prag_Nam); end if; end Ensure_Prior_Elaboration; -------------------------------------- -- Ensure_Prior_Elaboration_Dynamic -- -------------------------------------- procedure Ensure_Prior_Elaboration_Dynamic (N : Node_Id; Unit_Id : Entity_Id; Prag_Nam : Name_Id) is procedure Info_Missing_Pragma; pragma Inline (Info_Missing_Pragma); -- Output information concerning missing Elaborate or Elaborate_All -- pragma with name Prag_Nam for scenario N, which would ensure the -- prior elaboration of Unit_Id. ------------------------- -- Info_Missing_Pragma -- ------------------------- procedure Info_Missing_Pragma is begin -- Internal units are ignored as they cause unnecessary noise if not In_Internal_Unit (Unit_Id) then -- The name of the unit subjected to the elaboration pragma is -- fully qualified to improve the clarity of the info message. Error_Msg_Name_1 := Prag_Nam; Error_Msg_Qual_Level := Nat'Last; Error_Msg_NE ("info: missing pragma % for unit &", N, Unit_Id); Error_Msg_Qual_Level := 0; end if; end Info_Missing_Pragma; -- Local variables Elab_Attrs : Elaboration_Attributes; Level : Enclosing_Level_Kind; -- Start of processing for Ensure_Prior_Elaboration_Dynamic begin Elab_Attrs := Elaboration_Status (Unit_Id); -- Nothing to do when the unit is guaranteed prior elaboration by means -- of a source Elaborate[_All] pragma. if Present (Elab_Attrs.Source_Pragma) then return; end if; -- Output extra information on a missing Elaborate[_All] pragma when -- switch -gnatel (info messages on implicit Elaborate[_All] pragmas -- is in effect. if Elab_Info_Messages then -- Performance note: parent traversal Level := Find_Enclosing_Level (N); -- Declaration-level scenario if (Is_Suitable_Call (N) or else Is_Suitable_Instantiation (N)) and then Level = Declaration_Level then null; -- Library-level scenario elsif Level in Library_Level then null; -- Instantiation library-level scenario elsif Level = Instantiation then null; -- Otherwise the scenario does not appear at the proper level and -- cannot possibly act as a top-level scenario. else return; end if; Info_Missing_Pragma; end if; end Ensure_Prior_Elaboration_Dynamic; ------------------------------------- -- Ensure_Prior_Elaboration_Static -- ------------------------------------- procedure Ensure_Prior_Elaboration_Static (N : Node_Id; Unit_Id : Entity_Id; Prag_Nam : Name_Id) is function Find_With_Clause (Items : List_Id; Withed_Id : Entity_Id) return Node_Id; pragma Inline (Find_With_Clause); -- Find a nonlimited with clause in the list of context items Items -- that withs unit Withed_Id. Return Empty if no such clause is found. procedure Info_Implicit_Pragma; pragma Inline (Info_Implicit_Pragma); -- Output information concerning an implicitly generated Elaborate or -- Elaborate_All pragma with name Prag_Nam for scenario N which ensures -- the prior elaboration of unit Unit_Id. ---------------------- -- Find_With_Clause -- ---------------------- function Find_With_Clause (Items : List_Id; Withed_Id : Entity_Id) return Node_Id is Item : Node_Id; begin -- Examine the context clauses looking for a suitable with. Note that -- limited clauses do not affect the elaboration order. Item := First (Items); while Present (Item) loop if Nkind (Item) = N_With_Clause and then not Error_Posted (Item) and then not Limited_Present (Item) and then Entity (Name (Item)) = Withed_Id then return Item; end if; Next (Item); end loop; return Empty; end Find_With_Clause; -------------------------- -- Info_Implicit_Pragma -- -------------------------- procedure Info_Implicit_Pragma is begin -- Internal units are ignored as they cause unnecessary noise if not In_Internal_Unit (Unit_Id) then -- The name of the unit subjected to the elaboration pragma is -- fully qualified to improve the clarity of the info message. Error_Msg_Name_1 := Prag_Nam; Error_Msg_Qual_Level := Nat'Last; Error_Msg_NE ("info: implicit pragma % generated for unit &", N, Unit_Id); Error_Msg_Qual_Level := 0; Output_Active_Scenarios (N); end if; end Info_Implicit_Pragma; -- Local variables Main_Cunit : constant Node_Id := Cunit (Main_Unit); Loc : constant Source_Ptr := Sloc (Main_Cunit); Unit_Cunit : constant Node_Id := Compilation_Unit (Unit_Id); Clause : Node_Id; Elab_Attrs : Elaboration_Attributes; Items : List_Id; -- Start of processing for Ensure_Prior_Elaboration_Static begin Elab_Attrs := Elaboration_Status (Unit_Id); -- Nothing to do when the unit is guaranteed prior elaboration by means -- of a source Elaborate[_All] pragma. if Present (Elab_Attrs.Source_Pragma) then return; -- Nothing to do when the unit has an existing implicit Elaborate[_All] -- pragma installed by a previous scenario. elsif Present (Elab_Attrs.With_Clause) then -- The unit is already guaranteed prior elaboration by means of an -- implicit Elaborate pragma, however the current scenario imposes -- a stronger requirement of Elaborate_All. "Upgrade" the existing -- pragma to match this new requirement. if Elaborate_Desirable (Elab_Attrs.With_Clause) and then Prag_Nam = Name_Elaborate_All then Set_Elaborate_All_Desirable (Elab_Attrs.With_Clause); Set_Elaborate_Desirable (Elab_Attrs.With_Clause, False); end if; return; end if; -- At this point it is known that the unit has no prior elaboration -- according to pragmas and hierarchical relationships. Items := Context_Items (Main_Cunit); if No (Items) then Items := New_List; Set_Context_Items (Main_Cunit, Items); end if; -- Locate the with clause for the unit. Note that there may not be a -- clause if the unit is visible through a subunit-body, body-spec, or -- spec-parent relationship. Clause := Find_With_Clause (Items => Items, Withed_Id => Unit_Id); -- Generate: -- with Id; -- Note that adding implicit with clauses is safe because analysis, -- resolution, and expansion have already taken place and it is not -- possible to interfere with visibility. if No (Clause) then Clause := Make_With_Clause (Loc, Name => New_Occurrence_Of (Unit_Id, Loc)); Set_Implicit_With (Clause); Set_Library_Unit (Clause, Unit_Cunit); Append_To (Items, Clause); end if; -- Mark the with clause depending on the pragma required if Prag_Nam = Name_Elaborate then Set_Elaborate_Desirable (Clause); else Set_Elaborate_All_Desirable (Clause); end if; -- The implicit Elaborate[_All] ensures the prior elaboration of the -- unit. Include the unit in the elaboration context of the main unit. Set_Elaboration_Status (Unit_Id => Unit_Id, Val => Elaboration_Attributes'(Source_Pragma => Empty, With_Clause => Clause)); -- Output extra information on an implicit Elaborate[_All] pragma when -- switch -gnatel (info messages on implicit Elaborate[_All] pragmas is -- in effect. if Elab_Info_Messages then Info_Implicit_Pragma; end if; end Ensure_Prior_Elaboration_Static; ----------------------------- -- Extract_Assignment_Name -- ----------------------------- function Extract_Assignment_Name (Asmt : Node_Id) return Node_Id is Nam : Node_Id; begin Nam := Name (Asmt); -- When the name denotes an array or record component, find the whole -- object. while Nkind_In (Nam, N_Explicit_Dereference, N_Indexed_Component, N_Selected_Component, N_Slice) loop Nam := Prefix (Nam); end loop; return Nam; end Extract_Assignment_Name; ----------------------------- -- Extract_Call_Attributes -- ----------------------------- procedure Extract_Call_Attributes (Call : Node_Id; Target_Id : out Entity_Id; Attrs : out Call_Attributes) is From_Source : Boolean; In_Declarations : Boolean; Is_Dispatching : Boolean; begin -- Extraction for call markers if Nkind (Call) = N_Call_Marker then Target_Id := Target (Call); From_Source := Is_Source_Call (Call); In_Declarations := Is_Declaration_Level_Node (Call); Is_Dispatching := Is_Dispatching_Call (Call); -- Extraction for entry calls, requeue, and subprogram calls else pragma Assert (Nkind_In (Call, N_Entry_Call_Statement, N_Function_Call, N_Procedure_Call_Statement, N_Requeue_Statement)); Target_Id := Entity (Extract_Call_Name (Call)); From_Source := Comes_From_Source (Call); -- Performance note: parent traversal In_Declarations := Find_Enclosing_Level (Call) = Declaration_Level; Is_Dispatching := Nkind_In (Call, N_Function_Call, N_Procedure_Call_Statement) and then Present (Controlling_Argument (Call)); end if; -- Obtain the original entry or subprogram which the target may rename -- except when the target is an instantiation. In this case the alias -- is the internally generated subprogram which appears within the the -- anonymous package created for the instantiation. Such an alias is not -- a suitable target. if not (Is_Subprogram (Target_Id) and then Is_Generic_Instance (Target_Id)) then Target_Id := Get_Renamed_Entity (Target_Id); end if; -- Set all attributes Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Node (Call); Attrs.Elab_Warnings_OK := Is_Elaboration_Warnings_OK_Node (Call); Attrs.From_Source := From_Source; Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Node (Call); Attrs.In_Declarations := In_Declarations; Attrs.Is_Dispatching := Is_Dispatching; Attrs.SPARK_Mode_On := Is_SPARK_Mode_On_Node (Call); end Extract_Call_Attributes; ----------------------- -- Extract_Call_Name -- ----------------------- function Extract_Call_Name (Call : Node_Id) return Node_Id is Nam : Node_Id; begin Nam := Name (Call); -- When the call invokes an entry family, the name appears as an indexed -- component. if Nkind (Nam) = N_Indexed_Component then Nam := Prefix (Nam); end if; -- When the call employs the object.operation form, the name appears as -- a selected component. if Nkind (Nam) = N_Selected_Component then Nam := Selector_Name (Nam); end if; return Nam; end Extract_Call_Name; --------------------------------- -- Extract_Instance_Attributes -- --------------------------------- procedure Extract_Instance_Attributes (Exp_Inst : Node_Id; Inst_Body : out Node_Id; Inst_Decl : out Node_Id) is Body_Id : Entity_Id; begin -- Assume that the attributes are unavailable Inst_Body := Empty; Inst_Decl := Empty; -- Generic package or subprogram spec if Nkind_In (Exp_Inst, N_Package_Declaration, N_Subprogram_Declaration) then Inst_Decl := Exp_Inst; Body_Id := Corresponding_Body (Inst_Decl); if Present (Body_Id) then Inst_Body := Unit_Declaration_Node (Body_Id); end if; -- Generic package or subprogram body else pragma Assert (Nkind_In (Exp_Inst, N_Package_Body, N_Subprogram_Body)); Inst_Body := Exp_Inst; Inst_Decl := Unit_Declaration_Node (Corresponding_Spec (Inst_Body)); end if; end Extract_Instance_Attributes; -------------------------------------- -- Extract_Instantiation_Attributes -- -------------------------------------- procedure Extract_Instantiation_Attributes (Exp_Inst : Node_Id; Inst : out Node_Id; Inst_Id : out Entity_Id; Gen_Id : out Entity_Id; Attrs : out Instantiation_Attributes) is begin Inst := Original_Node (Exp_Inst); Inst_Id := Defining_Entity (Inst); -- Traverse a possible chain of renamings to obtain the original generic -- being instantiatied. Gen_Id := Get_Renamed_Entity (Entity (Name (Inst))); -- Set all attributes Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Node (Inst); Attrs.Elab_Warnings_OK := Is_Elaboration_Warnings_OK_Node (Inst); Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Node (Inst); Attrs.In_Declarations := Is_Declaration_Level_Node (Inst); Attrs.SPARK_Mode_On := Is_SPARK_Mode_On_Node (Inst); end Extract_Instantiation_Attributes; ------------------------------- -- Extract_Target_Attributes -- ------------------------------- procedure Extract_Target_Attributes (Target_Id : Entity_Id; Attrs : out Target_Attributes) is procedure Extract_Package_Or_Subprogram_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id); -- Obtain the attributes associated with a package or a subprogram. -- Spec_Id is the package or subprogram. Body_Decl is the declaration -- of the corresponding package or subprogram body. procedure Extract_Protected_Entry_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id; Body_Barf : out Node_Id); -- Obtain the attributes associated with a protected entry [family]. -- Spec_Id is the entity of the protected body subprogram. Body_Decl -- is the declaration of Spec_Id's corresponding body. Body_Barf is -- the declaration of the barrier function body. procedure Extract_Protected_Subprogram_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id); -- Obtain the attributes associated with a protected subprogram. Formal -- Spec_Id is the entity of the protected body subprogram. Body_Decl is -- the declaration of Spec_Id's corresponding body. procedure Extract_Task_Entry_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id); -- Obtain the attributes associated with a task entry [family]. Formal -- Spec_Id is the entity of the task body procedure. Body_Decl is the -- declaration of Spec_Id's corresponding body. ---------------------------------------------- -- Extract_Package_Or_Subprogram_Attributes -- ---------------------------------------------- procedure Extract_Package_Or_Subprogram_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id) is Body_Id : Entity_Id; Init_Id : Entity_Id; Spec_Decl : Node_Id; begin -- Assume that the body is not available Body_Decl := Empty; Spec_Id := Target_Id; -- For body retrieval purposes, the entity of the initial declaration -- is that of the spec. Init_Id := Spec_Id; -- The only exception to the above is a function which returns a -- constrained array type in a SPARK-to-C compilation. In this case -- the function receives a corresponding procedure which has an out -- parameter. The proper body for ABE checks and diagnostics is that -- of the procedure. if Ekind (Init_Id) = E_Function and then Rewritten_For_C (Init_Id) then Init_Id := Corresponding_Procedure (Init_Id); end if; -- Extract the attributes of the body Spec_Decl := Unit_Declaration_Node (Init_Id); -- The initial declaration is a stand alone subprogram body if Nkind (Spec_Decl) = N_Subprogram_Body then Body_Decl := Spec_Decl; -- Otherwise the package or subprogram has a spec and a completing -- body. elsif Nkind_In (Spec_Decl, N_Generic_Package_Declaration, N_Generic_Subprogram_Declaration, N_Package_Declaration, N_Subprogram_Body_Stub, N_Subprogram_Declaration) then Body_Id := Corresponding_Body (Spec_Decl); if Present (Body_Id) then Body_Decl := Unit_Declaration_Node (Body_Id); end if; end if; end Extract_Package_Or_Subprogram_Attributes; ---------------------------------------- -- Extract_Protected_Entry_Attributes -- ---------------------------------------- procedure Extract_Protected_Entry_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id; Body_Barf : out Node_Id) is Barf_Id : Entity_Id; Body_Id : Entity_Id; begin -- Assume that the bodies are not available Body_Barf := Empty; Body_Decl := Empty; -- When the entry [family] has already been expanded, it carries both -- the procedure which emulates the behavior of the entry [family] as -- well as the barrier function. if Present (Protected_Body_Subprogram (Target_Id)) then Spec_Id := Protected_Body_Subprogram (Target_Id); -- Extract the attributes of the barrier function Barf_Id := Corresponding_Body (Unit_Declaration_Node (Barrier_Function (Target_Id))); if Present (Barf_Id) then Body_Barf := Unit_Declaration_Node (Barf_Id); end if; -- Otherwise no expansion took place else Spec_Id := Target_Id; end if; -- Extract the attributes of the entry body Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); if Present (Body_Id) then Body_Decl := Unit_Declaration_Node (Body_Id); end if; end Extract_Protected_Entry_Attributes; --------------------------------------------- -- Extract_Protected_Subprogram_Attributes -- --------------------------------------------- procedure Extract_Protected_Subprogram_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id) is Body_Id : Entity_Id; begin -- Assume that the body is not available Body_Decl := Empty; -- When the protected subprogram has already been expanded, it -- carries the subprogram which seizes the lock and invokes the -- original statements. if Present (Protected_Subprogram (Target_Id)) then Spec_Id := Protected_Body_Subprogram (Protected_Subprogram (Target_Id)); -- Otherwise no expansion took place else Spec_Id := Target_Id; end if; -- Extract the attributes of the body Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); if Present (Body_Id) then Body_Decl := Unit_Declaration_Node (Body_Id); end if; end Extract_Protected_Subprogram_Attributes; ----------------------------------- -- Extract_Task_Entry_Attributes -- ----------------------------------- procedure Extract_Task_Entry_Attributes (Spec_Id : out Entity_Id; Body_Decl : out Node_Id) is Task_Typ : constant Entity_Id := Non_Private_View (Scope (Target_Id)); Body_Id : Entity_Id; begin -- Assume that the body is not available Body_Decl := Empty; -- The the task type has already been expanded, it carries the -- procedure which emulates the behavior of the task body. if Present (Task_Body_Procedure (Task_Typ)) then Spec_Id := Task_Body_Procedure (Task_Typ); -- Otherwise no expansion took place else Spec_Id := Task_Typ; end if; -- Extract the attributes of the body Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); if Present (Body_Id) then Body_Decl := Unit_Declaration_Node (Body_Id); end if; end Extract_Task_Entry_Attributes; -- Local variables Prag : constant Node_Id := SPARK_Pragma (Target_Id); Body_Barf : Node_Id; Body_Decl : Node_Id; Spec_Id : Entity_Id; -- Start of processing for Extract_Target_Attributes begin -- Assume that the body of the barrier function is not available Body_Barf := Empty; -- The target is a protected entry [family] if Is_Protected_Entry (Target_Id) then Extract_Protected_Entry_Attributes (Spec_Id => Spec_Id, Body_Decl => Body_Decl, Body_Barf => Body_Barf); -- The target is a protected subprogram elsif Is_Protected_Subp (Target_Id) or else Is_Protected_Body_Subp (Target_Id) then Extract_Protected_Subprogram_Attributes (Spec_Id => Spec_Id, Body_Decl => Body_Decl); -- The target is a task entry [family] elsif Is_Task_Entry (Target_Id) then Extract_Task_Entry_Attributes (Spec_Id => Spec_Id, Body_Decl => Body_Decl); -- Otherwise the target is a package or a subprogram else Extract_Package_Or_Subprogram_Attributes (Spec_Id => Spec_Id, Body_Decl => Body_Decl); end if; -- Set all attributes Attrs.Body_Barf := Body_Barf; Attrs.Body_Decl := Body_Decl; Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Id (Target_Id); Attrs.Elab_Warnings_OK := Is_Elaboration_Warnings_OK_Id (Target_Id); Attrs.From_Source := Comes_From_Source (Target_Id); Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Entity (Target_Id); Attrs.SPARK_Mode_On := Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On; Attrs.Spec_Decl := Unit_Declaration_Node (Spec_Id); Attrs.Spec_Id := Spec_Id; Attrs.Unit_Id := Find_Top_Unit (Target_Id); -- At this point certain attributes should always be available pragma Assert (Present (Attrs.Spec_Decl)); pragma Assert (Present (Attrs.Spec_Id)); pragma Assert (Present (Attrs.Unit_Id)); end Extract_Target_Attributes; ----------------------------- -- Extract_Task_Attributes -- ----------------------------- procedure Extract_Task_Attributes (Typ : Entity_Id; Attrs : out Task_Attributes) is Task_Typ : constant Entity_Id := Non_Private_View (Typ); Body_Decl : Node_Id; Body_Id : Entity_Id; Prag : Node_Id; Spec_Id : Entity_Id; begin -- Assume that the body of the task procedure is not available Body_Decl := Empty; -- The initial declaration is that of the task body procedure Spec_Id := Get_Task_Body_Procedure (Task_Typ); Body_Id := Corresponding_Body (Unit_Declaration_Node (Spec_Id)); if Present (Body_Id) then Body_Decl := Unit_Declaration_Node (Body_Id); end if; Prag := SPARK_Pragma (Task_Typ); -- Set all attributes Attrs.Body_Decl := Body_Decl; Attrs.Elab_Checks_OK := Is_Elaboration_Checks_OK_Id (Task_Typ); Attrs.Elab_Warnings_OK := Is_Elaboration_Warnings_OK_Id (Task_Typ); Attrs.Ghost_Mode_Ignore := Is_Ignored_Ghost_Entity (Task_Typ); Attrs.SPARK_Mode_On := Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On; Attrs.Spec_Id := Spec_Id; Attrs.Task_Decl := Declaration_Node (Task_Typ); Attrs.Unit_Id := Find_Top_Unit (Task_Typ); -- At this point certain attributes should always be available pragma Assert (Present (Attrs.Spec_Id)); pragma Assert (Present (Attrs.Task_Decl)); pragma Assert (Present (Attrs.Unit_Id)); end Extract_Task_Attributes; ------------------------------------------- -- Extract_Variable_Reference_Attributes -- ------------------------------------------- procedure Extract_Variable_Reference_Attributes (Ref : Node_Id; Var_Id : out Entity_Id; Attrs : out Variable_Attributes) is function Get_Renamed_Variable (Id : Entity_Id) return Entity_Id; -- Obtain the ultimate renamed variable of variable Id -------------------------- -- Get_Renamed_Variable -- -------------------------- function Get_Renamed_Variable (Id : Entity_Id) return Entity_Id is Ren_Id : Entity_Id; begin Ren_Id := Id; while Present (Renamed_Entity (Ren_Id)) and then Nkind (Renamed_Entity (Ren_Id)) in N_Entity loop Ren_Id := Renamed_Entity (Ren_Id); end loop; return Ren_Id; end Get_Renamed_Variable; -- Start of processing for Extract_Variable_Reference_Attributes begin -- Extraction for variable reference markers if Nkind (Ref) = N_Variable_Reference_Marker then Var_Id := Target (Ref); -- Extraction for expanded names and identifiers else Var_Id := Entity (Ref); end if; -- Obtain the original variable which the reference mentions Var_Id := Get_Renamed_Variable (Var_Id); Attrs.Unit_Id := Find_Top_Unit (Var_Id); -- At this point certain attributes should always be available pragma Assert (Present (Attrs.Unit_Id)); end Extract_Variable_Reference_Attributes; -------------------- -- Find_Code_Unit -- -------------------- function Find_Code_Unit (N : Node_Or_Entity_Id) return Entity_Id is begin return Find_Unit_Entity (Unit (Cunit (Get_Code_Unit (N)))); end Find_Code_Unit; ---------------------------- -- Find_Early_Call_Region -- ---------------------------- function Find_Early_Call_Region (Body_Decl : Node_Id; Assume_Elab_Body : Boolean := False; Skip_Memoization : Boolean := False) return Node_Id is -- NOTE: The routines within Find_Early_Call_Region are intentionally -- unnested to avoid deep indentation of code. ECR_Found : exception; -- This exception is raised when the early call region has been found Start : Node_Id := Empty; -- The start of the early call region. This variable is updated by the -- various nested routines. Due to the use of exceptions, the variable -- must be global to the nested routines. -- The algorithm implemented in this routine attempts to find the early -- call region of a subprogram body by inspecting constructs in reverse -- declarative order, while navigating the tree. The algorithm consists -- of an Inspection phase and an Advancement phase. The pseudocode is as -- follows: -- -- loop -- inspection phase -- advancement phase -- end loop -- -- The infinite loop is terminated by raising exception ECR_Found. The -- algorithm utilizes two pointers, Curr and Start, to represent the -- current construct to inspect and the start of the early call region. -- -- IMPORTANT: The algorithm must maintain the following invariant at all -- time for it to function properly - a nested construct is entered only -- when it contains suitable constructs. This guarantees that leaving a -- nested or encapsulating construct functions properly. -- -- The Inspection phase determines whether the current construct is non- -- preelaborable, and if it is, the algorithm terminates. -- -- The Advancement phase walks the tree in reverse declarative order, -- while entering and leaving nested and encapsulating constructs. It -- may also terminate the elaborithm. There are several special cases -- of advancement. -- -- 1) General case: -- -- -- ... -- <- Curr -- <- Start -- -- -- In the general case, a declarative or statement list is traversed in -- reverse order where Curr is the lead pointer, and Start indicates the -- last preelaborable construct. -- -- 2) Entering handled bodies -- -- package body Nested is <- Curr (2.3) -- <- Curr (2.2) -- begin -- <- Curr (2.1) -- end Nested; -- <- Start -- -- In this case, the algorithm enters a handled body by starting from -- the last statement (2.1), or the last declaration (2.2), or the body -- is consumed (2.3) because it is empty and thus preelaborable. -- -- 3) Entering package declarations -- -- package Nested is <- Curr (2.3) -- <- Curr (2.2) -- private -- <- Curr (2.1) -- end Nested; -- <- Start -- -- In this case, the algorithm enters a package declaration by starting -- from the last private declaration (2.1), the last visible declaration -- (2.2), or the package is consumed (2.3) because it is empty and thus -- preelaborable. -- -- 4) Transitioning from list to list of the same construct -- -- Certain constructs have two eligible lists. The algorithm must thus -- transition from the second to the first list when the second list is -- exhausted. -- -- declare <- Curr (4.2) -- <- Curr (4.1) -- begin -- <- Start -- end; -- -- In this case, the algorithm has exhausted the second list (statements -- in the example), and continues with the last declaration (4.1) or the -- construct is consumed (4.2) because it contains only preelaborable -- code. -- -- 5) Transitioning from list to construct -- -- tack body Task is <- Curr (5.1) -- <- Curr (Empty) -- <- Start -- -- In this case, the algorithm has exhausted a list, Curr is Empty, and -- the owner of the list is consumed (5.1). -- -- 6) Transitioning from unit to unit -- -- A package body with a spec subject to pragma Elaborate_Body extends -- the possible range of the early call region to the package spec. -- -- package Pack is <- Curr (6.3) -- pragma Elaborate_Body; <- Curr (6.2) -- <- Curr (6.2) -- private -- <- Curr (6.1) -- end Pack; -- -- package body Pack is <- Curr, Start -- -- In this case, the algorithm has reached a package body compilation -- unit whose spec is subject to pragma Elaborate_Body, or the caller -- of the algorithm has specified this behavior. This transition is -- equivalent to 3). -- -- 7) Transitioning from unit to termination -- -- Reaching a compilation unit always terminates the algorithm as there -- are no more lists to examine. This must take 6) into account. -- -- 8) Transitioning from subunit to stub -- -- package body Pack is separate; <- Curr (8.1) -- -- separate (...) -- package body Pack is <- Curr, Start -- -- Reaching a subunit continues the search from the corresponding stub -- (8.1). procedure Advance (Curr : in out Node_Id); pragma Inline (Advance); -- Update the Curr and Start pointers depending on their location in the -- tree to the next eligible construct. This routine raises ECR_Found. procedure Enter_Handled_Body (Curr : in out Node_Id); pragma Inline (Enter_Handled_Body); -- Update the Curr and Start pointers to enter a nested handled body if -- applicable. This routine raises ECR_Found. procedure Enter_Package_Declaration (Curr : in out Node_Id); pragma Inline (Enter_Package_Declaration); -- Update the Curr and Start pointers to enter a nested package spec if -- applicable. This routine raises ECR_Found. function Find_ECR (N : Node_Id) return Node_Id; pragma Inline (Find_ECR); -- Find an early call region starting from arbitrary node N function Has_Suitable_Construct (List : List_Id) return Boolean; pragma Inline (Has_Suitable_Construct); -- Determine whether list List contains at least one suitable construct -- for inclusion into an early call region. procedure Include (N : Node_Id; Curr : out Node_Id); pragma Inline (Include); -- Update the Curr and Start pointers to include arbitrary construct N -- in the early call region. This routine raises ECR_Found. function Is_OK_Preelaborable_Construct (N : Node_Id) return Boolean; pragma Inline (Is_OK_Preelaborable_Construct); -- Determine whether arbitrary node N denotes a preelaboration-safe -- construct. function Is_Suitable_Construct (N : Node_Id) return Boolean; pragma Inline (Is_Suitable_Construct); -- Determine whether arbitrary node N denotes a suitable construct for -- inclusion into the early call region. procedure Transition_Body_Declarations (Bod : Node_Id; Curr : out Node_Id); pragma Inline (Transition_Body_Declarations); -- Update the Curr and Start pointers when construct Bod denotes a block -- statement or a suitable body. This routine raises ECR_Found. procedure Transition_Handled_Statements (HSS : Node_Id; Curr : out Node_Id); pragma Inline (Transition_Handled_Statements); -- Update the Curr and Start pointers when node HSS denotes a handled -- sequence of statements. This routine raises ECR_Found. procedure Transition_Spec_Declarations (Spec : Node_Id; Curr : out Node_Id); pragma Inline (Transition_Spec_Declarations); -- Update the Curr and Start pointers when construct Spec denotes -- a concurrent definition or a package spec. This routine raises -- ECR_Found. procedure Transition_Unit (Unit : Node_Id; Curr : out Node_Id); pragma Inline (Transition_Unit); -- Update the Curr and Start pointers when node Unit denotes a potential -- compilation unit. This routine raises ECR_Found. ------------- -- Advance -- ------------- procedure Advance (Curr : in out Node_Id) is Context : Node_Id; begin -- Curr denotes one of the following cases upon entry into this -- routine: -- -- * Empty - There is no current construct when a declarative or a -- statement list has been exhausted. This does not necessarily -- indicate that the early call region has been computed as it -- may still be possible to transition to another list. -- -- * Encapsulator - The current construct encapsulates declarations -- and/or statements. This indicates that the early call region -- may extend within the nested construct. -- -- * Preelaborable - The current construct is always preelaborable -- because Find_ECR would not invoke Advance if this was not the -- case. -- The current construct is an encapsulator or is preelaborable if Present (Curr) then -- Enter encapsulators by inspecting their declarations and/or -- statements. if Nkind_In (Curr, N_Block_Statement, N_Package_Body) then Enter_Handled_Body (Curr); elsif Nkind (Curr) = N_Package_Declaration then Enter_Package_Declaration (Curr); -- Early call regions have a property which can be exploited to -- optimize the algorithm. -- -- -- -- ... -- -- -- -- If a traversal initiated from a subprogram body reaches a -- preceding subprogram body, then both bodies share the same -- early call region. -- -- The property results in the following desirable effects: -- -- * If the preceding body already has an early call region, then -- the initiating body can reuse it. This minimizes the amount -- of processing performed by the algorithm. -- -- * If the preceding body lack an early call region, then the -- algorithm can compute the early call region, and reuse it -- for the initiating body. This processing performs the same -- amount of work, but has the beneficial effect of computing -- the early call regions of all preceding bodies. elsif Nkind_In (Curr, N_Entry_Body, N_Subprogram_Body) then Start := Find_Early_Call_Region (Body_Decl => Curr, Assume_Elab_Body => Assume_Elab_Body, Skip_Memoization => Skip_Memoization); raise ECR_Found; -- Otherwise current construct is preelaborable. Unpdate the early -- call region to include it. else Include (Curr, Curr); end if; -- Otherwise the current construct is missing, indicating that the -- current list has been exhausted. Depending on the context of the -- list, several transitions are possible. else -- The invariant of the algorithm ensures that Curr and Start are -- at the same level of nesting at the point of a transition. The -- algorithm can determine which list the traversal came from by -- examining Start. Context := Parent (Start); -- Attempt the following transitions: -- -- private declarations -> visible declarations -- private declarations -> upper level -- private declarations -> terminate -- visible declarations -> upper level -- visible declarations -> terminate if Nkind_In (Context, N_Package_Specification, N_Protected_Definition, N_Task_Definition) then Transition_Spec_Declarations (Context, Curr); -- Attempt the following transitions: -- -- statements -> declarations -- statements -> upper level -- statements -> corresponding package spec (Elab_Body) -- statements -> terminate elsif Nkind (Context) = N_Handled_Sequence_Of_Statements then Transition_Handled_Statements (Context, Curr); -- Attempt the following transitions: -- -- declarations -> upper level -- declarations -> corresponding package spec (Elab_Body) -- declarations -> terminate elsif Nkind_In (Context, N_Block_Statement, N_Entry_Body, N_Package_Body, N_Protected_Body, N_Subprogram_Body, N_Task_Body) then Transition_Body_Declarations (Context, Curr); -- Otherwise it is not possible to transition. Stop the search -- because there are no more declarations or statements to check. else raise ECR_Found; end if; end if; end Advance; -------------------------- -- Enter_Handled_Body -- -------------------------- procedure Enter_Handled_Body (Curr : in out Node_Id) is Decls : constant List_Id := Declarations (Curr); HSS : constant Node_Id := Handled_Statement_Sequence (Curr); Stmts : List_Id := No_List; begin if Present (HSS) then Stmts := Statements (HSS); end if; -- The handled body has a non-empty statement sequence. The construct -- to inspect is the last statement. if Has_Suitable_Construct (Stmts) then Curr := Last (Stmts); -- The handled body lacks statements, but has non-empty declarations. -- The construct to inspect is the last declaration. elsif Has_Suitable_Construct (Decls) then Curr := Last (Decls); -- Otherwise the handled body lacks both declarations and statements. -- The construct to inspect is the node which precedes the handled -- body. Update the early call region to include the handled body. else Include (Curr, Curr); end if; end Enter_Handled_Body; ------------------------------- -- Enter_Package_Declaration -- ------------------------------- procedure Enter_Package_Declaration (Curr : in out Node_Id) is Pack_Spec : constant Node_Id := Specification (Curr); Prv_Decls : constant List_Id := Private_Declarations (Pack_Spec); Vis_Decls : constant List_Id := Visible_Declarations (Pack_Spec); begin -- The package has a non-empty private declarations. The construct to -- inspect is the last private declaration. if Has_Suitable_Construct (Prv_Decls) then Curr := Last (Prv_Decls); -- The package lacks private declarations, but has non-empty visible -- declarations. In this case the construct to inspect is the last -- visible declaration. elsif Has_Suitable_Construct (Vis_Decls) then Curr := Last (Vis_Decls); -- Otherwise the package lacks any declarations. The construct to -- inspect is the node which precedes the package. Update the early -- call region to include the package declaration. else Include (Curr, Curr); end if; end Enter_Package_Declaration; -------------- -- Find_ECR -- -------------- function Find_ECR (N : Node_Id) return Node_Id is Curr : Node_Id; begin -- The early call region starts at N Curr := Prev (N); Start := N; -- Inspect each node in reverse declarative order while going in and -- out of nested and enclosing constructs. Note that the only way to -- terminate this infinite loop is to raise exception ECR_Found. loop -- The current construct is not preelaboration-safe. Terminate the -- traversal. if Present (Curr) and then not Is_OK_Preelaborable_Construct (Curr) then raise ECR_Found; end if; -- Advance to the next suitable construct. This may terminate the -- traversal by raising ECR_Found. Advance (Curr); end loop; exception when ECR_Found => return Start; end Find_ECR; ---------------------------- -- Has_Suitable_Construct -- ---------------------------- function Has_Suitable_Construct (List : List_Id) return Boolean is Item : Node_Id; begin -- Examine the list in reverse declarative order, looking for a -- suitable construct. if Present (List) then Item := Last (List); while Present (Item) loop if Is_Suitable_Construct (Item) then return True; end if; Prev (Item); end loop; end if; return False; end Has_Suitable_Construct; ------------- -- Include -- ------------- procedure Include (N : Node_Id; Curr : out Node_Id) is begin Start := N; -- The input node is a compilation unit. This terminates the search -- because there are no more lists to inspect and there are no more -- enclosing constructs to climb up to. The transitions are: -- -- private declarations -> terminate -- visible declarations -> terminate -- statements -> terminate -- declarations -> terminate if Nkind (Parent (Start)) = N_Compilation_Unit then raise ECR_Found; -- Otherwise the input node is still within some list else Curr := Prev (Start); end if; end Include; ----------------------------------- -- Is_OK_Preelaborable_Construct -- ----------------------------------- function Is_OK_Preelaborable_Construct (N : Node_Id) return Boolean is begin -- Assignment statements are acceptable as long as they were produced -- by the ABE mechanism to update elaboration flags. if Nkind (N) = N_Assignment_Statement then return Is_Elaboration_Code (N); -- Block statements are acceptable even though they directly violate -- preelaborability. The intention is not to penalize the early call -- region when a block contains only preelaborable constructs. -- -- declare -- Val : constant Integer := 1; -- begin -- pragma Assert (Val = 1); -- null; -- end; -- -- Note that the Advancement phase does enter blocks, and will detect -- any non-preelaborable declarations or statements within. elsif Nkind (N) = N_Block_Statement then return True; end if; -- Otherwise the construct must be preelaborable. The check must take -- the syntactic and semantic structure of the construct. DO NOT use -- Is_Preelaborable_Construct here. return not Is_Non_Preelaborable_Construct (N); end Is_OK_Preelaborable_Construct; --------------------------- -- Is_Suitable_Construct -- --------------------------- function Is_Suitable_Construct (N : Node_Id) return Boolean is Context : constant Node_Id := Parent (N); begin -- An internally-generated statement sequence which contains only a -- single null statement is not a suitable construct because it is a -- byproduct of the parser. Such a null statement should be excluded -- from the early call region because it carries the source location -- of the "end" keyword, and may lead to confusing diagnistics. if Nkind (N) = N_Null_Statement and then not Comes_From_Source (N) and then Present (Context) and then Nkind (Context) = N_Handled_Sequence_Of_Statements then return False; end if; -- Otherwise only constructs which correspond to pure Ada constructs -- are considered suitable. case Nkind (N) is when N_Call_Marker | N_Freeze_Entity | N_Freeze_Generic_Entity | N_Implicit_Label_Declaration | N_Itype_Reference | N_Pop_Constraint_Error_Label | N_Pop_Program_Error_Label | N_Pop_Storage_Error_Label | N_Push_Constraint_Error_Label | N_Push_Program_Error_Label | N_Push_Storage_Error_Label | N_SCIL_Dispatch_Table_Tag_Init | N_SCIL_Dispatching_Call | N_SCIL_Membership_Test | N_Variable_Reference_Marker => return False; when others => return True; end case; end Is_Suitable_Construct; ---------------------------------- -- Transition_Body_Declarations -- ---------------------------------- procedure Transition_Body_Declarations (Bod : Node_Id; Curr : out Node_Id) is Decls : constant List_Id := Declarations (Bod); begin -- The search must come from the declarations of the body pragma Assert (Is_Non_Empty_List (Decls) and then List_Containing (Start) = Decls); -- The search finished inspecting the declarations. The construct -- to inspect is the node which precedes the handled body, unless -- the body is a compilation unit. The transitions are: -- -- declarations -> upper level -- declarations -> corresponding package spec (Elab_Body) -- declarations -> terminate Transition_Unit (Bod, Curr); end Transition_Body_Declarations; ----------------------------------- -- Transition_Handled_Statements -- ----------------------------------- procedure Transition_Handled_Statements (HSS : Node_Id; Curr : out Node_Id) is Bod : constant Node_Id := Parent (HSS); Decls : constant List_Id := Declarations (Bod); Stmts : constant List_Id := Statements (HSS); begin -- The search must come from the statements of certain bodies or -- statements. pragma Assert (Nkind_In (Bod, N_Block_Statement, N_Entry_Body, N_Package_Body, N_Protected_Body, N_Subprogram_Body, N_Task_Body)); -- The search must come from the statements of the handled sequence pragma Assert (Is_Non_Empty_List (Stmts) and then List_Containing (Start) = Stmts); -- The search finished inspecting the statements. The handled body -- has non-empty declarations. The construct to inspect is the last -- declaration. The transitions are: -- -- statements -> declarations if Has_Suitable_Construct (Decls) then Curr := Last (Decls); -- Otherwise the handled body lacks declarations. The construct to -- inspect is the node which precedes the handled body, unless the -- body is a compilation unit. The transitions are: -- -- statements -> upper level -- statements -> corresponding package spec (Elab_Body) -- statements -> terminate else Transition_Unit (Bod, Curr); end if; end Transition_Handled_Statements; ---------------------------------- -- Transition_Spec_Declarations -- ---------------------------------- procedure Transition_Spec_Declarations (Spec : Node_Id; Curr : out Node_Id) is Prv_Decls : constant List_Id := Private_Declarations (Spec); Vis_Decls : constant List_Id := Visible_Declarations (Spec); begin pragma Assert (Present (Start) and then Is_List_Member (Start)); -- The search came from the private declarations and finished their -- inspection. if Has_Suitable_Construct (Prv_Decls) and then List_Containing (Start) = Prv_Decls then -- The context has non-empty visible declarations. The node to -- inspect is the last visible declaration. The transitions are: -- -- private declarations -> visible declarations if Has_Suitable_Construct (Vis_Decls) then Curr := Last (Vis_Decls); -- Otherwise the context lacks visible declarations. The construct -- to inspect is the node which precedes the context unless the -- context is a compilation unit. The transitions are: -- -- private declarations -> upper level -- private declarations -> terminate else Transition_Unit (Parent (Spec), Curr); end if; -- The search came from the visible declarations and finished their -- inspections. The construct to inspect is the node which precedes -- the context, unless the context is a compilaton unit. The -- transitions are: -- -- visible declarations -> upper level -- visible declarations -> terminate elsif Has_Suitable_Construct (Vis_Decls) and then List_Containing (Start) = Vis_Decls then Transition_Unit (Parent (Spec), Curr); -- At this point both declarative lists are empty, but the traversal -- still came from within the spec. This indicates that the invariant -- of the algorithm has been violated. else pragma Assert (False); raise ECR_Found; end if; end Transition_Spec_Declarations; --------------------- -- Transition_Unit -- --------------------- procedure Transition_Unit (Unit : Node_Id; Curr : out Node_Id) is Context : constant Node_Id := Parent (Unit); begin -- The unit is a compilation unit. This terminates the search because -- there are no more lists to inspect and there are no more enclosing -- constructs to climb up to. if Nkind (Context) = N_Compilation_Unit then -- A package body with a corresponding spec subject to pragma -- Elaborate_Body is an exception to the above. The annotation -- allows the search to continue into the package declaration. -- The transitions are: -- -- statements -> corresponding package spec (Elab_Body) -- declarations -> corresponding package spec (Elab_Body) if Nkind (Unit) = N_Package_Body and then (Assume_Elab_Body or else Has_Pragma_Elaborate_Body (Corresponding_Spec (Unit))) then Curr := Unit_Declaration_Node (Corresponding_Spec (Unit)); Enter_Package_Declaration (Curr); -- Otherwise terminate the search. The transitions are: -- -- private declarations -> terminate -- visible declarations -> terminate -- statements -> terminate -- declarations -> terminate else raise ECR_Found; end if; -- The unit is a subunit. The construct to inspect is the node which -- precedes the corresponding stub. Update the early call region to -- include the unit. elsif Nkind (Context) = N_Subunit then Start := Unit; Curr := Corresponding_Stub (Context); -- Otherwise the unit is nested. The construct to inspect is the node -- which precedes the unit. Update the early call region to include -- the unit. else Include (Unit, Curr); end if; end Transition_Unit; -- Local variables Body_Id : constant Entity_Id := Defining_Entity (Body_Decl); Region : Node_Id; -- Start of processing for Find_Early_Call_Region begin -- The caller demands the start of the early call region without saving -- or retrieving it to/from internal data structures. if Skip_Memoization then Region := Find_ECR (Body_Decl); -- Default behavior else -- Check whether the early call region of the subprogram body is -- available. Region := Early_Call_Region (Body_Id); if No (Region) then -- Traverse the declarations in reverse order, starting from the -- subprogram body, searching for the nearest non-preelaborable -- construct. The early call region starts after this construct -- and ends at the subprogram body. Region := Find_ECR (Body_Decl); -- Associate the early call region with the subprogram body in -- case other scenarios need it. Set_Early_Call_Region (Body_Id, Region); end if; end if; -- A subprogram body must always have an early call region pragma Assert (Present (Region)); return Region; end Find_Early_Call_Region; --------------------------- -- Find_Elaborated_Units -- --------------------------- procedure Find_Elaborated_Units is procedure Add_Pragma (Prag : Node_Id); -- Determine whether pragma Prag denotes a legal Elaborate[_All] pragma. -- If this is the case, add the related unit to the elaboration context. -- For pragma Elaborate_All, include recursively all units withed by the -- related unit. procedure Add_Unit (Unit_Id : Entity_Id; Prag : Node_Id; Full_Context : Boolean); -- Add unit Unit_Id to the elaboration context. Prag denotes the pragma -- which prompted the inclusion of the unit to the elaboration context. -- If flag Full_Context is set, examine the nonlimited clauses of unit -- Unit_Id and add each withed unit to the context. procedure Find_Elaboration_Context (Comp_Unit : Node_Id); -- Examine the context items of compilation unit Comp_Unit for suitable -- elaboration-related pragmas and add all related units to the context. ---------------- -- Add_Pragma -- ---------------- procedure Add_Pragma (Prag : Node_Id) is Prag_Args : constant List_Id := Pragma_Argument_Associations (Prag); Prag_Nam : constant Name_Id := Pragma_Name (Prag); Unit_Arg : Node_Id; begin -- Nothing to do if the pragma is not related to elaboration if not Nam_In (Prag_Nam, Name_Elaborate, Name_Elaborate_All) then return; -- Nothing to do when the pragma is illegal elsif Error_Posted (Prag) then return; end if; Unit_Arg := Get_Pragma_Arg (First (Prag_Args)); -- The argument of the pragma may appear in package.package form if Nkind (Unit_Arg) = N_Selected_Component then Unit_Arg := Selector_Name (Unit_Arg); end if; Add_Unit (Unit_Id => Entity (Unit_Arg), Prag => Prag, Full_Context => Prag_Nam = Name_Elaborate_All); end Add_Pragma; -------------- -- Add_Unit -- -------------- procedure Add_Unit (Unit_Id : Entity_Id; Prag : Node_Id; Full_Context : Boolean) is Clause : Node_Id; Elab_Attrs : Elaboration_Attributes; begin -- Nothing to do when some previous error left a with clause or a -- pragma in a bad state. if No (Unit_Id) then return; end if; Elab_Attrs := Elaboration_Status (Unit_Id); -- The unit is already included in the context by means of pragma -- Elaborate[_All]. if Present (Elab_Attrs.Source_Pragma) then -- Upgrade an existing pragma Elaborate when the unit is subject -- to Elaborate_All because the new pragma covers a larger set of -- units. if Pragma_Name (Elab_Attrs.Source_Pragma) = Name_Elaborate and then Pragma_Name (Prag) = Name_Elaborate_All then Elab_Attrs.Source_Pragma := Prag; -- Otherwise the unit retains its existing pragma and does not -- need to be included in the context again. else return; end if; -- The current unit is not part of the context. Prepare a new set of -- attributes. else Elab_Attrs := Elaboration_Attributes'(Source_Pragma => Prag, With_Clause => Empty); end if; -- Add or update the attributes of the unit Set_Elaboration_Status (Unit_Id, Elab_Attrs); -- Includes all units withed by the current one when computing the -- full context. if Full_Context then -- Process all nonlimited with clauses found in the context of -- the current unit. Note that limited clauses do not impose an -- elaboration order. Clause := First (Context_Items (Compilation_Unit (Unit_Id))); while Present (Clause) loop if Nkind (Clause) = N_With_Clause and then not Error_Posted (Clause) and then not Limited_Present (Clause) then Add_Unit (Unit_Id => Entity (Name (Clause)), Prag => Prag, Full_Context => Full_Context); end if; Next (Clause); end loop; end if; end Add_Unit; ------------------------------ -- Find_Elaboration_Context -- ------------------------------ procedure Find_Elaboration_Context (Comp_Unit : Node_Id) is Prag : Node_Id; begin pragma Assert (Nkind (Comp_Unit) = N_Compilation_Unit); -- Process all elaboration-related pragmas found in the context of -- the compilation unit. Prag := First (Context_Items (Comp_Unit)); while Present (Prag) loop if Nkind (Prag) = N_Pragma then Add_Pragma (Prag); end if; Next (Prag); end loop; end Find_Elaboration_Context; -- Local variables Par_Id : Entity_Id; Unt : Node_Id; -- Start of processing for Find_Elaborated_Units begin -- Perform a traversal which examines the context of the main unit and -- populates the Elaboration_Context table with all units elaborated -- prior to the main unit. The traversal performs the following jumps: -- subunit -> parent subunit -- parent subunit -> body -- body -> spec -- spec -> parent spec -- parent spec -> grandparent spec and so on -- The traversal relies on units rather than scopes because the scope of -- a subunit is some spec, while this traversal must process the body as -- well. Given that protected and task bodies can also be subunits, this -- complicates the scope approach even further. Unt := Unit (Cunit (Main_Unit)); -- Perform the following traversals when the main unit is a subunit -- subunit -> parent subunit -- parent subunit -> body while Present (Unt) and then Nkind (Unt) = N_Subunit loop Find_Elaboration_Context (Parent (Unt)); -- Continue the traversal by going to the unit which contains the -- corresponding stub. if Present (Corresponding_Stub (Unt)) then Unt := Unit (Cunit (Get_Source_Unit (Corresponding_Stub (Unt)))); -- Otherwise the subunit may be erroneous or left in a bad state else exit; end if; end loop; -- Perform the following traversal now that subunits have been taken -- care of, or the main unit is a body. -- body -> spec if Present (Unt) and then Nkind_In (Unt, N_Package_Body, N_Subprogram_Body) then Find_Elaboration_Context (Parent (Unt)); -- Continue the traversal by going to the unit which contains the -- corresponding spec. if Present (Corresponding_Spec (Unt)) then Unt := Unit (Cunit (Get_Source_Unit (Corresponding_Spec (Unt)))); end if; end if; -- Perform the following traversals now that the body has been taken -- care of, or the main unit is a spec. -- spec -> parent spec -- parent spec -> grandparent spec and so on if Present (Unt) and then Nkind_In (Unt, N_Generic_Package_Declaration, N_Generic_Subprogram_Declaration, N_Package_Declaration, N_Subprogram_Declaration) then Find_Elaboration_Context (Parent (Unt)); -- Process a potential chain of parent units which ends with the -- main unit spec. The traversal can now safely rely on the scope -- chain. Par_Id := Scope (Defining_Entity (Unt)); while Present (Par_Id) and then Par_Id /= Standard_Standard loop Find_Elaboration_Context (Compilation_Unit (Par_Id)); Par_Id := Scope (Par_Id); end loop; end if; end Find_Elaborated_Units; ----------------------------- -- Find_Enclosing_Instance -- ----------------------------- function Find_Enclosing_Instance (N : Node_Id) return Node_Id is Par : Node_Id; Spec_Id : Entity_Id; begin -- Climb the parent chain looking for an enclosing instance spec or body Par := N; while Present (Par) loop -- Generic package or subprogram spec if Nkind_In (Par, N_Package_Declaration, N_Subprogram_Declaration) and then Is_Generic_Instance (Defining_Entity (Par)) then return Par; -- Generic package or subprogram body elsif Nkind_In (Par, N_Package_Body, N_Subprogram_Body) then Spec_Id := Corresponding_Spec (Par); if Present (Spec_Id) and then Is_Generic_Instance (Spec_Id) then return Par; end if; end if; Par := Parent (Par); end loop; return Empty; end Find_Enclosing_Instance; -------------------------- -- Find_Enclosing_Level -- -------------------------- function Find_Enclosing_Level (N : Node_Id) return Enclosing_Level_Kind is function Level_Of (Unit : Node_Id) return Enclosing_Level_Kind; -- Obtain the corresponding level of unit Unit -------------- -- Level_Of -- -------------- function Level_Of (Unit : Node_Id) return Enclosing_Level_Kind is Spec_Id : Entity_Id; begin if Nkind (Unit) in N_Generic_Instantiation then return Instantiation; elsif Nkind (Unit) = N_Generic_Package_Declaration then return Generic_Package_Spec; elsif Nkind (Unit) = N_Package_Declaration then return Package_Spec; elsif Nkind (Unit) = N_Package_Body then Spec_Id := Corresponding_Spec (Unit); -- The body belongs to a generic package if Present (Spec_Id) and then Ekind (Spec_Id) = E_Generic_Package then return Generic_Package_Body; -- Otherwise the body belongs to a non-generic package. This also -- treats an illegal package body without a corresponding spec as -- a non-generic package body. else return Package_Body; end if; end if; return No_Level; end Level_Of; -- Local variables Context : Node_Id; Curr : Node_Id; Prev : Node_Id; -- Start of processing for Find_Enclosing_Level begin -- Call markers and instantiations which appear at the declaration level -- but are later relocated in a different context retain their original -- declaration level. if Nkind_In (N, N_Call_Marker, N_Function_Instantiation, N_Package_Instantiation, N_Procedure_Instantiation) and then Is_Declaration_Level_Node (N) then return Declaration_Level; end if; -- Climb the parent chain looking at the enclosing levels Prev := N; Curr := Parent (Prev); while Present (Curr) loop -- A traversal from a subunit continues via the corresponding stub if Nkind (Curr) = N_Subunit then Curr := Corresponding_Stub (Curr); -- The current construct is a package. Packages are ignored because -- they are always elaborated when the enclosing context is invoked -- or elaborated. elsif Nkind_In (Curr, N_Package_Body, N_Package_Declaration) then null; -- The current construct is a block statement elsif Nkind (Curr) = N_Block_Statement then -- Ignore internally generated blocks created by the expander for -- various purposes such as abort defer/undefer. if not Comes_From_Source (Curr) then null; -- If the traversal came from the handled sequence of statments, -- then the node appears at the level of the enclosing construct. -- This is a more reliable test because transients scopes within -- the declarative region of the encapsulator are hard to detect. elsif Nkind (Prev) = N_Handled_Sequence_Of_Statements and then Handled_Statement_Sequence (Curr) = Prev then return Find_Enclosing_Level (Parent (Curr)); -- Otherwise the traversal came from the declarations, the node is -- at the declaration level. else return Declaration_Level; end if; -- The current construct is a declaration-level encapsulator elsif Nkind_In (Curr, N_Entry_Body, N_Subprogram_Body, N_Task_Body) then -- If the traversal came from the handled sequence of statments, -- then the node cannot possibly appear at any level. This is -- a more reliable test because transients scopes within the -- declarative region of the encapsulator are hard to detect. if Nkind (Prev) = N_Handled_Sequence_Of_Statements and then Handled_Statement_Sequence (Curr) = Prev then return No_Level; -- Otherwise the traversal came from the declarations, the node is -- at the declaration level. else return Declaration_Level; end if; -- The current construct is a non-library-level encapsulator which -- indicates that the node cannot possibly appear at any level. -- Note that this check must come after the declaration-level check -- because both predicates share certain nodes. elsif Is_Non_Library_Level_Encapsulator (Curr) then Context := Parent (Curr); -- The sole exception is when the encapsulator is the compilation -- utit itself because the compilation unit node requires special -- processing (see below). if Present (Context) and then Nkind (Context) = N_Compilation_Unit then null; -- Otherwise the node is not at any level else return No_Level; end if; -- The current construct is a compilation unit. The node appears at -- the [generic] library level when the unit is a [generic] package. elsif Nkind (Curr) = N_Compilation_Unit then return Level_Of (Unit (Curr)); end if; Prev := Curr; Curr := Parent (Prev); end loop; return No_Level; end Find_Enclosing_Level; ------------------- -- Find_Top_Unit -- ------------------- function Find_Top_Unit (N : Node_Or_Entity_Id) return Entity_Id is begin return Find_Unit_Entity (Unit (Cunit (Get_Top_Level_Code_Unit (N)))); end Find_Top_Unit; ---------------------- -- Find_Unit_Entity -- ---------------------- function Find_Unit_Entity (N : Node_Id) return Entity_Id is Context : constant Node_Id := Parent (N); Orig_N : constant Node_Id := Original_Node (N); begin -- The unit denotes a package body of an instantiation which acts as -- a compilation unit. The proper entity is that of the package spec. if Nkind (N) = N_Package_Body and then Nkind (Orig_N) = N_Package_Instantiation and then Nkind (Context) = N_Compilation_Unit then return Corresponding_Spec (N); -- The unit denotes an anonymous package created to wrap a subprogram -- instantiation which acts as a compilation unit. The proper entity is -- that of the "related instance". elsif Nkind (N) = N_Package_Declaration and then Nkind_In (Orig_N, N_Function_Instantiation, N_Procedure_Instantiation) and then Nkind (Context) = N_Compilation_Unit then return Related_Instance (Defining_Entity (N, Concurrent_Subunit => True)); -- Otherwise the proper entity is the defining entity else return Defining_Entity (N, Concurrent_Subunit => True); end if; end Find_Unit_Entity; ----------------------- -- First_Formal_Type -- ----------------------- function First_Formal_Type (Subp_Id : Entity_Id) return Entity_Id is Formal_Id : constant Entity_Id := First_Formal (Subp_Id); Typ : Entity_Id; begin if Present (Formal_Id) then Typ := Etype (Formal_Id); -- Handle various combinations of concurrent and private types loop if Ekind_In (Typ, E_Protected_Type, E_Task_Type) and then Present (Anonymous_Object (Typ)) then Typ := Anonymous_Object (Typ); elsif Is_Concurrent_Record_Type (Typ) then Typ := Corresponding_Concurrent_Type (Typ); elsif Is_Private_Type (Typ) and then Present (Full_View (Typ)) then Typ := Full_View (Typ); else exit; end if; end loop; return Typ; end if; return Empty; end First_Formal_Type; -------------- -- Has_Body -- -------------- function Has_Body (Pack_Decl : Node_Id) return Boolean is function Find_Corresponding_Body (Spec_Id : Entity_Id) return Node_Id; -- Try to locate the corresponding body of spec Spec_Id. If no body is -- found, return Empty. function Find_Body (Spec_Id : Entity_Id; From : Node_Id) return Node_Id; -- Try to locate the corresponding body of spec Spec_Id in the node list -- which follows arbitrary node From. If no body is found, return Empty. function Load_Package_Body (Unit_Nam : Unit_Name_Type) return Node_Id; -- Attempt to load the body of unit Unit_Nam. If the load failed, return -- Empty. If the compilation will not generate code, return Empty. ----------------------------- -- Find_Corresponding_Body -- ----------------------------- function Find_Corresponding_Body (Spec_Id : Entity_Id) return Node_Id is Context : constant Entity_Id := Scope (Spec_Id); Spec_Decl : constant Node_Id := Unit_Declaration_Node (Spec_Id); Body_Decl : Node_Id; Body_Id : Entity_Id; begin if Is_Compilation_Unit (Spec_Id) then Body_Id := Corresponding_Body (Spec_Decl); if Present (Body_Id) then return Unit_Declaration_Node (Body_Id); -- The package is at the library and requires a body. Load the -- corresponding body because the optional body may be declared -- there. elsif Unit_Requires_Body (Spec_Id) then return Load_Package_Body (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec_Decl)))); -- Otherwise there is no optional body else return Empty; end if; -- The immediate context is a package. The optional body may be -- within the body of that package. -- procedure Proc is -- package Nested_1 is -- package Nested_2 is -- generic -- package Pack is -- end Pack; -- end Nested_2; -- end Nested_1; -- package body Nested_1 is -- package body Nested_2 is separate; -- end Nested_1; -- separate (Proc.Nested_1.Nested_2) -- package body Nested_2 is -- package body Pack is -- optional body -- ... -- end Pack; -- end Nested_2; elsif Is_Package_Or_Generic_Package (Context) then Body_Decl := Find_Corresponding_Body (Context); -- The optional body is within the body of the enclosing package if Present (Body_Decl) then return Find_Body (Spec_Id => Spec_Id, From => First (Declarations (Body_Decl))); -- Otherwise the enclosing package does not have a body. This may -- be the result of an error or a genuine lack of a body. else return Empty; end if; -- Otherwise the immediate context is a body. The optional body may -- be within the same list as the spec. -- procedure Proc is -- generic -- package Pack is -- end Pack; -- package body Pack is -- optional body -- ... -- end Pack; else return Find_Body (Spec_Id => Spec_Id, From => Next (Spec_Decl)); end if; end Find_Corresponding_Body; --------------- -- Find_Body -- --------------- function Find_Body (Spec_Id : Entity_Id; From : Node_Id) return Node_Id is Spec_Nam : constant Name_Id := Chars (Spec_Id); Item : Node_Id; Lib_Unit : Node_Id; begin Item := From; while Present (Item) loop -- The current item denotes the optional body if Nkind (Item) = N_Package_Body and then Chars (Defining_Entity (Item)) = Spec_Nam then return Item; -- The current item denotes a stub, the optional body may be in -- the subunit. elsif Nkind (Item) = N_Package_Body_Stub and then Chars (Defining_Entity (Item)) = Spec_Nam then Lib_Unit := Library_Unit (Item); -- The corresponding subunit was previously loaded if Present (Lib_Unit) then return Lib_Unit; -- Otherwise attempt to load the corresponding subunit else return Load_Package_Body (Get_Unit_Name (Item)); end if; end if; Next (Item); end loop; return Empty; end Find_Body; ----------------------- -- Load_Package_Body -- ----------------------- function Load_Package_Body (Unit_Nam : Unit_Name_Type) return Node_Id is Body_Decl : Node_Id; Unit_Num : Unit_Number_Type; begin -- The load is performed only when the compilation will generate code if Operating_Mode = Generate_Code then Unit_Num := Load_Unit (Load_Name => Unit_Nam, Required => False, Subunit => False, Error_Node => Pack_Decl); -- The load failed most likely because the physical file is -- missing. if Unit_Num = No_Unit then return Empty; -- Otherwise the load was successful, return the body of the unit else Body_Decl := Unit (Cunit (Unit_Num)); -- If the unit is a subunit with an available proper body, -- return the proper body. if Nkind (Body_Decl) = N_Subunit and then Present (Proper_Body (Body_Decl)) then Body_Decl := Proper_Body (Body_Decl); end if; return Body_Decl; end if; end if; return Empty; end Load_Package_Body; -- Local variables Pack_Id : constant Entity_Id := Defining_Entity (Pack_Decl); -- Start of processing for Has_Body begin -- The body is available if Present (Corresponding_Body (Pack_Decl)) then return True; -- The body is required if the package spec contains a construct which -- requires a completion in a body. elsif Unit_Requires_Body (Pack_Id) then return True; -- The body may be optional else return Present (Find_Corresponding_Body (Pack_Id)); end if; end Has_Body; --------------------------- -- Has_Prior_Elaboration -- --------------------------- function Has_Prior_Elaboration (Unit_Id : Entity_Id; Context_OK : Boolean := False; Elab_Body_OK : Boolean := False; Same_Unit_OK : Boolean := False) return Boolean is Main_Id : constant Entity_Id := Cunit_Entity (Main_Unit); begin -- A preelaborated unit is always elaborated prior to the main unit if Is_Preelaborated_Unit (Unit_Id) then return True; -- An internal unit is always elaborated prior to a non-internal main -- unit. elsif In_Internal_Unit (Unit_Id) and then not In_Internal_Unit (Main_Id) then return True; -- A unit has prior elaboration if it appears within the context of the -- main unit. Consider this case only when requested by the caller. elsif Context_OK and then Elaboration_Status (Unit_Id) /= No_Elaboration_Attributes then return True; -- A unit whose body is elaborated together with its spec has prior -- elaboration except with respect to itself. Consider this case only -- when requested by the caller. elsif Elab_Body_OK and then Has_Pragma_Elaborate_Body (Unit_Id) and then not Is_Same_Unit (Unit_Id, Main_Id) then return True; -- A unit has no prior elaboration with respect to itself, but does not -- require any means of ensuring its own elaboration either. Treat this -- case as valid prior elaboration only when requested by the caller. elsif Same_Unit_OK and then Is_Same_Unit (Unit_Id, Main_Id) then return True; end if; return False; end Has_Prior_Elaboration; -------------------------- -- In_External_Instance -- -------------------------- function In_External_Instance (N : Node_Id; Target_Decl : Node_Id) return Boolean is Dummy : Node_Id; Inst_Body : Node_Id; Inst_Decl : Node_Id; begin -- Performance note: parent traversal Inst_Decl := Find_Enclosing_Instance (Target_Decl); -- The target declaration appears within an instance spec. Visibility is -- ignored because internally generated primitives for private types may -- reside in the private declarations and still be invoked from outside. if Present (Inst_Decl) and then Nkind (Inst_Decl) = N_Package_Declaration then -- The scenario comes from the main unit and the instance does not if In_Extended_Main_Code_Unit (N) and then not In_Extended_Main_Code_Unit (Inst_Decl) then return True; -- Otherwise the scenario must not appear within the instance spec or -- body. else Extract_Instance_Attributes (Exp_Inst => Inst_Decl, Inst_Body => Inst_Body, Inst_Decl => Dummy); -- Performance note: parent traversal return not In_Subtree (N => N, Root1 => Inst_Decl, Root2 => Inst_Body); end if; end if; return False; end In_External_Instance; --------------------- -- In_Main_Context -- --------------------- function In_Main_Context (N : Node_Id) return Boolean is begin -- Scenarios outside the main unit are not considered because the ALI -- information supplied to binde is for the main unit only. if not In_Extended_Main_Code_Unit (N) then return False; -- Scenarios within internal units are not considered unless switch -- -gnatdE (elaboration checks on predefined units) is in effect. elsif not Debug_Flag_EE and then In_Internal_Unit (N) then return False; end if; return True; end In_Main_Context; --------------------- -- In_Same_Context -- --------------------- function In_Same_Context (N1 : Node_Id; N2 : Node_Id; Nested_OK : Boolean := False) return Boolean is function Find_Enclosing_Context (N : Node_Id) return Node_Id; -- Return the nearest enclosing non-library-level or compilation unit -- node which which encapsulates arbitrary node N. Return Empty is no -- such context is available. function In_Nested_Context (Outer : Node_Id; Inner : Node_Id) return Boolean; -- Determine whether arbitrary node Outer encapsulates arbitrary node -- Inner. ---------------------------- -- Find_Enclosing_Context -- ---------------------------- function Find_Enclosing_Context (N : Node_Id) return Node_Id is Context : Node_Id; Par : Node_Id; begin Par := Parent (N); while Present (Par) loop -- A traversal from a subunit continues via the corresponding stub if Nkind (Par) = N_Subunit then Par := Corresponding_Stub (Par); -- Stop the traversal when the nearest enclosing non-library-level -- encapsulator has been reached. elsif Is_Non_Library_Level_Encapsulator (Par) then Context := Parent (Par); -- The sole exception is when the encapsulator is the unit of -- compilation because this case requires special processing -- (see below). if Present (Context) and then Nkind (Context) = N_Compilation_Unit then null; else return Par; end if; -- Reaching a compilation unit node without hitting a non-library- -- level encapsulator indicates that N is at the library level in -- which case the compilation unit is the context. elsif Nkind (Par) = N_Compilation_Unit then return Par; end if; Par := Parent (Par); end loop; return Empty; end Find_Enclosing_Context; ----------------------- -- In_Nested_Context -- ----------------------- function In_Nested_Context (Outer : Node_Id; Inner : Node_Id) return Boolean is Par : Node_Id; begin Par := Inner; while Present (Par) loop -- A traversal from a subunit continues via the corresponding stub if Nkind (Par) = N_Subunit then Par := Corresponding_Stub (Par); elsif Par = Outer then return True; end if; Par := Parent (Par); end loop; return False; end In_Nested_Context; -- Local variables Context_1 : constant Node_Id := Find_Enclosing_Context (N1); Context_2 : constant Node_Id := Find_Enclosing_Context (N2); -- Start of processing for In_Same_Context begin -- Both nodes appear within the same context if Context_1 = Context_2 then return True; -- Both nodes appear in compilation units. Determine whether one unit -- is the body of the other. elsif Nkind (Context_1) = N_Compilation_Unit and then Nkind (Context_2) = N_Compilation_Unit then return Is_Same_Unit (Unit_1 => Defining_Entity (Unit (Context_1)), Unit_2 => Defining_Entity (Unit (Context_2))); -- The context of N1 encloses the context of N2 elsif Nested_OK and then In_Nested_Context (Context_1, Context_2) then return True; end if; return False; end In_Same_Context; ------------------ -- In_Task_Body -- ------------------ function In_Task_Body (N : Node_Id) return Boolean is Par : Node_Id; begin -- Climb the parent chain looking for a task body [procedure] Par := N; while Present (Par) loop if Nkind (Par) = N_Task_Body then return True; elsif Nkind (Par) = N_Subprogram_Body and then Is_Task_Body_Procedure (Par) then return True; -- Prevent the search from going too far. Note that this predicate -- shares nodes with the two cases above, and must come last. elsif Is_Body_Or_Package_Declaration (Par) then return False; end if; Par := Parent (Par); end loop; return False; end In_Task_Body; ---------------- -- Initialize -- ---------------- procedure Initialize is begin -- Set the soft link which enables Atree.Rewrite to update a top-level -- scenario each time it is transformed into another node. Set_Rewriting_Proc (Update_Elaboration_Scenario'Access); end Initialize; --------------- -- Info_Call -- --------------- procedure Info_Call (Call : Node_Id; Target_Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean) is procedure Info_Accept_Alternative; pragma Inline (Info_Accept_Alternative); -- Output information concerning an accept alternative procedure Info_Simple_Call; pragma Inline (Info_Simple_Call); -- Output information concerning the call procedure Info_Type_Actions (Action : String); pragma Inline (Info_Type_Actions); -- Output information concerning action Action of a type procedure Info_Verification_Call (Pred : String; Id : Entity_Id; Id_Kind : String); pragma Inline (Info_Verification_Call); -- Output information concerning the verification of predicate Pred -- applied to related entity Id with kind Id_Kind. ----------------------------- -- Info_Accept_Alternative -- ----------------------------- procedure Info_Accept_Alternative is Entry_Id : constant Entity_Id := Receiving_Entry (Target_Id); begin pragma Assert (Present (Entry_Id)); Elab_Msg_NE (Msg => "accept for entry & during elaboration", N => Call, Id => Entry_Id, Info_Msg => Info_Msg, In_SPARK => In_SPARK); end Info_Accept_Alternative; ---------------------- -- Info_Simple_Call -- ---------------------- procedure Info_Simple_Call is begin Elab_Msg_NE (Msg => "call to & during elaboration", N => Call, Id => Target_Id, Info_Msg => Info_Msg, In_SPARK => In_SPARK); end Info_Simple_Call; ----------------------- -- Info_Type_Actions -- ----------------------- procedure Info_Type_Actions (Action : String) is Typ : constant Entity_Id := First_Formal_Type (Target_Id); begin pragma Assert (Present (Typ)); Elab_Msg_NE (Msg => Action & " actions for type & during elaboration", N => Call, Id => Typ, Info_Msg => Info_Msg, In_SPARK => In_SPARK); end Info_Type_Actions; ---------------------------- -- Info_Verification_Call -- ---------------------------- procedure Info_Verification_Call (Pred : String; Id : Entity_Id; Id_Kind : String) is begin pragma Assert (Present (Id)); Elab_Msg_NE (Msg => "verification of " & Pred & " of " & Id_Kind & " & during " & "elaboration", N => Call, Id => Id, Info_Msg => Info_Msg, In_SPARK => In_SPARK); end Info_Verification_Call; -- Start of processing for Info_Call begin -- Do not output anything for targets defined in internal units because -- this creates noise. if not In_Internal_Unit (Target_Id) then -- Accept alternative if Is_Accept_Alternative_Proc (Target_Id) then Info_Accept_Alternative; -- Adjustment elsif Is_TSS (Target_Id, TSS_Deep_Adjust) then Info_Type_Actions ("adjustment"); -- Default_Initial_Condition elsif Is_Default_Initial_Condition_Proc (Target_Id) then Info_Verification_Call (Pred => "Default_Initial_Condition", Id => First_Formal_Type (Target_Id), Id_Kind => "type"); -- Entries elsif Is_Protected_Entry (Target_Id) then Info_Simple_Call; -- Task entry calls are never processed because the entry being -- invoked does not have a corresponding "body", it has a select. elsif Is_Task_Entry (Target_Id) then null; -- Finalization elsif Is_TSS (Target_Id, TSS_Deep_Finalize) then Info_Type_Actions ("finalization"); -- Calls to _Finalizer procedures must not appear in the output -- because this creates confusing noise. elsif Is_Finalizer_Proc (Target_Id) then null; -- Initial_Condition elsif Is_Initial_Condition_Proc (Target_Id) then Info_Verification_Call (Pred => "Initial_Condition", Id => Find_Enclosing_Scope (Call), Id_Kind => "package"); -- Initialization elsif Is_Init_Proc (Target_Id) or else Is_TSS (Target_Id, TSS_Deep_Initialize) then Info_Type_Actions ("initialization"); -- Invariant elsif Is_Invariant_Proc (Target_Id) then Info_Verification_Call (Pred => "invariants", Id => First_Formal_Type (Target_Id), Id_Kind => "type"); -- Partial invariant calls must not appear in the output because this -- creates confusing noise. elsif Is_Partial_Invariant_Proc (Target_Id) then null; -- _Postconditions elsif Is_Postconditions_Proc (Target_Id) then Info_Verification_Call (Pred => "postconditions", Id => Find_Enclosing_Scope (Call), Id_Kind => "subprogram"); -- Subprograms must come last because some of the previous cases fall -- under this category. elsif Ekind (Target_Id) = E_Function then Info_Simple_Call; elsif Ekind (Target_Id) = E_Procedure then Info_Simple_Call; else pragma Assert (False); null; end if; end if; end Info_Call; ------------------------ -- Info_Instantiation -- ------------------------ procedure Info_Instantiation (Inst : Node_Id; Gen_Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean) is begin Elab_Msg_NE (Msg => "instantiation of & during elaboration", N => Inst, Id => Gen_Id, Info_Msg => Info_Msg, In_SPARK => In_SPARK); end Info_Instantiation; ----------------------------- -- Info_Variable_Reference -- ----------------------------- procedure Info_Variable_Reference (Ref : Node_Id; Var_Id : Entity_Id; Info_Msg : Boolean; In_SPARK : Boolean) is begin if Is_Read (Ref) then Elab_Msg_NE (Msg => "read of variable & during elaboration", N => Ref, Id => Var_Id, Info_Msg => Info_Msg, In_SPARK => In_SPARK); end if; end Info_Variable_Reference; -------------------- -- Insertion_Node -- -------------------- function Insertion_Node (N : Node_Id; Ins_Nod : Node_Id) return Node_Id is begin -- When the scenario denotes an instantiation, the proper insertion node -- is the instance spec. This ensures that the generic actuals will not -- be evaluated prior to a potential ABE. if Nkind (N) in N_Generic_Instantiation and then Present (Instance_Spec (N)) then return Instance_Spec (N); -- Otherwise the proper insertion node is the candidate insertion node else return Ins_Nod; end if; end Insertion_Node; ----------------------- -- Install_ABE_Check -- ----------------------- procedure Install_ABE_Check (N : Node_Id; Id : Entity_Id; Ins_Nod : Node_Id) is Check_Ins_Nod : constant Node_Id := Insertion_Node (N, Ins_Nod); -- Insert the check prior to this node Loc : constant Source_Ptr := Sloc (N); Spec_Id : constant Entity_Id := Unique_Entity (Id); Unit_Id : constant Entity_Id := Find_Top_Unit (Id); Scop_Id : Entity_Id; begin -- Nothing to do when compiling for GNATprove because raise statements -- are not supported. if GNATprove_Mode then return; -- Nothing to do when the compilation will not produce an executable elsif Serious_Errors_Detected > 0 then return; -- Nothing to do for a compilation unit because there is no executable -- environment at that level. elsif Nkind (Parent (Check_Ins_Nod)) = N_Compilation_Unit then return; -- Nothing to do when the unit is elaborated prior to the main unit. -- This check must also consider the following cases: -- * Id's unit appears in the context of the main unit -- * Id's unit is subject to pragma Elaborate_Body. An ABE check MUST -- NOT be generated because Id's unit is always elaborated prior to -- the main unit. -- * Id's unit is the main unit. An ABE check MUST be generated in this -- case because a conditional ABE may be raised depending on the flow -- of execution within the main unit (flag Same_Unit_OK is False). elsif Has_Prior_Elaboration (Unit_Id => Unit_Id, Context_OK => True, Elab_Body_OK => True) then return; end if; -- Prevent multiple scenarios from installing the same ABE check Set_Is_Elaboration_Checks_OK_Node (N, False); -- Install the nearest enclosing scope of the scenario as there must be -- something on the scope stack. -- Performance note: parent traversal Scop_Id := Find_Enclosing_Scope (Check_Ins_Nod); pragma Assert (Present (Scop_Id)); Push_Scope (Scop_Id); -- Generate: -- if not Spec_Id'Elaborated then -- raise Program_Error with "access before elaboration"; -- end if; Insert_Action (Check_Ins_Nod, Make_Raise_Program_Error (Loc, Condition => Make_Op_Not (Loc, Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Spec_Id, Loc), Attribute_Name => Name_Elaborated)), Reason => PE_Access_Before_Elaboration)); Pop_Scope; end Install_ABE_Check; ----------------------- -- Install_ABE_Check -- ----------------------- procedure Install_ABE_Check (N : Node_Id; Target_Id : Entity_Id; Target_Decl : Node_Id; Target_Body : Node_Id; Ins_Nod : Node_Id) is procedure Build_Elaboration_Entity; pragma Inline (Build_Elaboration_Entity); -- Create a new elaboration flag for Target_Id, insert it prior to -- Target_Decl, and set it after Body_Decl. ------------------------------ -- Build_Elaboration_Entity -- ------------------------------ procedure Build_Elaboration_Entity is Loc : constant Source_Ptr := Sloc (Target_Id); Flag_Id : Entity_Id; begin -- Create the declaration of the elaboration flag. The name carries a -- unique counter in case of name overloading. Flag_Id := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Target_Id), 'E', -1)); Set_Elaboration_Entity (Target_Id, Flag_Id); Set_Elaboration_Entity_Required (Target_Id); Push_Scope (Scope (Target_Id)); -- Generate: -- Enn : Short_Integer := 0; Insert_Action (Target_Decl, Make_Object_Declaration (Loc, Defining_Identifier => Flag_Id, Object_Definition => New_Occurrence_Of (Standard_Short_Integer, Loc), Expression => Make_Integer_Literal (Loc, Uint_0))); -- Generate: -- Enn := 1; Set_Elaboration_Flag (Target_Body, Target_Id); Pop_Scope; end Build_Elaboration_Entity; -- Local variables Target_Unit_Id : constant Entity_Id := Find_Top_Unit (Target_Id); -- Start for processing for Install_ABE_Check begin -- Nothing to do when compiling for GNATprove because raise statements -- are not supported. if GNATprove_Mode then return; -- Nothing to do when the compilation will not produce an executable elsif Serious_Errors_Detected > 0 then return; -- Nothing to do when the target is a protected subprogram because the -- check is associated with the protected body subprogram. elsif Is_Protected_Subp (Target_Id) then return; -- Nothing to do when the target is elaborated prior to the main unit. -- This check must also consider the following cases: -- * The unit of the target appears in the context of the main unit -- * The unit of the target is subject to pragma Elaborate_Body. An ABE -- check MUST NOT be generated because the unit is always elaborated -- prior to the main unit. -- * The unit of the target is the main unit. An ABE check MUST be added -- in this case because a conditional ABE may be raised depending on -- the flow of execution within the main unit (flag Same_Unit_OK is -- False). elsif Has_Prior_Elaboration (Unit_Id => Target_Unit_Id, Context_OK => True, Elab_Body_OK => True) then return; -- Create an elaboration flag for the target when it does not have one elsif No (Elaboration_Entity (Target_Id)) then Build_Elaboration_Entity; end if; Install_ABE_Check (N => N, Ins_Nod => Ins_Nod, Id => Target_Id); end Install_ABE_Check; ------------------------- -- Install_ABE_Failure -- ------------------------- procedure Install_ABE_Failure (N : Node_Id; Ins_Nod : Node_Id) is Fail_Ins_Nod : constant Node_Id := Insertion_Node (N, Ins_Nod); -- Insert the failure prior to this node Loc : constant Source_Ptr := Sloc (N); Scop_Id : Entity_Id; begin -- Nothing to do when compiling for GNATprove because raise statements -- are not supported. if GNATprove_Mode then return; -- Nothing to do when the compilation will not produce an executable elsif Serious_Errors_Detected > 0 then return; -- Do not install an ABE check for a compilation unit because there is -- no executable environment at that level. elsif Nkind (Parent (Fail_Ins_Nod)) = N_Compilation_Unit then return; end if; -- Prevent multiple scenarios from installing the same ABE failure Set_Is_Elaboration_Checks_OK_Node (N, False); -- Install the nearest enclosing scope of the scenario as there must be -- something on the scope stack. -- Performance note: parent traversal Scop_Id := Find_Enclosing_Scope (Fail_Ins_Nod); pragma Assert (Present (Scop_Id)); Push_Scope (Scop_Id); -- Generate: -- raise Program_Error with "access before elaboration"; Insert_Action (Fail_Ins_Nod, Make_Raise_Program_Error (Loc, Reason => PE_Access_Before_Elaboration)); Pop_Scope; end Install_ABE_Failure; -------------------------------- -- Is_Accept_Alternative_Proc -- -------------------------------- function Is_Accept_Alternative_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote a procedure with a receiving entry return Ekind (Id) = E_Procedure and then Present (Receiving_Entry (Id)); end Is_Accept_Alternative_Proc; ------------------------ -- Is_Activation_Proc -- ------------------------ function Is_Activation_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote one of the runtime procedures in -- charge of task activation. if Ekind (Id) = E_Procedure then if Restricted_Profile then return Is_RTE (Id, RE_Activate_Restricted_Tasks); else return Is_RTE (Id, RE_Activate_Tasks); end if; end if; return False; end Is_Activation_Proc; ---------------------------- -- Is_Ada_Semantic_Target -- ---------------------------- function Is_Ada_Semantic_Target (Id : Entity_Id) return Boolean is begin return Is_Activation_Proc (Id) or else Is_Controlled_Proc (Id, Name_Adjust) or else Is_Controlled_Proc (Id, Name_Finalize) or else Is_Controlled_Proc (Id, Name_Initialize) or else Is_Init_Proc (Id) or else Is_Invariant_Proc (Id) or else Is_Protected_Entry (Id) or else Is_Protected_Subp (Id) or else Is_Protected_Body_Subp (Id) or else Is_Task_Entry (Id); end Is_Ada_Semantic_Target; -------------------------------- -- Is_Assertion_Pragma_Target -- -------------------------------- function Is_Assertion_Pragma_Target (Id : Entity_Id) return Boolean is begin return Is_Default_Initial_Condition_Proc (Id) or else Is_Initial_Condition_Proc (Id) or else Is_Invariant_Proc (Id) or else Is_Partial_Invariant_Proc (Id) or else Is_Postconditions_Proc (Id); end Is_Assertion_Pragma_Target; ---------------------------- -- Is_Bodiless_Subprogram -- ---------------------------- function Is_Bodiless_Subprogram (Subp_Id : Entity_Id) return Boolean is begin -- An abstract subprogram does not have a body if Ekind_In (Subp_Id, E_Function, E_Operator, E_Procedure) and then Is_Abstract_Subprogram (Subp_Id) then return True; -- A formal subprogram does not have a body elsif Is_Formal_Subprogram (Subp_Id) then return True; -- An imported subprogram may have a body, however it is not known at -- compile or bind time where the body resides and whether it will be -- elaborated on time. elsif Is_Imported (Subp_Id) then return True; end if; return False; end Is_Bodiless_Subprogram; ------------------------ -- Is_Controlled_Proc -- ------------------------ function Is_Controlled_Proc (Subp_Id : Entity_Id; Subp_Nam : Name_Id) return Boolean is Formal_Id : Entity_Id; begin pragma Assert (Nam_In (Subp_Nam, Name_Adjust, Name_Finalize, Name_Initialize)); -- To qualify, the subprogram must denote a source procedure with name -- Adjust, Finalize, or Initialize where the sole formal is controlled. if Comes_From_Source (Subp_Id) and then Ekind (Subp_Id) = E_Procedure and then Chars (Subp_Id) = Subp_Nam then Formal_Id := First_Formal (Subp_Id); return Present (Formal_Id) and then Is_Controlled (Etype (Formal_Id)) and then No (Next_Formal (Formal_Id)); end if; return False; end Is_Controlled_Proc; --------------------------------------- -- Is_Default_Initial_Condition_Proc -- --------------------------------------- function Is_Default_Initial_Condition_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote a Default_Initial_Condition -- procedure. return Ekind (Id) = E_Procedure and then Is_DIC_Procedure (Id); end Is_Default_Initial_Condition_Proc; ----------------------- -- Is_Finalizer_Proc -- ----------------------- function Is_Finalizer_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote a _Finalizer procedure return Ekind (Id) = E_Procedure and then Chars (Id) = Name_uFinalizer; end Is_Finalizer_Proc; ----------------------- -- Is_Guaranteed_ABE -- ----------------------- function Is_Guaranteed_ABE (N : Node_Id; Target_Decl : Node_Id; Target_Body : Node_Id) return Boolean is begin -- Avoid cascaded errors if there were previous serious infractions. -- As a result the scenario will not be treated as a guaranteed ABE. -- This behaviour parallels that of the old ABE mechanism. if Serious_Errors_Detected > 0 then return False; -- The scenario and the target appear within the same context ignoring -- enclosing library levels. -- Performance note: parent traversal elsif In_Same_Context (N, Target_Decl) then -- The target body has already been encountered. The scenario results -- in a guaranteed ABE if it appears prior to the body. if Present (Target_Body) then return Earlier_In_Extended_Unit (N, Target_Body); -- Otherwise the body has not been encountered yet. The scenario is -- a guaranteed ABE since the body will appear later. It is assumed -- that the caller has already checked whether the scenario is ABE- -- safe as optional bodies are not considered here. else return True; end if; end if; return False; end Is_Guaranteed_ABE; ------------------------------- -- Is_Initial_Condition_Proc -- ------------------------------- function Is_Initial_Condition_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote an Initial_Condition procedure return Ekind (Id) = E_Procedure and then Is_Initial_Condition_Procedure (Id); end Is_Initial_Condition_Proc; -------------------- -- Is_Initialized -- -------------------- function Is_Initialized (Obj_Decl : Node_Id) return Boolean is begin -- To qualify, the object declaration must have an expression return Present (Expression (Obj_Decl)) or else Has_Init_Expression (Obj_Decl); end Is_Initialized; ----------------------- -- Is_Invariant_Proc -- ----------------------- function Is_Invariant_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote the "full" invariant procedure return Ekind (Id) = E_Procedure and then Is_Invariant_Procedure (Id); end Is_Invariant_Proc; --------------------------------------- -- Is_Non_Library_Level_Encapsulator -- --------------------------------------- function Is_Non_Library_Level_Encapsulator (N : Node_Id) return Boolean is begin case Nkind (N) is when N_Abstract_Subprogram_Declaration | N_Aspect_Specification | N_Component_Declaration | N_Entry_Body | N_Entry_Declaration | N_Expression_Function | N_Formal_Abstract_Subprogram_Declaration | N_Formal_Concrete_Subprogram_Declaration | N_Formal_Object_Declaration | N_Formal_Package_Declaration | N_Formal_Type_Declaration | N_Generic_Association | N_Implicit_Label_Declaration | N_Incomplete_Type_Declaration | N_Private_Extension_Declaration | N_Private_Type_Declaration | N_Protected_Body | N_Protected_Type_Declaration | N_Single_Protected_Declaration | N_Single_Task_Declaration | N_Subprogram_Body | N_Subprogram_Declaration | N_Task_Body | N_Task_Type_Declaration => return True; when others => return Is_Generic_Declaration_Or_Body (N); end case; end Is_Non_Library_Level_Encapsulator; ------------------------------- -- Is_Partial_Invariant_Proc -- ------------------------------- function Is_Partial_Invariant_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote the "partial" invariant procedure return Ekind (Id) = E_Procedure and then Is_Partial_Invariant_Procedure (Id); end Is_Partial_Invariant_Proc; ---------------------------- -- Is_Postconditions_Proc -- ---------------------------- function Is_Postconditions_Proc (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote a _Postconditions procedure return Ekind (Id) = E_Procedure and then Chars (Id) = Name_uPostconditions; end Is_Postconditions_Proc; --------------------------- -- Is_Preelaborated_Unit -- --------------------------- function Is_Preelaborated_Unit (Id : Entity_Id) return Boolean is begin return Is_Preelaborated (Id) or else Is_Pure (Id) or else Is_Remote_Call_Interface (Id) or else Is_Remote_Types (Id) or else Is_Shared_Passive (Id); end Is_Preelaborated_Unit; ------------------------ -- Is_Protected_Entry -- ------------------------ function Is_Protected_Entry (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote an entry defined in a protected -- type. return Is_Entry (Id) and then Is_Protected_Type (Non_Private_View (Scope (Id))); end Is_Protected_Entry; ----------------------- -- Is_Protected_Subp -- ----------------------- function Is_Protected_Subp (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote a subprogram defined within a -- protected type. return Ekind_In (Id, E_Function, E_Procedure) and then Is_Protected_Type (Non_Private_View (Scope (Id))); end Is_Protected_Subp; ---------------------------- -- Is_Protected_Body_Subp -- ---------------------------- function Is_Protected_Body_Subp (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote a subprogram with attribute -- Protected_Subprogram set. return Ekind_In (Id, E_Function, E_Procedure) and then Present (Protected_Subprogram (Id)); end Is_Protected_Body_Subp; -------------------------------- -- Is_Recorded_SPARK_Scenario -- -------------------------------- function Is_Recorded_SPARK_Scenario (N : Node_Id) return Boolean is begin if Recorded_SPARK_Scenarios_In_Use then return Recorded_SPARK_Scenarios.Get (N); end if; return Recorded_SPARK_Scenarios_No_Element; end Is_Recorded_SPARK_Scenario; ------------------------------------ -- Is_Recorded_Top_Level_Scenario -- ------------------------------------ function Is_Recorded_Top_Level_Scenario (N : Node_Id) return Boolean is begin if Recorded_Top_Level_Scenarios_In_Use then return Recorded_Top_Level_Scenarios.Get (N); end if; return Recorded_Top_Level_Scenarios_No_Element; end Is_Recorded_Top_Level_Scenario; ------------------------ -- Is_Safe_Activation -- ------------------------ function Is_Safe_Activation (Call : Node_Id; Task_Decl : Node_Id) return Boolean is begin -- The activation of a task coming from an external instance cannot -- cause an ABE because the generic was already instantiated. Note -- that the instantiation itself may lead to an ABE. return In_External_Instance (N => Call, Target_Decl => Task_Decl); end Is_Safe_Activation; ------------------ -- Is_Safe_Call -- ------------------ function Is_Safe_Call (Call : Node_Id; Target_Attrs : Target_Attributes) return Boolean is begin -- The target is either an abstract subprogram, formal subprogram, or -- imported, in which case it does not have a body at compile or bind -- time. Assume that the call is ABE-safe. if Is_Bodiless_Subprogram (Target_Attrs.Spec_Id) then return True; -- The target is an instantiation of a generic subprogram. The call -- cannot cause an ABE because the generic was already instantiated. -- Note that the instantiation itself may lead to an ABE. elsif Is_Generic_Instance (Target_Attrs.Spec_Id) then return True; -- The invocation of a target coming from an external instance cannot -- cause an ABE because the generic was already instantiated. Note that -- the instantiation itself may lead to an ABE. elsif In_External_Instance (N => Call, Target_Decl => Target_Attrs.Spec_Decl) then return True; -- The target is a subprogram body without a previous declaration. The -- call cannot cause an ABE because the body has already been seen. elsif Nkind (Target_Attrs.Spec_Decl) = N_Subprogram_Body and then No (Corresponding_Spec (Target_Attrs.Spec_Decl)) then return True; -- The target is a subprogram body stub without a prior declaration. -- The call cannot cause an ABE because the proper body substitutes -- the stub. elsif Nkind (Target_Attrs.Spec_Decl) = N_Subprogram_Body_Stub and then No (Corresponding_Spec_Of_Stub (Target_Attrs.Spec_Decl)) then return True; -- Subprogram bodies which wrap attribute references used as actuals -- in instantiations are always ABE-safe. These bodies are artifacts -- of expansion. elsif Present (Target_Attrs.Body_Decl) and then Nkind (Target_Attrs.Body_Decl) = N_Subprogram_Body and then Was_Attribute_Reference (Target_Attrs.Body_Decl) then return True; end if; return False; end Is_Safe_Call; --------------------------- -- Is_Safe_Instantiation -- --------------------------- function Is_Safe_Instantiation (Inst : Node_Id; Gen_Attrs : Target_Attributes) return Boolean is begin -- The generic is an intrinsic subprogram in which case it does not -- have a body at compile or bind time. Assume that the instantiation -- is ABE-safe. if Is_Bodiless_Subprogram (Gen_Attrs.Spec_Id) then return True; -- The instantiation of an external nested generic cannot cause an ABE -- if the outer generic was already instantiated. Note that the instance -- of the outer generic may lead to an ABE. elsif In_External_Instance (N => Inst, Target_Decl => Gen_Attrs.Spec_Decl) then return True; -- The generic is a package. The instantiation cannot cause an ABE when -- the package has no body. elsif Ekind (Gen_Attrs.Spec_Id) = E_Generic_Package and then not Has_Body (Gen_Attrs.Spec_Decl) then return True; end if; return False; end Is_Safe_Instantiation; ------------------ -- Is_Same_Unit -- ------------------ function Is_Same_Unit (Unit_1 : Entity_Id; Unit_2 : Entity_Id) return Boolean is begin return Unit_Entity (Unit_1) = Unit_Entity (Unit_2); end Is_Same_Unit; ----------------- -- Is_Scenario -- ----------------- function Is_Scenario (N : Node_Id) return Boolean is begin case Nkind (N) is when N_Assignment_Statement | N_Attribute_Reference | N_Call_Marker | N_Entry_Call_Statement | N_Expanded_Name | N_Function_Call | N_Function_Instantiation | N_Identifier | N_Package_Instantiation | N_Procedure_Call_Statement | N_Procedure_Instantiation | N_Requeue_Statement => return True; when others => return False; end case; end Is_Scenario; ------------------------------ -- Is_SPARK_Semantic_Target -- ------------------------------ function Is_SPARK_Semantic_Target (Id : Entity_Id) return Boolean is begin return Is_Default_Initial_Condition_Proc (Id) or else Is_Initial_Condition_Proc (Id); end Is_SPARK_Semantic_Target; ------------------------ -- Is_Suitable_Access -- ------------------------ function Is_Suitable_Access (N : Node_Id) return Boolean is Nam : Name_Id; Pref : Node_Id; Subp_Id : Entity_Id; begin -- This scenario is relevant only when the static model is in effect -- because it is graph-dependent and does not involve any run-time -- checks. Allowing it in the dynamic model would create confusing -- noise. if not Static_Elaboration_Checks then return False; -- Nothing to do when switch -gnatd.U (ignore 'Access) is in effect elsif Debug_Flag_Dot_UU then return False; -- Nothing to do when the scenario is not an attribute reference elsif Nkind (N) /= N_Attribute_Reference then return False; -- Nothing to do for internally-generated attributes because they are -- assumed to be ABE safe. elsif not Comes_From_Source (N) then return False; end if; Nam := Attribute_Name (N); Pref := Prefix (N); -- Sanitize the prefix of the attribute if not Is_Entity_Name (Pref) then return False; elsif No (Entity (Pref)) then return False; end if; Subp_Id := Entity (Pref); if not Is_Subprogram_Or_Entry (Subp_Id) then return False; end if; -- Traverse a possible chain of renamings to obtain the original entry -- or subprogram which the prefix may rename. Subp_Id := Get_Renamed_Entity (Subp_Id); -- To qualify, the attribute must meet the following prerequisites: return -- The prefix must denote a source entry, operator, or subprogram -- which is not imported. Comes_From_Source (Subp_Id) and then Is_Subprogram_Or_Entry (Subp_Id) and then not Is_Bodiless_Subprogram (Subp_Id) -- The attribute name must be one of the 'Access forms. Note that -- 'Unchecked_Access cannot apply to a subprogram. and then Nam_In (Nam, Name_Access, Name_Unrestricted_Access); end Is_Suitable_Access; ---------------------- -- Is_Suitable_Call -- ---------------------- function Is_Suitable_Call (N : Node_Id) return Boolean is begin -- Entry and subprogram calls are intentionally ignored because they -- may undergo expansion depending on the compilation mode, previous -- errors, generic context, etc. Call markers play the role of calls -- and provide a uniform foundation for ABE processing. return Nkind (N) = N_Call_Marker; end Is_Suitable_Call; ------------------------------- -- Is_Suitable_Instantiation -- ------------------------------- function Is_Suitable_Instantiation (N : Node_Id) return Boolean is Orig_N : constant Node_Id := Original_Node (N); -- Use the original node in case an instantiation library unit is -- rewritten as a package or subprogram. begin -- To qualify, the instantiation must come from source return Comes_From_Source (Orig_N) and then Nkind (Orig_N) in N_Generic_Instantiation; end Is_Suitable_Instantiation; -------------------------- -- Is_Suitable_Scenario -- -------------------------- function Is_Suitable_Scenario (N : Node_Id) return Boolean is begin -- NOTE: Derived types and pragma Refined_State are intentionally left -- out because they are not executable during elaboration. return Is_Suitable_Access (N) or else Is_Suitable_Call (N) or else Is_Suitable_Instantiation (N) or else Is_Suitable_Variable_Assignment (N) or else Is_Suitable_Variable_Reference (N); end Is_Suitable_Scenario; ------------------------------------ -- Is_Suitable_SPARK_Derived_Type -- ------------------------------------ function Is_Suitable_SPARK_Derived_Type (N : Node_Id) return Boolean is Prag : Node_Id; Typ : Entity_Id; begin -- To qualify, the type declaration must denote a derived tagged type -- with primitive operations, subject to pragma SPARK_Mode On. if Nkind (N) = N_Full_Type_Declaration and then Nkind (Type_Definition (N)) = N_Derived_Type_Definition then Typ := Defining_Entity (N); Prag := SPARK_Pragma (Typ); return Is_Tagged_Type (Typ) and then Has_Primitive_Operations (Typ) and then Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On; end if; return False; end Is_Suitable_SPARK_Derived_Type; ------------------------------------- -- Is_Suitable_SPARK_Instantiation -- ------------------------------------- function Is_Suitable_SPARK_Instantiation (N : Node_Id) return Boolean is Gen_Attrs : Target_Attributes; Gen_Id : Entity_Id; Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Inst_Id : Entity_Id; begin -- To qualify, both the instantiation and the generic must be subject to -- SPARK_Mode On. if Is_Suitable_Instantiation (N) then Extract_Instantiation_Attributes (Exp_Inst => N, Inst => Inst, Inst_Id => Inst_Id, Gen_Id => Gen_Id, Attrs => Inst_Attrs); Extract_Target_Attributes (Gen_Id, Gen_Attrs); return Inst_Attrs.SPARK_Mode_On and Gen_Attrs.SPARK_Mode_On; end if; return False; end Is_Suitable_SPARK_Instantiation; -------------------------------------------- -- Is_Suitable_SPARK_Refined_State_Pragma -- -------------------------------------------- function Is_Suitable_SPARK_Refined_State_Pragma (N : Node_Id) return Boolean is begin -- To qualfy, the pragma must denote Refined_State return Nkind (N) = N_Pragma and then Pragma_Name (N) = Name_Refined_State; end Is_Suitable_SPARK_Refined_State_Pragma; ------------------------------------- -- Is_Suitable_Variable_Assignment -- ------------------------------------- function Is_Suitable_Variable_Assignment (N : Node_Id) return Boolean is N_Unit : Node_Id; N_Unit_Id : Entity_Id; Nam : Node_Id; Var_Decl : Node_Id; Var_Id : Entity_Id; Var_Unit : Node_Id; Var_Unit_Id : Entity_Id; begin -- This scenario is relevant only when the static model is in effect -- because it is graph-dependent and does not involve any run-time -- checks. Allowing it in the dynamic model would create confusing -- noise. if not Static_Elaboration_Checks then return False; -- Nothing to do when the scenario is not an assignment elsif Nkind (N) /= N_Assignment_Statement then return False; -- Nothing to do for internally-generated assignments because they are -- assumed to be ABE safe. elsif not Comes_From_Source (N) then return False; -- Assignments are ignored in GNAT mode on the assumption that they are -- ABE-safe. This behaviour parallels that of the old ABE mechanism. elsif GNAT_Mode then return False; end if; Nam := Extract_Assignment_Name (N); -- Sanitize the left hand side of the assignment if not Is_Entity_Name (Nam) then return False; elsif No (Entity (Nam)) then return False; end if; Var_Id := Entity (Nam); -- Sanitize the variable if Var_Id = Any_Id then return False; elsif Ekind (Var_Id) /= E_Variable then return False; end if; Var_Decl := Declaration_Node (Var_Id); if Nkind (Var_Decl) /= N_Object_Declaration then return False; end if; N_Unit_Id := Find_Top_Unit (N); N_Unit := Unit_Declaration_Node (N_Unit_Id); Var_Unit_Id := Find_Top_Unit (Var_Decl); Var_Unit := Unit_Declaration_Node (Var_Unit_Id); -- To qualify, the assignment must meet the following prerequisites: return Comes_From_Source (Var_Id) -- The variable must be declared in the spec of compilation unit U and then Nkind (Var_Unit) = N_Package_Declaration -- Performance note: parent traversal and then Find_Enclosing_Level (Var_Decl) = Package_Spec -- The assignment must occur in the body of compilation unit U and then Nkind (N_Unit) = N_Package_Body and then Present (Corresponding_Body (Var_Unit)) and then Corresponding_Body (Var_Unit) = N_Unit_Id; end Is_Suitable_Variable_Assignment; ------------------------------------ -- Is_Suitable_Variable_Reference -- ------------------------------------ function Is_Suitable_Variable_Reference (N : Node_Id) return Boolean is begin -- Expanded names and identifiers are intentionally ignored because they -- be folded, optimized away, etc. Variable references markers play the -- role of variable references and provide a uniform foundation for ABE -- processing. return Nkind (N) = N_Variable_Reference_Marker; end Is_Suitable_Variable_Reference; ------------------------------------ -- Is_Synchronous_Suspension_Call -- ------------------------------------ function Is_Synchronous_Suspension_Call (N : Node_Id) return Boolean is Call_Attrs : Call_Attributes; Target_Id : Entity_Id; begin -- To qualify, the call must invoke one of the runtime routines which -- perform synchronous suspension. if Is_Suitable_Call (N) then Extract_Call_Attributes (Call => N, Target_Id => Target_Id, Attrs => Call_Attrs); return Is_RTE (Target_Id, RE_Suspend_Until_True) or else Is_RTE (Target_Id, RE_Wait_For_Release); end if; return False; end Is_Synchronous_Suspension_Call; ------------------- -- Is_Task_Entry -- ------------------- function Is_Task_Entry (Id : Entity_Id) return Boolean is begin -- To qualify, the entity must denote an entry defined in a task type return Is_Entry (Id) and then Is_Task_Type (Non_Private_View (Scope (Id))); end Is_Task_Entry; ------------------------ -- Is_Up_Level_Target -- ------------------------ function Is_Up_Level_Target (Target_Decl : Node_Id) return Boolean is Root : constant Node_Id := Root_Scenario; begin -- The root appears within the declaratons of a block statement, entry -- body, subprogram body, or task body ignoring enclosing packages. The -- root is always within the main unit. An up-level target is a notion -- applicable only to the static model because scenarios are reached by -- means of graph traversal started from a fixed declarative or library -- level. -- Performance note: parent traversal if Static_Elaboration_Checks and then Find_Enclosing_Level (Root) = Declaration_Level then -- The target is within the main unit. It acts as an up-level target -- when it appears within a context which encloses the root. -- package body Main_Unit is -- function Func ...; -- target -- procedure Proc is -- X : ... := Func; -- root scenario if In_Extended_Main_Code_Unit (Target_Decl) then -- Performance note: parent traversal return not In_Same_Context (Root, Target_Decl, Nested_OK => True); -- Otherwise the target is external to the main unit which makes it -- an up-level target. else return True; end if; end if; return False; end Is_Up_Level_Target; --------------------- -- Is_Visited_Body -- --------------------- function Is_Visited_Body (Body_Decl : Node_Id) return Boolean is begin if Visited_Bodies_In_Use then return Visited_Bodies.Get (Body_Decl); end if; return Visited_Bodies_No_Element; end Is_Visited_Body; ------------------------------- -- Kill_Elaboration_Scenario -- ------------------------------- procedure Kill_Elaboration_Scenario (N : Node_Id) is procedure Kill_SPARK_Scenario; pragma Inline (Kill_SPARK_Scenario); -- Eliminate scenario N from table SPARK_Scenarios if it is recorded -- there. procedure Kill_Top_Level_Scenario; pragma Inline (Kill_Top_Level_Scenario); -- Eliminate scenario N from table Top_Level_Scenarios if it is recorded -- there. ------------------------- -- Kill_SPARK_Scenario -- ------------------------- procedure Kill_SPARK_Scenario is package Scenarios renames SPARK_Scenarios; begin if Is_Recorded_SPARK_Scenario (N) then -- Performance note: list traversal for Index in Scenarios.First .. Scenarios.Last loop if Scenarios.Table (Index) = N then Scenarios.Table (Index) := Empty; -- The SPARK scenario is no longer recorded Set_Is_Recorded_SPARK_Scenario (N, False); return; end if; end loop; -- A recorded SPARK scenario must be in the table of recorded -- SPARK scenarios. pragma Assert (False); end if; end Kill_SPARK_Scenario; ----------------------------- -- Kill_Top_Level_Scenario -- ----------------------------- procedure Kill_Top_Level_Scenario is package Scenarios renames Top_Level_Scenarios; begin if Is_Recorded_Top_Level_Scenario (N) then -- Performance node: list traversal for Index in Scenarios.First .. Scenarios.Last loop if Scenarios.Table (Index) = N then Scenarios.Table (Index) := Empty; -- The top-level scenario is no longer recorded Set_Is_Recorded_Top_Level_Scenario (N, False); return; end if; end loop; -- A recorded top-level scenario must be in the table of recorded -- top-level scenarios. pragma Assert (False); end if; end Kill_Top_Level_Scenario; -- Start of processing for Kill_Elaboration_Scenario begin -- Nothing to do when switch -gnatH (legacy elaboration checking mode -- enabled) is in effect because the legacy ABE lechanism does not need -- to carry out this action. if Legacy_Elaboration_Checks then return; end if; -- Eliminate a recorded scenario when it appears within dead code -- because it will not be executed at elaboration time. if Is_Scenario (N) then Kill_SPARK_Scenario; Kill_Top_Level_Scenario; end if; end Kill_Elaboration_Scenario; ---------------------------------- -- Meet_Elaboration_Requirement -- ---------------------------------- procedure Meet_Elaboration_Requirement (N : Node_Id; Target_Id : Entity_Id; Req_Nam : Name_Id) is Main_Id : constant Entity_Id := Cunit_Entity (Main_Unit); Unit_Id : constant Entity_Id := Find_Top_Unit (Target_Id); function Find_Preelaboration_Pragma (Prag_Nam : Name_Id) return Node_Id; pragma Inline (Find_Preelaboration_Pragma); -- Traverse the visible declarations of unit Unit_Id and locate a source -- preelaboration-related pragma with name Prag_Nam. procedure Info_Requirement_Met (Prag : Node_Id); pragma Inline (Info_Requirement_Met); -- Output information concerning pragma Prag which meets requirement -- Req_Nam. procedure Info_Scenario; pragma Inline (Info_Scenario); -- Output information concerning scenario N -------------------------------- -- Find_Preelaboration_Pragma -- -------------------------------- function Find_Preelaboration_Pragma (Prag_Nam : Name_Id) return Node_Id is Spec : constant Node_Id := Parent (Unit_Id); Decl : Node_Id; begin -- A preelaboration-related pragma comes from source and appears at -- the top of the visible declarations of a package. if Nkind (Spec) = N_Package_Specification then Decl := First (Visible_Declarations (Spec)); while Present (Decl) loop if Comes_From_Source (Decl) then if Nkind (Decl) = N_Pragma and then Pragma_Name (Decl) = Prag_Nam then return Decl; -- Otherwise the construct terminates the region where the -- preelaboration-related pragma may appear. else exit; end if; end if; Next (Decl); end loop; end if; return Empty; end Find_Preelaboration_Pragma; -------------------------- -- Info_Requirement_Met -- -------------------------- procedure Info_Requirement_Met (Prag : Node_Id) is begin pragma Assert (Present (Prag)); Error_Msg_Name_1 := Req_Nam; Error_Msg_Sloc := Sloc (Prag); Error_Msg_NE ("\\% requirement for unit & met by pragma #", N, Unit_Id); end Info_Requirement_Met; ------------------- -- Info_Scenario -- ------------------- procedure Info_Scenario is begin if Is_Suitable_Call (N) then Info_Call (Call => N, Target_Id => Target_Id, Info_Msg => False, In_SPARK => True); elsif Is_Suitable_Instantiation (N) then Info_Instantiation (Inst => N, Gen_Id => Target_Id, Info_Msg => False, In_SPARK => True); elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then Error_Msg_N ("read of refinement constituents during elaboration in SPARK", N); elsif Is_Suitable_Variable_Reference (N) then Info_Variable_Reference (Ref => N, Var_Id => Target_Id, Info_Msg => False, In_SPARK => True); -- No other scenario may impose a requirement on the context of the -- main unit. else pragma Assert (False); null; end if; end Info_Scenario; -- Local variables Elab_Attrs : Elaboration_Attributes; Elab_Nam : Name_Id; Req_Met : Boolean; -- Start of processing for Meet_Elaboration_Requirement begin pragma Assert (Nam_In (Req_Nam, Name_Elaborate, Name_Elaborate_All)); -- Assume that the requirement has not been met Req_Met := False; -- Elaboration requirements are verified only when the static model is -- in effect because this diagnostic is graph-dependent. if not Static_Elaboration_Checks then return; -- If the target is within the main unit, either at the source level or -- through an instantiation, then there is no real requirement to meet -- because the main unit cannot force its own elaboration by means of an -- Elaborate[_All] pragma. Treat this case as valid coverage. elsif In_Extended_Main_Code_Unit (Target_Id) then Req_Met := True; -- Otherwise the target resides in an external unit -- The requirement is met when the target comes from an internal unit -- because such a unit is elaborated prior to a non-internal unit. elsif In_Internal_Unit (Unit_Id) and then not In_Internal_Unit (Main_Id) then Req_Met := True; -- The requirement is met when the target comes from a preelaborated -- unit. This portion must parallel predicate Is_Preelaborated_Unit. elsif Is_Preelaborated_Unit (Unit_Id) then Req_Met := True; -- Output extra information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas. if Elab_Info_Messages then if Is_Preelaborated (Unit_Id) then Elab_Nam := Name_Preelaborate; elsif Is_Pure (Unit_Id) then Elab_Nam := Name_Pure; elsif Is_Remote_Call_Interface (Unit_Id) then Elab_Nam := Name_Remote_Call_Interface; elsif Is_Remote_Types (Unit_Id) then Elab_Nam := Name_Remote_Types; else pragma Assert (Is_Shared_Passive (Unit_Id)); Elab_Nam := Name_Shared_Passive; end if; Info_Requirement_Met (Find_Preelaboration_Pragma (Elab_Nam)); end if; -- Determine whether the context of the main unit has a pragma strong -- enough to meet the requirement. else Elab_Attrs := Elaboration_Status (Unit_Id); -- The pragma must be either Elaborate_All or be as strong as the -- requirement. if Present (Elab_Attrs.Source_Pragma) and then Nam_In (Pragma_Name (Elab_Attrs.Source_Pragma), Name_Elaborate_All, Req_Nam) then Req_Met := True; -- Output extra information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas. if Elab_Info_Messages then Info_Requirement_Met (Elab_Attrs.Source_Pragma); end if; end if; end if; -- The requirement was not met by the context of the main unit, issue an -- error. if not Req_Met then Info_Scenario; Error_Msg_Name_1 := Req_Nam; Error_Msg_Node_2 := Unit_Id; Error_Msg_NE ("\\unit & requires pragma % for &", N, Main_Id); Output_Active_Scenarios (N); end if; end Meet_Elaboration_Requirement; ---------------------- -- Non_Private_View -- ---------------------- function Non_Private_View (Typ : Entity_Id) return Entity_Id is begin if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then return Full_View (Typ); else return Typ; end if; end Non_Private_View; ----------------------------- -- Output_Active_Scenarios -- ----------------------------- procedure Output_Active_Scenarios (Error_Nod : Node_Id) is procedure Output_Access (N : Node_Id); -- Emit a specific diagnostic message for 'Access denote by N procedure Output_Activation_Call (N : Node_Id); -- Emit a specific diagnostic message for task activation N procedure Output_Call (N : Node_Id; Target_Id : Entity_Id); -- Emit a specific diagnostic message for call N which invokes target -- Target_Id. procedure Output_Header; -- Emit a specific diagnostic message for the unit of the root scenario procedure Output_Instantiation (N : Node_Id); -- Emit a specific diagnostic message for instantiation N procedure Output_SPARK_Refined_State_Pragma (N : Node_Id); -- Emit a specific diagnostic message for Refined_State pragma N procedure Output_Variable_Assignment (N : Node_Id); -- Emit a specific diagnostic message for assignment statement N procedure Output_Variable_Reference (N : Node_Id); -- Emit a specific diagnostic message for reference N which mentions a -- variable. ------------------- -- Output_Access -- ------------------- procedure Output_Access (N : Node_Id) is Subp_Id : constant Entity_Id := Entity (Prefix (N)); begin Error_Msg_Name_1 := Attribute_Name (N); Error_Msg_Sloc := Sloc (N); Error_Msg_NE ("\\ % of & taken #", Error_Nod, Subp_Id); end Output_Access; ---------------------------- -- Output_Activation_Call -- ---------------------------- procedure Output_Activation_Call (N : Node_Id) is function Find_Activator (Call : Node_Id) return Entity_Id; -- Find the nearest enclosing construct which houses call Call -------------------- -- Find_Activator -- -------------------- function Find_Activator (Call : Node_Id) return Entity_Id is Par : Node_Id; begin -- Climb the parent chain looking for a package [body] or a -- construct with a statement sequence. Par := Parent (Call); while Present (Par) loop if Nkind_In (Par, N_Package_Body, N_Package_Declaration) then return Defining_Entity (Par); elsif Nkind (Par) = N_Handled_Sequence_Of_Statements then return Defining_Entity (Parent (Par)); end if; Par := Parent (Par); end loop; return Empty; end Find_Activator; -- Local variables Activator : constant Entity_Id := Find_Activator (N); -- Start of processing for Output_Activation_Call begin pragma Assert (Present (Activator)); Error_Msg_NE ("\\ local tasks of & activated", Error_Nod, Activator); end Output_Activation_Call; ----------------- -- Output_Call -- ----------------- procedure Output_Call (N : Node_Id; Target_Id : Entity_Id) is procedure Output_Accept_Alternative; pragma Inline (Output_Accept_Alternative); -- Emit a specific diagnostic message concerning an accept -- alternative. procedure Output_Call (Kind : String); pragma Inline (Output_Call); -- Emit a specific diagnostic message concerning a call of kind Kind procedure Output_Type_Actions (Action : String); pragma Inline (Output_Type_Actions); -- Emit a specific diagnostic message concerning action Action of a -- type. procedure Output_Verification_Call (Pred : String; Id : Entity_Id; Id_Kind : String); pragma Inline (Output_Verification_Call); -- Emit a specific diagnostic message concerning the verification of -- predicate Pred applied to related entity Id with kind Id_Kind. ------------------------------- -- Output_Accept_Alternative -- ------------------------------- procedure Output_Accept_Alternative is Entry_Id : constant Entity_Id := Receiving_Entry (Target_Id); begin pragma Assert (Present (Entry_Id)); Error_Msg_NE ("\\ entry & selected #", Error_Nod, Entry_Id); end Output_Accept_Alternative; ----------------- -- Output_Call -- ----------------- procedure Output_Call (Kind : String) is begin Error_Msg_NE ("\\ " & Kind & " & called #", Error_Nod, Target_Id); end Output_Call; ------------------------- -- Output_Type_Actions -- ------------------------- procedure Output_Type_Actions (Action : String) is Typ : constant Entity_Id := First_Formal_Type (Target_Id); begin pragma Assert (Present (Typ)); Error_Msg_NE ("\\ " & Action & " actions for type & #", Error_Nod, Typ); end Output_Type_Actions; ------------------------------ -- Output_Verification_Call -- ------------------------------ procedure Output_Verification_Call (Pred : String; Id : Entity_Id; Id_Kind : String) is begin pragma Assert (Present (Id)); Error_Msg_NE ("\\ " & Pred & " of " & Id_Kind & " & verified #", Error_Nod, Id); end Output_Verification_Call; -- Start of processing for Output_Call begin Error_Msg_Sloc := Sloc (N); -- Accept alternative if Is_Accept_Alternative_Proc (Target_Id) then Output_Accept_Alternative; -- Adjustment elsif Is_TSS (Target_Id, TSS_Deep_Adjust) then Output_Type_Actions ("adjustment"); -- Default_Initial_Condition elsif Is_Default_Initial_Condition_Proc (Target_Id) then Output_Verification_Call (Pred => "Default_Initial_Condition", Id => First_Formal_Type (Target_Id), Id_Kind => "type"); -- Entries elsif Is_Protected_Entry (Target_Id) then Output_Call ("entry"); -- Task entry calls are never processed because the entry being -- invoked does not have a corresponding "body", it has a select. A -- task entry call appears in the stack of active scenarios for the -- sole purpose of checking No_Entry_Calls_In_Elaboration_Code and -- nothing more. elsif Is_Task_Entry (Target_Id) then null; -- Finalization elsif Is_TSS (Target_Id, TSS_Deep_Finalize) then Output_Type_Actions ("finalization"); -- Calls to _Finalizer procedures must not appear in the output -- because this creates confusing noise. elsif Is_Finalizer_Proc (Target_Id) then null; -- Initial_Condition elsif Is_Initial_Condition_Proc (Target_Id) then Output_Verification_Call (Pred => "Initial_Condition", Id => Find_Enclosing_Scope (N), Id_Kind => "package"); -- Initialization elsif Is_Init_Proc (Target_Id) or else Is_TSS (Target_Id, TSS_Deep_Initialize) then Output_Type_Actions ("initialization"); -- Invariant elsif Is_Invariant_Proc (Target_Id) then Output_Verification_Call (Pred => "invariants", Id => First_Formal_Type (Target_Id), Id_Kind => "type"); -- Partial invariant calls must not appear in the output because this -- creates confusing noise. Note that a partial invariant is always -- invoked by the "full" invariant which is already placed on the -- stack. elsif Is_Partial_Invariant_Proc (Target_Id) then null; -- _Postconditions elsif Is_Postconditions_Proc (Target_Id) then Output_Verification_Call (Pred => "postconditions", Id => Find_Enclosing_Scope (N), Id_Kind => "subprogram"); -- Subprograms must come last because some of the previous cases fall -- under this category. elsif Ekind (Target_Id) = E_Function then Output_Call ("function"); elsif Ekind (Target_Id) = E_Procedure then Output_Call ("procedure"); else pragma Assert (False); null; end if; end Output_Call; ------------------- -- Output_Header -- ------------------- procedure Output_Header is Unit_Id : constant Entity_Id := Find_Top_Unit (Root_Scenario); begin if Ekind (Unit_Id) = E_Package then Error_Msg_NE ("\\ spec of unit & elaborated", Error_Nod, Unit_Id); elsif Ekind (Unit_Id) = E_Package_Body then Error_Msg_NE ("\\ body of unit & elaborated", Error_Nod, Unit_Id); else Error_Msg_NE ("\\ in body of unit &", Error_Nod, Unit_Id); end if; end Output_Header; -------------------------- -- Output_Instantiation -- -------------------------- procedure Output_Instantiation (N : Node_Id) is procedure Output_Instantiation (Gen_Id : Entity_Id; Kind : String); pragma Inline (Output_Instantiation); -- Emit a specific diagnostic message concerning an instantiation of -- generic unit Gen_Id. Kind denotes the kind of the instantiation. -------------------------- -- Output_Instantiation -- -------------------------- procedure Output_Instantiation (Gen_Id : Entity_Id; Kind : String) is begin Error_Msg_NE ("\\ " & Kind & " & instantiated as & #", Error_Nod, Gen_Id); end Output_Instantiation; -- Local variables Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Inst_Id : Entity_Id; Gen_Id : Entity_Id; -- Start of processing for Output_Instantiation begin Extract_Instantiation_Attributes (Exp_Inst => N, Inst => Inst, Inst_Id => Inst_Id, Gen_Id => Gen_Id, Attrs => Inst_Attrs); Error_Msg_Node_2 := Inst_Id; Error_Msg_Sloc := Sloc (Inst); if Nkind (Inst) = N_Function_Instantiation then Output_Instantiation (Gen_Id, "function"); elsif Nkind (Inst) = N_Package_Instantiation then Output_Instantiation (Gen_Id, "package"); elsif Nkind (Inst) = N_Procedure_Instantiation then Output_Instantiation (Gen_Id, "procedure"); else pragma Assert (False); null; end if; end Output_Instantiation; --------------------------------------- -- Output_SPARK_Refined_State_Pragma -- --------------------------------------- procedure Output_SPARK_Refined_State_Pragma (N : Node_Id) is begin Error_Msg_Sloc := Sloc (N); Error_Msg_N ("\\ refinement constituents read #", Error_Nod); end Output_SPARK_Refined_State_Pragma; -------------------------------- -- Output_Variable_Assignment -- -------------------------------- procedure Output_Variable_Assignment (N : Node_Id) is Var_Id : constant Entity_Id := Entity (Extract_Assignment_Name (N)); begin Error_Msg_Sloc := Sloc (N); Error_Msg_NE ("\\ variable & assigned #", Error_Nod, Var_Id); end Output_Variable_Assignment; ------------------------------- -- Output_Variable_Reference -- ------------------------------- procedure Output_Variable_Reference (N : Node_Id) is Dummy : Variable_Attributes; Var_Id : Entity_Id; begin Extract_Variable_Reference_Attributes (Ref => N, Var_Id => Var_Id, Attrs => Dummy); Error_Msg_Sloc := Sloc (N); if Is_Read (N) then Error_Msg_NE ("\\ variable & read #", Error_Nod, Var_Id); else pragma Assert (False); null; end if; end Output_Variable_Reference; -- Local variables package Stack renames Scenario_Stack; Dummy : Call_Attributes; N : Node_Id; Posted : Boolean; Target_Id : Entity_Id; -- Start of processing for Output_Active_Scenarios begin -- Active scenarios are emitted only when the static model is in effect -- because there is an inherent order by which all these scenarios were -- reached from the declaration or library level. if not Static_Elaboration_Checks then return; end if; Posted := False; for Index in Stack.First .. Stack.Last loop N := Stack.Table (Index); if not Posted then Posted := True; Output_Header; end if; -- 'Access if Nkind (N) = N_Attribute_Reference then Output_Access (N); -- Calls elsif Is_Suitable_Call (N) then Extract_Call_Attributes (Call => N, Target_Id => Target_Id, Attrs => Dummy); if Is_Activation_Proc (Target_Id) then Output_Activation_Call (N); else Output_Call (N, Target_Id); end if; -- Instantiations elsif Is_Suitable_Instantiation (N) then Output_Instantiation (N); -- Pragma Refined_State elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then Output_SPARK_Refined_State_Pragma (N); -- Variable assignments elsif Nkind (N) = N_Assignment_Statement then Output_Variable_Assignment (N); -- Variable references elsif Is_Suitable_Variable_Reference (N) then Output_Variable_Reference (N); else pragma Assert (False); null; end if; end loop; end Output_Active_Scenarios; ------------------------- -- Pop_Active_Scenario -- ------------------------- procedure Pop_Active_Scenario (N : Node_Id) is Top : Node_Id renames Scenario_Stack.Table (Scenario_Stack.Last); begin pragma Assert (Top = N); Scenario_Stack.Decrement_Last; end Pop_Active_Scenario; -------------------------------- -- Process_Activation_Generic -- -------------------------------- procedure Process_Activation_Generic (Call : Node_Id; Call_Attrs : Call_Attributes; State : Processing_Attributes) is procedure Process_Task_Object (Obj_Id : Entity_Id; Typ : Entity_Id); -- Perform ABE checks and diagnostics for object Obj_Id with type Typ. -- Typ may be a task type or a composite type with at least one task -- component. procedure Process_Task_Objects (List : List_Id); -- Perform ABE checks and diagnostics for all task objects found in the -- list List. ------------------------- -- Process_Task_Object -- ------------------------- procedure Process_Task_Object (Obj_Id : Entity_Id; Typ : Entity_Id) is Base_Typ : constant Entity_Id := Base_Type (Typ); Comp_Id : Entity_Id; Task_Attrs : Task_Attributes; New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state begin if Is_Task_Type (Typ) then Extract_Task_Attributes (Typ => Base_Typ, Attrs => Task_Attrs); -- Warnings are suppressed when a prior scenario is already in -- that mode, or when the object, activation call, or task type -- have warnings suppressed. Update the state of the Processing -- phase to reflect this. New_State.Suppress_Warnings := New_State.Suppress_Warnings or else not Is_Elaboration_Warnings_OK_Id (Obj_Id) or else not Call_Attrs.Elab_Warnings_OK or else not Task_Attrs.Elab_Warnings_OK; -- Update the state of the Processing phase to indicate that any -- further traversal is now within a task body. New_State.Within_Task_Body := True; Process_Single_Activation (Call => Call, Call_Attrs => Call_Attrs, Obj_Id => Obj_Id, Task_Attrs => Task_Attrs, State => New_State); -- Examine the component type when the object is an array elsif Is_Array_Type (Typ) and then Has_Task (Base_Typ) then Process_Task_Object (Obj_Id => Obj_Id, Typ => Component_Type (Typ)); -- Examine individual component types when the object is a record elsif Is_Record_Type (Typ) and then Has_Task (Base_Typ) then Comp_Id := First_Component (Typ); while Present (Comp_Id) loop Process_Task_Object (Obj_Id => Obj_Id, Typ => Etype (Comp_Id)); Next_Component (Comp_Id); end loop; end if; end Process_Task_Object; -------------------------- -- Process_Task_Objects -- -------------------------- procedure Process_Task_Objects (List : List_Id) is Item : Node_Id; Item_Id : Entity_Id; Item_Typ : Entity_Id; begin -- Examine the contents of the list looking for an object declaration -- of a task type or one that contains a task within. Item := First (List); while Present (Item) loop if Nkind (Item) = N_Object_Declaration then Item_Id := Defining_Entity (Item); Item_Typ := Etype (Item_Id); if Has_Task (Item_Typ) then Process_Task_Object (Obj_Id => Item_Id, Typ => Item_Typ); end if; end if; Next (Item); end loop; end Process_Task_Objects; -- Local variables Context : Node_Id; Spec : Node_Id; -- Start of processing for Process_Activation_Generic begin -- Nothing to do when the activation is a guaranteed ABE if Is_Known_Guaranteed_ABE (Call) then return; end if; -- Find the proper context of the activation call where all task objects -- being activated are declared. This is usually the immediate parent of -- the call. Context := Parent (Call); -- In the case of package bodies, the activation call is in the handled -- sequence of statements, but the task objects are in the declaration -- list of the body. if Nkind (Context) = N_Handled_Sequence_Of_Statements and then Nkind (Parent (Context)) = N_Package_Body then Context := Parent (Context); end if; -- Process all task objects defined in both the spec and body when the -- activation call precedes the "begin" of a package body. if Nkind (Context) = N_Package_Body then Spec := Specification (Unit_Declaration_Node (Corresponding_Spec (Context))); Process_Task_Objects (Visible_Declarations (Spec)); Process_Task_Objects (Private_Declarations (Spec)); Process_Task_Objects (Declarations (Context)); -- Process all task objects defined in the spec when the activation call -- appears at the end of a package spec. elsif Nkind (Context) = N_Package_Specification then Process_Task_Objects (Visible_Declarations (Context)); Process_Task_Objects (Private_Declarations (Context)); -- Otherwise the context of the activation is some construct with a -- declarative part. Note that the corresponding record type of a task -- type is controlled. Because of this, the finalization machinery must -- relocate the task object to the handled statements of the construct -- to perform proper finalization in case of an exception. Examine the -- statements of the construct rather than the declarations. else pragma Assert (Nkind (Context) = N_Handled_Sequence_Of_Statements); Process_Task_Objects (Statements (Context)); end if; end Process_Activation_Generic; ------------------------------------ -- Process_Conditional_ABE_Access -- ------------------------------------ procedure Process_Conditional_ABE_Access (Attr : Node_Id; State : Processing_Attributes) is function Build_Access_Marker (Target_Id : Entity_Id) return Node_Id; pragma Inline (Build_Access_Marker); -- Create a suitable call marker which invokes target Target_Id ------------------------- -- Build_Access_Marker -- ------------------------- function Build_Access_Marker (Target_Id : Entity_Id) return Node_Id is Marker : Node_Id; begin Marker := Make_Call_Marker (Sloc (Attr)); -- Inherit relevant attributes from the attribute -- Performance note: parent traversal Set_Target (Marker, Target_Id); Set_Is_Declaration_Level_Node (Marker, Find_Enclosing_Level (Attr) = Declaration_Level); Set_Is_Dispatching_Call (Marker, False); Set_Is_Elaboration_Checks_OK_Node (Marker, Is_Elaboration_Checks_OK_Node (Attr)); Set_Is_Elaboration_Warnings_OK_Node (Marker, Is_Elaboration_Warnings_OK_Node (Attr)); Set_Is_Source_Call (Marker, Comes_From_Source (Attr)); Set_Is_SPARK_Mode_On_Node (Marker, Is_SPARK_Mode_On_Node (Attr)); -- Partially insert the call marker into the tree by setting its -- parent pointer. Set_Parent (Marker, Attr); return Marker; end Build_Access_Marker; -- Local variables Root : constant Node_Id := Root_Scenario; Target_Id : constant Entity_Id := Entity (Prefix (Attr)); Target_Attrs : Target_Attributes; New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state -- Start of processing for Process_Conditional_ABE_Access begin -- Output relevant information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas) is in effect. if Elab_Info_Messages then Error_Msg_NE ("info: access to & during elaboration", Attr, Target_Id); end if; Extract_Target_Attributes (Target_Id => Target_Id, Attrs => Target_Attrs); -- Warnings are suppressed when a prior scenario is already in that -- mode, or when the attribute or the target have warnings suppressed. -- Update the state of the Processing phase to reflect this. New_State.Suppress_Warnings := New_State.Suppress_Warnings or else not Is_Elaboration_Warnings_OK_Node (Attr) or else not Target_Attrs.Elab_Warnings_OK; -- Do not emit any ABE diagnostics when the current or previous scenario -- in this traversal has suppressed elaboration warnings. if New_State.Suppress_Warnings then null; -- Both the attribute and the corresponding body are in the same unit. -- The corresponding body must appear prior to the root scenario which -- started the recursive search. If this is not the case, then there is -- a potential ABE if the access value is used to call the subprogram. -- Emit a warning only when switch -gnatw.f (warnings on suspucious -- 'Access) is in effect. elsif Warn_On_Elab_Access and then Present (Target_Attrs.Body_Decl) and then In_Extended_Main_Code_Unit (Target_Attrs.Body_Decl) and then Earlier_In_Extended_Unit (Root, Target_Attrs.Body_Decl) then Error_Msg_Name_1 := Attribute_Name (Attr); Error_Msg_NE ("??% attribute of & before body seen", Attr, Target_Id); Error_Msg_N ("\possible Program_Error on later references", Attr); Output_Active_Scenarios (Attr); end if; -- Treat the attribute as an immediate invocation of the target when -- switch -gnatd.o (conservative elaboration order for indirect calls) -- is in effect. Note that the prior elaboration of the unit containing -- the target is ensured processing the corresponding call marker. if Debug_Flag_Dot_O then Process_Conditional_ABE (N => Build_Access_Marker (Target_Id), State => New_State); -- Otherwise ensure that the unit with the corresponding body is -- elaborated prior to the main unit. else Ensure_Prior_Elaboration (N => Attr, Unit_Id => Target_Attrs.Unit_Id, Prag_Nam => Name_Elaborate_All, State => New_State); end if; end Process_Conditional_ABE_Access; --------------------------------------------- -- Process_Conditional_ABE_Activation_Impl -- --------------------------------------------- procedure Process_Conditional_ABE_Activation_Impl (Call : Node_Id; Call_Attrs : Call_Attributes; Obj_Id : Entity_Id; Task_Attrs : Task_Attributes; State : Processing_Attributes) is Check_OK : constant Boolean := not Is_Ignored_Ghost_Entity (Obj_Id) and then not Task_Attrs.Ghost_Mode_Ignore and then Is_Elaboration_Checks_OK_Id (Obj_Id) and then Task_Attrs.Elab_Checks_OK; -- A run-time ABE check may be installed only when the object and the -- task type have active elaboration checks, and both are not ignored -- Ghost constructs. Root : constant Node_Id := Root_Scenario; New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state begin -- Output relevant information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas) is in effect. if Elab_Info_Messages then Error_Msg_NE ("info: activation of & during elaboration", Call, Obj_Id); end if; -- Nothing to do when the call activates a task whose type is defined -- within an instance and switch -gnatd_i (ignore activations and calls -- to instances for elaboration) is in effect. if Debug_Flag_Underscore_I and then In_External_Instance (N => Call, Target_Decl => Task_Attrs.Task_Decl) then return; -- Nothing to do when the activation is a guaranteed ABE elsif Is_Known_Guaranteed_ABE (Call) then return; -- Nothing to do when the root scenario appears at the declaration -- level and the task is in the same unit, but outside this context. -- -- task type Task_Typ; -- task declaration -- -- procedure Proc is -- function A ... is -- begin -- if Some_Condition then -- declare -- T : Task_Typ; -- begin -- -- activation site -- end; -- ... -- end A; -- -- X : ... := A; -- root scenario -- ... -- -- task body Task_Typ is -- ... -- end Task_Typ; -- -- In the example above, the context of X is the declarative list of -- Proc. The "elaboration" of X may reach the activation of T whose body -- is defined outside of X's context. The task body is relevant only -- when Proc is invoked, but this happens only in "normal" elaboration, -- therefore the task body must not be considered if this is not the -- case. -- Performance note: parent traversal elsif Is_Up_Level_Target (Task_Attrs.Task_Decl) then return; -- Nothing to do when the activation is ABE-safe -- -- generic -- package Gen is -- task type Task_Typ; -- end Gen; -- -- package body Gen is -- task body Task_Typ is -- begin -- ... -- end Task_Typ; -- end Gen; -- -- with Gen; -- procedure Main is -- package Nested is -- package Inst is new Gen; -- T : Inst.Task_Typ; -- -- safe activation -- end Nested; -- ... elsif Is_Safe_Activation (Call, Task_Attrs.Task_Decl) then -- Note that the task body must still be examined for any nested -- scenarios. null; -- The activation call and the task body are both in the main unit elsif Present (Task_Attrs.Body_Decl) and then In_Extended_Main_Code_Unit (Task_Attrs.Body_Decl) then -- If the root scenario appears prior to the task body, then this is -- a possible ABE with respect to the root scenario. -- -- task type Task_Typ; -- -- function A ... is -- begin -- if Some_Condition then -- declare -- package Pack is -- T : Task_Typ; -- end Pack; -- activation of T -- ... -- end A; -- -- X : ... := A; -- root scenario -- -- task body Task_Typ is -- task body -- ... -- end Task_Typ; -- -- Y : ... := A; -- root scenario -- -- IMPORTANT: The activation of T is a possible ABE for X, but -- not for Y. Intalling an unconditional ABE raise prior to the -- activation call would be wrong as it will fail for Y as well -- but in Y's case the activation of T is never an ABE. if Earlier_In_Extended_Unit (Root, Task_Attrs.Body_Decl) then -- Do not emit any ABE diagnostics when a previous scenario in -- this traversal has suppressed elaboration warnings. if State.Suppress_Warnings then null; -- Do not emit any ABE diagnostics when the activation occurs in -- a partial finalization context because this leads to confusing -- noise. elsif State.Within_Partial_Finalization then null; -- ABE diagnostics are emitted only in the static model because -- there is a well-defined order to visiting scenarios. Without -- this order diagnostics appear jumbled and result in unwanted -- noise. elsif Static_Elaboration_Checks then Error_Msg_Sloc := Sloc (Call); Error_Msg_N ("??task & will be activated # before elaboration of its " & "body", Obj_Id); Error_Msg_N ("\Program_Error may be raised at run time", Obj_Id); Output_Active_Scenarios (Obj_Id); end if; -- Install a conditional run-time ABE check to verify that the -- task body has been elaborated prior to the activation call. if Check_OK then Install_ABE_Check (N => Call, Ins_Nod => Call, Target_Id => Task_Attrs.Spec_Id, Target_Decl => Task_Attrs.Task_Decl, Target_Body => Task_Attrs.Body_Decl); -- Update the state of the Processing phase to indicate that -- no implicit Elaborate[_All] pragmas must be generated from -- this point on. -- -- task type Task_Typ; -- -- function A ... is -- begin -- if Some_Condition then -- declare -- package Pack is -- -- T : Task_Typ; -- end Pack; -- activation of T -- ... -- end A; -- -- X : ... := A; -- -- task body Task_Typ is -- begin -- External.Subp; -- imparts Elaborate_All -- end Task_Typ; -- -- If Some_Condition is True, then the ABE check will fail at -- runtime and the call to External.Subp will never take place, -- rendering the implicit Elaborate_All useless. -- -- If Some_Condition is False, then the call to External.Subp -- will never take place, rendering the implicit Elaborate_All -- useless. New_State.Suppress_Implicit_Pragmas := True; end if; end if; -- Otherwise the task body is not available in this compilation or it -- resides in an external unit. Install a run-time ABE check to verify -- that the task body has been elaborated prior to the activation call -- when the dynamic model is in effect. elsif Dynamic_Elaboration_Checks and then Check_OK then Install_ABE_Check (N => Call, Ins_Nod => Call, Id => Task_Attrs.Unit_Id); end if; -- Both the activation call and task type are subject to SPARK_Mode -- On, this triggers the SPARK rules for task activation. Compared to -- calls and instantiations, task activation in SPARK does not require -- the presence of Elaborate[_All] pragmas in case the task type is -- defined outside the main unit. This is because SPARK utilizes a -- special policy which activates all tasks after the main unit has -- finished its elaboration. if Call_Attrs.SPARK_Mode_On and Task_Attrs.SPARK_Mode_On then null; -- Otherwise the Ada rules are in effect. Ensure that the unit with the -- task body is elaborated prior to the main unit. else Ensure_Prior_Elaboration (N => Call, Unit_Id => Task_Attrs.Unit_Id, Prag_Nam => Name_Elaborate_All, State => New_State); end if; Traverse_Body (N => Task_Attrs.Body_Decl, State => New_State); end Process_Conditional_ABE_Activation_Impl; procedure Process_Conditional_ABE_Activation is new Process_Activation_Generic (Process_Conditional_ABE_Activation_Impl); ---------------------------------- -- Process_Conditional_ABE_Call -- ---------------------------------- procedure Process_Conditional_ABE_Call (Call : Node_Id; Call_Attrs : Call_Attributes; Target_Id : Entity_Id; State : Processing_Attributes) is function In_Initialization_Context (N : Node_Id) return Boolean; -- Determine whether arbitrary node N appears within a type init proc, -- primitive [Deep_]Initialize, or a block created for initialization -- purposes. function Is_Partial_Finalization_Proc return Boolean; pragma Inline (Is_Partial_Finalization_Proc); -- Determine whether call Call with target Target_Id invokes a partial -- finalization procedure. ------------------------------- -- In_Initialization_Context -- ------------------------------- function In_Initialization_Context (N : Node_Id) return Boolean is Par : Node_Id; Spec_Id : Entity_Id; begin -- Climb the parent chain looking for initialization actions Par := Parent (N); while Present (Par) loop -- A block may be part of the initialization actions of a default -- initialized object. if Nkind (Par) = N_Block_Statement and then Is_Initialization_Block (Par) then return True; -- A subprogram body may denote an initialization routine elsif Nkind (Par) = N_Subprogram_Body then Spec_Id := Unique_Defining_Entity (Par); -- The current subprogram body denotes a type init proc or -- primitive [Deep_]Initialize. if Is_Init_Proc (Spec_Id) or else Is_Controlled_Proc (Spec_Id, Name_Initialize) or else Is_TSS (Spec_Id, TSS_Deep_Initialize) then return True; end if; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); end loop; return False; end In_Initialization_Context; ---------------------------------- -- Is_Partial_Finalization_Proc -- ---------------------------------- function Is_Partial_Finalization_Proc return Boolean is begin -- To qualify, the target must denote primitive [Deep_]Finalize or a -- finalizer procedure, and the call must appear in an initialization -- context. return (Is_Controlled_Proc (Target_Id, Name_Finalize) or else Is_Finalizer_Proc (Target_Id) or else Is_TSS (Target_Id, TSS_Deep_Finalize)) and then In_Initialization_Context (Call); end Is_Partial_Finalization_Proc; -- Local variables SPARK_Rules_On : Boolean; Target_Attrs : Target_Attributes; New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state -- Start of processing for Process_Conditional_ABE_Call begin Extract_Target_Attributes (Target_Id => Target_Id, Attrs => Target_Attrs); -- The SPARK rules are in effect when both the call and target are -- subject to SPARK_Mode On. SPARK_Rules_On := Call_Attrs.SPARK_Mode_On and Target_Attrs.SPARK_Mode_On; -- Output relevant information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas) is in effect. if Elab_Info_Messages then Info_Call (Call => Call, Target_Id => Target_Id, Info_Msg => True, In_SPARK => SPARK_Rules_On); end if; -- Check whether the invocation of an entry clashes with an existing -- restriction. if Is_Protected_Entry (Target_Id) then Check_Restriction (No_Entry_Calls_In_Elaboration_Code, Call); elsif Is_Task_Entry (Target_Id) then Check_Restriction (No_Entry_Calls_In_Elaboration_Code, Call); -- Task entry calls are never processed because the entry being -- invoked does not have a corresponding "body", it has a select. return; end if; -- Nothing to do when the call invokes a target defined within an -- instance and switch -gnatd_i (ignore activations and calls to -- instances for elaboration) is in effect. if Debug_Flag_Underscore_I and then In_External_Instance (N => Call, Target_Decl => Target_Attrs.Spec_Decl) then return; -- Nothing to do when the call is a guaranteed ABE elsif Is_Known_Guaranteed_ABE (Call) then return; -- Nothing to do when the root scenario appears at the declaration level -- and the target is in the same unit, but outside this context. -- -- function B ...; -- target declaration -- -- procedure Proc is -- function A ... is -- begin -- if Some_Condition then -- return B; -- call site -- ... -- end A; -- -- X : ... := A; -- root scenario -- ... -- -- function B ... is -- ... -- end B; -- -- In the example above, the context of X is the declarative region of -- Proc. The "elaboration" of X may eventually reach B which is defined -- outside of X's context. B is relevant only when Proc is invoked, but -- this happens only by means of "normal" elaboration, therefore B must -- not be considered if this is not the case. -- Performance note: parent traversal elsif Is_Up_Level_Target (Target_Attrs.Spec_Decl) then return; end if; -- Warnings are suppressed when a prior scenario is already in that -- mode, or the call or target have warnings suppressed. Update the -- state of the Processing phase to reflect this. New_State.Suppress_Warnings := New_State.Suppress_Warnings or else not Call_Attrs.Elab_Warnings_OK or else not Target_Attrs.Elab_Warnings_OK; -- The call occurs in an initial condition context when a prior scenario -- is already in that mode, or when the target is an Initial_Condition -- procedure. Update the state of the Processing phase to reflect this. New_State.Within_Initial_Condition := New_State.Within_Initial_Condition or else Is_Initial_Condition_Proc (Target_Id); -- The call occurs in a partial finalization context when a prior -- scenario is already in that mode, or when the target denotes a -- [Deep_]Finalize primitive or a finalizer within an initialization -- context. Update the state of the Processing phase to reflect this. New_State.Within_Partial_Finalization := New_State.Within_Partial_Finalization or else Is_Partial_Finalization_Proc; -- The SPARK rules are in effect. Note that -gnatd.v (enforce SPARK -- elaboration rules in SPARK code) is intentionally not taken into -- account here because Process_Conditional_ABE_Call_SPARK has two -- separate modes of operation. if SPARK_Rules_On then Process_Conditional_ABE_Call_SPARK (Call => Call, Target_Id => Target_Id, Target_Attrs => Target_Attrs, State => New_State); -- Otherwise the Ada rules are in effect else Process_Conditional_ABE_Call_Ada (Call => Call, Call_Attrs => Call_Attrs, Target_Id => Target_Id, Target_Attrs => Target_Attrs, State => New_State); end if; -- Inspect the target body (and barried function) for other suitable -- elaboration scenarios. Traverse_Body (N => Target_Attrs.Body_Barf, State => New_State); Traverse_Body (N => Target_Attrs.Body_Decl, State => New_State); end Process_Conditional_ABE_Call; -------------------------------------- -- Process_Conditional_ABE_Call_Ada -- -------------------------------------- procedure Process_Conditional_ABE_Call_Ada (Call : Node_Id; Call_Attrs : Call_Attributes; Target_Id : Entity_Id; Target_Attrs : Target_Attributes; State : Processing_Attributes) is Check_OK : constant Boolean := not Call_Attrs.Ghost_Mode_Ignore and then not Target_Attrs.Ghost_Mode_Ignore and then Call_Attrs.Elab_Checks_OK and then Target_Attrs.Elab_Checks_OK; -- A run-time ABE check may be installed only when both the call and the -- target have active elaboration checks, and both are not ignored Ghost -- constructs. Root : constant Node_Id := Root_Scenario; New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state begin -- Nothing to do for an Ada dispatching call because there are no ABE -- diagnostics for either models. ABE checks for the dynamic model are -- handled by Install_Primitive_Elaboration_Check. if Call_Attrs.Is_Dispatching then return; -- Nothing to do when the call is ABE-safe -- -- generic -- function Gen ...; -- -- function Gen ... is -- begin -- ... -- end Gen; -- -- with Gen; -- procedure Main is -- function Inst is new Gen; -- X : ... := Inst; -- safe call -- ... elsif Is_Safe_Call (Call, Target_Attrs) then return; -- The call and the target body are both in the main unit elsif Present (Target_Attrs.Body_Decl) and then In_Extended_Main_Code_Unit (Target_Attrs.Body_Decl) then -- If the root scenario appears prior to the target body, then this -- is a possible ABE with respect to the root scenario. -- -- function B ...; -- -- function A ... is -- begin -- if Some_Condition then -- return B; -- call site -- ... -- end A; -- -- X : ... := A; -- root scenario -- -- function B ... is -- target body -- ... -- end B; -- -- Y : ... := A; -- root scenario -- -- IMPORTANT: The call to B from A is a possible ABE for X, but not -- for Y. Installing an unconditional ABE raise prior to the call to -- B would be wrong as it will fail for Y as well, but in Y's case -- the call to B is never an ABE. if Earlier_In_Extended_Unit (Root, Target_Attrs.Body_Decl) then -- Do not emit any ABE diagnostics when a previous scenario in -- this traversal has suppressed elaboration warnings. if State.Suppress_Warnings then null; -- Do not emit any ABE diagnostics when the call occurs in a -- partial finalization context because this leads to confusing -- noise. elsif State.Within_Partial_Finalization then null; -- ABE diagnostics are emitted only in the static model because -- there is a well-defined order to visiting scenarios. Without -- this order diagnostics appear jumbled and result in unwanted -- noise. elsif Static_Elaboration_Checks then Error_Msg_NE ("??cannot call & before body seen", Call, Target_Id); Error_Msg_N ("\Program_Error may be raised at run time", Call); Output_Active_Scenarios (Call); end if; -- Install a conditional run-time ABE check to verify that the -- target body has been elaborated prior to the call. if Check_OK then Install_ABE_Check (N => Call, Ins_Nod => Call, Target_Id => Target_Attrs.Spec_Id, Target_Decl => Target_Attrs.Spec_Decl, Target_Body => Target_Attrs.Body_Decl); -- Update the state of the Processing phase to indicate that -- no implicit Elaborate[_All] pragmas must be generated from -- this point on. -- -- function B ...; -- -- function A ... is -- begin -- if Some_Condition then -- -- return B; -- ... -- end A; -- -- X : ... := A; -- -- function B ... is -- External.Subp; -- imparts Elaborate_All -- end B; -- -- If Some_Condition is True, then the ABE check will fail at -- runtime and the call to External.Subp will never take place, -- rendering the implicit Elaborate_All useless. -- -- If Some_Condition is False, then the call to External.Subp -- will never take place, rendering the implicit Elaborate_All -- useless. New_State.Suppress_Implicit_Pragmas := True; end if; end if; -- Otherwise the target body is not available in this compilation or it -- resides in an external unit. Install a run-time ABE check to verify -- that the target body has been elaborated prior to the call site when -- the dynamic model is in effect. elsif Dynamic_Elaboration_Checks and then Check_OK then Install_ABE_Check (N => Call, Ins_Nod => Call, Id => Target_Attrs.Unit_Id); end if; -- Ensure that the unit with the target body is elaborated prior to the -- main unit. The implicit Elaborate[_All] is generated only when the -- call has elaboration checks enabled. This behaviour parallels that of -- the old ABE mechanism. if Call_Attrs.Elab_Checks_OK then Ensure_Prior_Elaboration (N => Call, Unit_Id => Target_Attrs.Unit_Id, Prag_Nam => Name_Elaborate_All, State => New_State); end if; end Process_Conditional_ABE_Call_Ada; ---------------------------------------- -- Process_Conditional_ABE_Call_SPARK -- ---------------------------------------- procedure Process_Conditional_ABE_Call_SPARK (Call : Node_Id; Target_Id : Entity_Id; Target_Attrs : Target_Attributes; State : Processing_Attributes) is Region : Node_Id; begin -- Ensure that a suitable elaboration model is in effect for SPARK rule -- verification. Check_SPARK_Model_In_Effect (Call); -- The call and the target body are both in the main unit if Present (Target_Attrs.Body_Decl) and then In_Extended_Main_Code_Unit (Target_Attrs.Body_Decl) then -- If the call appears prior to the target body, then the call must -- appear within the early call region of the target body. -- -- function B ...; -- -- X : ... := B; -- call site -- -- --+ -- ... | early call region -- --+ -- -- function B ... is -- target body -- ... -- end B; -- -- When the call to B is not nested within some other scenario, the -- call is automatically illegal because it can never appear in the -- early call region of B's body. This is equivalent to a guaranteed -- ABE. -- -- --+ -- | -- function B ...; | -- | -- function A ... is | -- begin | early call region -- if Some_Condition then -- return B; -- call site -- ... -- end A; | -- | -- --+ -- -- function B ... is -- target body -- ... -- end B; -- -- When the call to B is nested within some other scenario, the call -- is always ABE-safe. It is not immediately obvious why this is the -- case. The elaboration safety follows from the early call region -- rule being applied to ALL calls preceding their associated bodies. -- -- In the example above, the call to B is safe as long as the call to -- A is safe. There are several cases to consider: -- -- -- function B ...; -- -- -- function A ... is -- begin -- if Some_Condition then -- return B; -- ... -- end A; -- -- -- function B ... is -- ... -- end B; -- -- * Call 1 - This call is either nested within some scenario or not, -- which falls under the two general cases outlined above. -- -- * Call 2 - This is the same case as Call 1. -- -- * Call 3 - The placement of this call limits the range of B's -- early call region unto call 3, therefore the call to B is no -- longer within the early call region of B's body, making it ABE- -- unsafe and therefore illegal. if Earlier_In_Extended_Unit (Call, Target_Attrs.Body_Decl) then -- Do not emit any ABE diagnostics when a previous scenario in -- this traversal has suppressed elaboration warnings. if State.Suppress_Warnings then null; -- Do not emit any ABE diagnostics when the call occurs in an -- initial condition context because this leads to incorrect -- diagnostics. elsif State.Within_Initial_Condition then null; -- Do not emit any ABE diagnostics when the call occurs in a -- partial finalization context because this leads to confusing -- noise. elsif State.Within_Partial_Finalization then null; -- ABE diagnostics are emitted only in the static model because -- there is a well-defined order to visiting scenarios. Without -- this order diagnostics appear jumbled and result in unwanted -- noise. elsif Static_Elaboration_Checks then -- Ensure that a call which textually precedes the subprogram -- body it invokes appears within the early call region of the -- subprogram body. -- IMPORTANT: This check must always be performed even when -- -gnatd.v (enforce SPARK elaboration rules in SPARK code) is -- not specified because the static model cannot guarantee the -- absence of elaboration issues in the presence of dispatching -- calls. Region := Find_Early_Call_Region (Target_Attrs.Body_Decl); if Earlier_In_Extended_Unit (Call, Region) then Error_Msg_NE ("call must appear within early call region of subprogram " & "body & (SPARK RM 7.7(3))", Call, Target_Id); Error_Msg_Sloc := Sloc (Region); Error_Msg_N ("\region starts #", Call); Error_Msg_Sloc := Sloc (Target_Attrs.Body_Decl); Error_Msg_N ("\region ends #", Call); Output_Active_Scenarios (Call); end if; end if; -- Otherwise the call appears after the target body. The call is -- ABE-safe as a consequence of applying the early call region rule -- to ALL calls preceding their associated bodies. else null; end if; end if; -- A call to a source target or to a target which emulates Ada or SPARK -- semantics imposes an Elaborate_All requirement on the context of the -- main unit. Determine whether the context has a pragma strong enough -- to meet the requirement. -- IMPORTANT: This check must be performed only when -gnatd.v (enforce -- SPARK elaboration rules in SPARK code) is active because the static -- model can ensure the prior elaboration of the unit which contains a -- body by installing an implicit Elaborate[_All] pragma. if Debug_Flag_Dot_V then if Target_Attrs.From_Source or else Is_Ada_Semantic_Target (Target_Id) or else Is_SPARK_Semantic_Target (Target_Id) then Meet_Elaboration_Requirement (N => Call, Target_Id => Target_Id, Req_Nam => Name_Elaborate_All); end if; -- Otherwise ensure that the unit with the target body is elaborated -- prior to the main unit. else Ensure_Prior_Elaboration (N => Call, Unit_Id => Target_Attrs.Unit_Id, Prag_Nam => Name_Elaborate_All, State => State); end if; end Process_Conditional_ABE_Call_SPARK; ------------------------------------------- -- Process_Conditional_ABE_Instantiation -- ------------------------------------------- procedure Process_Conditional_ABE_Instantiation (Exp_Inst : Node_Id; State : Processing_Attributes) is Gen_Attrs : Target_Attributes; Gen_Id : Entity_Id; Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Inst_Id : Entity_Id; SPARK_Rules_On : Boolean; -- This flag is set when the SPARK rules are in effect New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state begin Extract_Instantiation_Attributes (Exp_Inst => Exp_Inst, Inst => Inst, Inst_Id => Inst_Id, Gen_Id => Gen_Id, Attrs => Inst_Attrs); Extract_Target_Attributes (Gen_Id, Gen_Attrs); -- The SPARK rules are in effect when both the instantiation and generic -- are subject to SPARK_Mode On. SPARK_Rules_On := Inst_Attrs.SPARK_Mode_On and Gen_Attrs.SPARK_Mode_On; -- Output relevant information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas) is in effect. if Elab_Info_Messages then Info_Instantiation (Inst => Inst, Gen_Id => Gen_Id, Info_Msg => True, In_SPARK => SPARK_Rules_On); end if; -- Nothing to do when the instantiation is a guaranteed ABE if Is_Known_Guaranteed_ABE (Inst) then return; -- Nothing to do when the root scenario appears at the declaration level -- and the generic is in the same unit, but outside this context. -- -- generic -- procedure Gen is ...; -- generic declaration -- -- procedure Proc is -- function A ... is -- begin -- if Some_Condition then -- declare -- procedure I is new Gen; -- instantiation site -- ... -- ... -- end A; -- -- X : ... := A; -- root scenario -- ... -- -- procedure Gen is -- ... -- end Gen; -- -- In the example above, the context of X is the declarative region of -- Proc. The "elaboration" of X may eventually reach Gen which appears -- outside of X's context. Gen is relevant only when Proc is invoked, -- but this happens only by means of "normal" elaboration, therefore -- Gen must not be considered if this is not the case. -- Performance note: parent traversal elsif Is_Up_Level_Target (Gen_Attrs.Spec_Decl) then return; end if; -- Warnings are suppressed when a prior scenario is already in that -- mode, or when the instantiation has warnings suppressed. Update -- the state of the processing phase to reflect this. New_State.Suppress_Warnings := New_State.Suppress_Warnings or else not Inst_Attrs.Elab_Warnings_OK; -- The SPARK rules are in effect if SPARK_Rules_On then Process_Conditional_ABE_Instantiation_SPARK (Inst => Inst, Gen_Id => Gen_Id, Gen_Attrs => Gen_Attrs, State => New_State); -- Otherwise the Ada rules are in effect, or SPARK code is allowed to -- violate the SPARK rules. else Process_Conditional_ABE_Instantiation_Ada (Exp_Inst => Exp_Inst, Inst => Inst, Inst_Attrs => Inst_Attrs, Gen_Id => Gen_Id, Gen_Attrs => Gen_Attrs, State => New_State); end if; end Process_Conditional_ABE_Instantiation; ----------------------------------------------- -- Process_Conditional_ABE_Instantiation_Ada -- ----------------------------------------------- procedure Process_Conditional_ABE_Instantiation_Ada (Exp_Inst : Node_Id; Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Gen_Id : Entity_Id; Gen_Attrs : Target_Attributes; State : Processing_Attributes) is Check_OK : constant Boolean := not Inst_Attrs.Ghost_Mode_Ignore and then not Gen_Attrs.Ghost_Mode_Ignore and then Inst_Attrs.Elab_Checks_OK and then Gen_Attrs.Elab_Checks_OK; -- A run-time ABE check may be installed only when both the instance and -- the generic have active elaboration checks and both are not ignored -- Ghost constructs. Root : constant Node_Id := Root_Scenario; New_State : Processing_Attributes := State; -- Each step of the Processing phase constitutes a new state begin -- Nothing to do when the instantiation is ABE-safe -- -- generic -- package Gen is -- ... -- end Gen; -- -- package body Gen is -- ... -- end Gen; -- -- with Gen; -- procedure Main is -- package Inst is new Gen (ABE); -- safe instantiation -- ... if Is_Safe_Instantiation (Inst, Gen_Attrs) then return; -- The instantiation and the generic body are both in the main unit elsif Present (Gen_Attrs.Body_Decl) and then In_Extended_Main_Code_Unit (Gen_Attrs.Body_Decl) then -- If the root scenario appears prior to the generic body, then this -- is a possible ABE with respect to the root scenario. -- -- generic -- package Gen is -- ... -- end Gen; -- -- function A ... is -- begin -- if Some_Condition then -- declare -- package Inst is new Gen; -- instantiation site -- ... -- end A; -- -- X : ... := A; -- root scenario -- -- package body Gen is -- generic body -- ... -- end Gen; -- -- Y : ... := A; -- root scenario -- -- IMPORTANT: The instantiation of Gen is a possible ABE for X, but -- not for Y. Installing an unconditional ABE raise prior to the -- instance site would be wrong as it will fail for Y as well, but in -- Y's case the instantiation of Gen is never an ABE. if Earlier_In_Extended_Unit (Root, Gen_Attrs.Body_Decl) then -- Do not emit any ABE diagnostics when a previous scenario in -- this traversal has suppressed elaboration warnings. if State.Suppress_Warnings then null; -- Do not emit any ABE diagnostics when the instantiation occurs -- in partial finalization context because this leads to unwanted -- noise. elsif State.Within_Partial_Finalization then null; -- ABE diagnostics are emitted only in the static model because -- there is a well-defined order to visiting scenarios. Without -- this order diagnostics appear jumbled and result in unwanted -- noise. elsif Static_Elaboration_Checks then Error_Msg_NE ("??cannot instantiate & before body seen", Inst, Gen_Id); Error_Msg_N ("\Program_Error may be raised at run time", Inst); Output_Active_Scenarios (Inst); end if; -- Install a conditional run-time ABE check to verify that the -- generic body has been elaborated prior to the instantiation. if Check_OK then Install_ABE_Check (N => Inst, Ins_Nod => Exp_Inst, Target_Id => Gen_Attrs.Spec_Id, Target_Decl => Gen_Attrs.Spec_Decl, Target_Body => Gen_Attrs.Body_Decl); -- Update the state of the Processing phase to indicate that -- no implicit Elaborate[_All] pragmas must be generated from -- this point on. -- -- generic -- package Gen is -- ... -- end Gen; -- -- function A ... is -- begin -- if Some_Condition then -- -- declare Inst is new Gen; -- ... -- end A; -- -- X : ... := A; -- -- package body Gen is -- begin -- External.Subp; -- imparts Elaborate_All -- end Gen; -- -- If Some_Condition is True, then the ABE check will fail at -- runtime and the call to External.Subp will never take place, -- rendering the implicit Elaborate_All useless. -- -- If Some_Condition is False, then the call to External.Subp -- will never take place, rendering the implicit Elaborate_All -- useless. New_State.Suppress_Implicit_Pragmas := True; end if; end if; -- Otherwise the generic body is not available in this compilation or it -- resides in an external unit. Install a run-time ABE check to verify -- that the generic body has been elaborated prior to the instantiation -- when the dynamic model is in effect. elsif Dynamic_Elaboration_Checks and then Check_OK then Install_ABE_Check (N => Inst, Ins_Nod => Exp_Inst, Id => Gen_Attrs.Unit_Id); end if; -- Ensure that the unit with the generic body is elaborated prior to -- the main unit. No implicit pragma is generated if the instantiation -- has elaboration checks suppressed. This behaviour parallels that of -- the old ABE mechanism. if Inst_Attrs.Elab_Checks_OK then Ensure_Prior_Elaboration (N => Inst, Unit_Id => Gen_Attrs.Unit_Id, Prag_Nam => Name_Elaborate, State => New_State); end if; end Process_Conditional_ABE_Instantiation_Ada; ------------------------------------------------- -- Process_Conditional_ABE_Instantiation_SPARK -- ------------------------------------------------- procedure Process_Conditional_ABE_Instantiation_SPARK (Inst : Node_Id; Gen_Id : Entity_Id; Gen_Attrs : Target_Attributes; State : Processing_Attributes) is Req_Nam : Name_Id; begin -- Ensure that a suitable elaboration model is in effect for SPARK rule -- verification. Check_SPARK_Model_In_Effect (Inst); -- A source instantiation imposes an Elaborate[_All] requirement on the -- context of the main unit. Determine whether the context has a pragma -- strong enough to meet the requirement. The check is orthogonal to the -- ABE ramifications of the instantiation. -- IMPORTANT: This check must be performed only when -gnatd.v (enforce -- SPARK elaboration rules in SPARK code) is active because the static -- model can ensure the prior elaboration of the unit which contains a -- body by installing an implicit Elaborate[_All] pragma. if Debug_Flag_Dot_V then if Nkind (Inst) = N_Package_Instantiation then Req_Nam := Name_Elaborate_All; else Req_Nam := Name_Elaborate; end if; Meet_Elaboration_Requirement (N => Inst, Target_Id => Gen_Id, Req_Nam => Req_Nam); -- Otherwise ensure that the unit with the target body is elaborated -- prior to the main unit. else Ensure_Prior_Elaboration (N => Inst, Unit_Id => Gen_Attrs.Unit_Id, Prag_Nam => Name_Elaborate, State => State); end if; end Process_Conditional_ABE_Instantiation_SPARK; ------------------------------------------------- -- Process_Conditional_ABE_Variable_Assignment -- ------------------------------------------------- procedure Process_Conditional_ABE_Variable_Assignment (Asmt : Node_Id) is Var_Id : constant Entity_Id := Entity (Extract_Assignment_Name (Asmt)); Prag : constant Node_Id := SPARK_Pragma (Var_Id); SPARK_Rules_On : Boolean; -- This flag is set when the SPARK rules are in effect begin -- The SPARK rules are in effect when both the assignment and the -- variable are subject to SPARK_Mode On. SPARK_Rules_On := Present (Prag) and then Get_SPARK_Mode_From_Annotation (Prag) = On and then Is_SPARK_Mode_On_Node (Asmt); -- Output relevant information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas) is in effect. if Elab_Info_Messages then Elab_Msg_NE (Msg => "assignment to & during elaboration", N => Asmt, Id => Var_Id, Info_Msg => True, In_SPARK => SPARK_Rules_On); end if; -- The SPARK rules are in effect. These rules are applied regardless of -- whether -gnatd.v (enforce SPARK elaboration rules in SPARK code) is -- in effect because the static model cannot ensure safe assignment of -- variables. if SPARK_Rules_On then Process_Conditional_ABE_Variable_Assignment_SPARK (Asmt => Asmt, Var_Id => Var_Id); -- Otherwise the Ada rules are in effect else Process_Conditional_ABE_Variable_Assignment_Ada (Asmt => Asmt, Var_Id => Var_Id); end if; end Process_Conditional_ABE_Variable_Assignment; ----------------------------------------------------- -- Process_Conditional_ABE_Variable_Assignment_Ada -- ----------------------------------------------------- procedure Process_Conditional_ABE_Variable_Assignment_Ada (Asmt : Node_Id; Var_Id : Entity_Id) is Var_Decl : constant Node_Id := Declaration_Node (Var_Id); Spec_Id : constant Entity_Id := Find_Top_Unit (Var_Decl); begin -- Emit a warning when an uninitialized variable declared in a package -- spec without a pragma Elaborate_Body is initialized by elaboration -- code within the corresponding body. if Is_Elaboration_Warnings_OK_Id (Var_Id) and then not Is_Initialized (Var_Decl) and then not Has_Pragma_Elaborate_Body (Spec_Id) then Error_Msg_NE ("??variable & can be accessed by clients before this " & "initialization", Asmt, Var_Id); Error_Msg_NE ("\add pragma ""Elaborate_Body"" to spec & to ensure proper " & "initialization", Asmt, Spec_Id); Output_Active_Scenarios (Asmt); -- Generate an implicit Elaborate_Body in the spec Set_Elaborate_Body_Desirable (Spec_Id); end if; end Process_Conditional_ABE_Variable_Assignment_Ada; ------------------------------------------------------- -- Process_Conditional_ABE_Variable_Assignment_SPARK -- ------------------------------------------------------- procedure Process_Conditional_ABE_Variable_Assignment_SPARK (Asmt : Node_Id; Var_Id : Entity_Id) is Var_Decl : constant Node_Id := Declaration_Node (Var_Id); Spec_Id : constant Entity_Id := Find_Top_Unit (Var_Decl); begin -- Ensure that a suitable elaboration model is in effect for SPARK rule -- verification. Check_SPARK_Model_In_Effect (Asmt); -- Emit an error when an initialized variable declared in a package spec -- without pragma Elaborate_Body is further modified by elaboration code -- within the corresponding body. if Is_Elaboration_Warnings_OK_Id (Var_Id) and then Is_Initialized (Var_Decl) and then not Has_Pragma_Elaborate_Body (Spec_Id) then Error_Msg_NE ("variable & modified by elaboration code in package body", Asmt, Var_Id); Error_Msg_NE ("\add pragma ""Elaborate_Body"" to spec & to ensure full " & "initialization", Asmt, Spec_Id); Output_Active_Scenarios (Asmt); end if; end Process_Conditional_ABE_Variable_Assignment_SPARK; ------------------------------------------------ -- Process_Conditional_ABE_Variable_Reference -- ------------------------------------------------ procedure Process_Conditional_ABE_Variable_Reference (Ref : Node_Id) is Var_Attrs : Variable_Attributes; Var_Id : Entity_Id; begin Extract_Variable_Reference_Attributes (Ref => Ref, Var_Id => Var_Id, Attrs => Var_Attrs); if Is_Read (Ref) then Process_Conditional_ABE_Variable_Reference_Read (Ref => Ref, Var_Id => Var_Id, Attrs => Var_Attrs); end if; end Process_Conditional_ABE_Variable_Reference; ----------------------------------------------------- -- Process_Conditional_ABE_Variable_Reference_Read -- ----------------------------------------------------- procedure Process_Conditional_ABE_Variable_Reference_Read (Ref : Node_Id; Var_Id : Entity_Id; Attrs : Variable_Attributes) is begin -- Output relevant information when switch -gnatel (info messages on -- implicit Elaborate[_All] pragmas) is in effect. if Elab_Info_Messages then Elab_Msg_NE (Msg => "read of variable & during elaboration", N => Ref, Id => Var_Id, Info_Msg => True, In_SPARK => True); end if; -- Nothing to do when the variable appears within the main unit because -- diagnostics on reads are relevant only for external variables. if Is_Same_Unit (Attrs.Unit_Id, Cunit_Entity (Main_Unit)) then null; -- Nothing to do when the variable is already initialized. Note that the -- variable may be further modified by the external unit. elsif Is_Initialized (Declaration_Node (Var_Id)) then null; -- Nothing to do when the external unit guarantees the initialization of -- the variable by means of pragma Elaborate_Body. elsif Has_Pragma_Elaborate_Body (Attrs.Unit_Id) then null; -- A variable read imposes an Elaborate requirement on the context of -- the main unit. Determine whether the context has a pragma strong -- enough to meet the requirement. else Meet_Elaboration_Requirement (N => Ref, Target_Id => Var_Id, Req_Nam => Name_Elaborate); end if; end Process_Conditional_ABE_Variable_Reference_Read; ----------------------------- -- Process_Conditional_ABE -- ----------------------------- -- NOTE: The body of this routine is intentionally out of order because it -- invokes an instantiated subprogram (Process_Conditional_ABE_Activation). -- Placing the body in alphabetical order will result in a guaranteed ABE. procedure Process_Conditional_ABE (N : Node_Id; State : Processing_Attributes := Initial_State) is Call_Attrs : Call_Attributes; Target_Id : Entity_Id; begin -- Add the current scenario to the stack of active scenarios Push_Active_Scenario (N); -- 'Access if Is_Suitable_Access (N) then Process_Conditional_ABE_Access (Attr => N, State => State); -- Activations and calls elsif Is_Suitable_Call (N) then -- In general, only calls found within the main unit are processed -- because the ALI information supplied to binde is for the main -- unit only. However, to preserve the consistency of the tree and -- ensure proper serialization of internal names, external calls -- also receive corresponding call markers (see Build_Call_Marker). -- Regardless of the reason, external calls must not be processed. if In_Main_Context (N) then Extract_Call_Attributes (Call => N, Target_Id => Target_Id, Attrs => Call_Attrs); if Is_Activation_Proc (Target_Id) then Process_Conditional_ABE_Activation (Call => N, Call_Attrs => Call_Attrs, State => State); else Process_Conditional_ABE_Call (Call => N, Call_Attrs => Call_Attrs, Target_Id => Target_Id, State => State); end if; end if; -- Instantiations elsif Is_Suitable_Instantiation (N) then Process_Conditional_ABE_Instantiation (Exp_Inst => N, State => State); -- Variable assignments elsif Is_Suitable_Variable_Assignment (N) then Process_Conditional_ABE_Variable_Assignment (N); -- Variable references elsif Is_Suitable_Variable_Reference (N) then -- In general, only variable references found within the main unit -- are processed because the ALI information supplied to binde is for -- the main unit only. However, to preserve the consistency of the -- tree and ensure proper serialization of internal names, external -- variable references also receive corresponding variable reference -- markers (see Build_Varaible_Reference_Marker). Regardless of the -- reason, external variable references must not be processed. if In_Main_Context (N) then Process_Conditional_ABE_Variable_Reference (N); end if; end if; -- Remove the current scenario from the stack of active scenarios once -- all ABE diagnostics and checks have been performed. Pop_Active_Scenario (N); end Process_Conditional_ABE; -------------------------------------------- -- Process_Guaranteed_ABE_Activation_Impl -- -------------------------------------------- procedure Process_Guaranteed_ABE_Activation_Impl (Call : Node_Id; Call_Attrs : Call_Attributes; Obj_Id : Entity_Id; Task_Attrs : Task_Attributes; State : Processing_Attributes) is pragma Unreferenced (State); Check_OK : constant Boolean := not Is_Ignored_Ghost_Entity (Obj_Id) and then not Task_Attrs.Ghost_Mode_Ignore and then Is_Elaboration_Checks_OK_Id (Obj_Id) and then Task_Attrs.Elab_Checks_OK; -- A run-time ABE check may be installed only when the object and the -- task type have active elaboration checks, and both are not ignored -- Ghost constructs. begin -- Nothing to do when the root scenario appears at the declaration -- level and the task is in the same unit, but outside this context. -- -- task type Task_Typ; -- task declaration -- -- procedure Proc is -- function A ... is -- begin -- if Some_Condition then -- declare -- T : Task_Typ; -- begin -- -- activation site -- end; -- ... -- end A; -- -- X : ... := A; -- root scenario -- ... -- -- task body Task_Typ is -- ... -- end Task_Typ; -- -- In the example above, the context of X is the declarative list of -- Proc. The "elaboration" of X may reach the activation of T whose body -- is defined outside of X's context. The task body is relevant only -- when Proc is invoked, but this happens only in "normal" elaboration, -- therefore the task body must not be considered if this is not the -- case. -- Performance note: parent traversal if Is_Up_Level_Target (Task_Attrs.Task_Decl) then return; -- Nothing to do when the activation is ABE-safe -- -- generic -- package Gen is -- task type Task_Typ; -- end Gen; -- -- package body Gen is -- task body Task_Typ is -- begin -- ... -- end Task_Typ; -- end Gen; -- -- with Gen; -- procedure Main is -- package Nested is -- package Inst is new Gen; -- T : Inst.Task_Typ; -- end Nested; -- safe activation -- ... elsif Is_Safe_Activation (Call, Task_Attrs.Task_Decl) then return; -- An activation call leads to a guaranteed ABE when the activation -- call and the task appear within the same context ignoring library -- levels, and the body of the task has not been seen yet or appears -- after the activation call. -- -- procedure Guaranteed_ABE is -- task type Task_Typ; -- -- package Nested is -- T : Task_Typ; -- -- guaranteed ABE -- end Nested; -- -- task body Task_Typ is -- ... -- end Task_Typ; -- ... -- Performance note: parent traversal elsif Is_Guaranteed_ABE (N => Call, Target_Decl => Task_Attrs.Task_Decl, Target_Body => Task_Attrs.Body_Decl) then if Call_Attrs.Elab_Warnings_OK then Error_Msg_Sloc := Sloc (Call); Error_Msg_N ("??task & will be activated # before elaboration of its body", Obj_Id); Error_Msg_N ("\Program_Error will be raised at run time", Obj_Id); end if; -- Mark the activation call as a guaranteed ABE Set_Is_Known_Guaranteed_ABE (Call); -- Install a run-time ABE failue because this activation call will -- always result in an ABE. if Check_OK then Install_ABE_Failure (N => Call, Ins_Nod => Call); end if; end if; end Process_Guaranteed_ABE_Activation_Impl; procedure Process_Guaranteed_ABE_Activation is new Process_Activation_Generic (Process_Guaranteed_ABE_Activation_Impl); --------------------------------- -- Process_Guaranteed_ABE_Call -- --------------------------------- procedure Process_Guaranteed_ABE_Call (Call : Node_Id; Call_Attrs : Call_Attributes; Target_Id : Entity_Id) is Target_Attrs : Target_Attributes; begin Extract_Target_Attributes (Target_Id => Target_Id, Attrs => Target_Attrs); -- Nothing to do when the root scenario appears at the declaration level -- and the target is in the same unit, but outside this context. -- -- function B ...; -- target declaration -- -- procedure Proc is -- function A ... is -- begin -- if Some_Condition then -- return B; -- call site -- ... -- end A; -- -- X : ... := A; -- root scenario -- ... -- -- function B ... is -- ... -- end B; -- -- In the example above, the context of X is the declarative region of -- Proc. The "elaboration" of X may eventually reach B which is defined -- outside of X's context. B is relevant only when Proc is invoked, but -- this happens only by means of "normal" elaboration, therefore B must -- not be considered if this is not the case. -- Performance note: parent traversal if Is_Up_Level_Target (Target_Attrs.Spec_Decl) then return; -- Nothing to do when the call is ABE-safe -- -- generic -- function Gen ...; -- -- function Gen ... is -- begin -- ... -- end Gen; -- -- with Gen; -- procedure Main is -- function Inst is new Gen; -- X : ... := Inst; -- safe call -- ... elsif Is_Safe_Call (Call, Target_Attrs) then return; -- A call leads to a guaranteed ABE when the call and the target appear -- within the same context ignoring library levels, and the body of the -- target has not been seen yet or appears after the call. -- -- procedure Guaranteed_ABE is -- function Func ...; -- -- package Nested is -- Obj : ... := Func; -- guaranteed ABE -- end Nested; -- -- function Func ... is -- ... -- end Func; -- ... -- Performance note: parent traversal elsif Is_Guaranteed_ABE (N => Call, Target_Decl => Target_Attrs.Spec_Decl, Target_Body => Target_Attrs.Body_Decl) then if Call_Attrs.Elab_Warnings_OK then Error_Msg_NE ("??cannot call & before body seen", Call, Target_Id); Error_Msg_N ("\Program_Error will be raised at run time", Call); end if; -- Mark the call as a guarnateed ABE Set_Is_Known_Guaranteed_ABE (Call); -- Install a run-time ABE failure because the call will always result -- in an ABE. The failure is installed when both the call and target -- have enabled elaboration checks, and both are not ignored Ghost -- constructs. if Call_Attrs.Elab_Checks_OK and then Target_Attrs.Elab_Checks_OK and then not Call_Attrs.Ghost_Mode_Ignore and then not Target_Attrs.Ghost_Mode_Ignore then Install_ABE_Failure (N => Call, Ins_Nod => Call); end if; end if; end Process_Guaranteed_ABE_Call; ------------------------------------------ -- Process_Guaranteed_ABE_Instantiation -- ------------------------------------------ procedure Process_Guaranteed_ABE_Instantiation (Exp_Inst : Node_Id) is Gen_Attrs : Target_Attributes; Gen_Id : Entity_Id; Inst : Node_Id; Inst_Attrs : Instantiation_Attributes; Inst_Id : Entity_Id; begin Extract_Instantiation_Attributes (Exp_Inst => Exp_Inst, Inst => Inst, Inst_Id => Inst_Id, Gen_Id => Gen_Id, Attrs => Inst_Attrs); Extract_Target_Attributes (Gen_Id, Gen_Attrs); -- Nothing to do when the root scenario appears at the declaration level -- and the generic is in the same unit, but outside this context. -- -- generic -- procedure Gen is ...; -- generic declaration -- -- procedure Proc is -- function A ... is -- begin -- if Some_Condition then -- declare -- procedure I is new Gen; -- instantiation site -- ... -- ... -- end A; -- -- X : ... := A; -- root scenario -- ... -- -- procedure Gen is -- ... -- end Gen; -- -- In the example above, the context of X is the declarative region of -- Proc. The "elaboration" of X may eventually reach Gen which appears -- outside of X's context. Gen is relevant only when Proc is invoked, -- but this happens only by means of "normal" elaboration, therefore -- Gen must not be considered if this is not the case. -- Performance note: parent traversal if Is_Up_Level_Target (Gen_Attrs.Spec_Decl) then return; -- Nothing to do when the instantiation is ABE-safe -- -- generic -- package Gen is -- ... -- end Gen; -- -- package body Gen is -- ... -- end Gen; -- -- with Gen; -- procedure Main is -- package Inst is new Gen (ABE); -- safe instantiation -- ... elsif Is_Safe_Instantiation (Inst, Gen_Attrs) then return; -- An instantiation leads to a guaranteed ABE when the instantiation and -- the generic appear within the same context ignoring library levels, -- and the body of the generic has not been seen yet or appears after -- the instantiation. -- -- procedure Guaranteed_ABE is -- generic -- procedure Gen; -- -- package Nested is -- procedure Inst is new Gen; -- guaranteed ABE -- end Nested; -- -- procedure Gen is -- ... -- end Gen; -- ... -- Performance note: parent traversal elsif Is_Guaranteed_ABE (N => Inst, Target_Decl => Gen_Attrs.Spec_Decl, Target_Body => Gen_Attrs.Body_Decl) then if Inst_Attrs.Elab_Warnings_OK then Error_Msg_NE ("??cannot instantiate & before body seen", Inst, Gen_Id); Error_Msg_N ("\Program_Error will be raised at run time", Inst); end if; -- Mark the instantiation as a guarantee ABE. This automatically -- suppresses the instantiation of the generic body. Set_Is_Known_Guaranteed_ABE (Inst); -- Install a run-time ABE failure because the instantiation will -- always result in an ABE. The failure is installed when both the -- instance and the generic have enabled elaboration checks, and both -- are not ignored Ghost constructs. if Inst_Attrs.Elab_Checks_OK and then Gen_Attrs.Elab_Checks_OK and then not Inst_Attrs.Ghost_Mode_Ignore and then not Gen_Attrs.Ghost_Mode_Ignore then Install_ABE_Failure (N => Inst, Ins_Nod => Exp_Inst); end if; end if; end Process_Guaranteed_ABE_Instantiation; ---------------------------- -- Process_Guaranteed_ABE -- ---------------------------- -- NOTE: The body of this routine is intentionally out of order because it -- invokes an instantiated subprogram (Process_Guaranteed_ABE_Activation). -- Placing the body in alphabetical order will result in a guaranteed ABE. procedure Process_Guaranteed_ABE (N : Node_Id) is Call_Attrs : Call_Attributes; Target_Id : Entity_Id; begin -- Add the current scenario to the stack of active scenarios Push_Active_Scenario (N); -- Only calls, instantiations, and task activations may result in a -- guaranteed ABE. if Is_Suitable_Call (N) then Extract_Call_Attributes (Call => N, Target_Id => Target_Id, Attrs => Call_Attrs); if Is_Activation_Proc (Target_Id) then Process_Guaranteed_ABE_Activation (Call => N, Call_Attrs => Call_Attrs, State => Initial_State); else Process_Guaranteed_ABE_Call (Call => N, Call_Attrs => Call_Attrs, Target_Id => Target_Id); end if; elsif Is_Suitable_Instantiation (N) then Process_Guaranteed_ABE_Instantiation (N); end if; -- Remove the current scenario from the stack of active scenarios once -- all ABE diagnostics and checks have been performed. Pop_Active_Scenario (N); end Process_Guaranteed_ABE; -------------------------- -- Push_Active_Scenario -- -------------------------- procedure Push_Active_Scenario (N : Node_Id) is begin Scenario_Stack.Append (N); end Push_Active_Scenario; --------------------------------- -- Record_Elaboration_Scenario -- --------------------------------- procedure Record_Elaboration_Scenario (N : Node_Id) is Level : Enclosing_Level_Kind; Any_Level_OK : Boolean; -- This flag is set when a particular scenario is allowed to appear at -- any level. Declaration_Level_OK : Boolean; -- This flag is set when a particular scenario is allowed to appear at -- the declaration level. Library_Level_OK : Boolean; -- This flag is set when a particular scenario is allowed to appear at -- the library level. begin -- Assume that the scenario cannot appear on any level Any_Level_OK := False; Declaration_Level_OK := False; Library_Level_OK := False; -- Nothing to do when switch -gnatH (legacy elaboration checking mode -- enabled) is in effect because the legacy ABE mechanism does not need -- to carry out this action. if Legacy_Elaboration_Checks then return; -- Nothing to do for ASIS because ABE checks and diagnostics are not -- performed in this mode. elsif ASIS_Mode then return; -- Nothing to do when the scenario is being preanalyzed elsif Preanalysis_Active then return; end if; -- Ensure that a library-level call does not appear in a preelaborated -- unit. The check must come before ignoring scenarios within external -- units or inside generics because calls in those context must also be -- verified. if Is_Suitable_Call (N) then Check_Preelaborated_Call (N); end if; -- Nothing to do when the scenario does not appear within the main unit if not In_Main_Context (N) then return; -- Scenarios within a generic unit are never considered because generics -- cannot be elaborated. elsif Inside_A_Generic then return; -- Scenarios which do not fall in one of the elaboration categories -- listed below are not considered. The categories are: -- 'Access for entries, operators, and subprograms -- Assignments to variables -- Calls (includes task activation) -- Derived types -- Instantiations -- Pragma Refined_State -- Reads of variables elsif Is_Suitable_Access (N) then Library_Level_OK := True; -- Signal any enclosing local exception handlers that the 'Access may -- raise Program_Error due to a failed ABE check when switch -gnatd.o -- (conservative elaboration order for indirect calls) is in effect. -- Marking the exception handlers ensures proper expansion by both -- the front and back end restriction when No_Exception_Propagation -- is in effect. if Debug_Flag_Dot_O then Possible_Local_Raise (N, Standard_Program_Error); end if; elsif Is_Suitable_Call (N) or else Is_Suitable_Instantiation (N) then Declaration_Level_OK := True; Library_Level_OK := True; -- Signal any enclosing local exception handlers that the call or -- instantiation may raise Program_Error due to a failed ABE check. -- Marking the exception handlers ensures proper expansion by both -- the front and back end restriction when No_Exception_Propagation -- is in effect. Possible_Local_Raise (N, Standard_Program_Error); elsif Is_Suitable_SPARK_Derived_Type (N) then Any_Level_OK := True; elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then Library_Level_OK := True; elsif Is_Suitable_Variable_Assignment (N) or else Is_Suitable_Variable_Reference (N) then Library_Level_OK := True; -- Otherwise the input does not denote a suitable scenario else return; end if; -- The static model imposes additional restrictions on the placement of -- scenarios. In contrast, the dynamic model assumes that every scenario -- will be elaborated or invoked at some point. if Static_Elaboration_Checks then -- Certain scenarios are allowed to appear at any level. This check -- is performed here in order to save on a parent traversal. if Any_Level_OK then null; -- Otherwise the scenario must appear at a specific level else -- Performance note: parent traversal Level := Find_Enclosing_Level (N); -- Declaration-level scenario if Declaration_Level_OK and then Level = Declaration_Level then null; -- Library-level or instantiation scenario elsif Library_Level_OK and then Level in Library_Or_Instantiation_Level then null; -- Otherwise the scenario does not appear at the proper level and -- cannot possibly act as a top-level scenario. else return; end if; end if; end if; -- Derived types subject to SPARK_Mode On require elaboration-related -- checks even though the type may not be declared within elaboration -- code. The types are recorded in a separate table which is examined -- during the Processing phase. Note that the checks must be delayed -- because the bodies of overriding primitives are not available yet. if Is_Suitable_SPARK_Derived_Type (N) then Record_SPARK_Elaboration_Scenario (N); -- Nothing left to do for derived types return; -- Instantiations of generics both subject to SPARK_Mode On require -- elaboration-related checks even though the instantiations may not -- appear within elaboration code. The instantiations are recored in -- a separate table which is examined during the Procesing phase. Note -- that the checks must be delayed because it is not known yet whether -- the generic unit has a body or not. -- IMPORTANT: A SPARK instantiation is also a normal instantiation which -- is subject to common conditional and guaranteed ABE checks. elsif Is_Suitable_SPARK_Instantiation (N) then Record_SPARK_Elaboration_Scenario (N); -- External constituents that refine abstract states which appear in -- pragma Initializes require elaboration-related checks even though -- a Refined_State pragma lacks any elaboration semantic. elsif Is_Suitable_SPARK_Refined_State_Pragma (N) then Record_SPARK_Elaboration_Scenario (N); -- Nothing left to do for pragma Refined_State return; end if; -- Perform early detection of guaranteed ABEs in order to suppress the -- instantiation of generic bodies as gigi cannot handle certain types -- of premature instantiations. Process_Guaranteed_ABE (N); -- At this point all checks have been performed. Record the scenario for -- later processing by the ABE phase. Top_Level_Scenarios.Append (N); Set_Is_Recorded_Top_Level_Scenario (N); end Record_Elaboration_Scenario; --------------------------------------- -- Record_SPARK_Elaboration_Scenario -- --------------------------------------- procedure Record_SPARK_Elaboration_Scenario (N : Node_Id) is begin SPARK_Scenarios.Append (N); Set_Is_Recorded_SPARK_Scenario (N); end Record_SPARK_Elaboration_Scenario; ----------------------------------- -- Recorded_SPARK_Scenarios_Hash -- ----------------------------------- function Recorded_SPARK_Scenarios_Hash (Key : Node_Id) return Recorded_SPARK_Scenarios_Index is begin return Recorded_SPARK_Scenarios_Index (Key mod Recorded_SPARK_Scenarios_Max); end Recorded_SPARK_Scenarios_Hash; --------------------------------------- -- Recorded_Top_Level_Scenarios_Hash -- --------------------------------------- function Recorded_Top_Level_Scenarios_Hash (Key : Node_Id) return Recorded_Top_Level_Scenarios_Index is begin return Recorded_Top_Level_Scenarios_Index (Key mod Recorded_Top_Level_Scenarios_Max); end Recorded_Top_Level_Scenarios_Hash; -------------------------- -- Reset_Visited_Bodies -- -------------------------- procedure Reset_Visited_Bodies is begin if Visited_Bodies_In_Use then Visited_Bodies_In_Use := False; Visited_Bodies.Reset; end if; end Reset_Visited_Bodies; ------------------- -- Root_Scenario -- ------------------- function Root_Scenario return Node_Id is package Stack renames Scenario_Stack; begin -- Ensure that the scenario stack has at least one active scenario in -- it. The one at the bottom (index First) is the root scenario. pragma Assert (Stack.Last >= Stack.First); return Stack.Table (Stack.First); end Root_Scenario; --------------------------- -- Set_Early_Call_Region -- --------------------------- procedure Set_Early_Call_Region (Body_Id : Entity_Id; Start : Node_Id) is begin pragma Assert (Ekind_In (Body_Id, E_Entry, E_Entry_Family, E_Function, E_Procedure, E_Subprogram_Body)); Early_Call_Regions_In_Use := True; Early_Call_Regions.Set (Body_Id, Start); end Set_Early_Call_Region; ---------------------------- -- Set_Elaboration_Status -- ---------------------------- procedure Set_Elaboration_Status (Unit_Id : Entity_Id; Val : Elaboration_Attributes) is begin Elaboration_Statuses_In_Use := True; Elaboration_Statuses.Set (Unit_Id, Val); end Set_Elaboration_Status; ------------------------------------ -- Set_Is_Recorded_SPARK_Scenario -- ------------------------------------ procedure Set_Is_Recorded_SPARK_Scenario (N : Node_Id; Val : Boolean := True) is begin Recorded_SPARK_Scenarios_In_Use := True; Recorded_SPARK_Scenarios.Set (N, Val); end Set_Is_Recorded_SPARK_Scenario; ---------------------------------------- -- Set_Is_Recorded_Top_Level_Scenario -- ---------------------------------------- procedure Set_Is_Recorded_Top_Level_Scenario (N : Node_Id; Val : Boolean := True) is begin Recorded_Top_Level_Scenarios_In_Use := True; Recorded_Top_Level_Scenarios.Set (N, Val); end Set_Is_Recorded_Top_Level_Scenario; ------------------------- -- Set_Is_Visited_Body -- ------------------------- procedure Set_Is_Visited_Body (Subp_Body : Node_Id) is begin Visited_Bodies_In_Use := True; Visited_Bodies.Set (Subp_Body, True); end Set_Is_Visited_Body; ------------------------------- -- Static_Elaboration_Checks -- ------------------------------- function Static_Elaboration_Checks return Boolean is begin return not Dynamic_Elaboration_Checks; end Static_Elaboration_Checks; ------------------- -- Traverse_Body -- ------------------- procedure Traverse_Body (N : Node_Id; State : Processing_Attributes) is procedure Find_And_Process_Nested_Scenarios; pragma Inline (Find_And_Process_Nested_Scenarios); -- Examine the declarations and statements of subprogram body N for -- suitable scenarios. --------------------------------------- -- Find_And_Process_Nested_Scenarios -- --------------------------------------- procedure Find_And_Process_Nested_Scenarios is function Is_Potential_Scenario (Nod : Node_Id) return Traverse_Result; -- Determine whether arbitrary node Nod denotes a suitable scenario. -- If it does, save it in the Nested_Scenarios list of the subprogram -- body, and process it. procedure Traverse_List (List : List_Id); pragma Inline (Traverse_List); -- Invoke Traverse_Potential_Scenarios on each node in list List procedure Traverse_Potential_Scenarios is new Traverse_Proc (Is_Potential_Scenario); --------------------------- -- Is_Potential_Scenario -- --------------------------- function Is_Potential_Scenario (Nod : Node_Id) return Traverse_Result is begin -- Special cases -- Skip constructs which do not have elaboration of their own and -- need to be elaborated by other means such as invocation, task -- activation, etc. if Is_Non_Library_Level_Encapsulator (Nod) then return Skip; -- Terminate the traversal of a task body when encountering an -- accept or select statement, and -- -- * Entry calls during elaboration are not allowed. In this -- case the accept or select statement will cause the task -- to block at elaboration time because there are no entry -- calls to unblock it. -- -- or -- -- * Switch -gnatd_a (stop elaboration checks on accept or -- select statement) is in effect. elsif (Debug_Flag_Underscore_A or else Restriction_Active (No_Entry_Calls_In_Elaboration_Code)) and then Nkind_In (Original_Node (Nod), N_Accept_Statement, N_Selective_Accept) then return Abandon; -- Terminate the traversal of a task body when encountering a -- suspension call, and -- -- * Entry calls during elaboration are not allowed. In this -- case the suspension call emulates an entry call and will -- cause the task to block at elaboration time. -- -- or -- -- * Switch -gnatd_s (stop elaboration checks on synchronous -- suspension) is in effect. -- -- Note that the guard should not be checking the state of flag -- Within_Task_Body because only suspension calls which appear -- immediately within the statements of the task are supported. -- Flag Within_Task_Body carries over to deeper levels of the -- traversal. elsif (Debug_Flag_Underscore_S or else Restriction_Active (No_Entry_Calls_In_Elaboration_Code)) and then Is_Synchronous_Suspension_Call (Nod) and then In_Task_Body (Nod) then return Abandon; -- Certain nodes carry semantic lists which act as repositories -- until expansion transforms the node and relocates the contents. -- Examine these lists in case expansion is disabled. elsif Nkind_In (Nod, N_And_Then, N_Or_Else) then Traverse_List (Actions (Nod)); elsif Nkind_In (Nod, N_Elsif_Part, N_Iteration_Scheme) then Traverse_List (Condition_Actions (Nod)); elsif Nkind (Nod) = N_If_Expression then Traverse_List (Then_Actions (Nod)); Traverse_List (Else_Actions (Nod)); elsif Nkind_In (Nod, N_Component_Association, N_Iterated_Component_Association) then Traverse_List (Loop_Actions (Nod)); -- General case elsif Is_Suitable_Scenario (Nod) then Process_Conditional_ABE (N => Nod, State => State); end if; return OK; end Is_Potential_Scenario; ------------------- -- Traverse_List -- ------------------- procedure Traverse_List (List : List_Id) is Item : Node_Id; begin Item := First (List); while Present (Item) loop Traverse_Potential_Scenarios (Item); Next (Item); end loop; end Traverse_List; -- Start of processing for Find_And_Process_Nested_Scenarios begin -- Examine the declarations for suitable scenarios Traverse_List (Declarations (N)); -- Examine the handled sequence of statements. This also includes any -- exceptions handlers. Traverse_Potential_Scenarios (Handled_Statement_Sequence (N)); end Find_And_Process_Nested_Scenarios; -- Start of processing for Traverse_Body begin -- Nothing to do when there is no body if No (N) then return; elsif Nkind (N) /= N_Subprogram_Body then return; end if; -- Nothing to do if the body was already traversed during the processing -- of the same top-level scenario. if Is_Visited_Body (N) then return; -- Otherwise mark the body as traversed else Set_Is_Visited_Body (N); end if; -- Examine the declarations and statements of the subprogram body for -- suitable scenarios, save and process them accordingly. Find_And_Process_Nested_Scenarios; end Traverse_Body; ----------------- -- Unit_Entity -- ----------------- function Unit_Entity (Unit_Id : Entity_Id) return Entity_Id is function Is_Subunit (Id : Entity_Id) return Boolean; pragma Inline (Is_Subunit); -- Determine whether the entity of an initial declaration denotes a -- subunit. ---------------- -- Is_Subunit -- ---------------- function Is_Subunit (Id : Entity_Id) return Boolean is Decl : constant Node_Id := Unit_Declaration_Node (Id); begin return Nkind_In (Decl, N_Generic_Package_Declaration, N_Generic_Subprogram_Declaration, N_Package_Declaration, N_Protected_Type_Declaration, N_Subprogram_Declaration, N_Task_Type_Declaration) and then Present (Corresponding_Body (Decl)) and then Nkind (Parent (Unit_Declaration_Node (Corresponding_Body (Decl)))) = N_Subunit; end Is_Subunit; -- Local variables Id : Entity_Id; -- Start of processing for Unit_Entity begin Id := Unique_Entity (Unit_Id); -- Skip all subunits found in the scope chain which ends at the input -- unit. while Is_Subunit (Id) loop Id := Scope (Id); end loop; return Id; end Unit_Entity; --------------------------------- -- Update_Elaboration_Scenario -- --------------------------------- procedure Update_Elaboration_Scenario (New_N : Node_Id; Old_N : Node_Id) is procedure Update_SPARK_Scenario; pragma Inline (Update_SPARK_Scenario); -- Update the contents of table SPARK_Scenarios if Old_N is recorded -- there. procedure Update_Top_Level_Scenario; pragma Inline (Update_Top_Level_Scenario); -- Update the contexts of table Top_Level_Scenarios if Old_N is recorded -- there. --------------------------- -- Update_SPARK_Scenario -- --------------------------- procedure Update_SPARK_Scenario is package Scenarios renames SPARK_Scenarios; begin if Is_Recorded_SPARK_Scenario (Old_N) then -- Performance note: list traversal for Index in Scenarios.First .. Scenarios.Last loop if Scenarios.Table (Index) = Old_N then Scenarios.Table (Index) := New_N; -- The old SPARK scenario is no longer recorded, but the new -- one is. Set_Is_Recorded_Top_Level_Scenario (Old_N, False); Set_Is_Recorded_Top_Level_Scenario (New_N); return; end if; end loop; -- A recorded SPARK scenario must be in the table of recorded -- SPARK scenarios. pragma Assert (False); end if; end Update_SPARK_Scenario; ------------------------------- -- Update_Top_Level_Scenario -- ------------------------------- procedure Update_Top_Level_Scenario is package Scenarios renames Top_Level_Scenarios; begin if Is_Recorded_Top_Level_Scenario (Old_N) then -- Performance note: list traversal for Index in Scenarios.First .. Scenarios.Last loop if Scenarios.Table (Index) = Old_N then Scenarios.Table (Index) := New_N; -- The old top-level scenario is no longer recorded, but the -- new one is. Set_Is_Recorded_Top_Level_Scenario (Old_N, False); Set_Is_Recorded_Top_Level_Scenario (New_N); return; end if; end loop; -- A recorded top-level scenario must be in the table of recorded -- top-level scenarios. pragma Assert (False); end if; end Update_Top_Level_Scenario; -- Start of processing for Update_Elaboration_Requirement begin -- Nothing to do when the old and new scenarios are one and the same if Old_N = New_N then return; -- A scenario is being transformed by Atree.Rewrite. Update all relevant -- internal data structures to reflect this change. This ensures that a -- potential run-time conditional ABE check or a guaranteed ABE failure -- is inserted at the proper place in the tree. elsif Is_Scenario (Old_N) then Update_SPARK_Scenario; Update_Top_Level_Scenario; end if; end Update_Elaboration_Scenario; ------------------------- -- Visited_Bodies_Hash -- ------------------------- function Visited_Bodies_Hash (Key : Node_Id) return Visited_Bodies_Index is begin return Visited_Bodies_Index (Key mod Visited_Bodies_Max); end Visited_Bodies_Hash; --------------------------------------------------------------------------- -- -- -- L E G A C Y A C C E S S B E F O R E E L A B O R A T I O N -- -- -- -- M E C H A N I S M -- -- -- --------------------------------------------------------------------------- -- This section contains the implementation of the pre-18.x legacy ABE -- mechanism. The mechanism can be activated using switch -gnatH (legacy -- elaboration checking mode enabled). ----------------------------- -- Description of Approach -- ----------------------------- -- Every non-static call that is encountered by Sem_Res results in a call -- to Check_Elab_Call, with N being the call node, and Outer set to its -- default value of True. In addition X'Access is treated like a call -- for the access-to-procedure case, and in SPARK mode only we also -- check variable references. -- The goal of Check_Elab_Call is to determine whether or not the reference -- in question can generate an access before elaboration error (raising -- Program_Error) either by directly calling a subprogram whose body -- has not yet been elaborated, or indirectly, by calling a subprogram -- whose body has been elaborated, but which contains a call to such a -- subprogram. -- In addition, in SPARK mode, we are checking for a variable reference in -- another package, which requires an explicit Elaborate_All pragma. -- The only references that we need to look at the outer level are -- references that occur in elaboration code. There are two cases. The -- reference can be at the outer level of elaboration code, or it can -- be within another unit, e.g. the elaboration code of a subprogram. -- In the case of an elaboration call at the outer level, we must trace -- all calls to outer level routines either within the current unit or to -- other units that are with'ed. For calls within the current unit, we can -- determine if the body has been elaborated or not, and if it has not, -- then a warning is generated. -- Note that there are two subcases. If the original call directly calls a -- subprogram whose body has not been elaborated, then we know that an ABE -- will take place, and we replace the call by a raise of Program_Error. -- If the call is indirect, then we don't know that the PE will be raised, -- since the call might be guarded by a conditional. In this case we set -- Do_Elab_Check on the call so that a dynamic check is generated, and -- output a warning. -- For calls to a subprogram in a with'ed unit or a 'Access or variable -- reference (SPARK mode case), we require that a pragma Elaborate_All -- or pragma Elaborate be present, or that the referenced unit have a -- pragma Preelaborate, pragma Pure, or pragma Elaborate_Body. If none -- of these conditions is met, then a warning is generated that a pragma -- Elaborate_All may be needed (error in the SPARK case), or an implicit -- pragma is generated. -- For the case of an elaboration call at some inner level, we are -- interested in tracing only calls to subprograms at the same level, i.e. -- those that can be called during elaboration. Any calls to outer level -- routines cannot cause ABE's as a result of the original call (there -- might be an outer level call to the subprogram from outside that causes -- the ABE, but that gets analyzed separately). -- Note that we never trace calls to inner level subprograms, since these -- cannot result in ABE's unless there is an elaboration problem at a lower -- level, which will be separately detected. -- Note on pragma Elaborate. The checking here assumes that a pragma -- Elaborate on a with'ed unit guarantees that subprograms within the unit -- can be called without causing an ABE. This is not in fact the case since -- pragma Elaborate does not guarantee the transitive coverage guaranteed -- by Elaborate_All. However, we decide to trust the user in this case. -------------------------------------- -- Instantiation Elaboration Errors -- -------------------------------------- -- A special case arises when an instantiation appears in a context that is -- known to be before the body is elaborated, e.g. -- generic package x is ... -- ... -- package xx is new x; -- ... -- package body x is ... -- In this situation it is certain that an elaboration error will occur, -- and an unconditional raise Program_Error statement is inserted before -- the instantiation, and a warning generated. -- The problem is that in this case we have no place to put the body of -- the instantiation. We can't put it in the normal place, because it is -- too early, and will cause errors to occur as a result of referencing -- entities before they are declared. -- Our approach in this case is simply to avoid creating the body of the -- instantiation in such a case. The instantiation spec is modified to -- include dummy bodies for all subprograms, so that the resulting code -- does not contain subprogram specs with no corresponding bodies. -- The following table records the recursive call chain for output in the -- Output routine. Each entry records the call node and the entity of the -- called routine. The number of entries in the table (i.e. the value of -- Elab_Call.Last) indicates the current depth of recursion and is used to -- identify the outer level. type Elab_Call_Element is record Cloc : Source_Ptr; Ent : Entity_Id; end record; package Elab_Call is new Table.Table (Table_Component_Type => Elab_Call_Element, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 50, Table_Increment => 100, Table_Name => "Elab_Call"); -- The following table records all calls that have been processed starting -- from an outer level call. The table prevents both infinite recursion and -- useless reanalysis of calls within the same context. The use of context -- is important because it allows for proper checks in more complex code: -- if ... then -- Call; -- requires a check -- Call; -- does not need a check thanks to the table -- elsif ... then -- Call; -- requires a check, different context -- end if; -- Call; -- requires a check, different context type Visited_Element is record Subp_Id : Entity_Id; -- The entity of the subprogram being called Context : Node_Id; -- The context where the call to the subprogram occurs end record; package Elab_Visited is new Table.Table (Table_Component_Type => Visited_Element, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 200, Table_Increment => 100, Table_Name => "Elab_Visited"); -- The following table records delayed calls which must be examined after -- all generic bodies have been instantiated. type Delay_Element is record N : Node_Id; -- The parameter N from the call to Check_Internal_Call. Note that this -- node may get rewritten over the delay period by expansion in the call -- case (but not in the instantiation case). E : Entity_Id; -- The parameter E from the call to Check_Internal_Call Orig_Ent : Entity_Id; -- The parameter Orig_Ent from the call to Check_Internal_Call Curscop : Entity_Id; -- The current scope of the call. This is restored when we complete the -- delayed call, so that we do this in the right scope. Outer_Scope : Entity_Id; -- Save scope of outer level call From_Elab_Code : Boolean; -- Save indication of whether this call is from elaboration code In_Task_Activation : Boolean; -- Save indication of whether this call is from a task body. Tasks are -- activated at the "begin", which is after all local procedure bodies, -- so calls to those procedures can't fail, even if they occur after the -- task body. From_SPARK_Code : Boolean; -- Save indication of whether this call is under SPARK_Mode => On end record; package Delay_Check is new Table.Table (Table_Component_Type => Delay_Element, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 1000, Table_Increment => 100, Table_Name => "Delay_Check"); C_Scope : Entity_Id; -- Top-level scope of current scope. Compute this only once at the outer -- level, i.e. for a call to Check_Elab_Call from outside this unit. Outer_Level_Sloc : Source_Ptr; -- Save Sloc value for outer level call node for comparisons of source -- locations. A body is too late if it appears after the *outer* level -- call, not the particular call that is being analyzed. From_Elab_Code : Boolean; -- This flag shows whether the outer level call currently being examined -- is or is not in elaboration code. We are only interested in calls to -- routines in other units if this flag is True. In_Task_Activation : Boolean := False; -- This flag indicates whether we are performing elaboration checks on task -- bodies, at the point of activation. If true, we do not raise -- Program_Error for calls to local procedures, because all local bodies -- are known to be elaborated. However, we still need to trace such calls, -- because a local procedure could call a procedure in another package, -- so we might need an implicit Elaborate_All. Delaying_Elab_Checks : Boolean := True; -- This is set True till the compilation is complete, including the -- insertion of all instance bodies. Then when Check_Elab_Calls is called, -- the delay table is used to make the delayed calls and this flag is reset -- to False, so that the calls are processed. ----------------------- -- Local Subprograms -- ----------------------- -- Note: Outer_Scope in all following specs represents the scope of -- interest of the outer level call. If it is set to Standard_Standard, -- then it means the outer level call was at elaboration level, and that -- thus all calls are of interest. If it was set to some other scope, -- then the original call was an inner call, and we are not interested -- in calls that go outside this scope. procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id); -- Analysis of construct N shows that we should set Elaborate_All_Desirable -- for the WITH clause for unit U (which will always be present). A special -- case is when N is a function or procedure instantiation, in which case -- it is sufficient to set Elaborate_Desirable, since in this case there is -- no possibility of transitive elaboration issues. procedure Check_A_Call (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Inter_Unit_Only : Boolean; Generate_Warnings : Boolean := True; In_Init_Proc : Boolean := False); -- This is the internal recursive routine that is called to check for -- possible elaboration error. The argument N is a subprogram call or -- generic instantiation, or 'Access attribute reference to be checked, and -- E is the entity of the called subprogram, or instantiated generic unit, -- or subprogram referenced by 'Access. -- -- In SPARK mode, N can also be a variable reference, since in SPARK this -- also triggers a requirement for Elaborate_All, and in this case E is the -- entity being referenced. -- -- Outer_Scope is the outer level scope for the original reference. -- Inter_Unit_Only is set if the call is only to be checked in the -- case where it is to another unit (and skipped if within a unit). -- Generate_Warnings is set to False to suppress warning messages about -- missing pragma Elaborate_All's. These messages are not wanted for -- inner calls in the dynamic model. Note that an instance of the Access -- attribute applied to a subprogram also generates a call to this -- procedure (since the referenced subprogram may be called later -- indirectly). Flag In_Init_Proc should be set whenever the current -- context is a type init proc. -- -- Note: this might better be called Check_A_Reference to recognize the -- variable case for SPARK, but we prefer to retain the historical name -- since in practice this is mostly about checking calls for the possible -- occurrence of an access-before-elaboration exception. procedure Check_Bad_Instantiation (N : Node_Id); -- N is a node for an instantiation (if called with any other node kind, -- Check_Bad_Instantiation ignores the call). This subprogram checks for -- the special case of a generic instantiation of a generic spec in the -- same declarative part as the instantiation where a body is present and -- has not yet been seen. This is an obvious error, but needs to be checked -- specially at the time of the instantiation, since it is a case where we -- cannot insert the body anywhere. If this case is detected, warnings are -- generated, and a raise of Program_Error is inserted. In addition any -- subprograms in the generic spec are stubbed, and the Bad_Instantiation -- flag is set on the instantiation node. The caller in Sem_Ch12 uses this -- flag as an indication that no attempt should be made to insert an -- instance body. procedure Check_Internal_Call (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Orig_Ent : Entity_Id); -- N is a function call or procedure statement call node and E is the -- entity of the called function, which is within the current compilation -- unit (where subunits count as part of the parent). This call checks if -- this call, or any call within any accessed body could cause an ABE, and -- if so, outputs a warning. Orig_Ent differs from E only in the case of -- renamings, and points to the original name of the entity. This is used -- for error messages. Outer_Scope is the outer level scope for the -- original call. procedure Check_Internal_Call_Continue (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Orig_Ent : Entity_Id); -- The processing for Check_Internal_Call is divided up into two phases, -- and this represents the second phase. The second phase is delayed if -- Delaying_Elab_Checks is set to True. In this delayed case, the first -- phase makes an entry in the Delay_Check table, which is processed when -- Check_Elab_Calls is called. N, E and Orig_Ent are as for the call to -- Check_Internal_Call. Outer_Scope is the outer level scope for the -- original call. function Get_Referenced_Ent (N : Node_Id) return Entity_Id; -- N is either a function or procedure call or an access attribute that -- references a subprogram. This call retrieves the relevant entity. If -- this is a call to a protected subprogram, the entity is a selected -- component. The callable entity may be absent, in which case Empty is -- returned. This happens with non-analyzed calls in nested generics. -- -- If SPARK_Mode is On, then N can also be a reference to an E_Variable -- entity, in which case, the value returned is simply this entity. function Has_Generic_Body (N : Node_Id) return Boolean; -- N is a generic package instantiation node, and this routine determines -- if this package spec does in fact have a generic body. If so, then -- True is returned, otherwise False. Note that this is not at all the -- same as checking if the unit requires a body, since it deals with -- the case of optional bodies accurately (i.e. if a body is optional, -- then it looks to see if a body is actually present). Note: this -- function can only do a fully correct job if in generating code mode -- where all bodies have to be present. If we are operating in semantics -- check only mode, then in some cases of optional bodies, a result of -- False may incorrectly be given. In practice this simply means that -- some cases of warnings for incorrect order of elaboration will only -- be given when generating code, which is not a big problem (and is -- inevitable, given the optional body semantics of Ada). procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty); -- Given code for an elaboration check (or unconditional raise if the check -- is not needed), inserts the code in the appropriate place. N is the call -- or instantiation node for which the check code is required. C is the -- test whose failure triggers the raise. function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean; -- Returns True if node N is a call to a generic formal subprogram function Is_Finalization_Procedure (Id : Entity_Id) return Boolean; -- Determine whether entity Id denotes a [Deep_]Finalize procedure procedure Output_Calls (N : Node_Id; Check_Elab_Flag : Boolean); -- Outputs chain of calls stored in the Elab_Call table. The caller has -- already generated the main warning message, so the warnings generated -- are all continuation messages. The argument is the call node at which -- the messages are to be placed. When Check_Elab_Flag is set, calls are -- enumerated only when flag Elab_Warning is set for the dynamic case or -- when flag Elab_Info_Messages is set for the static case. function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean; -- Given two scopes, determine whether they are the same scope from an -- elaboration point of view, i.e. packages and blocks are ignored. procedure Set_C_Scope; -- On entry C_Scope is set to some scope. On return, C_Scope is reset -- to be the enclosing compilation unit of this scope. procedure Set_Elaboration_Constraint (Call : Node_Id; Subp : Entity_Id; Scop : Entity_Id); -- The current unit U may depend semantically on some unit P that is not -- in the current context. If there is an elaboration call that reaches P, -- we need to indicate that P requires an Elaborate_All, but this is not -- effective in U's ali file, if there is no with_clause for P. In this -- case we add the Elaborate_All on the unit Q that directly or indirectly -- makes P available. This can happen in two cases: -- -- a) Q declares a subtype of a type declared in P, and the call is an -- initialization call for an object of that subtype. -- -- b) Q declares an object of some tagged type whose root type is -- declared in P, and the initialization call uses object notation on -- that object to reach a primitive operation or a classwide operation -- declared in P. -- -- If P appears in the context of U, the current processing is correct. -- Otherwise we must identify these two cases to retrieve Q and place the -- Elaborate_All_Desirable on it. function Spec_Entity (E : Entity_Id) return Entity_Id; -- Given a compilation unit entity, if it is a spec entity, it is returned -- unchanged. If it is a body entity, then the spec for the corresponding -- spec is returned function Within (E1, E2 : Entity_Id) return Boolean; -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or is one -- of its contained scopes, False otherwise. function Within_Elaborate_All (Unit : Unit_Number_Type; E : Entity_Id) return Boolean; -- Return True if we are within the scope of an Elaborate_All for E, or if -- we are within the scope of an Elaborate_All for some other unit U, and U -- with's E. This prevents spurious warnings when the called entity is -- renamed within U, or in case of generic instances. -------------------------------------- -- Activate_Elaborate_All_Desirable -- -------------------------------------- procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id) is UN : constant Unit_Number_Type := Get_Code_Unit (N); CU : constant Node_Id := Cunit (UN); UE : constant Entity_Id := Cunit_Entity (UN); Unm : constant Unit_Name_Type := Unit_Name (UN); CI : constant List_Id := Context_Items (CU); Itm : Node_Id; Ent : Entity_Id; procedure Add_To_Context_And_Mark (Itm : Node_Id); -- This procedure is called when the elaborate indication must be -- applied to a unit not in the context of the referencing unit. The -- unit gets added to the context as an implicit with. function In_Withs_Of (UEs : Entity_Id) return Boolean; -- UEs is the spec entity of a unit. If the unit to be marked is -- in the context item list of this unit spec, then the call returns -- True and Itm is left set to point to the relevant N_With_Clause node. procedure Set_Elab_Flag (Itm : Node_Id); -- Sets Elaborate_[All_]Desirable as appropriate on Itm ----------------------------- -- Add_To_Context_And_Mark -- ----------------------------- procedure Add_To_Context_And_Mark (Itm : Node_Id) is CW : constant Node_Id := Make_With_Clause (Sloc (Itm), Name => Name (Itm)); begin Set_Library_Unit (CW, Library_Unit (Itm)); Set_Implicit_With (CW); -- Set elaborate all desirable on copy and then append the copy to -- the list of body with's and we are done. Set_Elab_Flag (CW); Append_To (CI, CW); end Add_To_Context_And_Mark; ----------------- -- In_Withs_Of -- ----------------- function In_Withs_Of (UEs : Entity_Id) return Boolean is UNs : constant Unit_Number_Type := Get_Source_Unit (UEs); CUs : constant Node_Id := Cunit (UNs); CIs : constant List_Id := Context_Items (CUs); begin Itm := First (CIs); while Present (Itm) loop if Nkind (Itm) = N_With_Clause then Ent := Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); if U = Ent then return True; end if; end if; Next (Itm); end loop; return False; end In_Withs_Of; ------------------- -- Set_Elab_Flag -- ------------------- procedure Set_Elab_Flag (Itm : Node_Id) is begin if Nkind (N) in N_Subprogram_Instantiation then Set_Elaborate_Desirable (Itm); else Set_Elaborate_All_Desirable (Itm); end if; end Set_Elab_Flag; -- Start of processing for Activate_Elaborate_All_Desirable begin -- Do not set binder indication if expansion is disabled, as when -- compiling a generic unit. if not Expander_Active then return; end if; -- If an instance of a generic package contains a controlled object (so -- we're calling Initialize at elaboration time), and the instance is in -- a package body P that says "with P;", then we need to return without -- adding "pragma Elaborate_All (P);" to P. if U = Main_Unit_Entity then return; end if; Itm := First (CI); while Present (Itm) loop if Nkind (Itm) = N_With_Clause then Ent := Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); -- If we find it, then mark elaborate all desirable and return if U = Ent then Set_Elab_Flag (Itm); return; end if; end if; Next (Itm); end loop; -- If we fall through then the with clause is not present in the -- current unit. One legitimate possibility is that the with clause -- is present in the spec when we are a body. if Is_Body_Name (Unm) and then In_Withs_Of (Spec_Entity (UE)) then Add_To_Context_And_Mark (Itm); return; end if; -- Similarly, we may be in the spec or body of a child unit, where -- the unit in question is with'ed by some ancestor of the child unit. if Is_Child_Name (Unm) then declare Pkg : Entity_Id; begin Pkg := UE; loop Pkg := Scope (Pkg); exit when Pkg = Standard_Standard; if In_Withs_Of (Pkg) then Add_To_Context_And_Mark (Itm); return; end if; end loop; end; end if; -- Here if we do not find with clause on spec or body. We just ignore -- this case; it means that the elaboration involves some other unit -- than the unit being compiled, and will be caught elsewhere. end Activate_Elaborate_All_Desirable; ------------------ -- Check_A_Call -- ------------------ procedure Check_A_Call (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Inter_Unit_Only : Boolean; Generate_Warnings : Boolean := True; In_Init_Proc : Boolean := False) is Access_Case : constant Boolean := Nkind (N) = N_Attribute_Reference; -- Indicates if we have Access attribute case function Call_To_Instance_From_Outside (Id : Entity_Id) return Boolean; -- True if we're calling an instance of a generic subprogram, or a -- subprogram in an instance of a generic package, and the call is -- outside that instance. procedure Elab_Warning (Msg_D : String; Msg_S : String; Ent : Node_Or_Entity_Id); -- Generate a call to Error_Msg_NE with parameters Msg_D or Msg_S (for -- dynamic or static elaboration model), N and Ent. Msg_D is a real -- warning (output if Msg_D is non-null and Elab_Warnings is set), -- Msg_S is an info message (output if Elab_Info_Messages is set). function Find_W_Scope return Entity_Id; -- Find top-level scope for called entity (not following renamings -- or derivations). This is where the Elaborate_All will go if it is -- needed. We start with the called entity, except in the case of an -- initialization procedure outside the current package, where the init -- proc is in the root package, and we start from the entity of the name -- in the call. ----------------------------------- -- Call_To_Instance_From_Outside -- ----------------------------------- function Call_To_Instance_From_Outside (Id : Entity_Id) return Boolean is Scop : Entity_Id := Id; begin loop if Scop = Standard_Standard then return False; end if; if Is_Generic_Instance (Scop) then return not In_Open_Scopes (Scop); end if; Scop := Scope (Scop); end loop; end Call_To_Instance_From_Outside; ------------------ -- Elab_Warning -- ------------------ procedure Elab_Warning (Msg_D : String; Msg_S : String; Ent : Node_Or_Entity_Id) is begin -- Dynamic elaboration checks, real warning if Dynamic_Elaboration_Checks then if not Access_Case then if Msg_D /= "" and then Elab_Warnings then Error_Msg_NE (Msg_D, N, Ent); end if; -- In the access case emit first warning message as well, -- otherwise list of calls will appear as errors. elsif Elab_Warnings then Error_Msg_NE (Msg_S, N, Ent); end if; -- Static elaboration checks, info message else if Elab_Info_Messages then Error_Msg_NE (Msg_S, N, Ent); end if; end if; end Elab_Warning; ------------------ -- Find_W_Scope -- ------------------ function Find_W_Scope return Entity_Id is Refed_Ent : constant Entity_Id := Get_Referenced_Ent (N); W_Scope : Entity_Id; begin if Is_Init_Proc (Refed_Ent) and then not In_Same_Extended_Unit (N, Refed_Ent) then W_Scope := Scope (Refed_Ent); else W_Scope := E; end if; -- Now loop through scopes to get to the enclosing compilation unit while not Is_Compilation_Unit (W_Scope) loop W_Scope := Scope (W_Scope); end loop; return W_Scope; end Find_W_Scope; -- Local variables Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation; -- Indicates if we have instantiation case Loc : constant Source_Ptr := Sloc (N); Variable_Case : constant Boolean := Nkind (N) in N_Has_Entity and then Present (Entity (N)) and then Ekind (Entity (N)) = E_Variable; -- Indicates if we have variable reference case W_Scope : constant Entity_Id := Find_W_Scope; -- Top-level scope of directly called entity for subprogram. This -- differs from E_Scope in the case where renamings or derivations -- are involved, since it does not follow these links. W_Scope is -- generally in a visible unit, and it is this scope that may require -- an Elaborate_All. However, there are some cases (initialization -- calls and calls involving object notation) where W_Scope might not -- be in the context of the current unit, and there is an intermediate -- package that is, in which case the Elaborate_All has to be placed -- on this intermediate package. These special cases are handled in -- Set_Elaboration_Constraint. Ent : Entity_Id; Callee_Unit_Internal : Boolean; Caller_Unit_Internal : Boolean; Decl : Node_Id; Inst_Callee : Source_Ptr; Inst_Caller : Source_Ptr; Unit_Callee : Unit_Number_Type; Unit_Caller : Unit_Number_Type; Body_Acts_As_Spec : Boolean; -- Set to true if call is to body acting as spec (no separate spec) Cunit_SC : Boolean := False; -- Set to suppress dynamic elaboration checks where one of the -- enclosing scopes has Elaboration_Checks_Suppressed set, or else -- if a pragma Elaborate[_All] applies to that scope, in which case -- warnings on the scope are also suppressed. For the internal case, -- we ignore this flag. E_Scope : Entity_Id; -- Top-level scope of entity for called subprogram. This value includes -- following renamings and derivations, so this scope can be in a -- non-visible unit. This is the scope that is to be investigated to -- see whether an elaboration check is required. Is_DIC : Boolean; -- Flag set when the subprogram being invoked is the procedure generated -- for pragma Default_Initial_Condition. SPARK_Elab_Errors : Boolean; -- Flag set when an entity is called or a variable is read during SPARK -- dynamic elaboration. -- Start of processing for Check_A_Call begin -- If the call is known to be within a local Suppress Elaboration -- pragma, nothing to check. This can happen in task bodies. But -- we ignore this for a call to a generic formal. if Nkind (N) in N_Subprogram_Call and then No_Elaboration_Check (N) and then not Is_Call_Of_Generic_Formal (N) then return; -- If this is a rewrite of a Valid_Scalars attribute, then nothing to -- check, we don't mind in this case if the call occurs before the body -- since this is all generated code. elsif Nkind (Original_Node (N)) = N_Attribute_Reference and then Attribute_Name (Original_Node (N)) = Name_Valid_Scalars then return; -- Intrinsics such as instances of Unchecked_Deallocation do not have -- any body, so elaboration checking is not needed, and would be wrong. elsif Is_Intrinsic_Subprogram (E) then return; -- Do not consider references to internal variables for SPARK semantics elsif Variable_Case and then not Comes_From_Source (E) then return; end if; -- Proceed with check Ent := E; -- For a variable reference, just set Body_Acts_As_Spec to False if Variable_Case then Body_Acts_As_Spec := False; -- Additional checks for all other cases else -- Go to parent for derived subprogram, or to original subprogram in -- the case of a renaming (Alias covers both these cases). loop if (Suppress_Elaboration_Warnings (Ent) or else Elaboration_Checks_Suppressed (Ent)) and then (Inst_Case or else No (Alias (Ent))) then return; end if; -- Nothing to do for imported entities if Is_Imported (Ent) then return; end if; exit when Inst_Case or else No (Alias (Ent)); Ent := Alias (Ent); end loop; Decl := Unit_Declaration_Node (Ent); if Nkind (Decl) = N_Subprogram_Body then Body_Acts_As_Spec := True; elsif Nkind_In (Decl, N_Subprogram_Declaration, N_Subprogram_Body_Stub) or else Inst_Case then Body_Acts_As_Spec := False; -- If we have none of an instantiation, subprogram body or subprogram -- declaration, or in the SPARK case, a variable reference, then -- it is not a case that we want to check. (One case is a call to a -- generic formal subprogram, where we do not want the check in the -- template). else return; end if; end if; E_Scope := Ent; loop if Elaboration_Checks_Suppressed (E_Scope) or else Suppress_Elaboration_Warnings (E_Scope) then Cunit_SC := True; end if; -- Exit when we get to compilation unit, not counting subunits exit when Is_Compilation_Unit (E_Scope) and then (Is_Child_Unit (E_Scope) or else Scope (E_Scope) = Standard_Standard); pragma Assert (E_Scope /= Standard_Standard); -- Move up a scope looking for compilation unit E_Scope := Scope (E_Scope); end loop; -- No checks needed for pure or preelaborated compilation units if Is_Pure (E_Scope) or else Is_Preelaborated (E_Scope) then return; end if; -- If the generic entity is within a deeper instance than we are, then -- either the instantiation to which we refer itself caused an ABE, in -- which case that will be handled separately, or else we know that the -- body we need appears as needed at the point of the instantiation. -- However, this assumption is only valid if we are in static mode. if not Dynamic_Elaboration_Checks and then Instantiation_Depth (Sloc (Ent)) > Instantiation_Depth (Sloc (N)) then return; end if; -- Do not give a warning for a package with no body if Ekind (Ent) = E_Generic_Package and then not Has_Generic_Body (N) then return; end if; -- Case of entity is in same unit as call or instantiation. In the -- instantiation case, W_Scope may be different from E_Scope; we want -- the unit in which the instantiation occurs, since we're analyzing -- based on the expansion. if W_Scope = C_Scope then if not Inter_Unit_Only then Check_Internal_Call (N, Ent, Outer_Scope, E); end if; return; end if; -- Case of entity is not in current unit (i.e. with'ed unit case) -- We are only interested in such calls if the outer call was from -- elaboration code, or if we are in Dynamic_Elaboration_Checks mode. if not From_Elab_Code and then not Dynamic_Elaboration_Checks then return; end if; -- Nothing to do if some scope said that no checks were required if Cunit_SC then return; end if; -- Nothing to do for a generic instance, because a call to an instance -- cannot fail the elaboration check, because the body of the instance -- is always elaborated immediately after the spec. if Call_To_Instance_From_Outside (Ent) then return; end if; -- Nothing to do if subprogram with no separate spec. However, a call -- to Deep_Initialize may result in a call to a user-defined Initialize -- procedure, which imposes a body dependency. This happens only if the -- type is controlled and the Initialize procedure is not inherited. if Body_Acts_As_Spec then if Is_TSS (Ent, TSS_Deep_Initialize) then declare Typ : constant Entity_Id := Etype (First_Formal (Ent)); Init : Entity_Id; begin if not Is_Controlled (Typ) then return; else Init := Find_Prim_Op (Typ, Name_Initialize); if Comes_From_Source (Init) then Ent := Init; else return; end if; end if; end; else return; end if; end if; -- Check cases of internal units Callee_Unit_Internal := In_Internal_Unit (E_Scope); -- Do not give a warning if the with'ed unit is internal and this is -- the generic instantiation case (this saves a lot of hassle dealing -- with the Text_IO special child units) if Callee_Unit_Internal and Inst_Case then return; end if; if C_Scope = Standard_Standard then Caller_Unit_Internal := False; else Caller_Unit_Internal := In_Internal_Unit (C_Scope); end if; -- Do not give a warning if the with'ed unit is internal and the caller -- is not internal (since the binder always elaborates internal units -- first). if Callee_Unit_Internal and not Caller_Unit_Internal then return; end if; -- For now, if debug flag -gnatdE is not set, do no checking for one -- internal unit withing another. This fixes the problem with the sgi -- build and storage errors. To be resolved later ??? if (Callee_Unit_Internal and Caller_Unit_Internal) and not Debug_Flag_EE then return; end if; if Is_TSS (E, TSS_Deep_Initialize) then Ent := E; end if; -- If the call is in an instance, and the called entity is not -- defined in the same instance, then the elaboration issue focuses -- around the unit containing the template, it is this unit that -- requires an Elaborate_All. -- However, if we are doing dynamic elaboration, we need to chase the -- call in the usual manner. -- We also need to chase the call in the usual manner if it is a call -- to a generic formal parameter, since that case was not handled as -- part of the processing of the template. Inst_Caller := Instantiation (Get_Source_File_Index (Sloc (N))); Inst_Callee := Instantiation (Get_Source_File_Index (Sloc (Ent))); if Inst_Caller = No_Location then Unit_Caller := No_Unit; else Unit_Caller := Get_Source_Unit (N); end if; if Inst_Callee = No_Location then Unit_Callee := No_Unit; else Unit_Callee := Get_Source_Unit (Ent); end if; if Unit_Caller /= No_Unit and then Unit_Callee /= Unit_Caller and then not Dynamic_Elaboration_Checks and then not Is_Call_Of_Generic_Formal (N) then E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller)); -- If we don't get a spec entity, just ignore call. Not quite -- clear why this check is necessary. ??? if No (E_Scope) then return; end if; -- Otherwise step to enclosing compilation unit while not Is_Compilation_Unit (E_Scope) loop E_Scope := Scope (E_Scope); end loop; -- For the case where N is not an instance, and is not a call within -- instance to other than a generic formal, we recompute E_Scope -- for the error message, since we do NOT want to go to the unit -- that has the ultimate declaration in the case of renaming and -- derivation and we also want to go to the generic unit in the -- case of an instance, and no further. else -- Loop to carefully follow renamings and derivations one step -- outside the current unit, but not further. if not (Inst_Case or Variable_Case) and then Present (Alias (Ent)) then E_Scope := Alias (Ent); else E_Scope := Ent; end if; loop while not Is_Compilation_Unit (E_Scope) loop E_Scope := Scope (E_Scope); end loop; -- If E_Scope is the same as C_Scope, it means that there -- definitely was a local renaming or derivation, and we -- are not yet out of the current unit. exit when E_Scope /= C_Scope; Ent := Alias (Ent); E_Scope := Ent; -- If no alias, there could be a previous error, but not if we've -- already reached the outermost level (Standard). if No (Ent) then return; end if; end loop; end if; if Within_Elaborate_All (Current_Sem_Unit, E_Scope) then return; end if; -- Determine whether the Default_Initial_Condition procedure of some -- type is being invoked. Is_DIC := Ekind (Ent) = E_Procedure and then Is_DIC_Procedure (Ent); -- Checks related to Default_Initial_Condition fall under the SPARK -- umbrella because this is a SPARK-specific annotation. SPARK_Elab_Errors := SPARK_Mode = On and (Is_DIC or Dynamic_Elaboration_Checks); -- Now check if an Elaborate_All (or dynamic check) is needed if (Elab_Info_Messages or Elab_Warnings or SPARK_Elab_Errors) and then Generate_Warnings and then not Suppress_Elaboration_Warnings (Ent) and then not Elaboration_Checks_Suppressed (Ent) and then not Suppress_Elaboration_Warnings (E_Scope) and then not Elaboration_Checks_Suppressed (E_Scope) then -- Instantiation case if Inst_Case then if Comes_From_Source (Ent) and then SPARK_Elab_Errors then Error_Msg_NE ("instantiation of & during elaboration in SPARK", N, Ent); else Elab_Warning ("instantiation of & may raise Program_Error?l?", "info: instantiation of & during elaboration?$?", Ent); end if; -- Indirect call case, info message only in static elaboration -- case, because the attribute reference itself cannot raise an -- exception. Note that SPARK does not permit indirect calls. elsif Access_Case then Elab_Warning ("", "info: access to & during elaboration?$?", Ent); -- Variable reference in SPARK mode elsif Variable_Case then if Comes_From_Source (Ent) and then SPARK_Elab_Errors then Error_Msg_NE ("reference to & during elaboration in SPARK", N, Ent); end if; -- Subprogram call case else if Nkind (Name (N)) in N_Has_Entity and then Is_Init_Proc (Entity (Name (N))) and then Comes_From_Source (Ent) then Elab_Warning ("implicit call to & may raise Program_Error?l?", "info: implicit call to & during elaboration?$?", Ent); elsif SPARK_Elab_Errors then -- Emit a specialized error message when the elaboration of an -- object of a private type evaluates the expression of pragma -- Default_Initial_Condition. This prevents the internal name -- of the procedure from appearing in the error message. if Is_DIC then Error_Msg_N ("call to Default_Initial_Condition during elaboration in " & "SPARK", N); else Error_Msg_NE ("call to & during elaboration in SPARK", N, Ent); end if; else Elab_Warning ("call to & may raise Program_Error?l?", "info: call to & during elaboration?$?", Ent); end if; end if; Error_Msg_Qual_Level := Nat'Last; -- Case of Elaborate_All not present and required, for SPARK this -- is an error, so give an error message. if SPARK_Elab_Errors then Error_Msg_NE -- CODEFIX ("\Elaborate_All pragma required for&", N, W_Scope); -- Otherwise we generate an implicit pragma. For a subprogram -- instantiation, Elaborate is good enough, since no transitive -- call is possible at elaboration time in this case. elsif Nkind (N) in N_Subprogram_Instantiation then Elab_Warning ("\missing pragma Elaborate for&?l?", "\implicit pragma Elaborate for& generated?$?", W_Scope); -- For all other cases, we need an implicit Elaborate_All else Elab_Warning ("\missing pragma Elaborate_All for&?l?", "\implicit pragma Elaborate_All for & generated?$?", W_Scope); end if; Error_Msg_Qual_Level := 0; -- Take into account the flags related to elaboration warning -- messages when enumerating the various calls involved. This -- ensures the proper pairing of the main warning and the -- clarification messages generated by Output_Calls. Output_Calls (N, Check_Elab_Flag => True); -- Set flag to prevent further warnings for same unit unless in -- All_Errors_Mode. if not All_Errors_Mode and not Dynamic_Elaboration_Checks then Set_Suppress_Elaboration_Warnings (W_Scope); end if; end if; -- Check for runtime elaboration check required if Dynamic_Elaboration_Checks then if not Elaboration_Checks_Suppressed (Ent) and then not Elaboration_Checks_Suppressed (W_Scope) and then not Elaboration_Checks_Suppressed (E_Scope) and then not Cunit_SC then -- Runtime elaboration check required. Generate check of the -- elaboration Boolean for the unit containing the entity. -- Note that for this case, we do check the real unit (the one -- from following renamings, since that is the issue). -- Could this possibly miss a useless but required PE??? Insert_Elab_Check (N, Make_Attribute_Reference (Loc, Attribute_Name => Name_Elaborated, Prefix => New_Occurrence_Of (Spec_Entity (E_Scope), Loc))); -- Prevent duplicate elaboration checks on the same call, which -- can happen if the body enclosing the call appears itself in a -- call whose elaboration check is delayed. if Nkind (N) in N_Subprogram_Call then Set_No_Elaboration_Check (N); end if; end if; -- Case of static elaboration model else -- Do not do anything if elaboration checks suppressed. Note that -- we check Ent here, not E, since we want the real entity for the -- body to see if checks are suppressed for it, not the dummy -- entry for renamings or derivations. if Elaboration_Checks_Suppressed (Ent) or else Elaboration_Checks_Suppressed (E_Scope) or else Elaboration_Checks_Suppressed (W_Scope) then null; -- Do not generate an Elaborate_All for finalization routines -- that perform partial clean up as part of initialization. elsif In_Init_Proc and then Is_Finalization_Procedure (Ent) then null; -- Here we need to generate an implicit elaborate all else -- Generate Elaborate_All warning unless suppressed if (Elab_Info_Messages and Generate_Warnings and not Inst_Case) and then not Suppress_Elaboration_Warnings (Ent) and then not Suppress_Elaboration_Warnings (E_Scope) and then not Suppress_Elaboration_Warnings (W_Scope) then Error_Msg_Node_2 := W_Scope; Error_Msg_NE ("info: call to& in elaboration code requires pragma " & "Elaborate_All on&?$?", N, E); end if; -- Set indication for binder to generate Elaborate_All Set_Elaboration_Constraint (N, E, W_Scope); end if; end if; end Check_A_Call; ----------------------------- -- Check_Bad_Instantiation -- ----------------------------- procedure Check_Bad_Instantiation (N : Node_Id) is Ent : Entity_Id; begin -- Nothing to do if we do not have an instantiation (happens in some -- error cases, and also in the formal package declaration case) if Nkind (N) not in N_Generic_Instantiation then return; -- Nothing to do if serious errors detected (avoid cascaded errors) elsif Serious_Errors_Detected /= 0 then return; -- Nothing to do if not in full analysis mode elsif not Full_Analysis then return; -- Nothing to do if inside a generic template elsif Inside_A_Generic then return; -- Nothing to do if a library level instantiation elsif Nkind (Parent (N)) = N_Compilation_Unit then return; -- Nothing to do if we are compiling a proper body for semantic -- purposes only. The generic body may be in another proper body. elsif Nkind (Parent (Unit_Declaration_Node (Main_Unit_Entity))) = N_Subunit then return; end if; Ent := Get_Generic_Entity (N); -- The case we are interested in is when the generic spec is in the -- current declarative part if not Same_Elaboration_Scope (Current_Scope, Scope (Ent)) or else not In_Same_Extended_Unit (N, Ent) then return; end if; -- If the generic entity is within a deeper instance than we are, then -- either the instantiation to which we refer itself caused an ABE, in -- which case that will be handled separately. Otherwise, we know that -- the body we need appears as needed at the point of the instantiation. -- If they are both at the same level but not within the same instance -- then the body of the generic will be in the earlier instance. declare D1 : constant Nat := Instantiation_Depth (Sloc (Ent)); D2 : constant Nat := Instantiation_Depth (Sloc (N)); begin if D1 > D2 then return; elsif D1 = D2 and then Is_Generic_Instance (Scope (Ent)) and then not In_Open_Scopes (Scope (Ent)) then return; end if; end; -- Now we can proceed, if the entity being called has a completion, -- then we are definitely OK, since we have already seen the body. if Has_Completion (Ent) then return; end if; -- If there is no body, then nothing to do if not Has_Generic_Body (N) then return; end if; -- Here we definitely have a bad instantiation Error_Msg_Warn := SPARK_Mode /= On; Error_Msg_NE ("cannot instantiate& before body seen<<", N, Ent); Error_Msg_N ("\Program_Error [<<", N); Insert_Elab_Check (N); Set_Is_Known_Guaranteed_ABE (N); end Check_Bad_Instantiation; --------------------- -- Check_Elab_Call -- --------------------- procedure Check_Elab_Call (N : Node_Id; Outer_Scope : Entity_Id := Empty; In_Init_Proc : Boolean := False) is Ent : Entity_Id; P : Node_Id; begin pragma Assert (Legacy_Elaboration_Checks); -- If the reference is not in the main unit, there is nothing to check. -- Elaboration call from units in the context of the main unit will lead -- to semantic dependencies when those units are compiled. if not In_Extended_Main_Code_Unit (N) then return; end if; -- For an entry call, check relevant restriction if Nkind (N) = N_Entry_Call_Statement and then not In_Subprogram_Or_Concurrent_Unit then Check_Restriction (No_Entry_Calls_In_Elaboration_Code, N); -- Nothing to do if this is not an expected type of reference (happens -- in some error conditions, and in some cases where rewriting occurs). elsif Nkind (N) not in N_Subprogram_Call and then Nkind (N) /= N_Attribute_Reference and then (SPARK_Mode /= On or else Nkind (N) not in N_Has_Entity or else No (Entity (N)) or else Ekind (Entity (N)) /= E_Variable) then return; -- Nothing to do if this is a call already rewritten for elab checking. -- Such calls appear as the targets of If_Expressions. -- This check MUST be wrong, it catches far too much elsif Nkind (Parent (N)) = N_If_Expression then return; -- Nothing to do if inside a generic template elsif Inside_A_Generic and then No (Enclosing_Generic_Body (N)) then return; -- Nothing to do if call is being preanalyzed, as when within a -- pre/postcondition, a predicate, or an invariant. elsif In_Spec_Expression then return; end if; -- Nothing to do if this is a call to a postcondition, which is always -- within a subprogram body, even though the current scope may be the -- enclosing scope of the subprogram. if Nkind (N) = N_Procedure_Call_Statement and then Is_Entity_Name (Name (N)) and then Chars (Entity (Name (N))) = Name_uPostconditions then return; end if; -- Here we have a reference at elaboration time that must be checked if Debug_Flag_Underscore_LL then Write_Str (" Check_Elab_Ref: "); if Nkind (N) = N_Attribute_Reference then if not Is_Entity_Name (Prefix (N)) then Write_Str ("<>"); else Write_Name (Chars (Entity (Prefix (N)))); end if; Write_Str ("'Access"); elsif No (Name (N)) or else not Is_Entity_Name (Name (N)) then Write_Str ("<> "); else Write_Name (Chars (Entity (Name (N)))); end if; Write_Str (" reference at "); Write_Location (Sloc (N)); Write_Eol; end if; -- Climb up the tree to make sure we are not inside default expression -- of a parameter specification or a record component, since in both -- these cases, we will be doing the actual reference later, not now, -- and it is at the time of the actual reference (statically speaking) -- that we must do our static check, not at the time of its initial -- analysis). -- However, we have to check references within component definitions -- (e.g. a function call that determines an array component bound), -- so we terminate the loop in that case. P := Parent (N); while Present (P) loop if Nkind_In (P, N_Parameter_Specification, N_Component_Declaration) then return; -- The reference occurs within the constraint of a component, -- so it must be checked. elsif Nkind (P) = N_Component_Definition then exit; else P := Parent (P); end if; end loop; -- Stuff that happens only at the outer level if No (Outer_Scope) then Elab_Visited.Set_Last (0); -- Nothing to do if current scope is Standard (this is a bit odd, but -- it happens in the case of generic instantiations). C_Scope := Current_Scope; if C_Scope = Standard_Standard then return; end if; -- First case, we are in elaboration code From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; if From_Elab_Code then -- Complain if ref that comes from source in preelaborated unit -- and we are not inside a subprogram (i.e. we are in elab code). if Comes_From_Source (N) and then In_Preelaborated_Unit and then not In_Inlined_Body and then Nkind (N) /= N_Attribute_Reference then -- This is a warning in GNAT mode allowing such calls to be -- used in the predefined library with appropriate care. Error_Msg_Warn := GNAT_Mode; Error_Msg_N ("< Ent, Context => Parent (N)); begin for Index in 1 .. Elab_Visited.Last loop if Self = Elab_Visited.Table (Index) then return; end if; end loop; end; -- See if we need to analyze this reference. We analyze it if either of -- the following conditions is met: -- It is an inner level call (since in this case it was triggered -- by an outer level call from elaboration code), but only if the -- call is within the scope of the original outer level call. -- It is an outer level reference from elaboration code, or a call to -- an entity is in the same elaboration scope. -- And in these cases, we will check both inter-unit calls and -- intra-unit (within a single unit) calls. C_Scope := Current_Scope; -- If not outer level reference, then we follow it if it is within the -- original scope of the outer reference. if Present (Outer_Scope) and then Within (Scope (Ent), Outer_Scope) then Set_C_Scope; Check_A_Call (N => N, E => Ent, Outer_Scope => Outer_Scope, Inter_Unit_Only => False, In_Init_Proc => In_Init_Proc); -- Nothing to do if elaboration checks suppressed for this scope. -- However, an interesting exception, the fact that elaboration checks -- are suppressed within an instance (because we can trace the body when -- we process the template) does not extend to calls to generic formal -- subprograms. elsif Elaboration_Checks_Suppressed (Current_Scope) and then not Is_Call_Of_Generic_Formal (N) then null; elsif From_Elab_Code then Set_C_Scope; Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False); elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then Set_C_Scope; Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); -- If none of those cases holds, but Dynamic_Elaboration_Checks mode -- is set, then we will do the check, but only in the inter-unit case -- (this is to accommodate unguarded elaboration calls from other units -- in which this same mode is set). We don't want warnings in this case, -- it would generate warnings having nothing to do with elaboration. elsif Dynamic_Elaboration_Checks then Set_C_Scope; Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => True, Generate_Warnings => False); -- Otherwise nothing to do else return; end if; -- A call to an Init_Proc in elaboration code may bring additional -- dependencies, if some of the record components thereof have -- initializations that are function calls that come from source. We -- treat the current node as a call to each of these functions, to check -- their elaboration impact. if Is_Init_Proc (Ent) and then From_Elab_Code then Process_Init_Proc : declare Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent); function Check_Init_Call (Nod : Node_Id) return Traverse_Result; -- Find subprogram calls within body of Init_Proc for Traverse -- instantiation below. procedure Traverse_Body is new Traverse_Proc (Check_Init_Call); -- Traversal procedure to find all calls with body of Init_Proc --------------------- -- Check_Init_Call -- --------------------- function Check_Init_Call (Nod : Node_Id) return Traverse_Result is Func : Entity_Id; begin if Nkind (Nod) in N_Subprogram_Call and then Is_Entity_Name (Name (Nod)) then Func := Entity (Name (Nod)); if Comes_From_Source (Func) then Check_A_Call (N, Func, Standard_Standard, Inter_Unit_Only => True); end if; return OK; else return OK; end if; end Check_Init_Call; -- Start of processing for Process_Init_Proc begin if Nkind (Unit_Decl) = N_Subprogram_Body then Traverse_Body (Handled_Statement_Sequence (Unit_Decl)); end if; end Process_Init_Proc; end if; end Check_Elab_Call; ----------------------- -- Check_Elab_Assign -- ----------------------- procedure Check_Elab_Assign (N : Node_Id) is Ent : Entity_Id; Scop : Entity_Id; Pkg_Spec : Entity_Id; Pkg_Body : Entity_Id; begin pragma Assert (Legacy_Elaboration_Checks); -- For record or array component, check prefix. If it is an access type, -- then there is nothing to do (we do not know what is being assigned), -- but otherwise this is an assignment to the prefix. if Nkind_In (N, N_Indexed_Component, N_Selected_Component, N_Slice) then if not Is_Access_Type (Etype (Prefix (N))) then Check_Elab_Assign (Prefix (N)); end if; return; end if; -- For type conversion, check expression if Nkind (N) = N_Type_Conversion then Check_Elab_Assign (Expression (N)); return; end if; -- Nothing to do if this is not an entity reference otherwise get entity if Is_Entity_Name (N) then Ent := Entity (N); else return; end if; -- What we are looking for is a reference in the body of a package that -- modifies a variable declared in the visible part of the package spec. if Present (Ent) and then Comes_From_Source (N) and then not Suppress_Elaboration_Warnings (Ent) and then Ekind (Ent) = E_Variable and then not In_Private_Part (Ent) and then Is_Library_Level_Entity (Ent) then Scop := Current_Scope; loop if No (Scop) or else Scop = Standard_Standard then return; elsif Ekind (Scop) = E_Package and then Is_Compilation_Unit (Scop) then exit; else Scop := Scope (Scop); end if; end loop; -- Here Scop points to the containing library package Pkg_Spec := Scop; Pkg_Body := Body_Entity (Pkg_Spec); -- All OK if the package has an Elaborate_Body pragma if Has_Pragma_Elaborate_Body (Scop) then return; end if; -- OK if entity being modified is not in containing package spec if not In_Same_Source_Unit (Scop, Ent) then return; end if; -- All OK if entity appears in generic package or generic instance. -- We just get too messed up trying to give proper warnings in the -- presence of generics. Better no message than a junk one. Scop := Scope (Ent); while Present (Scop) and then Scop /= Pkg_Spec loop if Ekind (Scop) = E_Generic_Package then return; elsif Ekind (Scop) = E_Package and then Is_Generic_Instance (Scop) then return; end if; Scop := Scope (Scop); end loop; -- All OK if in task, don't issue warnings there if In_Task_Activation then return; end if; -- OK if no package body if No (Pkg_Body) then return; end if; -- OK if reference is not in package body if not In_Same_Source_Unit (Pkg_Body, N) then return; end if; -- OK if package body has no handled statement sequence declare HSS : constant Node_Id := Handled_Statement_Sequence (Declaration_Node (Pkg_Body)); begin if No (HSS) or else not Comes_From_Source (HSS) then return; end if; end; -- We definitely have a case of a modification of an entity in -- the package spec from the elaboration code of the package body. -- We may not give the warning (because there are some additional -- checks to avoid too many false positives), but it would be a good -- idea for the binder to try to keep the body elaboration close to -- the spec elaboration. Set_Elaborate_Body_Desirable (Pkg_Spec); -- All OK in gnat mode (we know what we are doing) if GNAT_Mode then return; end if; -- All OK if all warnings suppressed if Warning_Mode = Suppress then return; end if; -- All OK if elaboration checks suppressed for entity if Checks_May_Be_Suppressed (Ent) and then Is_Check_Suppressed (Ent, Elaboration_Check) then return; end if; -- OK if the entity is initialized. Note that the No_Initialization -- flag usually means that the initialization has been rewritten into -- assignments, but that still counts for us. declare Decl : constant Node_Id := Declaration_Node (Ent); begin if Nkind (Decl) = N_Object_Declaration and then (Present (Expression (Decl)) or else No_Initialization (Decl)) then return; end if; end; -- Here is where we give the warning -- All OK if warnings suppressed on the entity if not Has_Warnings_Off (Ent) then Error_Msg_Sloc := Sloc (Ent); Error_Msg_NE ("??& can be accessed by clients before this initialization", N, Ent); Error_Msg_NE ("\??add Elaborate_Body to spec to ensure & is initialized", N, Ent); end if; if not All_Errors_Mode then Set_Suppress_Elaboration_Warnings (Ent); end if; end if; end Check_Elab_Assign; ---------------------- -- Check_Elab_Calls -- ---------------------- -- WARNING: This routine manages SPARK regions procedure Check_Elab_Calls is Saved_SM : SPARK_Mode_Type; Saved_SMP : Node_Id; begin pragma Assert (Legacy_Elaboration_Checks); -- If expansion is disabled, do not generate any checks, unless we -- are in GNATprove mode, so that errors are issued in GNATprove for -- violations of static elaboration rules in SPARK code. Also skip -- checks if any subunits are missing because in either case we lack the -- full information that we need, and no object file will be created in -- any case. if (not Expander_Active and not GNATprove_Mode) or else Is_Generic_Unit (Cunit_Entity (Main_Unit)) or else Subunits_Missing then return; end if; -- Skip delayed calls if we had any errors if Serious_Errors_Detected = 0 then Delaying_Elab_Checks := False; Expander_Mode_Save_And_Set (True); for J in Delay_Check.First .. Delay_Check.Last loop Push_Scope (Delay_Check.Table (J).Curscop); From_Elab_Code := Delay_Check.Table (J).From_Elab_Code; In_Task_Activation := Delay_Check.Table (J).In_Task_Activation; Saved_SM := SPARK_Mode; Saved_SMP := SPARK_Mode_Pragma; -- Set appropriate value of SPARK_Mode if Delay_Check.Table (J).From_SPARK_Code then SPARK_Mode := On; end if; Check_Internal_Call_Continue (N => Delay_Check.Table (J).N, E => Delay_Check.Table (J).E, Outer_Scope => Delay_Check.Table (J).Outer_Scope, Orig_Ent => Delay_Check.Table (J).Orig_Ent); Restore_SPARK_Mode (Saved_SM, Saved_SMP); Pop_Scope; end loop; -- Set Delaying_Elab_Checks back on for next main compilation Expander_Mode_Restore; Delaying_Elab_Checks := True; end if; end Check_Elab_Calls; ------------------------------ -- Check_Elab_Instantiation -- ------------------------------ procedure Check_Elab_Instantiation (N : Node_Id; Outer_Scope : Entity_Id := Empty) is Ent : Entity_Id; begin pragma Assert (Legacy_Elaboration_Checks); -- Check for and deal with bad instantiation case. There is some -- duplicated code here, but we will worry about this later ??? Check_Bad_Instantiation (N); if Is_Known_Guaranteed_ABE (N) then return; end if; -- Nothing to do if we do not have an instantiation (happens in some -- error cases, and also in the formal package declaration case) if Nkind (N) not in N_Generic_Instantiation then return; end if; -- Nothing to do if inside a generic template if Inside_A_Generic then return; end if; -- Nothing to do if the instantiation is not in the main unit if not In_Extended_Main_Code_Unit (N) then return; end if; Ent := Get_Generic_Entity (N); From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; -- See if we need to analyze this instantiation. We analyze it if -- either of the following conditions is met: -- It is an inner level instantiation (since in this case it was -- triggered by an outer level call from elaboration code), but -- only if the instantiation is within the scope of the original -- outer level call. -- It is an outer level instantiation from elaboration code, or the -- instantiated entity is in the same elaboration scope. -- And in these cases, we will check both the inter-unit case and -- the intra-unit (within a single unit) case. C_Scope := Current_Scope; if Present (Outer_Scope) and then Within (Scope (Ent), Outer_Scope) then Set_C_Scope; Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False); elsif From_Elab_Code then Set_C_Scope; Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False); elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then Set_C_Scope; Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); -- If none of those cases holds, but Dynamic_Elaboration_Checks mode is -- set, then we will do the check, but only in the inter-unit case (this -- is to accommodate unguarded elaboration calls from other units in -- which this same mode is set). We inhibit warnings in this case, since -- this instantiation is not occurring in elaboration code. elsif Dynamic_Elaboration_Checks then Set_C_Scope; Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => True, Generate_Warnings => False); else return; end if; end Check_Elab_Instantiation; ------------------------- -- Check_Internal_Call -- ------------------------- procedure Check_Internal_Call (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Orig_Ent : Entity_Id) is function Within_Initial_Condition (Call : Node_Id) return Boolean; -- Determine whether call Call occurs within pragma Initial_Condition or -- pragma Check with check_kind set to Initial_Condition. ------------------------------ -- Within_Initial_Condition -- ------------------------------ function Within_Initial_Condition (Call : Node_Id) return Boolean is Args : List_Id; Nam : Name_Id; Par : Node_Id; begin -- Traverse the parent chain looking for an enclosing pragma Par := Call; while Present (Par) loop if Nkind (Par) = N_Pragma then Nam := Pragma_Name (Par); -- Pragma Initial_Condition appears in its alternative from as -- Check (Initial_Condition, ...). if Nam = Name_Check then Args := Pragma_Argument_Associations (Par); -- Pragma Check should have at least two arguments pragma Assert (Present (Args)); return Chars (Expression (First (Args))) = Name_Initial_Condition; -- Direct match elsif Nam = Name_Initial_Condition then return True; -- Since pragmas are never nested within other pragmas, stop -- the traversal. else return False; end if; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); -- If assertions are not enabled, the check pragma is rewritten -- as an if_statement in sem_prag, to generate various warnings -- on boolean expressions. Retrieve the original pragma. if Nkind (Original_Node (Par)) = N_Pragma then Par := Original_Node (Par); end if; end loop; return False; end Within_Initial_Condition; -- Local variables Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation; -- Start of processing for Check_Internal_Call begin -- For P'Access, we want to warn if the -gnatw.f switch is set, and the -- node comes from source. if Nkind (N) = N_Attribute_Reference and then ((not Warn_On_Elab_Access and then not Debug_Flag_Dot_O) or else not Comes_From_Source (N)) then return; -- If not function or procedure call, instantiation, or 'Access, then -- ignore call (this happens in some error cases and rewriting cases). elsif not Nkind_In (N, N_Attribute_Reference, N_Function_Call, N_Procedure_Call_Statement) and then not Inst_Case then return; -- Nothing to do if this is a call or instantiation that has already -- been found to be a sure ABE. elsif Nkind (N) /= N_Attribute_Reference and then Is_Known_Guaranteed_ABE (N) then return; -- Nothing to do if errors already detected (avoid cascaded errors) elsif Serious_Errors_Detected /= 0 then return; -- Nothing to do if not in full analysis mode elsif not Full_Analysis then return; -- Nothing to do if analyzing in special spec-expression mode, since the -- call is not actually being made at this time. elsif In_Spec_Expression then return; -- Nothing to do for call to intrinsic subprogram elsif Is_Intrinsic_Subprogram (E) then return; -- Nothing to do if call is within a generic unit elsif Inside_A_Generic then return; -- Nothing to do when the call appears within pragma Initial_Condition. -- The pragma is part of the elaboration statements of a package body -- and may only call external subprograms or subprograms whose body is -- already available. elsif Within_Initial_Condition (N) then return; end if; -- Delay this call if we are still delaying calls if Delaying_Elab_Checks then Delay_Check.Append ((N => N, E => E, Orig_Ent => Orig_Ent, Curscop => Current_Scope, Outer_Scope => Outer_Scope, From_Elab_Code => From_Elab_Code, In_Task_Activation => In_Task_Activation, From_SPARK_Code => SPARK_Mode = On)); return; -- Otherwise, call phase 2 continuation right now else Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent); end if; end Check_Internal_Call; ---------------------------------- -- Check_Internal_Call_Continue -- ---------------------------------- procedure Check_Internal_Call_Continue (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Orig_Ent : Entity_Id) is function Find_Elab_Reference (N : Node_Id) return Traverse_Result; -- Function applied to each node as we traverse the body. Checks for -- call or entity reference that needs checking, and if so checks it. -- Always returns OK, so entire tree is traversed, except that as -- described below subprogram bodies are skipped for now. procedure Traverse is new Atree.Traverse_Proc (Find_Elab_Reference); -- Traverse procedure using above Find_Elab_Reference function ------------------------- -- Find_Elab_Reference -- ------------------------- function Find_Elab_Reference (N : Node_Id) return Traverse_Result is Actual : Node_Id; begin -- If user has specified that there are no entry calls in elaboration -- code, do not trace past an accept statement, because the rendez- -- vous will happen after elaboration. if Nkind_In (Original_Node (N), N_Accept_Statement, N_Selective_Accept) and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code) then return Abandon; -- If we have a function call, check it elsif Nkind (N) = N_Function_Call then Check_Elab_Call (N, Outer_Scope); return OK; -- If we have a procedure call, check the call, and also check -- arguments that are assignments (OUT or IN OUT mode formals). elsif Nkind (N) = N_Procedure_Call_Statement then Check_Elab_Call (N, Outer_Scope, In_Init_Proc => Is_Init_Proc (E)); Actual := First_Actual (N); while Present (Actual) loop if Known_To_Be_Assigned (Actual) then Check_Elab_Assign (Actual); end if; Next_Actual (Actual); end loop; return OK; -- If we have an access attribute for a subprogram, check it. -- Suppress this behavior under debug flag. elsif not Debug_Flag_Dot_UU and then Nkind (N) = N_Attribute_Reference and then Nam_In (Attribute_Name (N), Name_Access, Name_Unrestricted_Access) and then Is_Entity_Name (Prefix (N)) and then Is_Subprogram (Entity (Prefix (N))) then Check_Elab_Call (N, Outer_Scope); return OK; -- In SPARK mode, if we have an entity reference to a variable, then -- check it. For now we consider any reference. elsif SPARK_Mode = On and then Nkind (N) in N_Has_Entity and then Present (Entity (N)) and then Ekind (Entity (N)) = E_Variable then Check_Elab_Call (N, Outer_Scope); return OK; -- If we have a generic instantiation, check it elsif Nkind (N) in N_Generic_Instantiation then Check_Elab_Instantiation (N, Outer_Scope); return OK; -- Skip subprogram bodies that come from source (wait for call to -- analyze these). The reason for the come from source test is to -- avoid catching task bodies. -- For task bodies, we should really avoid these too, waiting for the -- task activation, but that's too much trouble to catch for now, so -- we go in unconditionally. This is not so terrible, it means the -- error backtrace is not quite complete, and we are too eager to -- scan bodies of tasks that are unused, but this is hardly very -- significant. elsif Nkind (N) = N_Subprogram_Body and then Comes_From_Source (N) then return Skip; elsif Nkind (N) = N_Assignment_Statement and then Comes_From_Source (N) then Check_Elab_Assign (Name (N)); return OK; else return OK; end if; end Find_Elab_Reference; Inst_Case : constant Boolean := Is_Generic_Unit (E); Loc : constant Source_Ptr := Sloc (N); Ebody : Entity_Id; Sbody : Node_Id; -- Start of processing for Check_Internal_Call_Continue begin -- Save outer level call if at outer level if Elab_Call.Last = 0 then Outer_Level_Sloc := Loc; end if; -- If the call is to a function that renames a literal, no check needed if Ekind (E) = E_Enumeration_Literal then return; end if; -- Register the subprogram as examined within this particular context. -- This ensures that calls to the same subprogram but in different -- contexts receive warnings and checks of their own since the calls -- may be reached through different flow paths. Elab_Visited.Append ((Subp_Id => E, Context => Parent (N))); Sbody := Unit_Declaration_Node (E); if not Nkind_In (Sbody, N_Subprogram_Body, N_Package_Body) then Ebody := Corresponding_Body (Sbody); if No (Ebody) then return; else Sbody := Unit_Declaration_Node (Ebody); end if; end if; -- If the body appears after the outer level call or instantiation then -- we have an error case handled below. if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody)) and then not In_Task_Activation then null; -- If we have the instantiation case we are done, since we now know that -- the body of the generic appeared earlier. elsif Inst_Case then return; -- Otherwise we have a call, so we trace through the called body to see -- if it has any problems. else pragma Assert (Nkind (Sbody) = N_Subprogram_Body); Elab_Call.Append ((Cloc => Loc, Ent => E)); if Debug_Flag_Underscore_LL then Write_Str ("Elab_Call.Last = "); Write_Int (Int (Elab_Call.Last)); Write_Str (" Ent = "); Write_Name (Chars (E)); Write_Str (" at "); Write_Location (Sloc (N)); Write_Eol; end if; -- Now traverse declarations and statements of subprogram body. Note -- that we cannot simply Traverse (Sbody), since traverse does not -- normally visit subprogram bodies. declare Decl : Node_Id; begin Decl := First (Declarations (Sbody)); while Present (Decl) loop Traverse (Decl); Next (Decl); end loop; end; Traverse (Handled_Statement_Sequence (Sbody)); Elab_Call.Decrement_Last; return; end if; -- Here is the case of calling a subprogram where the body has not yet -- been encountered. A warning message is needed, except if this is the -- case of appearing within an aspect specification that results in -- a check call, we do not really have such a situation, so no warning -- is needed (e.g. the case of a precondition, where the call appears -- textually before the body, but in actual fact is moved to the -- appropriate subprogram body and so does not need a check). declare P : Node_Id; O : Node_Id; begin P := Parent (N); loop -- Keep looking at parents if we are still in the subexpression if Nkind (P) in N_Subexpr then P := Parent (P); -- Here P is the parent of the expression, check for special case else O := Original_Node (P); -- Definitely not the special case if orig node is not a pragma exit when Nkind (O) /= N_Pragma; -- Check we have an If statement or a null statement (happens -- when the If has been expanded to be True). exit when not Nkind_In (P, N_If_Statement, N_Null_Statement); -- Our special case will be indicated either by the pragma -- coming from an aspect ... if Present (Corresponding_Aspect (O)) then return; -- Or, in the case of an initial condition, specifically by a -- Check pragma specifying an Initial_Condition check. elsif Pragma_Name (O) = Name_Check and then Chars (Expression (First (Pragma_Argument_Associations (O)))) = Name_Initial_Condition then return; -- For anything else, we have an error else exit; end if; end if; end loop; end; -- Not that special case, warning and dynamic check is required -- If we have nothing in the call stack, then this is at the outer -- level, and the ABE is bound to occur, unless it's a 'Access, or -- it's a renaming. if Elab_Call.Last = 0 then Error_Msg_Warn := SPARK_Mode /= On; declare Insert_Check : Boolean := True; -- This flag is set to True if an elaboration check should be -- inserted. begin if In_Task_Activation then Insert_Check := False; elsif Inst_Case then Error_Msg_NE ("cannot instantiate& before body seen<<", N, Orig_Ent); elsif Nkind (N) = N_Attribute_Reference then Error_Msg_NE ("Access attribute of & before body seen<<", N, Orig_Ent); Error_Msg_N ("\possible Program_Error on later references<", N); Insert_Check := False; elsif Nkind (Unit_Declaration_Node (Orig_Ent)) /= N_Subprogram_Renaming_Declaration then Error_Msg_NE ("cannot call& before body seen<<", N, Orig_Ent); elsif not Is_Generic_Actual_Subprogram (Orig_Ent) then Insert_Check := False; end if; if Insert_Check then Error_Msg_N ("\Program_Error [<<", N); Insert_Elab_Check (N); end if; end; -- Call is not at outer level else -- Do not generate elaboration checks in GNATprove mode because the -- elaboration counter and the check are both forms of expansion. if GNATprove_Mode then null; -- Generate an elaboration check elsif not Elaboration_Checks_Suppressed (E) then Set_Elaboration_Entity_Required (E); -- Create a declaration of the elaboration entity, and insert it -- prior to the subprogram or the generic unit, within the same -- scope. Since the subprogram may be overloaded, create a unique -- entity. if No (Elaboration_Entity (E)) then declare Loce : constant Source_Ptr := Sloc (E); Ent : constant Entity_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (E), 'E', -1)); begin Set_Elaboration_Entity (E, Ent); Push_Scope (Scope (E)); Insert_Action (Declaration_Node (E), Make_Object_Declaration (Loce, Defining_Identifier => Ent, Object_Definition => New_Occurrence_Of (Standard_Short_Integer, Loce), Expression => Make_Integer_Literal (Loc, Uint_0))); -- Set elaboration flag at the point of the body Set_Elaboration_Flag (Sbody, E); -- Kill current value indication. This is necessary because -- the tests of this flag are inserted out of sequence and -- must not pick up bogus indications of the wrong constant -- value. Also, this is never a true constant, since one way -- or another, it gets reset. Set_Current_Value (Ent, Empty); Set_Last_Assignment (Ent, Empty); Set_Is_True_Constant (Ent, False); Pop_Scope; end; end if; -- Generate: -- if Enn = 0 then -- raise Program_Error with "access before elaboration"; -- end if; Insert_Elab_Check (N, Make_Attribute_Reference (Loc, Attribute_Name => Name_Elaborated, Prefix => New_Occurrence_Of (E, Loc))); end if; -- Generate the warning if not Suppress_Elaboration_Warnings (E) and then not Elaboration_Checks_Suppressed (E) -- Suppress this warning if we have a function call that occurred -- within an assertion expression, since we can get false warnings -- in this case, due to the out of order handling in this case. and then (Nkind (Original_Node (N)) /= N_Function_Call or else not In_Assertion_Expression_Pragma (Original_Node (N))) then Error_Msg_Warn := SPARK_Mode /= On; if Inst_Case then Error_Msg_NE ("instantiation of& may occur before body is seen> Output_Calls (N, Check_Elab_Flag => False); end if; end if; end Check_Internal_Call_Continue; --------------------------- -- Check_Task_Activation -- --------------------------- procedure Check_Task_Activation (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Inter_Procs : constant Elist_Id := New_Elmt_List; Intra_Procs : constant Elist_Id := New_Elmt_List; Ent : Entity_Id; P : Entity_Id; Task_Scope : Entity_Id; Cunit_SC : Boolean := False; Decl : Node_Id; Elmt : Elmt_Id; Enclosing : Entity_Id; procedure Add_Task_Proc (Typ : Entity_Id); -- Add to Task_Procs the task body procedure(s) of task types in Typ. -- For record types, this procedure recurses over component types. procedure Collect_Tasks (Decls : List_Id); -- Collect the types of the tasks that are to be activated in the given -- list of declarations, in order to perform elaboration checks on the -- corresponding task procedures that are called implicitly here. function Outer_Unit (E : Entity_Id) return Entity_Id; -- find enclosing compilation unit of Entity, ignoring subunits, or -- else enclosing subprogram. If E is not a package, there is no need -- for inter-unit elaboration checks. ------------------- -- Add_Task_Proc -- ------------------- procedure Add_Task_Proc (Typ : Entity_Id) is Comp : Entity_Id; Proc : Entity_Id := Empty; begin if Is_Task_Type (Typ) then Proc := Get_Task_Body_Procedure (Typ); elsif Is_Array_Type (Typ) and then Has_Task (Base_Type (Typ)) then Add_Task_Proc (Component_Type (Typ)); elsif Is_Record_Type (Typ) and then Has_Task (Base_Type (Typ)) then Comp := First_Component (Typ); while Present (Comp) loop Add_Task_Proc (Etype (Comp)); Comp := Next_Component (Comp); end loop; end if; -- If the task type is another unit, we will perform the usual -- elaboration check on its enclosing unit. If the type is in the -- same unit, we can trace the task body as for an internal call, -- but we only need to examine other external calls, because at -- the point the task is activated, internal subprogram bodies -- will have been elaborated already. We keep separate lists for -- each kind of task. -- Skip this test if errors have occurred, since in this case -- we can get false indications. if Serious_Errors_Detected /= 0 then return; end if; if Present (Proc) then if Outer_Unit (Scope (Proc)) = Enclosing then if No (Corresponding_Body (Unit_Declaration_Node (Proc))) and then (not Is_Generic_Instance (Scope (Proc)) or else Scope (Proc) = Scope (Defining_Identifier (Decl))) then Error_Msg_Warn := SPARK_Mode /= On; Error_Msg_N ("task will be activated before elaboration of its body<<", Decl); Error_Msg_N ("\Program_Error [<<", Decl); elsif Present (Corresponding_Body (Unit_Declaration_Node (Proc))) then Append_Elmt (Proc, Intra_Procs); end if; else -- No need for multiple entries of the same type Elmt := First_Elmt (Inter_Procs); while Present (Elmt) loop if Node (Elmt) = Proc then return; end if; Next_Elmt (Elmt); end loop; Append_Elmt (Proc, Inter_Procs); end if; end if; end Add_Task_Proc; ------------------- -- Collect_Tasks -- ------------------- procedure Collect_Tasks (Decls : List_Id) is begin if Present (Decls) then Decl := First (Decls); while Present (Decl) loop if Nkind (Decl) = N_Object_Declaration and then Has_Task (Etype (Defining_Identifier (Decl))) then Add_Task_Proc (Etype (Defining_Identifier (Decl))); end if; Next (Decl); end loop; end if; end Collect_Tasks; ---------------- -- Outer_Unit -- ---------------- function Outer_Unit (E : Entity_Id) return Entity_Id is Outer : Entity_Id; begin Outer := E; while Present (Outer) loop if Elaboration_Checks_Suppressed (Outer) then Cunit_SC := True; end if; exit when Is_Child_Unit (Outer) or else Scope (Outer) = Standard_Standard or else Ekind (Outer) /= E_Package; Outer := Scope (Outer); end loop; return Outer; end Outer_Unit; -- Start of processing for Check_Task_Activation begin pragma Assert (Legacy_Elaboration_Checks); Enclosing := Outer_Unit (Current_Scope); -- Find all tasks declared in the current unit if Nkind (N) = N_Package_Body then P := Unit_Declaration_Node (Corresponding_Spec (N)); Collect_Tasks (Declarations (N)); Collect_Tasks (Visible_Declarations (Specification (P))); Collect_Tasks (Private_Declarations (Specification (P))); elsif Nkind (N) = N_Package_Declaration then Collect_Tasks (Visible_Declarations (Specification (N))); Collect_Tasks (Private_Declarations (Specification (N))); else Collect_Tasks (Declarations (N)); end if; -- We only perform detailed checks in all tasks that are library level -- entities. If the master is a subprogram or task, activation will -- depend on the activation of the master itself. -- Should dynamic checks be added in the more general case??? if Ekind (Enclosing) /= E_Package then return; end if; -- For task types defined in other units, we want the unit containing -- the task body to be elaborated before the current one. Elmt := First_Elmt (Inter_Procs); while Present (Elmt) loop Ent := Node (Elmt); Task_Scope := Outer_Unit (Scope (Ent)); if not Is_Compilation_Unit (Task_Scope) then null; elsif Suppress_Elaboration_Warnings (Task_Scope) or else Elaboration_Checks_Suppressed (Task_Scope) then null; elsif Dynamic_Elaboration_Checks then if not Elaboration_Checks_Suppressed (Ent) and then not Cunit_SC and then not Restriction_Active (No_Entry_Calls_In_Elaboration_Code) then -- Runtime elaboration check required. Generate check of the -- elaboration counter for the unit containing the entity. Insert_Elab_Check (N, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Spec_Entity (Task_Scope), Loc), Attribute_Name => Name_Elaborated)); end if; else -- Force the binder to elaborate other unit first if Elab_Info_Messages and then not Suppress_Elaboration_Warnings (Ent) and then not Elaboration_Checks_Suppressed (Ent) and then not Suppress_Elaboration_Warnings (Task_Scope) and then not Elaboration_Checks_Suppressed (Task_Scope) then Error_Msg_Node_2 := Task_Scope; Error_Msg_NE ("info: activation of an instance of task type & requires " & "pragma Elaborate_All on &?$?", N, Ent); end if; Activate_Elaborate_All_Desirable (N, Task_Scope); Set_Suppress_Elaboration_Warnings (Task_Scope); end if; Next_Elmt (Elmt); end loop; -- For tasks declared in the current unit, trace other calls within the -- task procedure bodies, which are available. if not Debug_Flag_Dot_Y then In_Task_Activation := True; Elmt := First_Elmt (Intra_Procs); while Present (Elmt) loop Ent := Node (Elmt); Check_Internal_Call_Continue (N, Ent, Enclosing, Ent); Next_Elmt (Elmt); end loop; In_Task_Activation := False; end if; end Check_Task_Activation; ------------------------ -- Get_Referenced_Ent -- ------------------------ function Get_Referenced_Ent (N : Node_Id) return Entity_Id is Nam : Node_Id; begin if Nkind (N) in N_Has_Entity and then Present (Entity (N)) and then Ekind (Entity (N)) = E_Variable then return Entity (N); end if; if Nkind (N) = N_Attribute_Reference then Nam := Prefix (N); else Nam := Name (N); end if; if No (Nam) then return Empty; elsif Nkind (Nam) = N_Selected_Component then return Entity (Selector_Name (Nam)); elsif not Is_Entity_Name (Nam) then return Empty; else return Entity (Nam); end if; end Get_Referenced_Ent; ---------------------- -- Has_Generic_Body -- ---------------------- function Has_Generic_Body (N : Node_Id) return Boolean is Ent : constant Entity_Id := Get_Generic_Entity (N); Decl : constant Node_Id := Unit_Declaration_Node (Ent); Scop : Entity_Id; function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id; -- Determine if the list of nodes headed by N and linked by Next -- contains a package body for the package spec entity E, and if so -- return the package body. If not, then returns Empty. function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id; -- This procedure is called load the unit whose name is given by Nam. -- This unit is being loaded to see whether it contains an optional -- generic body. The returned value is the loaded unit, which is always -- a package body (only package bodies can contain other entities in the -- sense in which Has_Generic_Body is interested). We only attempt to -- load bodies if we are generating code. If we are in semantics check -- only mode, then it would be wrong to load bodies that are not -- required from a semantic point of view, so in this case we return -- Empty. The result is that the caller may incorrectly decide that a -- generic spec does not have a body when in fact it does, but the only -- harm in this is that some warnings on elaboration problems may be -- lost in semantic checks only mode, which is not big loss. We also -- return Empty if we go for a body and it is not there. function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id; -- PE is the entity for a package spec. This function locates the -- corresponding package body, returning Empty if none is found. The -- package body returned is fully parsed but may not yet be analyzed, -- so only syntactic fields should be referenced. ------------------ -- Find_Body_In -- ------------------ function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id is Nod : Node_Id; begin Nod := N; while Present (Nod) loop -- If we found the package body we are looking for, return it if Nkind (Nod) = N_Package_Body and then Chars (Defining_Unit_Name (Nod)) = Chars (E) then return Nod; -- If we found the stub for the body, go after the subunit, -- loading it if necessary. elsif Nkind (Nod) = N_Package_Body_Stub and then Chars (Defining_Identifier (Nod)) = Chars (E) then if Present (Library_Unit (Nod)) then return Unit (Library_Unit (Nod)); else return Load_Package_Body (Get_Unit_Name (Nod)); end if; -- If neither package body nor stub, keep looking on chain else Next (Nod); end if; end loop; return Empty; end Find_Body_In; ----------------------- -- Load_Package_Body -- ----------------------- function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id is U : Unit_Number_Type; begin if Operating_Mode /= Generate_Code then return Empty; else U := Load_Unit (Load_Name => Nam, Required => False, Subunit => False, Error_Node => N); if U = No_Unit then return Empty; else return Unit (Cunit (U)); end if; end if; end Load_Package_Body; ------------------------------- -- Locate_Corresponding_Body -- ------------------------------- function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id is Spec : constant Node_Id := Declaration_Node (PE); Decl : constant Node_Id := Parent (Spec); Scop : constant Entity_Id := Scope (PE); PBody : Node_Id; begin if Is_Library_Level_Entity (PE) then -- If package is a library unit that requires a body, we have no -- choice but to go after that body because it might contain an -- optional body for the original generic package. if Unit_Requires_Body (PE) then -- Load the body. Note that we are a little careful here to use -- Spec to get the unit number, rather than PE or Decl, since -- in the case where the package is itself a library level -- instantiation, Spec will properly reference the generic -- template, which is what we really want. return Load_Package_Body (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec)))); -- But if the package is a library unit that does NOT require -- a body, then no body is permitted, so we are sure that there -- is no body for the original generic package. else return Empty; end if; -- Otherwise look and see if we are embedded in a further package elsif Is_Package_Or_Generic_Package (Scop) then -- If so, get the body of the enclosing package, and look in -- its package body for the package body we are looking for. PBody := Locate_Corresponding_Body (Scop); if No (PBody) then return Empty; else return Find_Body_In (PE, First (Declarations (PBody))); end if; -- If we are not embedded in a further package, then the body -- must be in the same declarative part as we are. else return Find_Body_In (PE, Next (Decl)); end if; end Locate_Corresponding_Body; -- Start of processing for Has_Generic_Body begin if Present (Corresponding_Body (Decl)) then return True; elsif Unit_Requires_Body (Ent) then return True; -- Compilation units cannot have optional bodies elsif Is_Compilation_Unit (Ent) then return False; -- Otherwise look at what scope we are in else Scop := Scope (Ent); -- Case of entity is in other than a package spec, in this case -- the body, if present, must be in the same declarative part. if not Is_Package_Or_Generic_Package (Scop) then declare P : Node_Id; begin -- Declaration node may get us a spec, so if so, go to -- the parent declaration. P := Declaration_Node (Ent); while not Is_List_Member (P) loop P := Parent (P); end loop; return Present (Find_Body_In (Ent, Next (P))); end; -- If the entity is in a package spec, then we have to locate -- the corresponding package body, and look there. else declare PBody : constant Node_Id := Locate_Corresponding_Body (Scop); begin if No (PBody) then return False; else return Present (Find_Body_In (Ent, (First (Declarations (PBody))))); end if; end; end if; end if; end Has_Generic_Body; ----------------------- -- Insert_Elab_Check -- ----------------------- procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty) is Nod : Node_Id; Loc : constant Source_Ptr := Sloc (N); Chk : Node_Id; -- The check (N_Raise_Program_Error) node to be inserted begin -- If expansion is disabled, do not generate any checks. Also -- skip checks if any subunits are missing because in either -- case we lack the full information that we need, and no object -- file will be created in any case. if not Expander_Active or else Subunits_Missing then return; end if; -- If we have a generic instantiation, where Instance_Spec is set, -- then this field points to a generic instance spec that has -- been inserted before the instantiation node itself, so that -- is where we want to insert a check. if Nkind (N) in N_Generic_Instantiation and then Present (Instance_Spec (N)) then Nod := Instance_Spec (N); else Nod := N; end if; -- Build check node, possibly with condition Chk := Make_Raise_Program_Error (Loc, Reason => PE_Access_Before_Elaboration); if Present (C) then Set_Condition (Chk, Make_Op_Not (Loc, Right_Opnd => C)); end if; -- If we are inserting at the top level, insert in Aux_Decls if Nkind (Parent (Nod)) = N_Compilation_Unit then declare ADN : constant Node_Id := Aux_Decls_Node (Parent (Nod)); begin if No (Declarations (ADN)) then Set_Declarations (ADN, New_List (Chk)); else Append_To (Declarations (ADN), Chk); end if; Analyze (Chk); end; -- Otherwise just insert as an action on the node in question else Insert_Action (Nod, Chk); end if; end Insert_Elab_Check; ------------------------------- -- Is_Call_Of_Generic_Formal -- ------------------------------- function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean is begin return Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) -- Always return False if debug flag -gnatd.G is set and then not Debug_Flag_Dot_GG -- For now, we detect this by looking for the strange identifier -- node, whose Chars reflect the name of the generic formal, but -- the Chars of the Entity references the generic actual. and then Nkind (Name (N)) = N_Identifier and then Chars (Name (N)) /= Chars (Entity (Name (N))); end Is_Call_Of_Generic_Formal; ------------------------------- -- Is_Finalization_Procedure -- ------------------------------- function Is_Finalization_Procedure (Id : Entity_Id) return Boolean is begin -- Check whether Id is a procedure with at least one parameter if Ekind (Id) = E_Procedure and then Present (First_Formal (Id)) then declare Typ : constant Entity_Id := Etype (First_Formal (Id)); Deep_Fin : Entity_Id := Empty; Fin : Entity_Id := Empty; begin -- If the type of the first formal does not require finalization -- actions, then this is definitely not [Deep_]Finalize. if not Needs_Finalization (Typ) then return False; end if; -- At this point we have the following scenario: -- procedure Name (Param1 : [in] [out] Ctrl[; Param2 : ...]); -- Recover the two possible versions of [Deep_]Finalize using the -- type of the first parameter and compare with the input. Deep_Fin := TSS (Typ, TSS_Deep_Finalize); if Is_Controlled (Typ) then Fin := Find_Prim_Op (Typ, Name_Finalize); end if; return (Present (Deep_Fin) and then Id = Deep_Fin) or else (Present (Fin) and then Id = Fin); end; end if; return False; end Is_Finalization_Procedure; ------------------ -- Output_Calls -- ------------------ procedure Output_Calls (N : Node_Id; Check_Elab_Flag : Boolean) is function Emit (Flag : Boolean) return Boolean; -- Determine whether to emit an error message based on the combination -- of flags Check_Elab_Flag and Flag. function Is_Printable_Error_Name return Boolean; -- An internal function, used to determine if a name, stored in the -- Name_Buffer, is either a non-internal name, or is an internal name -- that is printable by the error message circuits (i.e. it has a single -- upper case letter at the end). ---------- -- Emit -- ---------- function Emit (Flag : Boolean) return Boolean is begin if Check_Elab_Flag then return Flag; else return True; end if; end Emit; ----------------------------- -- Is_Printable_Error_Name -- ----------------------------- function Is_Printable_Error_Name return Boolean is begin if not Is_Internal_Name then return True; elsif Name_Len = 1 then return False; else Name_Len := Name_Len - 1; return not Is_Internal_Name; end if; end Is_Printable_Error_Name; -- Local variables Ent : Entity_Id; -- Start of processing for Output_Calls begin for J in reverse 1 .. Elab_Call.Last loop Error_Msg_Sloc := Elab_Call.Table (J).Cloc; Ent := Elab_Call.Table (J).Ent; Get_Name_String (Chars (Ent)); -- Dynamic elaboration model, warnings controlled by -gnatwl if Dynamic_Elaboration_Checks then if Emit (Elab_Warnings) then if Is_Generic_Unit (Ent) then Error_Msg_NE ("\\?l?& instantiated #", N, Ent); elsif Is_Init_Proc (Ent) then Error_Msg_N ("\\?l?initialization procedure called #", N); elsif Is_Printable_Error_Name then Error_Msg_NE ("\\?l?& called #", N, Ent); else Error_Msg_N ("\\?l?called #", N); end if; end if; -- Static elaboration model, info messages controlled by -gnatel else if Emit (Elab_Info_Messages) then if Is_Generic_Unit (Ent) then Error_Msg_NE ("\\?$?& instantiated #", N, Ent); elsif Is_Init_Proc (Ent) then Error_Msg_N ("\\?$?initialization procedure called #", N); elsif Is_Printable_Error_Name then Error_Msg_NE ("\\?$?& called #", N, Ent); else Error_Msg_N ("\\?$?called #", N); end if; end if; end if; end loop; end Output_Calls; ---------------------------- -- Same_Elaboration_Scope -- ---------------------------- function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is S1 : Entity_Id; S2 : Entity_Id; begin -- Find elaboration scope for Scop1 -- This is either a subprogram or a compilation unit. S1 := Scop1; while S1 /= Standard_Standard and then not Is_Compilation_Unit (S1) and then Ekind_In (S1, E_Package, E_Protected_Type, E_Block) loop S1 := Scope (S1); end loop; -- Find elaboration scope for Scop2 S2 := Scop2; while S2 /= Standard_Standard and then not Is_Compilation_Unit (S2) and then Ekind_In (S2, E_Package, E_Protected_Type, E_Block) loop S2 := Scope (S2); end loop; return S1 = S2; end Same_Elaboration_Scope; ----------------- -- Set_C_Scope -- ----------------- procedure Set_C_Scope is begin while not Is_Compilation_Unit (C_Scope) loop C_Scope := Scope (C_Scope); end loop; end Set_C_Scope; -------------------------------- -- Set_Elaboration_Constraint -- -------------------------------- procedure Set_Elaboration_Constraint (Call : Node_Id; Subp : Entity_Id; Scop : Entity_Id) is Elab_Unit : Entity_Id; -- Check whether this is a call to an Initialize subprogram for a -- controlled type. Note that Call can also be a 'Access attribute -- reference, which now generates an elaboration check. Init_Call : constant Boolean := Nkind (Call) = N_Procedure_Call_Statement and then Chars (Subp) = Name_Initialize and then Comes_From_Source (Subp) and then Present (Parameter_Associations (Call)) and then Is_Controlled (Etype (First_Actual (Call))); begin -- If the unit is mentioned in a with_clause of the current unit, it is -- visible, and we can set the elaboration flag. if Is_Immediately_Visible (Scop) or else (Is_Child_Unit (Scop) and then Is_Visible_Lib_Unit (Scop)) then Activate_Elaborate_All_Desirable (Call, Scop); Set_Suppress_Elaboration_Warnings (Scop); return; end if; -- If this is not an initialization call or a call using object notation -- we know that the unit of the called entity is in the context, and we -- can set the flag as well. The unit need not be visible if the call -- occurs within an instantiation. if Is_Init_Proc (Subp) or else Init_Call or else Nkind (Original_Node (Call)) = N_Selected_Component then null; -- detailed processing follows. else Activate_Elaborate_All_Desirable (Call, Scop); Set_Suppress_Elaboration_Warnings (Scop); return; end if; -- If the unit is not in the context, there must be an intermediate unit -- that is, on which we need to place to elaboration flag. This happens -- with init proc calls. if Is_Init_Proc (Subp) or else Init_Call then -- The initialization call is on an object whose type is not declared -- in the same scope as the subprogram. The type of the object must -- be a subtype of the type of operation. This object is the first -- actual in the call. declare Typ : constant Entity_Id := Etype (First (Parameter_Associations (Call))); begin Elab_Unit := Scope (Typ); while (Present (Elab_Unit)) and then not Is_Compilation_Unit (Elab_Unit) loop Elab_Unit := Scope (Elab_Unit); end loop; end; -- If original node uses selected component notation, the prefix is -- visible and determines the scope that must be elaborated. After -- rewriting, the prefix is the first actual in the call. elsif Nkind (Original_Node (Call)) = N_Selected_Component then Elab_Unit := Scope (Etype (First (Parameter_Associations (Call)))); -- Not one of special cases above else -- Using previously computed scope. If the elaboration check is -- done after analysis, the scope is not visible any longer, but -- must still be in the context. Elab_Unit := Scop; end if; Activate_Elaborate_All_Desirable (Call, Elab_Unit); Set_Suppress_Elaboration_Warnings (Elab_Unit); end Set_Elaboration_Constraint; ----------------- -- Spec_Entity -- ----------------- function Spec_Entity (E : Entity_Id) return Entity_Id is Decl : Node_Id; begin -- Check for case of body entity -- Why is the check for E_Void needed??? if Ekind_In (E, E_Void, E_Subprogram_Body, E_Package_Body) then Decl := E; loop Decl := Parent (Decl); exit when Nkind (Decl) in N_Proper_Body; end loop; return Corresponding_Spec (Decl); else return E; end if; end Spec_Entity; ------------ -- Within -- ------------ function Within (E1, E2 : Entity_Id) return Boolean is Scop : Entity_Id; begin Scop := E1; loop if Scop = E2 then return True; elsif Scop = Standard_Standard then return False; else Scop := Scope (Scop); end if; end loop; end Within; -------------------------- -- Within_Elaborate_All -- -------------------------- function Within_Elaborate_All (Unit : Unit_Number_Type; E : Entity_Id) return Boolean is type Unit_Number_Set is array (Main_Unit .. Last_Unit) of Boolean; pragma Pack (Unit_Number_Set); Seen : Unit_Number_Set := (others => False); -- Seen (X) is True after we have seen unit X in the walk. This is used -- to prevent processing the same unit more than once. Result : Boolean := False; procedure Helper (Unit : Unit_Number_Type); -- This helper procedure does all the work for Within_Elaborate_All. It -- walks the dependency graph, and sets Result to True if it finds an -- appropriate Elaborate_All. ------------ -- Helper -- ------------ procedure Helper (Unit : Unit_Number_Type) is CU : constant Node_Id := Cunit (Unit); Item : Node_Id; Item2 : Node_Id; Elab_Id : Entity_Id; Par : Node_Id; begin if Seen (Unit) then return; else Seen (Unit) := True; end if; -- First, check for Elaborate_Alls on this unit Item := First (Context_Items (CU)); while Present (Item) loop if Nkind (Item) = N_Pragma and then Pragma_Name (Item) = Name_Elaborate_All then -- Return if some previous error on the pragma itself. The -- pragma may be unanalyzed, because of a previous error, or -- if it is the context of a subunit, inherited by its parent. if Error_Posted (Item) or else not Analyzed (Item) then return; end if; Elab_Id := Entity (Expression (First (Pragma_Argument_Associations (Item)))); if E = Elab_Id then Result := True; return; end if; Par := Parent (Unit_Declaration_Node (Elab_Id)); Item2 := First (Context_Items (Par)); while Present (Item2) loop if Nkind (Item2) = N_With_Clause and then Entity (Name (Item2)) = E and then not Limited_Present (Item2) then Result := True; return; end if; Next (Item2); end loop; end if; Next (Item); end loop; -- Second, recurse on with's. We could do this as part of the above -- loop, but it's probably more efficient to have two loops, because -- the relevant Elaborate_All is likely to be on the initial unit. In -- other words, we're walking the with's breadth-first. This part is -- only necessary in the dynamic elaboration model. if Dynamic_Elaboration_Checks then Item := First (Context_Items (CU)); while Present (Item) loop if Nkind (Item) = N_With_Clause and then not Limited_Present (Item) then -- Note: the following call to Get_Cunit_Unit_Number does a -- linear search, which could be slow, but it's OK because -- we're about to give a warning anyway. Also, there might -- be hundreds of units, but not millions. If it turns out -- to be a problem, we could store the Get_Cunit_Unit_Number -- in each N_Compilation_Unit node, but that would involve -- rearranging N_Compilation_Unit_Aux to make room. Helper (Get_Cunit_Unit_Number (Library_Unit (Item))); if Result then return; end if; end if; Next (Item); end loop; end if; end Helper; -- Start of processing for Within_Elaborate_All begin Helper (Unit); return Result; end Within_Elaborate_All; end Sem_Elab;