------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E X P _ U T I L -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2019, 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 Aspects; use Aspects; with Atree; use Atree; with Casing; use Casing; with Checks; use Checks; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Aggr; use Exp_Aggr; with Exp_Ch2; use Exp_Ch2; with Exp_Ch6; use Exp_Ch6; with Exp_Ch7; use Exp_Ch7; with Exp_Ch11; use Exp_Ch11; with Ghost; use Ghost; with Inline; use Inline; with Itypes; use Itypes; with Lib; use Lib; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Restrict; use Restrict; with Rident; use Rident; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Ch3; use Sem_Ch3; with Sem_Ch6; use Sem_Ch6; with Sem_Ch8; use Sem_Ch8; with Sem_Ch12; use Sem_Ch12; with Sem_Ch13; use Sem_Ch13; with Sem_Disp; use Sem_Disp; with Sem_Elab; use Sem_Elab; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Type; use Sem_Type; with Sem_Util; use Sem_Util; with Snames; use Snames; with Stand; use Stand; with Stringt; use Stringt; with Targparm; use Targparm; with Tbuild; use Tbuild; with Ttypes; use Ttypes; with Urealp; use Urealp; with Validsw; use Validsw; with GNAT.HTable; package body Exp_Util is --------------------------------------------------------- -- Handling of inherited class-wide pre/postconditions -- --------------------------------------------------------- -- Following AI12-0113, the expression for a class-wide condition is -- transformed for a subprogram that inherits it, by replacing calls -- to primitive operations of the original controlling type into the -- corresponding overriding operations of the derived type. The following -- hash table manages this mapping, and is expanded on demand whenever -- such inherited expression needs to be constructed. -- The mapping is also used to check whether an inherited operation has -- a condition that depends on overridden operations. For such an -- operation we must create a wrapper that is then treated as a normal -- overriding. In SPARK mode such operations are illegal. -- For a given root type there may be several type extensions with their -- own overriding operations, so at various times a given operation of -- the root will be mapped into different overridings. The root type is -- also mapped into the current type extension to indicate that its -- operations are mapped into the overriding operations of that current -- type extension. -- The contents of the map are as follows: -- Key Value -- Discriminant (Entity_Id) Discriminant (Entity_Id) -- Discriminant (Entity_Id) Non-discriminant name (Entity_Id) -- Discriminant (Entity_Id) Expression (Node_Id) -- Primitive subprogram (Entity_Id) Primitive subprogram (Entity_Id) -- Type (Entity_Id) Type (Entity_Id) Type_Map_Size : constant := 511; subtype Type_Map_Header is Integer range 0 .. Type_Map_Size - 1; function Type_Map_Hash (Id : Entity_Id) return Type_Map_Header; package Type_Map is new GNAT.HTable.Simple_HTable (Header_Num => Type_Map_Header, Key => Entity_Id, Element => Node_Or_Entity_Id, No_element => Empty, Hash => Type_Map_Hash, Equal => "="); ----------------------- -- Local Subprograms -- ----------------------- function Build_Task_Array_Image (Loc : Source_Ptr; Id_Ref : Node_Id; A_Type : Entity_Id; Dyn : Boolean := False) return Node_Id; -- Build function to generate the image string for a task that is an array -- component, concatenating the images of each index. To avoid storage -- leaks, the string is built with successive slice assignments. The flag -- Dyn indicates whether this is called for the initialization procedure of -- an array of tasks, or for the name of a dynamically created task that is -- assigned to an indexed component. function Build_Task_Image_Function (Loc : Source_Ptr; Decls : List_Id; Stats : List_Id; Res : Entity_Id) return Node_Id; -- Common processing for Task_Array_Image and Task_Record_Image. Build -- function body that computes image. procedure Build_Task_Image_Prefix (Loc : Source_Ptr; Len : out Entity_Id; Res : out Entity_Id; Pos : out Entity_Id; Prefix : Entity_Id; Sum : Node_Id; Decls : List_Id; Stats : List_Id); -- Common processing for Task_Array_Image and Task_Record_Image. Create -- local variables and assign prefix of name to result string. function Build_Task_Record_Image (Loc : Source_Ptr; Id_Ref : Node_Id; Dyn : Boolean := False) return Node_Id; -- Build function to generate the image string for a task that is a record -- component. Concatenate name of variable with that of selector. The flag -- Dyn indicates whether this is called for the initialization procedure of -- record with task components, or for a dynamically created task that is -- assigned to a selected component. procedure Evaluate_Slice_Bounds (Slice : Node_Id); -- Force evaluation of bounds of a slice, which may be given by a range -- or by a subtype indication with or without a constraint. function Is_Verifiable_DIC_Pragma (Prag : Node_Id) return Boolean; -- Determine whether pragma Default_Initial_Condition denoted by Prag has -- an assertion expression that should be verified at run time. function Make_CW_Equivalent_Type (T : Entity_Id; E : Node_Id) return Entity_Id; -- T is a class-wide type entity, E is the initial expression node that -- constrains T in case such as: " X: T := E" or "new T'(E)". This function -- returns the entity of the Equivalent type and inserts on the fly the -- necessary declaration such as: -- -- type anon is record -- _parent : Root_Type (T); constrained with E discriminants (if any) -- Extension : String (1 .. expr to match size of E); -- end record; -- -- This record is compatible with any object of the class of T thanks to -- the first field and has the same size as E thanks to the second. function Make_Literal_Range (Loc : Source_Ptr; Literal_Typ : Entity_Id) return Node_Id; -- Produce a Range node whose bounds are: -- Low_Bound (Literal_Type) .. -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1) -- this is used for expanding declarations like X : String := "sdfgdfg"; -- -- If the index type of the target array is not integer, we generate: -- Low_Bound (Literal_Type) .. -- Literal_Type'Val -- (Literal_Type'Pos (Low_Bound (Literal_Type)) -- + (Length (Literal_Typ) -1)) function Make_Non_Empty_Check (Loc : Source_Ptr; N : Node_Id) return Node_Id; -- Produce a boolean expression checking that the unidimensional array -- node N is not empty. function New_Class_Wide_Subtype (CW_Typ : Entity_Id; N : Node_Id) return Entity_Id; -- Create an implicit subtype of CW_Typ attached to node N function Requires_Cleanup_Actions (L : List_Id; Lib_Level : Boolean; Nested_Constructs : Boolean) return Boolean; -- Given a list L, determine whether it contains one of the following: -- -- 1) controlled objects -- 2) library-level tagged types -- -- Lib_Level is True when the list comes from a construct at the library -- level, and False otherwise. Nested_Constructs is True when any nested -- packages declared in L must be processed, and False otherwise. ------------------------------------- -- Activate_Atomic_Synchronization -- ------------------------------------- procedure Activate_Atomic_Synchronization (N : Node_Id) is Msg_Node : Node_Id; begin case Nkind (Parent (N)) is -- Check for cases of appearing in the prefix of a construct where we -- don't need atomic synchronization for this kind of usage. when -- Nothing to do if we are the prefix of an attribute, since we -- do not want an atomic sync operation for things like 'Size. N_Attribute_Reference -- The N_Reference node is like an attribute | N_Reference -- Nothing to do for a reference to a component (or components) -- of a composite object. Only reads and updates of the object -- as a whole require atomic synchronization (RM C.6 (15)). | N_Indexed_Component | N_Selected_Component | N_Slice => -- For all the above cases, nothing to do if we are the prefix if Prefix (Parent (N)) = N then return; end if; when others => null; end case; -- Nothing to do for the identifier in an object renaming declaration, -- the renaming itself does not need atomic synchronization. if Nkind (Parent (N)) = N_Object_Renaming_Declaration then return; end if; -- Go ahead and set the flag Set_Atomic_Sync_Required (N); -- Generate info message if requested if Warn_On_Atomic_Synchronization then case Nkind (N) is when N_Identifier => Msg_Node := N; when N_Expanded_Name | N_Selected_Component => Msg_Node := Selector_Name (N); when N_Explicit_Dereference | N_Indexed_Component => Msg_Node := Empty; when others => pragma Assert (False); return; end case; if Present (Msg_Node) then Error_Msg_N ("info: atomic synchronization set for &?N?", Msg_Node); else Error_Msg_N ("info: atomic synchronization set?N?", N); end if; end if; end Activate_Atomic_Synchronization; ---------------------- -- Adjust_Condition -- ---------------------- procedure Adjust_Condition (N : Node_Id) is begin if No (N) then return; end if; declare Loc : constant Source_Ptr := Sloc (N); T : constant Entity_Id := Etype (N); Ti : Entity_Id; begin -- Defend against a call where the argument has no type, or has a -- type that is not Boolean. This can occur because of prior errors. if No (T) or else not Is_Boolean_Type (T) then return; end if; -- Apply validity checking if needed if Validity_Checks_On and Validity_Check_Tests then Ensure_Valid (N); end if; -- Immediate return if standard boolean, the most common case, -- where nothing needs to be done. if Base_Type (T) = Standard_Boolean then return; end if; -- Case of zero/nonzero semantics or nonstandard enumeration -- representation. In each case, we rewrite the node as: -- ityp!(N) /= False'Enum_Rep -- where ityp is an integer type with large enough size to hold any -- value of type T. if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then if Esize (T) <= Esize (Standard_Integer) then Ti := Standard_Integer; else Ti := Standard_Long_Long_Integer; end if; Rewrite (N, Make_Op_Ne (Loc, Left_Opnd => Unchecked_Convert_To (Ti, N), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Enum_Rep, Prefix => New_Occurrence_Of (First_Literal (T), Loc)))); Analyze_And_Resolve (N, Standard_Boolean); else Rewrite (N, Convert_To (Standard_Boolean, N)); Analyze_And_Resolve (N, Standard_Boolean); end if; end; end Adjust_Condition; ------------------------ -- Adjust_Result_Type -- ------------------------ procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is begin -- Ignore call if current type is not Standard.Boolean if Etype (N) /= Standard_Boolean then return; end if; -- If result is already of correct type, nothing to do. Note that -- this will get the most common case where everything has a type -- of Standard.Boolean. if Base_Type (T) = Standard_Boolean then return; else declare KP : constant Node_Kind := Nkind (Parent (N)); begin -- If result is to be used as a Condition in the syntax, no need -- to convert it back, since if it was changed to Standard.Boolean -- using Adjust_Condition, that is just fine for this usage. if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then return; -- If result is an operand of another logical operation, no need -- to reset its type, since Standard.Boolean is just fine, and -- such operations always do Adjust_Condition on their operands. elsif KP in N_Op_Boolean or else KP in N_Short_Circuit or else KP = N_Op_Not then return; -- Otherwise we perform a conversion from the current type, which -- must be Standard.Boolean, to the desired type. Use the base -- type to prevent spurious constraint checks that are extraneous -- to the transformation. The type and its base have the same -- representation, standard or otherwise. else Set_Analyzed (N); Rewrite (N, Convert_To (Base_Type (T), N)); Analyze_And_Resolve (N, Base_Type (T)); end if; end; end if; end Adjust_Result_Type; -------------------------- -- Append_Freeze_Action -- -------------------------- procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is Fnode : Node_Id; begin Ensure_Freeze_Node (T); Fnode := Freeze_Node (T); if No (Actions (Fnode)) then Set_Actions (Fnode, New_List (N)); else Append (N, Actions (Fnode)); end if; end Append_Freeze_Action; --------------------------- -- Append_Freeze_Actions -- --------------------------- procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is Fnode : Node_Id; begin if No (L) then return; end if; Ensure_Freeze_Node (T); Fnode := Freeze_Node (T); if No (Actions (Fnode)) then Set_Actions (Fnode, L); else Append_List (L, Actions (Fnode)); end if; end Append_Freeze_Actions; -------------------------------------- -- Attr_Constrained_Statically_True -- -------------------------------------- function Attribute_Constrained_Static_Value (Pref : Node_Id) return Boolean is Ptyp : constant Entity_Id := Etype (Pref); Formal_Ent : constant Entity_Id := Param_Entity (Pref); function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean; -- Ada 2005 (AI-363): Returns True if the object name Obj denotes a -- view of an aliased object whose subtype is constrained. --------------------------------- -- Is_Constrained_Aliased_View -- --------------------------------- function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is E : Entity_Id; begin if Is_Entity_Name (Obj) then E := Entity (Obj); if Present (Renamed_Object (E)) then return Is_Constrained_Aliased_View (Renamed_Object (E)); else return Is_Aliased (E) and then Is_Constrained (Etype (E)); end if; else return Is_Aliased_View (Obj) and then (Is_Constrained (Etype (Obj)) or else (Nkind (Obj) = N_Explicit_Dereference and then not Object_Type_Has_Constrained_Partial_View (Typ => Base_Type (Etype (Obj)), Scop => Current_Scope))); end if; end Is_Constrained_Aliased_View; -- Start of processing for Attribute_Constrained_Static_Value begin -- We are in a case where the attribute is known statically, and -- implicit dereferences have been rewritten. pragma Assert (not (Present (Formal_Ent) and then Ekind (Formal_Ent) /= E_Constant and then Present (Extra_Constrained (Formal_Ent))) and then not (Is_Access_Type (Etype (Pref)) and then (not Is_Entity_Name (Pref) or else Is_Object (Entity (Pref)))) and then not (Nkind (Pref) = N_Identifier and then Ekind (Entity (Pref)) = E_Variable and then Present (Extra_Constrained (Entity (Pref))))); if Is_Entity_Name (Pref) then declare Ent : constant Entity_Id := Entity (Pref); Res : Boolean; begin -- (RM J.4) obsolescent cases if Is_Type (Ent) then -- Private type if Is_Private_Type (Ent) then Res := not Has_Discriminants (Ent) or else Is_Constrained (Ent); -- It not a private type, must be a generic actual type -- that corresponded to a private type. We know that this -- correspondence holds, since otherwise the reference -- within the generic template would have been illegal. else if Is_Composite_Type (Underlying_Type (Ent)) then Res := Is_Constrained (Ent); else Res := True; end if; end if; else -- If the prefix is not a variable or is aliased, then -- definitely true; if it's a formal parameter without an -- associated extra formal, then treat it as constrained. -- Ada 2005 (AI-363): An aliased prefix must be known to be -- constrained in order to set the attribute to True. if not Is_Variable (Pref) or else Present (Formal_Ent) or else (Ada_Version < Ada_2005 and then Is_Aliased_View (Pref)) or else (Ada_Version >= Ada_2005 and then Is_Constrained_Aliased_View (Pref)) then Res := True; -- Variable case, look at type to see if it is constrained. -- Note that the one case where this is not accurate (the -- procedure formal case), has been handled above. -- We use the Underlying_Type here (and below) in case the -- type is private without discriminants, but the full type -- has discriminants. This case is illegal, but we generate -- it internally for passing to the Extra_Constrained -- parameter. else -- In Ada 2012, test for case of a limited tagged type, -- in which case the attribute is always required to -- return True. The underlying type is tested, to make -- sure we also return True for cases where there is an -- unconstrained object with an untagged limited partial -- view which has defaulted discriminants (such objects -- always produce a False in earlier versions of -- Ada). (Ada 2012: AI05-0214) Res := Is_Constrained (Underlying_Type (Etype (Ent))) or else (Ada_Version >= Ada_2012 and then Is_Tagged_Type (Underlying_Type (Ptyp)) and then Is_Limited_Type (Ptyp)); end if; end if; return Res; end; -- Prefix is not an entity name. These are also cases where we can -- always tell at compile time by looking at the form and type of the -- prefix. If an explicit dereference of an object with constrained -- partial view, this is unconstrained (Ada 2005: AI95-0363). If the -- underlying type is a limited tagged type, then Constrained is -- required to always return True (Ada 2012: AI05-0214). else return not Is_Variable (Pref) or else (Nkind (Pref) = N_Explicit_Dereference and then not Object_Type_Has_Constrained_Partial_View (Typ => Base_Type (Ptyp), Scop => Current_Scope)) or else Is_Constrained (Underlying_Type (Ptyp)) or else (Ada_Version >= Ada_2012 and then Is_Tagged_Type (Underlying_Type (Ptyp)) and then Is_Limited_Type (Ptyp)); end if; end Attribute_Constrained_Static_Value; ------------------------------------ -- Build_Allocate_Deallocate_Proc -- ------------------------------------ procedure Build_Allocate_Deallocate_Proc (N : Node_Id; Is_Allocate : Boolean) is function Find_Object (E : Node_Id) return Node_Id; -- Given an arbitrary expression of an allocator, try to find an object -- reference in it, otherwise return the original expression. function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean; -- Determine whether subprogram Subp denotes a custom allocate or -- deallocate. ----------------- -- Find_Object -- ----------------- function Find_Object (E : Node_Id) return Node_Id is Expr : Node_Id; begin pragma Assert (Is_Allocate); Expr := E; loop if Nkind (Expr) = N_Explicit_Dereference then Expr := Prefix (Expr); elsif Nkind (Expr) = N_Qualified_Expression then Expr := Expression (Expr); elsif Nkind (Expr) = N_Unchecked_Type_Conversion then -- When interface class-wide types are involved in allocation, -- the expander introduces several levels of address arithmetic -- to perform dispatch table displacement. In this scenario the -- object appears as: -- Tag_Ptr (Base_Address ('Address)) -- Detect this case and utilize the whole expression as the -- "object" since it now points to the proper dispatch table. if Is_RTE (Etype (Expr), RE_Tag_Ptr) then exit; -- Continue to strip the object else Expr := Expression (Expr); end if; else exit; end if; end loop; return Expr; end Find_Object; --------------------------------- -- Is_Allocate_Deallocate_Proc -- --------------------------------- function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean is begin -- Look for a subprogram body with only one statement which is a -- call to Allocate_Any_Controlled / Deallocate_Any_Controlled. if Ekind (Subp) = E_Procedure and then Nkind (Parent (Parent (Subp))) = N_Subprogram_Body then declare HSS : constant Node_Id := Handled_Statement_Sequence (Parent (Parent (Subp))); Proc : Entity_Id; begin if Present (Statements (HSS)) and then Nkind (First (Statements (HSS))) = N_Procedure_Call_Statement then Proc := Entity (Name (First (Statements (HSS)))); return Is_RTE (Proc, RE_Allocate_Any_Controlled) or else Is_RTE (Proc, RE_Deallocate_Any_Controlled); end if; end; end if; return False; end Is_Allocate_Deallocate_Proc; -- Local variables Desig_Typ : Entity_Id; Expr : Node_Id; Needs_Fin : Boolean; Pool_Id : Entity_Id; Proc_To_Call : Node_Id := Empty; Ptr_Typ : Entity_Id; -- Start of processing for Build_Allocate_Deallocate_Proc begin -- Obtain the attributes of the allocation / deallocation if Nkind (N) = N_Free_Statement then Expr := Expression (N); Ptr_Typ := Base_Type (Etype (Expr)); Proc_To_Call := Procedure_To_Call (N); else if Nkind (N) = N_Object_Declaration then Expr := Expression (N); else Expr := N; end if; -- In certain cases an allocator with a qualified expression may -- be relocated and used as the initialization expression of a -- temporary: -- before: -- Obj : Ptr_Typ := new Desig_Typ'(...); -- after: -- Tmp : Ptr_Typ := new Desig_Typ'(...); -- Obj : Ptr_Typ := Tmp; -- Since the allocator is always marked as analyzed to avoid infinite -- expansion, it will never be processed by this routine given that -- the designated type needs finalization actions. Detect this case -- and complete the expansion of the allocator. if Nkind (Expr) = N_Identifier and then Nkind (Parent (Entity (Expr))) = N_Object_Declaration and then Nkind (Expression (Parent (Entity (Expr)))) = N_Allocator then Build_Allocate_Deallocate_Proc (Parent (Entity (Expr)), True); return; end if; -- The allocator may have been rewritten into something else in which -- case the expansion performed by this routine does not apply. if Nkind (Expr) /= N_Allocator then return; end if; Ptr_Typ := Base_Type (Etype (Expr)); Proc_To_Call := Procedure_To_Call (Expr); end if; Pool_Id := Associated_Storage_Pool (Ptr_Typ); Desig_Typ := Available_View (Designated_Type (Ptr_Typ)); -- Handle concurrent types if Is_Concurrent_Type (Desig_Typ) and then Present (Corresponding_Record_Type (Desig_Typ)) then Desig_Typ := Corresponding_Record_Type (Desig_Typ); end if; -- Do not process allocations / deallocations without a pool if No (Pool_Id) then return; -- Do not process allocations on / deallocations from the secondary -- stack. elsif Is_RTE (Pool_Id, RE_SS_Pool) or else (Nkind (Expr) = N_Allocator and then Is_RTE (Storage_Pool (Expr), RE_SS_Pool)) then return; -- Optimize the case where we are using the default Global_Pool_Object, -- and we don't need the heavy finalization machinery. elsif Pool_Id = RTE (RE_Global_Pool_Object) and then not Needs_Finalization (Desig_Typ) then return; -- Do not replicate the machinery if the allocator / free has already -- been expanded and has a custom Allocate / Deallocate. elsif Present (Proc_To_Call) and then Is_Allocate_Deallocate_Proc (Proc_To_Call) then return; end if; -- Finalization actions are required when the object to be allocated or -- deallocated needs these actions and the associated access type is not -- subject to pragma No_Heap_Finalization. Needs_Fin := Needs_Finalization (Desig_Typ) and then not No_Heap_Finalization (Ptr_Typ); if Needs_Fin then -- Do nothing if the access type may never allocate / deallocate -- objects. if No_Pool_Assigned (Ptr_Typ) then return; end if; -- The allocation / deallocation of a controlled object must be -- chained on / detached from a finalization master. pragma Assert (Present (Finalization_Master (Ptr_Typ))); -- The only other kind of allocation / deallocation supported by this -- routine is on / from a subpool. elsif Nkind (Expr) = N_Allocator and then No (Subpool_Handle_Name (Expr)) then return; end if; declare Loc : constant Source_Ptr := Sloc (N); Addr_Id : constant Entity_Id := Make_Temporary (Loc, 'A'); Alig_Id : constant Entity_Id := Make_Temporary (Loc, 'L'); Proc_Id : constant Entity_Id := Make_Temporary (Loc, 'P'); Size_Id : constant Entity_Id := Make_Temporary (Loc, 'S'); Actuals : List_Id; Fin_Addr_Id : Entity_Id; Fin_Mas_Act : Node_Id; Fin_Mas_Id : Entity_Id; Proc_To_Call : Entity_Id; Subpool : Node_Id := Empty; begin -- Step 1: Construct all the actuals for the call to library routine -- Allocate_Any_Controlled / Deallocate_Any_Controlled. -- a) Storage pool Actuals := New_List (New_Occurrence_Of (Pool_Id, Loc)); if Is_Allocate then -- b) Subpool if Nkind (Expr) = N_Allocator then Subpool := Subpool_Handle_Name (Expr); end if; -- If a subpool is present it can be an arbitrary name, so make -- the actual by copying the tree. if Present (Subpool) then Append_To (Actuals, New_Copy_Tree (Subpool, New_Sloc => Loc)); else Append_To (Actuals, Make_Null (Loc)); end if; -- c) Finalization master if Needs_Fin then Fin_Mas_Id := Finalization_Master (Ptr_Typ); Fin_Mas_Act := New_Occurrence_Of (Fin_Mas_Id, Loc); -- Handle the case where the master is actually a pointer to a -- master. This case arises in build-in-place functions. if Is_Access_Type (Etype (Fin_Mas_Id)) then Append_To (Actuals, Fin_Mas_Act); else Append_To (Actuals, Make_Attribute_Reference (Loc, Prefix => Fin_Mas_Act, Attribute_Name => Name_Unrestricted_Access)); end if; else Append_To (Actuals, Make_Null (Loc)); end if; -- d) Finalize_Address -- Primitive Finalize_Address is never generated in CodePeer mode -- since it contains an Unchecked_Conversion. if Needs_Fin and then not CodePeer_Mode then Fin_Addr_Id := Finalize_Address (Desig_Typ); pragma Assert (Present (Fin_Addr_Id)); Append_To (Actuals, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Fin_Addr_Id, Loc), Attribute_Name => Name_Unrestricted_Access)); else Append_To (Actuals, Make_Null (Loc)); end if; end if; -- e) Address -- f) Storage_Size -- g) Alignment Append_To (Actuals, New_Occurrence_Of (Addr_Id, Loc)); Append_To (Actuals, New_Occurrence_Of (Size_Id, Loc)); if Is_Allocate or else not Is_Class_Wide_Type (Desig_Typ) then Append_To (Actuals, New_Occurrence_Of (Alig_Id, Loc)); -- For deallocation of class-wide types we obtain the value of -- alignment from the Type Specific Record of the deallocated object. -- This is needed because the frontend expansion of class-wide types -- into equivalent types confuses the back end. else -- Generate: -- Obj.all'Alignment -- ... because 'Alignment applied to class-wide types is expanded -- into the code that reads the value of alignment from the TSD -- (see Expand_N_Attribute_Reference) Append_To (Actuals, Unchecked_Convert_To (RTE (RE_Storage_Offset), Make_Attribute_Reference (Loc, Prefix => Make_Explicit_Dereference (Loc, Relocate_Node (Expr)), Attribute_Name => Name_Alignment))); end if; -- h) Is_Controlled if Needs_Fin then Is_Controlled : declare Flag_Id : constant Entity_Id := Make_Temporary (Loc, 'F'); Flag_Expr : Node_Id; Param : Node_Id; Pref : Node_Id; Temp : Node_Id; begin if Is_Allocate then Temp := Find_Object (Expression (Expr)); else Temp := Expr; end if; -- Processing for allocations where the expression is a subtype -- indication. if Is_Allocate and then Is_Entity_Name (Temp) and then Is_Type (Entity (Temp)) then Flag_Expr := New_Occurrence_Of (Boolean_Literals (Needs_Finalization (Entity (Temp))), Loc); -- The allocation / deallocation of a class-wide object relies -- on a runtime check to determine whether the object is truly -- controlled or not. Depending on this check, the finalization -- machinery will request or reclaim extra storage reserved for -- a list header. elsif Is_Class_Wide_Type (Desig_Typ) then -- Detect a special case where interface class-wide types -- are involved as the object appears as: -- Tag_Ptr (Base_Address ('Address)) -- The expression already yields the proper tag, generate: -- Temp.all if Is_RTE (Etype (Temp), RE_Tag_Ptr) then Param := Make_Explicit_Dereference (Loc, Prefix => Relocate_Node (Temp)); -- In the default case, obtain the tag of the object about -- to be allocated / deallocated. Generate: -- Temp'Tag -- If the object is an unchecked conversion (typically to -- an access to class-wide type), we must preserve the -- conversion to ensure that the object is seen as tagged -- in the code that follows. else Pref := Temp; if Nkind (Parent (Pref)) = N_Unchecked_Type_Conversion then Pref := Parent (Pref); end if; Param := Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Pref), Attribute_Name => Name_Tag); end if; -- Generate: -- Needs_Finalization () Flag_Expr := Make_Function_Call (Loc, Name => New_Occurrence_Of (RTE (RE_Needs_Finalization), Loc), Parameter_Associations => New_List (Param)); -- Processing for generic actuals elsif Is_Generic_Actual_Type (Desig_Typ) then Flag_Expr := New_Occurrence_Of (Boolean_Literals (Needs_Finalization (Base_Type (Desig_Typ))), Loc); -- The object does not require any specialized checks, it is -- known to be controlled. else Flag_Expr := New_Occurrence_Of (Standard_True, Loc); end if; -- Create the temporary which represents the finalization state -- of the expression. Generate: -- -- F : constant Boolean := ; Insert_Action (N, Make_Object_Declaration (Loc, Defining_Identifier => Flag_Id, Constant_Present => True, Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc), Expression => Flag_Expr)); Append_To (Actuals, New_Occurrence_Of (Flag_Id, Loc)); end Is_Controlled; -- The object is not controlled else Append_To (Actuals, New_Occurrence_Of (Standard_False, Loc)); end if; -- i) On_Subpool if Is_Allocate then Append_To (Actuals, New_Occurrence_Of (Boolean_Literals (Present (Subpool)), Loc)); end if; -- Step 2: Build a wrapper Allocate / Deallocate which internally -- calls Allocate_Any_Controlled / Deallocate_Any_Controlled. -- Select the proper routine to call if Is_Allocate then Proc_To_Call := RTE (RE_Allocate_Any_Controlled); else Proc_To_Call := RTE (RE_Deallocate_Any_Controlled); end if; -- Create a custom Allocate / Deallocate routine which has identical -- profile to that of System.Storage_Pools. Insert_Action (N, Make_Subprogram_Body (Loc, Specification => -- procedure Pnn Make_Procedure_Specification (Loc, Defining_Unit_Name => Proc_Id, Parameter_Specifications => New_List ( -- P : Root_Storage_Pool Make_Parameter_Specification (Loc, Defining_Identifier => Make_Temporary (Loc, 'P'), Parameter_Type => New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc)), -- A : [out] Address Make_Parameter_Specification (Loc, Defining_Identifier => Addr_Id, Out_Present => Is_Allocate, Parameter_Type => New_Occurrence_Of (RTE (RE_Address), Loc)), -- S : Storage_Count Make_Parameter_Specification (Loc, Defining_Identifier => Size_Id, Parameter_Type => New_Occurrence_Of (RTE (RE_Storage_Count), Loc)), -- L : Storage_Count Make_Parameter_Specification (Loc, Defining_Identifier => Alig_Id, Parameter_Type => New_Occurrence_Of (RTE (RE_Storage_Count), Loc)))), Declarations => No_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_To_Call, Loc), Parameter_Associations => Actuals)))), Suppress => All_Checks); -- The newly generated Allocate / Deallocate becomes the default -- procedure to call when the back end processes the allocation / -- deallocation. if Is_Allocate then Set_Procedure_To_Call (Expr, Proc_Id); else Set_Procedure_To_Call (N, Proc_Id); end if; end; end Build_Allocate_Deallocate_Proc; ------------------------------- -- Build_Abort_Undefer_Block -- ------------------------------- function Build_Abort_Undefer_Block (Loc : Source_Ptr; Stmts : List_Id; Context : Node_Id) return Node_Id is Exceptions_OK : constant Boolean := not Restriction_Active (No_Exception_Propagation); AUD : Entity_Id; Blk : Node_Id; Blk_Id : Entity_Id; HSS : Node_Id; begin -- The block should be generated only when undeferring abort in the -- context of a potential exception. pragma Assert (Abort_Allowed and Exceptions_OK); -- Generate: -- begin -- -- at end -- Abort_Undefer_Direct; -- end; AUD := RTE (RE_Abort_Undefer_Direct); HSS := Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts, At_End_Proc => New_Occurrence_Of (AUD, Loc)); Blk := Make_Block_Statement (Loc, Handled_Statement_Sequence => HSS); Set_Is_Abort_Block (Blk); Add_Block_Identifier (Blk, Blk_Id); Expand_At_End_Handler (HSS, Blk_Id); -- Present the Abort_Undefer_Direct function to the back end to inline -- the call to the routine. Add_Inlined_Body (AUD, Context); return Blk; end Build_Abort_Undefer_Block; --------------------------------- -- Build_Class_Wide_Expression -- --------------------------------- procedure Build_Class_Wide_Expression (Prag : Node_Id; Subp : Entity_Id; Par_Subp : Entity_Id; Adjust_Sloc : Boolean; Needs_Wrapper : out Boolean) is function Replace_Entity (N : Node_Id) return Traverse_Result; -- Replace reference to formal of inherited operation or to primitive -- operation of root type, with corresponding entity for derived type, -- when constructing the class-wide condition of an overriding -- subprogram. -------------------- -- Replace_Entity -- -------------------- function Replace_Entity (N : Node_Id) return Traverse_Result is New_E : Entity_Id; begin if Adjust_Sloc then Adjust_Inherited_Pragma_Sloc (N); end if; if Nkind (N) = N_Identifier and then Present (Entity (N)) and then (Is_Formal (Entity (N)) or else Is_Subprogram (Entity (N))) and then (Nkind (Parent (N)) /= N_Attribute_Reference or else Attribute_Name (Parent (N)) /= Name_Class) then -- The replacement does not apply to dispatching calls within the -- condition, but only to calls whose static tag is that of the -- parent type. if Is_Subprogram (Entity (N)) and then Nkind (Parent (N)) = N_Function_Call and then Present (Controlling_Argument (Parent (N))) then return OK; end if; -- Determine whether entity has a renaming New_E := Type_Map.Get (Entity (N)); if Present (New_E) then Rewrite (N, New_Occurrence_Of (New_E, Sloc (N))); -- AI12-0166: a precondition for a protected operation -- cannot include an internal call to a protected function -- of the type. In the case of an inherited condition for an -- overriding operation, both the operation and the function -- are given by primitive wrappers. if Ekind (New_E) = E_Function and then Is_Primitive_Wrapper (New_E) and then Is_Primitive_Wrapper (Subp) and then Scope (Subp) = Scope (New_E) then Error_Msg_Node_2 := Wrapped_Entity (Subp); Error_Msg_NE ("internal call to& cannot appear in inherited " & "precondition of protected operation&", N, Wrapped_Entity (New_E)); end if; -- If the entity is an overridden primitive and we are not -- in GNATprove mode, we must build a wrapper for the current -- inherited operation. If the reference is the prefix of an -- attribute such as 'Result (or others ???) there is no need -- for a wrapper: the condition is just rewritten in terms of -- the inherited subprogram. if Is_Subprogram (New_E) and then Nkind (Parent (N)) /= N_Attribute_Reference and then not GNATprove_Mode then Needs_Wrapper := True; end if; end if; -- Check that there are no calls left to abstract operations if -- the current subprogram is not abstract. if Nkind (Parent (N)) = N_Function_Call and then N = Name (Parent (N)) then if not Is_Abstract_Subprogram (Subp) and then Is_Abstract_Subprogram (Entity (N)) then Error_Msg_Sloc := Sloc (Current_Scope); Error_Msg_Node_2 := Subp; if Comes_From_Source (Subp) then Error_Msg_NE ("cannot call abstract subprogram & in inherited " & "condition for&#", Subp, Entity (N)); else Error_Msg_NE ("cannot call abstract subprogram & in inherited " & "condition for inherited&#", Subp, Entity (N)); end if; -- In SPARK mode, reject an inherited condition for an -- inherited operation if it contains a call to an overriding -- operation, because this implies that the pre/postconditions -- of the inherited operation have changed silently. elsif SPARK_Mode = On and then Warn_On_Suspicious_Contract and then Present (Alias (Subp)) and then Present (New_E) and then Comes_From_Source (New_E) then Error_Msg_N ("cannot modify inherited condition (SPARK RM 6.1.1(1))", Parent (Subp)); Error_Msg_Sloc := Sloc (New_E); Error_Msg_Node_2 := Subp; Error_Msg_NE ("\overriding of&# forces overriding of&", Parent (Subp), New_E); end if; end if; -- Update type of function call node, which should be the same as -- the function's return type. if Is_Subprogram (Entity (N)) and then Nkind (Parent (N)) = N_Function_Call then Set_Etype (Parent (N), Etype (Entity (N))); end if; -- The whole expression will be reanalyzed elsif Nkind (N) in N_Has_Etype then Set_Analyzed (N, False); end if; return OK; end Replace_Entity; procedure Replace_Condition_Entities is new Traverse_Proc (Replace_Entity); -- Local variables Par_Formal : Entity_Id; Subp_Formal : Entity_Id; -- Start of processing for Build_Class_Wide_Expression begin Needs_Wrapper := False; -- Add mapping from old formals to new formals Par_Formal := First_Formal (Par_Subp); Subp_Formal := First_Formal (Subp); while Present (Par_Formal) and then Present (Subp_Formal) loop Type_Map.Set (Par_Formal, Subp_Formal); Next_Formal (Par_Formal); Next_Formal (Subp_Formal); end loop; Replace_Condition_Entities (Prag); end Build_Class_Wide_Expression; -------------------- -- Build_DIC_Call -- -------------------- function Build_DIC_Call (Loc : Source_Ptr; Obj_Id : Entity_Id; Typ : Entity_Id) return Node_Id is Proc_Id : constant Entity_Id := DIC_Procedure (Typ); Formal_Typ : constant Entity_Id := Etype (First_Formal (Proc_Id)); begin return Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Id, Loc), Parameter_Associations => New_List ( Make_Unchecked_Type_Conversion (Loc, Subtype_Mark => New_Occurrence_Of (Formal_Typ, Loc), Expression => New_Occurrence_Of (Obj_Id, Loc)))); end Build_DIC_Call; ------------------------------ -- Build_DIC_Procedure_Body -- ------------------------------ -- WARNING: This routine manages Ghost regions. Return statements must be -- replaced by gotos which jump to the end of the routine and restore the -- Ghost mode. procedure Build_DIC_Procedure_Body (Typ : Entity_Id; For_Freeze : Boolean := False) is procedure Add_DIC_Check (DIC_Prag : Node_Id; DIC_Expr : Node_Id; Stmts : in out List_Id); -- Subsidiary to all Add_xxx_DIC routines. Add a runtime check to verify -- assertion expression DIC_Expr of pragma DIC_Prag. All generated code -- is added to list Stmts. procedure Add_Inherited_DIC (DIC_Prag : Node_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Stmts : in out List_Id); -- Add a runtime check to verify the assertion expression of inherited -- pragma DIC_Prag. Par_Typ is parent type, which is also the owner of -- the DIC pragma. Deriv_Typ is the derived type inheriting the DIC -- pragma. All generated code is added to list Stmts. procedure Add_Inherited_Tagged_DIC (DIC_Prag : Node_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Stmts : in out List_Id); -- Add a runtime check to verify assertion expression DIC_Expr of -- inherited pragma DIC_Prag. This routine applies class-wide pre- and -- postcondition-like runtime semantics to the check. Par_Typ is the -- parent type whose DIC pragma is being inherited. Deriv_Typ is the -- derived type inheriting the DIC pragma. All generated code is added -- to list Stmts. procedure Add_Own_DIC (DIC_Prag : Node_Id; DIC_Typ : Entity_Id; Stmts : in out List_Id); -- Add a runtime check to verify the assertion expression of pragma -- DIC_Prag. DIC_Typ is the owner of the DIC pragma. All generated code -- is added to list Stmts. ------------------- -- Add_DIC_Check -- ------------------- procedure Add_DIC_Check (DIC_Prag : Node_Id; DIC_Expr : Node_Id; Stmts : in out List_Id) is Loc : constant Source_Ptr := Sloc (DIC_Prag); Nam : constant Name_Id := Original_Aspect_Pragma_Name (DIC_Prag); begin -- The DIC pragma is ignored, nothing left to do if Is_Ignored (DIC_Prag) then null; -- Otherwise the DIC expression must be checked at run time. -- Generate: -- pragma Check (, ); else Append_New_To (Stmts, Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Loc, Name_Check), Pragma_Argument_Associations => New_List ( Make_Pragma_Argument_Association (Loc, Expression => Make_Identifier (Loc, Nam)), Make_Pragma_Argument_Association (Loc, Expression => DIC_Expr)))); end if; end Add_DIC_Check; ----------------------- -- Add_Inherited_DIC -- ----------------------- procedure Add_Inherited_DIC (DIC_Prag : Node_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Stmts : in out List_Id) is Deriv_Proc : constant Entity_Id := DIC_Procedure (Deriv_Typ); Deriv_Obj : constant Entity_Id := First_Entity (Deriv_Proc); Par_Proc : constant Entity_Id := DIC_Procedure (Par_Typ); Par_Obj : constant Entity_Id := First_Entity (Par_Proc); Loc : constant Source_Ptr := Sloc (DIC_Prag); begin pragma Assert (Present (Deriv_Proc) and then Present (Par_Proc)); -- Verify the inherited DIC assertion expression by calling the DIC -- procedure of the parent type. -- Generate: -- DIC (Par_Typ (_object)); Append_New_To (Stmts, Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Par_Proc, Loc), Parameter_Associations => New_List ( Convert_To (Typ => Etype (Par_Obj), Expr => New_Occurrence_Of (Deriv_Obj, Loc))))); end Add_Inherited_DIC; ------------------------------ -- Add_Inherited_Tagged_DIC -- ------------------------------ procedure Add_Inherited_Tagged_DIC (DIC_Prag : Node_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Stmts : in out List_Id) is Deriv_Proc : constant Entity_Id := DIC_Procedure (Deriv_Typ); DIC_Args : constant List_Id := Pragma_Argument_Associations (DIC_Prag); DIC_Arg : constant Node_Id := First (DIC_Args); DIC_Expr : constant Node_Id := Expression_Copy (DIC_Arg); Par_Proc : constant Entity_Id := DIC_Procedure (Par_Typ); Expr : Node_Id; begin -- The processing of an inherited DIC assertion expression starts off -- with a copy of the original parent expression where all references -- to the parent type have already been replaced with references to -- the _object formal parameter of the parent type's DIC procedure. pragma Assert (Present (DIC_Expr)); Expr := New_Copy_Tree (DIC_Expr); -- Perform the following substitutions: -- * Replace a reference to the _object parameter of the parent -- type's DIC procedure with a reference to the _object parameter -- of the derived types' DIC procedure. -- * Replace a reference to a discriminant of the parent type with -- a suitable value from the point of view of the derived type. -- * Replace a call to an overridden parent primitive with a call -- to the overriding derived type primitive. -- * Replace a call to an inherited parent primitive with a call to -- the internally-generated inherited derived type primitive. -- Note that primitives defined in the private part are automatically -- handled by the overriding/inheritance mechanism and do not require -- an extra replacement pass. pragma Assert (Present (Deriv_Proc) and then Present (Par_Proc)); Replace_References (Expr => Expr, Par_Typ => Par_Typ, Deriv_Typ => Deriv_Typ, Par_Obj => First_Formal (Par_Proc), Deriv_Obj => First_Formal (Deriv_Proc)); -- Once the DIC assertion expression is fully processed, add a check -- to the statements of the DIC procedure. Add_DIC_Check (DIC_Prag => DIC_Prag, DIC_Expr => Expr, Stmts => Stmts); end Add_Inherited_Tagged_DIC; ----------------- -- Add_Own_DIC -- ----------------- procedure Add_Own_DIC (DIC_Prag : Node_Id; DIC_Typ : Entity_Id; Stmts : in out List_Id) is DIC_Args : constant List_Id := Pragma_Argument_Associations (DIC_Prag); DIC_Arg : constant Node_Id := First (DIC_Args); DIC_Asp : constant Node_Id := Corresponding_Aspect (DIC_Prag); DIC_Expr : constant Node_Id := Get_Pragma_Arg (DIC_Arg); DIC_Proc : constant Entity_Id := DIC_Procedure (DIC_Typ); Obj_Id : constant Entity_Id := First_Formal (DIC_Proc); procedure Preanalyze_Own_DIC_For_ASIS; -- Preanalyze the original DIC expression of an aspect or a source -- pragma for ASIS. --------------------------------- -- Preanalyze_Own_DIC_For_ASIS -- --------------------------------- procedure Preanalyze_Own_DIC_For_ASIS is Expr : Node_Id := Empty; begin -- The DIC pragma is a source construct, preanalyze the original -- expression of the pragma. if Comes_From_Source (DIC_Prag) then Expr := DIC_Expr; -- Otherwise preanalyze the expression of the corresponding aspect elsif Present (DIC_Asp) then Expr := Expression (DIC_Asp); end if; -- The expression must be subjected to the same substitutions as -- the copy used in the generation of the runtime check. if Present (Expr) then Replace_Type_References (Expr => Expr, Typ => DIC_Typ, Obj_Id => Obj_Id); Preanalyze_Assert_Expression (Expr, Any_Boolean); end if; end Preanalyze_Own_DIC_For_ASIS; -- Local variables Typ_Decl : constant Node_Id := Declaration_Node (DIC_Typ); Expr : Node_Id; -- Start of processing for Add_Own_DIC begin pragma Assert (Present (DIC_Expr)); Expr := New_Copy_Tree (DIC_Expr); -- Perform the following substitution: -- * Replace the current instance of DIC_Typ with a reference to -- the _object formal parameter of the DIC procedure. Replace_Type_References (Expr => Expr, Typ => DIC_Typ, Obj_Id => Obj_Id); -- Preanalyze the DIC expression to detect errors and at the same -- time capture the visibility of the proper package part. Set_Parent (Expr, Typ_Decl); Preanalyze_Assert_Expression (Expr, Any_Boolean); -- Save a copy of the expression with all replacements and analysis -- already taken place in case a derived type inherits the pragma. -- The copy will be used as the foundation of the derived type's own -- version of the DIC assertion expression. if Is_Tagged_Type (DIC_Typ) then Set_Expression_Copy (DIC_Arg, New_Copy_Tree (Expr)); end if; -- If the pragma comes from an aspect specification, replace the -- saved expression because all type references must be substituted -- for the call to Preanalyze_Spec_Expression in Check_Aspect_At_xxx -- routines. if Present (DIC_Asp) then Set_Entity (Identifier (DIC_Asp), New_Copy_Tree (Expr)); end if; -- Preanalyze the original DIC expression for ASIS if ASIS_Mode then Preanalyze_Own_DIC_For_ASIS; end if; -- Once the DIC assertion expression is fully processed, add a check -- to the statements of the DIC procedure. Add_DIC_Check (DIC_Prag => DIC_Prag, DIC_Expr => Expr, Stmts => Stmts); end Add_Own_DIC; -- Local variables Loc : constant Source_Ptr := Sloc (Typ); Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; Saved_IGR : constant Node_Id := Ignored_Ghost_Region; -- Save the Ghost-related attributes to restore on exit DIC_Prag : Node_Id; DIC_Typ : Entity_Id; Dummy_1 : Entity_Id; Dummy_2 : Entity_Id; Proc_Body : Node_Id; Proc_Body_Id : Entity_Id; Proc_Decl : Node_Id; Proc_Id : Entity_Id; Stmts : List_Id := No_List; Build_Body : Boolean := False; -- Flag set when the type requires a DIC procedure body to be built Work_Typ : Entity_Id; -- The working type -- Start of processing for Build_DIC_Procedure_Body begin Work_Typ := Base_Type (Typ); -- Do not process class-wide types as these are Itypes, but lack a first -- subtype (see below). if Is_Class_Wide_Type (Work_Typ) then return; -- Do not process the underlying full view of a private type. There is -- no way to get back to the partial view, plus the body will be built -- by the full view or the base type. elsif Is_Underlying_Full_View (Work_Typ) then return; -- Use the first subtype when dealing with various base types elsif Is_Itype (Work_Typ) then Work_Typ := First_Subtype (Work_Typ); -- The input denotes the corresponding record type of a protected or a -- task type. Work with the concurrent type because the corresponding -- record type may not be visible to clients of the type. elsif Ekind (Work_Typ) = E_Record_Type and then Is_Concurrent_Record_Type (Work_Typ) then Work_Typ := Corresponding_Concurrent_Type (Work_Typ); end if; -- The working type may be subject to pragma Ghost. Set the mode now to -- ensure that the DIC procedure is properly marked as Ghost. Set_Ghost_Mode (Work_Typ); -- The working type must be either define a DIC pragma of its own or -- inherit one from a parent type. pragma Assert (Has_DIC (Work_Typ)); -- Recover the type which defines the DIC pragma. This is either the -- working type itself or a parent type when the pragma is inherited. DIC_Typ := Find_DIC_Type (Work_Typ); pragma Assert (Present (DIC_Typ)); DIC_Prag := Get_Pragma (DIC_Typ, Pragma_Default_Initial_Condition); pragma Assert (Present (DIC_Prag)); -- Nothing to do if pragma DIC appears without an argument or its sole -- argument is "null". if not Is_Verifiable_DIC_Pragma (DIC_Prag) then goto Leave; end if; -- The working type may lack a DIC procedure declaration. This may be -- due to several reasons: -- * The working type's own DIC pragma does not contain a verifiable -- assertion expression. In this case there is no need to build a -- DIC procedure because there is nothing to check. -- * The working type derives from a parent type. In this case a DIC -- procedure should be built only when the inherited DIC pragma has -- a verifiable assertion expression. Proc_Id := DIC_Procedure (Work_Typ); -- Build a DIC procedure declaration when the working type derives from -- a parent type. if No (Proc_Id) then Build_DIC_Procedure_Declaration (Work_Typ); Proc_Id := DIC_Procedure (Work_Typ); end if; -- At this point there should be a DIC procedure declaration pragma Assert (Present (Proc_Id)); Proc_Decl := Unit_Declaration_Node (Proc_Id); -- Nothing to do if the DIC procedure already has a body if Present (Corresponding_Body (Proc_Decl)) then goto Leave; end if; -- Emulate the environment of the DIC procedure by installing its scope -- and formal parameters. Push_Scope (Proc_Id); Install_Formals (Proc_Id); -- The working type defines its own DIC pragma. Replace the current -- instance of the working type with the formal of the DIC procedure. -- Note that there is no need to consider inherited DIC pragmas from -- parent types because the working type's DIC pragma "hides" all -- inherited DIC pragmas. if Has_Own_DIC (Work_Typ) then pragma Assert (DIC_Typ = Work_Typ); Add_Own_DIC (DIC_Prag => DIC_Prag, DIC_Typ => DIC_Typ, Stmts => Stmts); Build_Body := True; -- Otherwise the working type inherits a DIC pragma from a parent type. -- This processing is carried out when the type is frozen because the -- state of all parent discriminants is known at that point. Note that -- it is semantically sound to delay the creation of the DIC procedure -- body till the freeze point. If the type has a DIC pragma of its own, -- then the DIC procedure body would have already been constructed at -- the end of the visible declarations and all parent DIC pragmas are -- effectively "hidden" and irrelevant. elsif For_Freeze then pragma Assert (Has_Inherited_DIC (Work_Typ)); pragma Assert (DIC_Typ /= Work_Typ); -- The working type is tagged. The verification of the assertion -- expression is subject to the same semantics as class-wide pre- -- and postconditions. if Is_Tagged_Type (Work_Typ) then Add_Inherited_Tagged_DIC (DIC_Prag => DIC_Prag, Par_Typ => DIC_Typ, Deriv_Typ => Work_Typ, Stmts => Stmts); -- Otherwise the working type is not tagged. Verify the assertion -- expression of the inherited DIC pragma by directly calling the -- DIC procedure of the parent type. else Add_Inherited_DIC (DIC_Prag => DIC_Prag, Par_Typ => DIC_Typ, Deriv_Typ => Work_Typ, Stmts => Stmts); end if; Build_Body := True; end if; End_Scope; if Build_Body then -- Produce an empty completing body in the following cases: -- * Assertions are disabled -- * The DIC Assertion_Policy is Ignore if No (Stmts) then Stmts := New_List (Make_Null_Statement (Loc)); end if; -- Generate: -- procedure DIC (_object : ) is -- begin -- -- end DIC; Proc_Body := Make_Subprogram_Body (Loc, Specification => Copy_Subprogram_Spec (Parent (Proc_Id)), Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)); Proc_Body_Id := Defining_Entity (Proc_Body); -- Perform minor decoration in case the body is not analyzed Set_Ekind (Proc_Body_Id, E_Subprogram_Body); Set_Etype (Proc_Body_Id, Standard_Void_Type); Set_Scope (Proc_Body_Id, Current_Scope); Set_SPARK_Pragma (Proc_Body_Id, SPARK_Pragma (Proc_Id)); Set_SPARK_Pragma_Inherited (Proc_Body_Id, SPARK_Pragma_Inherited (Proc_Id)); -- Link both spec and body to avoid generating duplicates Set_Corresponding_Body (Proc_Decl, Proc_Body_Id); Set_Corresponding_Spec (Proc_Body, Proc_Id); -- The body should not be inserted into the tree when the context -- is ASIS or a generic unit because it is not part of the template. -- Note that the body must still be generated in order to resolve the -- DIC assertion expression. if ASIS_Mode or Inside_A_Generic then null; -- Semi-insert the body into the tree for GNATprove by setting its -- Parent field. This allows for proper upstream tree traversals. elsif GNATprove_Mode then Set_Parent (Proc_Body, Parent (Declaration_Node (Work_Typ))); -- Otherwise the body is part of the freezing actions of the working -- type. else Append_Freeze_Action (Work_Typ, Proc_Body); end if; end if; <> Restore_Ghost_Region (Saved_GM, Saved_IGR); end Build_DIC_Procedure_Body; ------------------------------------- -- Build_DIC_Procedure_Declaration -- ------------------------------------- -- WARNING: This routine manages Ghost regions. Return statements must be -- replaced by gotos which jump to the end of the routine and restore the -- Ghost mode. procedure Build_DIC_Procedure_Declaration (Typ : Entity_Id) is Loc : constant Source_Ptr := Sloc (Typ); Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; Saved_IGR : constant Node_Id := Ignored_Ghost_Region; -- Save the Ghost-related attributes to restore on exit DIC_Prag : Node_Id; DIC_Typ : Entity_Id; Proc_Decl : Node_Id; Proc_Id : Entity_Id; Typ_Decl : Node_Id; CRec_Typ : Entity_Id; -- The corresponding record type of Full_Typ Full_Base : Entity_Id; -- The base type of Full_Typ Full_Typ : Entity_Id; -- The full view of working type Obj_Id : Entity_Id; -- The _object formal parameter of the DIC procedure Priv_Typ : Entity_Id; -- The partial view of working type Work_Typ : Entity_Id; -- The working type begin Work_Typ := Base_Type (Typ); -- Do not process class-wide types as these are Itypes, but lack a first -- subtype (see below). if Is_Class_Wide_Type (Work_Typ) then return; -- Do not process the underlying full view of a private type. There is -- no way to get back to the partial view, plus the body will be built -- by the full view or the base type. elsif Is_Underlying_Full_View (Work_Typ) then return; -- Use the first subtype when dealing with various base types elsif Is_Itype (Work_Typ) then Work_Typ := First_Subtype (Work_Typ); -- The input denotes the corresponding record type of a protected or a -- task type. Work with the concurrent type because the corresponding -- record type may not be visible to clients of the type. elsif Ekind (Work_Typ) = E_Record_Type and then Is_Concurrent_Record_Type (Work_Typ) then Work_Typ := Corresponding_Concurrent_Type (Work_Typ); end if; -- The working type may be subject to pragma Ghost. Set the mode now to -- ensure that the DIC procedure is properly marked as Ghost. Set_Ghost_Mode (Work_Typ); -- The type must be either subject to a DIC pragma or inherit one from a -- parent type. pragma Assert (Has_DIC (Work_Typ)); -- Recover the type which defines the DIC pragma. This is either the -- working type itself or a parent type when the pragma is inherited. DIC_Typ := Find_DIC_Type (Work_Typ); pragma Assert (Present (DIC_Typ)); DIC_Prag := Get_Pragma (DIC_Typ, Pragma_Default_Initial_Condition); pragma Assert (Present (DIC_Prag)); -- Nothing to do if pragma DIC appears without an argument or its sole -- argument is "null". if not Is_Verifiable_DIC_Pragma (DIC_Prag) then goto Leave; -- Nothing to do if the type already has a DIC procedure elsif Present (DIC_Procedure (Work_Typ)) then goto Leave; end if; Proc_Id := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Work_Typ), "Default_Initial_Condition")); -- Perform minor decoration in case the declaration is not analyzed Set_Ekind (Proc_Id, E_Procedure); Set_Etype (Proc_Id, Standard_Void_Type); Set_Is_DIC_Procedure (Proc_Id); Set_Scope (Proc_Id, Current_Scope); Set_SPARK_Pragma (Proc_Id, SPARK_Mode_Pragma); Set_SPARK_Pragma_Inherited (Proc_Id); Set_DIC_Procedure (Work_Typ, Proc_Id); -- The DIC procedure requires debug info when the assertion expression -- is subject to Source Coverage Obligations. if Generate_SCO then Set_Debug_Info_Needed (Proc_Id); end if; -- Obtain all views of the input type Get_Views (Work_Typ, Priv_Typ, Full_Typ, Full_Base, CRec_Typ); -- Associate the DIC procedure and various relevant flags with all views Propagate_DIC_Attributes (Priv_Typ, From_Typ => Work_Typ); Propagate_DIC_Attributes (Full_Typ, From_Typ => Work_Typ); Propagate_DIC_Attributes (Full_Base, From_Typ => Work_Typ); Propagate_DIC_Attributes (CRec_Typ, From_Typ => Work_Typ); -- The declaration of the DIC procedure must be inserted after the -- declaration of the partial view as this allows for proper external -- visibility. if Present (Priv_Typ) then Typ_Decl := Declaration_Node (Priv_Typ); -- Derived types with the full view as parent do not have a partial -- view. Insert the DIC procedure after the derived type. else Typ_Decl := Declaration_Node (Full_Typ); end if; -- The type should have a declarative node pragma Assert (Present (Typ_Decl)); -- Create the formal parameter which emulates the variable-like behavior -- of the type's current instance. Obj_Id := Make_Defining_Identifier (Loc, Chars => Name_uObject); -- Perform minor decoration in case the declaration is not analyzed Set_Ekind (Obj_Id, E_In_Parameter); Set_Etype (Obj_Id, Work_Typ); Set_Scope (Obj_Id, Proc_Id); Set_First_Entity (Proc_Id, Obj_Id); Set_Last_Entity (Proc_Id, Obj_Id); -- Generate: -- procedure DIC (_object : ); Proc_Decl := Make_Subprogram_Declaration (Loc, Specification => Make_Procedure_Specification (Loc, Defining_Unit_Name => Proc_Id, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Obj_Id, Parameter_Type => New_Occurrence_Of (Work_Typ, Loc))))); -- The declaration should not be inserted into the tree when the context -- is ASIS or a generic unit because it is not part of the template. if ASIS_Mode or Inside_A_Generic then null; -- Semi-insert the declaration into the tree for GNATprove by setting -- its Parent field. This allows for proper upstream tree traversals. elsif GNATprove_Mode then Set_Parent (Proc_Decl, Parent (Typ_Decl)); -- Otherwise insert the declaration else Insert_After_And_Analyze (Typ_Decl, Proc_Decl); end if; <> Restore_Ghost_Region (Saved_GM, Saved_IGR); end Build_DIC_Procedure_Declaration; ------------------------------------ -- Build_Invariant_Procedure_Body -- ------------------------------------ -- WARNING: This routine manages Ghost regions. Return statements must be -- replaced by gotos which jump to the end of the routine and restore the -- Ghost mode. procedure Build_Invariant_Procedure_Body (Typ : Entity_Id; Partial_Invariant : Boolean := False) is Loc : constant Source_Ptr := Sloc (Typ); Pragmas_Seen : Elist_Id := No_Elist; -- This list contains all invariant pragmas processed so far. The list -- is used to avoid generating redundant invariant checks. Produced_Check : Boolean := False; -- This flag tracks whether the type has produced at least one invariant -- check. The flag is used as a sanity check at the end of the routine. -- NOTE: most of the routines in Build_Invariant_Procedure_Body are -- intentionally unnested to avoid deep indentation of code. -- NOTE: all Add_xxx_Invariants routines are reactive. In other words -- they emit checks, loops (for arrays) and case statements (for record -- variant parts) only when there are invariants to verify. This keeps -- the body of the invariant procedure free of useless code. procedure Add_Array_Component_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id); -- Generate an invariant check for each component of array type T. -- Obj_Id denotes the entity of the _object formal parameter of the -- invariant procedure. All created checks are added to list Checks. procedure Add_Inherited_Invariants (T : Entity_Id; Priv_Typ : Entity_Id; Full_Typ : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id); -- Generate an invariant check for each inherited class-wide invariant -- coming from all parent types of type T. Priv_Typ and Full_Typ denote -- the partial and full view of the parent type. Obj_Id denotes the -- entity of the _object formal parameter of the invariant procedure. -- All created checks are added to list Checks. procedure Add_Interface_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id); -- Generate an invariant check for each inherited class-wide invariant -- coming from all interfaces implemented by type T. Obj_Id denotes the -- entity of the _object formal parameter of the invariant procedure. -- All created checks are added to list Checks. procedure Add_Invariant_Check (Prag : Node_Id; Expr : Node_Id; Checks : in out List_Id; Inherited : Boolean := False); -- Subsidiary to all Add_xxx_Invariant routines. Add a runtime check to -- verify assertion expression Expr of pragma Prag. All generated code -- is added to list Checks. Flag Inherited should be set when the pragma -- is inherited from a parent or interface type. procedure Add_Own_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id; Priv_Item : Node_Id := Empty); -- Generate an invariant check for each invariant found for type T. -- Obj_Id denotes the entity of the _object formal parameter of the -- invariant procedure. All created checks are added to list Checks. -- Priv_Item denotes the first rep item of the private type. procedure Add_Parent_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id); -- Generate an invariant check for each inherited class-wide invariant -- coming from all parent types of type T. Obj_Id denotes the entity of -- the _object formal parameter of the invariant procedure. All created -- checks are added to list Checks. procedure Add_Record_Component_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id); -- Generate an invariant check for each component of record type T. -- Obj_Id denotes the entity of the _object formal parameter of the -- invariant procedure. All created checks are added to list Checks. ------------------------------------ -- Add_Array_Component_Invariants -- ------------------------------------ procedure Add_Array_Component_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id) is Comp_Typ : constant Entity_Id := Component_Type (T); Dims : constant Pos := Number_Dimensions (T); procedure Process_Array_Component (Indices : List_Id; Comp_Checks : in out List_Id); -- Generate an invariant check for an array component identified by -- the indices in list Indices. All created checks are added to list -- Comp_Checks. procedure Process_One_Dimension (Dim : Pos; Indices : List_Id; Dim_Checks : in out List_Id); -- Generate a loop over the Nth dimension Dim of an array type. List -- Indices contains all array indices for the dimension. All created -- checks are added to list Dim_Checks. ----------------------------- -- Process_Array_Component -- ----------------------------- procedure Process_Array_Component (Indices : List_Id; Comp_Checks : in out List_Id) is Proc_Id : Entity_Id; begin if Has_Invariants (Comp_Typ) then -- In GNATprove mode, the component invariants are checked by -- other means. They should not be added to the array type -- invariant procedure, so that the procedure can be used to -- check the array type invariants if any. if GNATprove_Mode then null; else Proc_Id := Invariant_Procedure (Base_Type (Comp_Typ)); -- The component type should have an invariant procedure -- if it has invariants of its own or inherits class-wide -- invariants from parent or interface types. pragma Assert (Present (Proc_Id)); -- Generate: -- Invariant (_object ()); -- Note that the invariant procedure may have a null body if -- assertions are disabled or Assertion_Policy Ignore is in -- effect. if not Has_Null_Body (Proc_Id) then Append_New_To (Comp_Checks, Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Id, Loc), Parameter_Associations => New_List ( Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Obj_Id, Loc), Expressions => New_Copy_List (Indices))))); end if; end if; Produced_Check := True; end if; end Process_Array_Component; --------------------------- -- Process_One_Dimension -- --------------------------- procedure Process_One_Dimension (Dim : Pos; Indices : List_Id; Dim_Checks : in out List_Id) is Comp_Checks : List_Id := No_List; Index : Entity_Id; begin -- Generate the invariant checks for the array component after all -- dimensions have produced their respective loops. if Dim > Dims then Process_Array_Component (Indices => Indices, Comp_Checks => Dim_Checks); -- Otherwise create a loop for the current dimension else -- Create a new loop variable for each dimension Index := Make_Defining_Identifier (Loc, Chars => New_External_Name ('I', Dim)); Append_To (Indices, New_Occurrence_Of (Index, Loc)); Process_One_Dimension (Dim => Dim + 1, Indices => Indices, Dim_Checks => Comp_Checks); -- Generate: -- for I in _object'Range () loop -- -- end loop; -- Note that the invariant procedure may have a null body if -- assertions are disabled or Assertion_Policy Ignore is in -- effect. if Present (Comp_Checks) then Append_New_To (Dim_Checks, Make_Implicit_Loop_Statement (T, Identifier => Empty, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => Index, Discrete_Subtype_Definition => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Obj_Id, Loc), Attribute_Name => Name_Range, Expressions => New_List ( Make_Integer_Literal (Loc, Dim))))), Statements => Comp_Checks)); end if; end if; end Process_One_Dimension; -- Start of processing for Add_Array_Component_Invariants begin Process_One_Dimension (Dim => 1, Indices => New_List, Dim_Checks => Checks); end Add_Array_Component_Invariants; ------------------------------ -- Add_Inherited_Invariants -- ------------------------------ procedure Add_Inherited_Invariants (T : Entity_Id; Priv_Typ : Entity_Id; Full_Typ : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id) is Deriv_Typ : Entity_Id; Expr : Node_Id; Prag : Node_Id; Prag_Expr : Node_Id; Prag_Expr_Arg : Node_Id; Prag_Typ : Node_Id; Prag_Typ_Arg : Node_Id; Par_Proc : Entity_Id; -- The "partial" invariant procedure of Par_Typ Par_Typ : Entity_Id; -- The suitable view of the parent type used in the substitution of -- type attributes. begin if not Present (Priv_Typ) and then not Present (Full_Typ) then return; end if; -- When the type inheriting the class-wide invariant is a concurrent -- type, use the corresponding record type because it contains all -- primitive operations of the concurrent type and allows for proper -- substitution. if Is_Concurrent_Type (T) then Deriv_Typ := Corresponding_Record_Type (T); else Deriv_Typ := T; end if; pragma Assert (Present (Deriv_Typ)); -- Determine which rep item chain to use. Precedence is given to that -- of the parent type's partial view since it usually carries all the -- class-wide invariants. if Present (Priv_Typ) then Prag := First_Rep_Item (Priv_Typ); else Prag := First_Rep_Item (Full_Typ); end if; while Present (Prag) loop if Nkind (Prag) = N_Pragma and then Pragma_Name (Prag) = Name_Invariant then -- Nothing to do if the pragma was already processed if Contains (Pragmas_Seen, Prag) then return; -- Nothing to do when the caller requests the processing of all -- inherited class-wide invariants, but the pragma does not -- fall in this category. elsif not Class_Present (Prag) then return; end if; -- Extract the arguments of the invariant pragma Prag_Typ_Arg := First (Pragma_Argument_Associations (Prag)); Prag_Expr_Arg := Next (Prag_Typ_Arg); Prag_Expr := Expression_Copy (Prag_Expr_Arg); Prag_Typ := Get_Pragma_Arg (Prag_Typ_Arg); -- The pragma applies to the partial view of the parent type if Present (Priv_Typ) and then Entity (Prag_Typ) = Priv_Typ then Par_Typ := Priv_Typ; -- The pragma applies to the full view of the parent type elsif Present (Full_Typ) and then Entity (Prag_Typ) = Full_Typ then Par_Typ := Full_Typ; -- Otherwise the pragma does not belong to the parent type and -- should not be considered. else return; end if; -- Perform the following substitutions: -- * Replace a reference to the _object parameter of the -- parent type's partial invariant procedure with a -- reference to the _object parameter of the derived -- type's full invariant procedure. -- * Replace a reference to a discriminant of the parent type -- with a suitable value from the point of view of the -- derived type. -- * Replace a call to an overridden parent primitive with a -- call to the overriding derived type primitive. -- * Replace a call to an inherited parent primitive with a -- call to the internally-generated inherited derived type -- primitive. Expr := New_Copy_Tree (Prag_Expr); -- The parent type must have a "partial" invariant procedure -- because class-wide invariants are captured exclusively by -- it. Par_Proc := Partial_Invariant_Procedure (Par_Typ); pragma Assert (Present (Par_Proc)); Replace_References (Expr => Expr, Par_Typ => Par_Typ, Deriv_Typ => Deriv_Typ, Par_Obj => First_Formal (Par_Proc), Deriv_Obj => Obj_Id); Add_Invariant_Check (Prag, Expr, Checks, Inherited => True); end if; Next_Rep_Item (Prag); end loop; end Add_Inherited_Invariants; ------------------------------ -- Add_Interface_Invariants -- ------------------------------ procedure Add_Interface_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id) is Iface_Elmt : Elmt_Id; Ifaces : Elist_Id; begin -- Generate an invariant check for each class-wide invariant coming -- from all interfaces implemented by type T. if Is_Tagged_Type (T) then Collect_Interfaces (T, Ifaces); -- Process the class-wide invariants of all implemented interfaces Iface_Elmt := First_Elmt (Ifaces); while Present (Iface_Elmt) loop -- The Full_Typ parameter is intentionally left Empty because -- interfaces are treated as the partial view of a private type -- in order to achieve uniformity with the general case. Add_Inherited_Invariants (T => T, Priv_Typ => Node (Iface_Elmt), Full_Typ => Empty, Obj_Id => Obj_Id, Checks => Checks); Next_Elmt (Iface_Elmt); end loop; end if; end Add_Interface_Invariants; ------------------------- -- Add_Invariant_Check -- ------------------------- procedure Add_Invariant_Check (Prag : Node_Id; Expr : Node_Id; Checks : in out List_Id; Inherited : Boolean := False) is Args : constant List_Id := Pragma_Argument_Associations (Prag); Nam : constant Name_Id := Original_Aspect_Pragma_Name (Prag); Ploc : constant Source_Ptr := Sloc (Prag); Str_Arg : constant Node_Id := Next (Next (First (Args))); Assoc : List_Id; Str : String_Id; begin -- The invariant is ignored, nothing left to do if Is_Ignored (Prag) then null; -- Otherwise the invariant is checked. Build a pragma Check to verify -- the expression at run time. else Assoc := New_List ( Make_Pragma_Argument_Association (Ploc, Expression => Make_Identifier (Ploc, Nam)), Make_Pragma_Argument_Association (Ploc, Expression => Expr)); -- Handle the String argument (if any) if Present (Str_Arg) then Str := Strval (Get_Pragma_Arg (Str_Arg)); -- When inheriting an invariant, modify the message from -- "failed invariant" to "failed inherited invariant". if Inherited then String_To_Name_Buffer (Str); if Name_Buffer (1 .. 16) = "failed invariant" then Insert_Str_In_Name_Buffer ("inherited ", 8); Str := String_From_Name_Buffer; end if; end if; Append_To (Assoc, Make_Pragma_Argument_Association (Ploc, Expression => Make_String_Literal (Ploc, Str))); end if; -- Generate: -- pragma Check (, , ); Append_New_To (Checks, Make_Pragma (Ploc, Chars => Name_Check, Pragma_Argument_Associations => Assoc)); end if; -- Output an info message when inheriting an invariant and the -- listing option is enabled. if Inherited and Opt.List_Inherited_Aspects then Error_Msg_Sloc := Sloc (Prag); Error_Msg_N ("info: & inherits `Invariant''Class` aspect from #?L?", Typ); end if; -- Add the pragma to the list of processed pragmas Append_New_Elmt (Prag, Pragmas_Seen); Produced_Check := True; end Add_Invariant_Check; --------------------------- -- Add_Parent_Invariants -- --------------------------- procedure Add_Parent_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id) is Dummy_1 : Entity_Id; Dummy_2 : Entity_Id; Curr_Typ : Entity_Id; -- The entity of the current type being examined Full_Typ : Entity_Id; -- The full view of Par_Typ Par_Typ : Entity_Id; -- The entity of the parent type Priv_Typ : Entity_Id; -- The partial view of Par_Typ begin -- Do not process array types because they cannot have true parent -- types. This also prevents the generation of a duplicate invariant -- check when the input type is an array base type because its Etype -- denotes the first subtype, both of which share the same component -- type. if Is_Array_Type (T) then return; end if; -- Climb the parent type chain Curr_Typ := T; loop -- Do not consider subtypes as they inherit the invariants -- from their base types. Par_Typ := Base_Type (Etype (Curr_Typ)); -- Stop the climb once the root of the parent chain is -- reached. exit when Curr_Typ = Par_Typ; -- Process the class-wide invariants of the parent type Get_Views (Par_Typ, Priv_Typ, Full_Typ, Dummy_1, Dummy_2); -- Process the elements of an array type if Is_Array_Type (Full_Typ) then Add_Array_Component_Invariants (Full_Typ, Obj_Id, Checks); -- Process the components of a record type elsif Ekind (Full_Typ) = E_Record_Type then Add_Record_Component_Invariants (Full_Typ, Obj_Id, Checks); end if; Add_Inherited_Invariants (T => T, Priv_Typ => Priv_Typ, Full_Typ => Full_Typ, Obj_Id => Obj_Id, Checks => Checks); Curr_Typ := Par_Typ; end loop; end Add_Parent_Invariants; ------------------------ -- Add_Own_Invariants -- ------------------------ procedure Add_Own_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id; Priv_Item : Node_Id := Empty) is ASIS_Expr : Node_Id; Expr : Node_Id; Prag : Node_Id; Prag_Asp : Node_Id; Prag_Expr : Node_Id; Prag_Expr_Arg : Node_Id; Prag_Typ : Node_Id; Prag_Typ_Arg : Node_Id; begin if not Present (T) then return; end if; Prag := First_Rep_Item (T); while Present (Prag) loop if Nkind (Prag) = N_Pragma and then Pragma_Name (Prag) = Name_Invariant then -- Stop the traversal of the rep item chain once a specific -- item is encountered. if Present (Priv_Item) and then Prag = Priv_Item then exit; end if; -- Nothing to do if the pragma was already processed if Contains (Pragmas_Seen, Prag) then return; end if; -- Extract the arguments of the invariant pragma Prag_Typ_Arg := First (Pragma_Argument_Associations (Prag)); Prag_Expr_Arg := Next (Prag_Typ_Arg); Prag_Expr := Get_Pragma_Arg (Prag_Expr_Arg); Prag_Typ := Get_Pragma_Arg (Prag_Typ_Arg); Prag_Asp := Corresponding_Aspect (Prag); -- Verify the pragma belongs to T, otherwise the pragma applies -- to a parent type in which case it will be processed later by -- Add_Parent_Invariants or Add_Interface_Invariants. if Entity (Prag_Typ) /= T then return; end if; Expr := New_Copy_Tree (Prag_Expr); -- Substitute all references to type T with references to the -- _object formal parameter. Replace_Type_References (Expr, T, Obj_Id); -- Preanalyze the invariant expression to detect errors and at -- the same time capture the visibility of the proper package -- part. Set_Parent (Expr, Parent (Prag_Expr)); Preanalyze_Assert_Expression (Expr, Any_Boolean); -- Save a copy of the expression when T is tagged to detect -- errors and capture the visibility of the proper package part -- for the generation of inherited type invariants. if Is_Tagged_Type (T) then Set_Expression_Copy (Prag_Expr_Arg, New_Copy_Tree (Expr)); end if; -- If the pragma comes from an aspect specification, replace -- the saved expression because all type references must be -- substituted for the call to Preanalyze_Spec_Expression in -- Check_Aspect_At_xxx routines. if Present (Prag_Asp) then Set_Entity (Identifier (Prag_Asp), New_Copy_Tree (Expr)); end if; -- Analyze the original invariant expression for ASIS if ASIS_Mode then ASIS_Expr := Empty; if Comes_From_Source (Prag) then ASIS_Expr := Prag_Expr; elsif Present (Prag_Asp) then ASIS_Expr := Expression (Prag_Asp); end if; if Present (ASIS_Expr) then Replace_Type_References (ASIS_Expr, T, Obj_Id); Preanalyze_Assert_Expression (ASIS_Expr, Any_Boolean); end if; end if; Add_Invariant_Check (Prag, Expr, Checks); end if; Next_Rep_Item (Prag); end loop; end Add_Own_Invariants; ------------------------------------- -- Add_Record_Component_Invariants -- ------------------------------------- procedure Add_Record_Component_Invariants (T : Entity_Id; Obj_Id : Entity_Id; Checks : in out List_Id) is procedure Process_Component_List (Comp_List : Node_Id; CL_Checks : in out List_Id); -- Generate invariant checks for all record components found in -- component list Comp_List, including variant parts. All created -- checks are added to list CL_Checks. procedure Process_Record_Component (Comp_Id : Entity_Id; Comp_Checks : in out List_Id); -- Generate an invariant check for a record component identified by -- Comp_Id. All created checks are added to list Comp_Checks. ---------------------------- -- Process_Component_List -- ---------------------------- procedure Process_Component_List (Comp_List : Node_Id; CL_Checks : in out List_Id) is Comp : Node_Id; Var : Node_Id; Var_Alts : List_Id := No_List; Var_Checks : List_Id := No_List; Var_Stmts : List_Id; Produced_Variant_Check : Boolean := False; -- This flag tracks whether the component has produced at least -- one invariant check. begin -- Traverse the component items Comp := First (Component_Items (Comp_List)); while Present (Comp) loop if Nkind (Comp) = N_Component_Declaration then -- Generate the component invariant check Process_Record_Component (Comp_Id => Defining_Entity (Comp), Comp_Checks => CL_Checks); end if; Next (Comp); end loop; -- Traverse the variant part if Present (Variant_Part (Comp_List)) then Var := First (Variants (Variant_Part (Comp_List))); while Present (Var) loop Var_Checks := No_List; -- Generate invariant checks for all components and variant -- parts that qualify. Process_Component_List (Comp_List => Component_List (Var), CL_Checks => Var_Checks); -- The components of the current variant produced at least -- one invariant check. if Present (Var_Checks) then Var_Stmts := Var_Checks; Produced_Variant_Check := True; -- Otherwise there are either no components with invariants, -- assertions are disabled, or Assertion_Policy Ignore is in -- effect. else Var_Stmts := New_List (Make_Null_Statement (Loc)); end if; Append_New_To (Var_Alts, Make_Case_Statement_Alternative (Loc, Discrete_Choices => New_Copy_List (Discrete_Choices (Var)), Statements => Var_Stmts)); Next (Var); end loop; -- Create a case statement which verifies the invariant checks -- of a particular component list depending on the discriminant -- values only when there is at least one real invariant check. if Produced_Variant_Check then Append_New_To (CL_Checks, Make_Case_Statement (Loc, Expression => Make_Selected_Component (Loc, Prefix => New_Occurrence_Of (Obj_Id, Loc), Selector_Name => New_Occurrence_Of (Entity (Name (Variant_Part (Comp_List))), Loc)), Alternatives => Var_Alts)); end if; end if; end Process_Component_List; ------------------------------ -- Process_Record_Component -- ------------------------------ procedure Process_Record_Component (Comp_Id : Entity_Id; Comp_Checks : in out List_Id) is Comp_Typ : constant Entity_Id := Etype (Comp_Id); Proc_Id : Entity_Id; Produced_Component_Check : Boolean := False; -- This flag tracks whether the component has produced at least -- one invariant check. begin -- Nothing to do for internal component _parent. Note that it is -- not desirable to check whether the component comes from source -- because protected type components are relocated to an internal -- corresponding record, but still need processing. if Chars (Comp_Id) = Name_uParent then return; end if; -- Verify the invariant of the component. Note that an access -- type may have an invariant when it acts as the full view of a -- private type and the invariant appears on the partial view. In -- this case verify the access value itself. if Has_Invariants (Comp_Typ) then -- In GNATprove mode, the component invariants are checked by -- other means. They should not be added to the record type -- invariant procedure, so that the procedure can be used to -- check the record type invariants if any. if GNATprove_Mode then null; else Proc_Id := Invariant_Procedure (Base_Type (Comp_Typ)); -- The component type should have an invariant procedure -- if it has invariants of its own or inherits class-wide -- invariants from parent or interface types. pragma Assert (Present (Proc_Id)); -- Generate: -- Invariant (T (_object).); -- Note that the invariant procedure may have a null body if -- assertions are disabled or Assertion_Policy Ignore is in -- effect. if not Has_Null_Body (Proc_Id) then Append_New_To (Comp_Checks, Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Id, Loc), Parameter_Associations => New_List ( Make_Selected_Component (Loc, Prefix => Unchecked_Convert_To (T, New_Occurrence_Of (Obj_Id, Loc)), Selector_Name => New_Occurrence_Of (Comp_Id, Loc))))); end if; end if; Produced_Check := True; Produced_Component_Check := True; end if; if Produced_Component_Check and then Has_Unchecked_Union (T) then Error_Msg_NE ("invariants cannot be checked on components of " & "unchecked_union type &?", Comp_Id, T); end if; end Process_Record_Component; -- Local variables Comps : Node_Id; Def : Node_Id; -- Start of processing for Add_Record_Component_Invariants begin -- An untagged derived type inherits the components of its parent -- type. In order to avoid creating redundant invariant checks, do -- not process the components now. Instead wait until the ultimate -- parent of the untagged derivation chain is reached. if not Is_Untagged_Derivation (T) then Def := Type_Definition (Parent (T)); if Nkind (Def) = N_Derived_Type_Definition then Def := Record_Extension_Part (Def); end if; pragma Assert (Nkind (Def) = N_Record_Definition); Comps := Component_List (Def); if Present (Comps) then Process_Component_List (Comp_List => Comps, CL_Checks => Checks); end if; end if; end Add_Record_Component_Invariants; -- Local variables Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; Saved_IGR : constant Node_Id := Ignored_Ghost_Region; -- Save the Ghost-related attributes to restore on exit Dummy : Entity_Id; Priv_Item : Node_Id; Proc_Body : Node_Id; Proc_Body_Id : Entity_Id; Proc_Decl : Node_Id; Proc_Id : Entity_Id; Stmts : List_Id := No_List; CRec_Typ : Entity_Id := Empty; -- The corresponding record type of Full_Typ Full_Proc : Entity_Id := Empty; -- The entity of the "full" invariant procedure Full_Typ : Entity_Id := Empty; -- The full view of the working type Obj_Id : Entity_Id := Empty; -- The _object formal parameter of the invariant procedure Part_Proc : Entity_Id := Empty; -- The entity of the "partial" invariant procedure Priv_Typ : Entity_Id := Empty; -- The partial view of the working type Work_Typ : Entity_Id := Empty; -- The working type -- Start of processing for Build_Invariant_Procedure_Body begin Work_Typ := Typ; -- The input type denotes the implementation base type of a constrained -- array type. Work with the first subtype as all invariant pragmas are -- on its rep item chain. if Ekind (Work_Typ) = E_Array_Type and then Is_Itype (Work_Typ) then Work_Typ := First_Subtype (Work_Typ); -- The input type denotes the corresponding record type of a protected -- or task type. Work with the concurrent type because the corresponding -- record type may not be visible to clients of the type. elsif Ekind (Work_Typ) = E_Record_Type and then Is_Concurrent_Record_Type (Work_Typ) then Work_Typ := Corresponding_Concurrent_Type (Work_Typ); end if; -- The working type may be subject to pragma Ghost. Set the mode now to -- ensure that the invariant procedure is properly marked as Ghost. Set_Ghost_Mode (Work_Typ); -- The type must either have invariants of its own, inherit class-wide -- invariants from parent types or interfaces, or be an array or record -- type whose components have invariants. pragma Assert (Has_Invariants (Work_Typ)); -- Interfaces are treated as the partial view of a private type in order -- to achieve uniformity with the general case. if Is_Interface (Work_Typ) then Priv_Typ := Work_Typ; -- Otherwise obtain both views of the type else Get_Views (Work_Typ, Priv_Typ, Full_Typ, Dummy, CRec_Typ); end if; -- The caller requests a body for the partial invariant procedure if Partial_Invariant then Full_Proc := Invariant_Procedure (Work_Typ); Proc_Id := Partial_Invariant_Procedure (Work_Typ); -- The "full" invariant procedure body was already created if Present (Full_Proc) and then Present (Corresponding_Body (Unit_Declaration_Node (Full_Proc))) then -- This scenario happens only when the type is an untagged -- derivation from a private parent and the underlying full -- view was processed before the partial view. pragma Assert (Is_Untagged_Private_Derivation (Priv_Typ, Full_Typ)); -- Nothing to do because the processing of the underlying full -- view already checked the invariants of the partial view. goto Leave; end if; -- Create a declaration for the "partial" invariant procedure if it -- is not available. if No (Proc_Id) then Build_Invariant_Procedure_Declaration (Typ => Work_Typ, Partial_Invariant => True); Proc_Id := Partial_Invariant_Procedure (Work_Typ); end if; -- The caller requests a body for the "full" invariant procedure else Proc_Id := Invariant_Procedure (Work_Typ); Part_Proc := Partial_Invariant_Procedure (Work_Typ); -- Create a declaration for the "full" invariant procedure if it is -- not available. if No (Proc_Id) then Build_Invariant_Procedure_Declaration (Work_Typ); Proc_Id := Invariant_Procedure (Work_Typ); end if; end if; -- At this point there should be an invariant procedure declaration pragma Assert (Present (Proc_Id)); Proc_Decl := Unit_Declaration_Node (Proc_Id); -- Nothing to do if the invariant procedure already has a body if Present (Corresponding_Body (Proc_Decl)) then goto Leave; end if; -- Emulate the environment of the invariant procedure by installing its -- scope and formal parameters. Note that this is not needed, but having -- the scope installed helps with the detection of invariant-related -- errors. Push_Scope (Proc_Id); Install_Formals (Proc_Id); Obj_Id := First_Formal (Proc_Id); pragma Assert (Present (Obj_Id)); -- The "partial" invariant procedure verifies the invariants of the -- partial view only. if Partial_Invariant then pragma Assert (Present (Priv_Typ)); Add_Own_Invariants (T => Priv_Typ, Obj_Id => Obj_Id, Checks => Stmts); -- Otherwise the "full" invariant procedure verifies the invariants of -- the full view, all array or record components, as well as class-wide -- invariants inherited from parent types or interfaces. In addition, it -- indirectly verifies the invariants of the partial view by calling the -- "partial" invariant procedure. else pragma Assert (Present (Full_Typ)); -- Check the invariants of the partial view by calling the "partial" -- invariant procedure. Generate: -- Partial_Invariant (_object); if Present (Part_Proc) then Append_New_To (Stmts, Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Part_Proc, Loc), Parameter_Associations => New_List ( New_Occurrence_Of (Obj_Id, Loc)))); Produced_Check := True; end if; Priv_Item := Empty; -- Derived subtypes do not have a partial view if Present (Priv_Typ) then -- The processing of the "full" invariant procedure intentionally -- skips the partial view because a) this may result in changes of -- visibility and b) lead to duplicate checks. However, when the -- full view is the underlying full view of an untagged derived -- type whose parent type is private, partial invariants appear on -- the rep item chain of the partial view only. -- package Pack_1 is -- type Root ... is private; -- private -- -- end Pack_1; -- with Pack_1; -- package Pack_2 is -- type Child is new Pack_1.Root with Type_Invariant => ...; -- -- end Pack_2; -- As a result, the processing of the full view must also consider -- all invariants of the partial view. if Is_Untagged_Private_Derivation (Priv_Typ, Full_Typ) then null; -- Otherwise the invariants of the partial view are ignored else -- Note that the rep item chain is shared between the partial -- and full views of a type. To avoid processing the invariants -- of the partial view, signal the logic to stop when the first -- rep item of the partial view has been reached. Priv_Item := First_Rep_Item (Priv_Typ); -- Ignore the invariants of the partial view by eliminating the -- view. Priv_Typ := Empty; end if; end if; -- Process the invariants of the full view and in certain cases those -- of the partial view. This also handles any invariants on array or -- record components. Add_Own_Invariants (T => Priv_Typ, Obj_Id => Obj_Id, Checks => Stmts, Priv_Item => Priv_Item); Add_Own_Invariants (T => Full_Typ, Obj_Id => Obj_Id, Checks => Stmts, Priv_Item => Priv_Item); -- Process the elements of an array type if Is_Array_Type (Full_Typ) then Add_Array_Component_Invariants (Full_Typ, Obj_Id, Stmts); -- Process the components of a record type elsif Ekind (Full_Typ) = E_Record_Type then Add_Record_Component_Invariants (Full_Typ, Obj_Id, Stmts); -- Process the components of a corresponding record elsif Present (CRec_Typ) then Add_Record_Component_Invariants (CRec_Typ, Obj_Id, Stmts); end if; -- Process the inherited class-wide invariants of all parent types. -- This also handles any invariants on record components. Add_Parent_Invariants (Full_Typ, Obj_Id, Stmts); -- Process the inherited class-wide invariants of all implemented -- interface types. Add_Interface_Invariants (Full_Typ, Obj_Id, Stmts); end if; End_Scope; -- At this point there should be at least one invariant check. If this -- is not the case, then the invariant-related flags were not properly -- set, or there is a missing invariant procedure on one of the array -- or record components. pragma Assert (Produced_Check); -- Account for the case where assertions are disabled or all invariant -- checks are subject to Assertion_Policy Ignore. Produce a completing -- empty body. if No (Stmts) then Stmts := New_List (Make_Null_Statement (Loc)); end if; -- Generate: -- procedure [Partial_]Invariant (_object : ) is -- begin -- -- end [Partial_]Invariant; Proc_Body := Make_Subprogram_Body (Loc, Specification => Copy_Subprogram_Spec (Parent (Proc_Id)), Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)); Proc_Body_Id := Defining_Entity (Proc_Body); -- Perform minor decoration in case the body is not analyzed Set_Ekind (Proc_Body_Id, E_Subprogram_Body); Set_Etype (Proc_Body_Id, Standard_Void_Type); Set_Scope (Proc_Body_Id, Current_Scope); -- Link both spec and body to avoid generating duplicates Set_Corresponding_Body (Proc_Decl, Proc_Body_Id); Set_Corresponding_Spec (Proc_Body, Proc_Id); -- The body should not be inserted into the tree when the context is -- ASIS or a generic unit because it is not part of the template. Note -- that the body must still be generated in order to resolve the -- invariants. if ASIS_Mode or Inside_A_Generic then null; -- Semi-insert the body into the tree for GNATprove by setting its -- Parent field. This allows for proper upstream tree traversals. elsif GNATprove_Mode then Set_Parent (Proc_Body, Parent (Declaration_Node (Work_Typ))); -- Otherwise the body is part of the freezing actions of the type else Append_Freeze_Action (Work_Typ, Proc_Body); end if; <> Restore_Ghost_Region (Saved_GM, Saved_IGR); end Build_Invariant_Procedure_Body; ------------------------------------------- -- Build_Invariant_Procedure_Declaration -- ------------------------------------------- -- WARNING: This routine manages Ghost regions. Return statements must be -- replaced by gotos which jump to the end of the routine and restore the -- Ghost mode. procedure Build_Invariant_Procedure_Declaration (Typ : Entity_Id; Partial_Invariant : Boolean := False) is Loc : constant Source_Ptr := Sloc (Typ); Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; Saved_IGR : constant Node_Id := Ignored_Ghost_Region; -- Save the Ghost-related attributes to restore on exit Proc_Decl : Node_Id; Proc_Id : Entity_Id; Proc_Nam : Name_Id; Typ_Decl : Node_Id; CRec_Typ : Entity_Id; -- The corresponding record type of Full_Typ Full_Base : Entity_Id; -- The base type of Full_Typ Full_Typ : Entity_Id; -- The full view of working type Obj_Id : Entity_Id; -- The _object formal parameter of the invariant procedure Obj_Typ : Entity_Id; -- The type of the _object formal parameter Priv_Typ : Entity_Id; -- The partial view of working type Work_Typ : Entity_Id; -- The working type begin Work_Typ := Typ; -- The input type denotes the implementation base type of a constrained -- array type. Work with the first subtype as all invariant pragmas are -- on its rep item chain. if Ekind (Work_Typ) = E_Array_Type and then Is_Itype (Work_Typ) then Work_Typ := First_Subtype (Work_Typ); -- The input denotes the corresponding record type of a protected or a -- task type. Work with the concurrent type because the corresponding -- record type may not be visible to clients of the type. elsif Ekind (Work_Typ) = E_Record_Type and then Is_Concurrent_Record_Type (Work_Typ) then Work_Typ := Corresponding_Concurrent_Type (Work_Typ); end if; -- The working type may be subject to pragma Ghost. Set the mode now to -- ensure that the invariant procedure is properly marked as Ghost. Set_Ghost_Mode (Work_Typ); -- The type must either have invariants of its own, inherit class-wide -- invariants from parent or interface types, or be an array or record -- type whose components have invariants. pragma Assert (Has_Invariants (Work_Typ)); -- Nothing to do if the type already has a "partial" invariant procedure if Partial_Invariant then if Present (Partial_Invariant_Procedure (Work_Typ)) then goto Leave; end if; -- Nothing to do if the type already has a "full" invariant procedure elsif Present (Invariant_Procedure (Work_Typ)) then goto Leave; end if; -- The caller requests the declaration of the "partial" invariant -- procedure. if Partial_Invariant then Proc_Nam := New_External_Name (Chars (Work_Typ), "Partial_Invariant"); -- Otherwise the caller requests the declaration of the "full" invariant -- procedure. else Proc_Nam := New_External_Name (Chars (Work_Typ), "Invariant"); end if; Proc_Id := Make_Defining_Identifier (Loc, Chars => Proc_Nam); -- Perform minor decoration in case the declaration is not analyzed Set_Ekind (Proc_Id, E_Procedure); Set_Etype (Proc_Id, Standard_Void_Type); Set_Scope (Proc_Id, Current_Scope); if Partial_Invariant then Set_Is_Partial_Invariant_Procedure (Proc_Id); Set_Partial_Invariant_Procedure (Work_Typ, Proc_Id); else Set_Is_Invariant_Procedure (Proc_Id); Set_Invariant_Procedure (Work_Typ, Proc_Id); end if; -- The invariant procedure requires debug info when the invariants are -- subject to Source Coverage Obligations. if Generate_SCO then Set_Debug_Info_Needed (Proc_Id); end if; -- Obtain all views of the input type Get_Views (Work_Typ, Priv_Typ, Full_Typ, Full_Base, CRec_Typ); -- Associate the invariant procedure with all views Propagate_Invariant_Attributes (Priv_Typ, From_Typ => Work_Typ); Propagate_Invariant_Attributes (Full_Typ, From_Typ => Work_Typ); Propagate_Invariant_Attributes (Full_Base, From_Typ => Work_Typ); Propagate_Invariant_Attributes (CRec_Typ, From_Typ => Work_Typ); -- The declaration of the invariant procedure is inserted after the -- declaration of the partial view as this allows for proper external -- visibility. if Present (Priv_Typ) then Typ_Decl := Declaration_Node (Priv_Typ); -- Anonymous arrays in object declarations have no explicit declaration -- so use the related object declaration as the insertion point. elsif Is_Itype (Work_Typ) and then Is_Array_Type (Work_Typ) then Typ_Decl := Associated_Node_For_Itype (Work_Typ); -- Derived types with the full view as parent do not have a partial -- view. Insert the invariant procedure after the derived type. else Typ_Decl := Declaration_Node (Full_Typ); end if; -- The type should have a declarative node pragma Assert (Present (Typ_Decl)); -- Create the formal parameter which emulates the variable-like behavior -- of the current type instance. Obj_Id := Make_Defining_Identifier (Loc, Chars => Name_uObject); -- When generating an invariant procedure declaration for an abstract -- type (including interfaces), use the class-wide type as the _object -- type. This has several desirable effects: -- * The invariant procedure does not become a primitive of the type. -- This eliminates the need to either special case the treatment of -- invariant procedures, or to make it a predefined primitive and -- force every derived type to potentially provide an empty body. -- * The invariant procedure does not need to be declared as abstract. -- This allows for a proper body, which in turn avoids redundant -- processing of the same invariants for types with multiple views. -- * The class-wide type allows for calls to abstract primitives -- within a nonabstract subprogram. The calls are treated as -- dispatching and require additional processing when they are -- remapped to call primitives of derived types. See routine -- Replace_References for details. if Is_Abstract_Type (Work_Typ) then Obj_Typ := Class_Wide_Type (Work_Typ); else Obj_Typ := Work_Typ; end if; -- Perform minor decoration in case the declaration is not analyzed Set_Ekind (Obj_Id, E_In_Parameter); Set_Etype (Obj_Id, Obj_Typ); Set_Scope (Obj_Id, Proc_Id); Set_First_Entity (Proc_Id, Obj_Id); Set_Last_Entity (Proc_Id, Obj_Id); -- Generate: -- procedure [Partial_]Invariant (_object : ); Proc_Decl := Make_Subprogram_Declaration (Loc, Specification => Make_Procedure_Specification (Loc, Defining_Unit_Name => Proc_Id, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Obj_Id, Parameter_Type => New_Occurrence_Of (Obj_Typ, Loc))))); -- The declaration should not be inserted into the tree when the context -- is ASIS or a generic unit because it is not part of the template. if ASIS_Mode or Inside_A_Generic then null; -- Semi-insert the declaration into the tree for GNATprove by setting -- its Parent field. This allows for proper upstream tree traversals. elsif GNATprove_Mode then Set_Parent (Proc_Decl, Parent (Typ_Decl)); -- Otherwise insert the declaration else pragma Assert (Present (Typ_Decl)); Insert_After_And_Analyze (Typ_Decl, Proc_Decl); end if; <> Restore_Ghost_Region (Saved_GM, Saved_IGR); end Build_Invariant_Procedure_Declaration; -------------------------- -- Build_Procedure_Form -- -------------------------- procedure Build_Procedure_Form (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Subp : constant Entity_Id := Defining_Entity (N); Func_Formal : Entity_Id; Proc_Formals : List_Id; Proc_Decl : Node_Id; begin -- No action needed if this transformation was already done, or in case -- of subprogram renaming declarations. if Nkind (Specification (N)) = N_Procedure_Specification or else Nkind (N) = N_Subprogram_Renaming_Declaration then return; end if; -- Ditto when dealing with an expression function, where both the -- original expression and the generated declaration end up being -- expanded here. if Rewritten_For_C (Subp) then return; end if; Proc_Formals := New_List; -- Create a list of formal parameters with the same types as the -- function. Func_Formal := First_Formal (Subp); while Present (Func_Formal) loop Append_To (Proc_Formals, Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Chars (Func_Formal)), Parameter_Type => New_Occurrence_Of (Etype (Func_Formal), Loc))); Next_Formal (Func_Formal); end loop; -- Add an extra out parameter to carry the function result Name_Len := 6; Name_Buffer (1 .. Name_Len) := "RESULT"; Append_To (Proc_Formals, Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Chars => Name_Find), Out_Present => True, Parameter_Type => New_Occurrence_Of (Etype (Subp), Loc))); -- The new procedure declaration is inserted immediately after the -- function declaration. The processing in Build_Procedure_Body_Form -- relies on this order. Proc_Decl := Make_Subprogram_Declaration (Loc, Specification => Make_Procedure_Specification (Loc, Defining_Unit_Name => Make_Defining_Identifier (Loc, Chars (Subp)), Parameter_Specifications => Proc_Formals)); Insert_After_And_Analyze (Unit_Declaration_Node (Subp), Proc_Decl); -- Entity of procedure must remain invisible so that it does not -- overload subsequent references to the original function. Set_Is_Immediately_Visible (Defining_Entity (Proc_Decl), False); -- Mark the function as having a procedure form and link the function -- and its internally built procedure. Set_Rewritten_For_C (Subp); Set_Corresponding_Procedure (Subp, Defining_Entity (Proc_Decl)); Set_Corresponding_Function (Defining_Entity (Proc_Decl), Subp); end Build_Procedure_Form; ------------------------ -- Build_Runtime_Call -- ------------------------ function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is begin -- If entity is not available, we can skip making the call (this avoids -- junk duplicated error messages in a number of cases). if not RTE_Available (RE) then return Make_Null_Statement (Loc); else return Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (RTE (RE), Loc)); end if; end Build_Runtime_Call; ------------------------ -- Build_SS_Mark_Call -- ------------------------ function Build_SS_Mark_Call (Loc : Source_Ptr; Mark : Entity_Id) return Node_Id is begin -- Generate: -- Mark : constant Mark_Id := SS_Mark; return Make_Object_Declaration (Loc, Defining_Identifier => Mark, Constant_Present => True, Object_Definition => New_Occurrence_Of (RTE (RE_Mark_Id), Loc), Expression => Make_Function_Call (Loc, Name => New_Occurrence_Of (RTE (RE_SS_Mark), Loc))); end Build_SS_Mark_Call; --------------------------- -- Build_SS_Release_Call -- --------------------------- function Build_SS_Release_Call (Loc : Source_Ptr; Mark : Entity_Id) return Node_Id is begin -- Generate: -- SS_Release (Mark); return Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (RTE (RE_SS_Release), Loc), Parameter_Associations => New_List ( New_Occurrence_Of (Mark, Loc))); end Build_SS_Release_Call; ---------------------------- -- Build_Task_Array_Image -- ---------------------------- -- This function generates the body for a function that constructs the -- image string for a task that is an array component. The function is -- local to the init proc for the array type, and is called for each one -- of the components. The constructed image has the form of an indexed -- component, whose prefix is the outer variable of the array type. -- The n-dimensional array type has known indexes Index, Index2... -- Id_Ref is an indexed component form created by the enclosing init proc. -- Its successive indexes are Val1, Val2, ... which are the loop variables -- in the loops that call the individual task init proc on each component. -- The generated function has the following structure: -- function F return String is -- Pref : string renames Task_Name; -- T1 : String := Index1'Image (Val1); -- ... -- Tn : String := indexn'image (Valn); -- Len : Integer := T1'Length + ... + Tn'Length + n + 1; -- -- Len includes commas and the end parentheses. -- Res : String (1..Len); -- Pos : Integer := Pref'Length; -- -- begin -- Res (1 .. Pos) := Pref; -- Pos := Pos + 1; -- Res (Pos) := '('; -- Pos := Pos + 1; -- Res (Pos .. Pos + T1'Length - 1) := T1; -- Pos := Pos + T1'Length; -- Res (Pos) := '.'; -- Pos := Pos + 1; -- ... -- Res (Pos .. Pos + Tn'Length - 1) := Tn; -- Res (Len) := ')'; -- -- return Res; -- end F; -- -- Needless to say, multidimensional arrays of tasks are rare enough that -- the bulkiness of this code is not really a concern. function Build_Task_Array_Image (Loc : Source_Ptr; Id_Ref : Node_Id; A_Type : Entity_Id; Dyn : Boolean := False) return Node_Id is Dims : constant Nat := Number_Dimensions (A_Type); -- Number of dimensions for array of tasks Temps : array (1 .. Dims) of Entity_Id; -- Array of temporaries to hold string for each index Indx : Node_Id; -- Index expression Len : Entity_Id; -- Total length of generated name Pos : Entity_Id; -- Running index for substring assignments Pref : constant Entity_Id := Make_Temporary (Loc, 'P'); -- Name of enclosing variable, prefix of resulting name Res : Entity_Id; -- String to hold result Val : Node_Id; -- Value of successive indexes Sum : Node_Id; -- Expression to compute total size of string T : Entity_Id; -- Entity for name at one index position Decls : constant List_Id := New_List; Stats : constant List_Id := New_List; begin -- For a dynamic task, the name comes from the target variable. For a -- static one it is a formal of the enclosing init proc. if Dyn then Get_Name_String (Chars (Entity (Prefix (Id_Ref)))); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Pref, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); else Append_To (Decls, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Pref, Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), Name => Make_Identifier (Loc, Name_uTask_Name))); end if; Indx := First_Index (A_Type); Val := First (Expressions (Id_Ref)); for J in 1 .. Dims loop T := Make_Temporary (Loc, 'T'); Temps (J) := T; Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => T, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_Attribute_Reference (Loc, Attribute_Name => Name_Image, Prefix => New_Occurrence_Of (Etype (Indx), Loc), Expressions => New_List (New_Copy_Tree (Val))))); Next_Index (Indx); Next (Val); end loop; Sum := Make_Integer_Literal (Loc, Dims + 1); Sum := Make_Op_Add (Loc, Left_Opnd => Sum, Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Pref, Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))); for J in 1 .. Dims loop Sum := Make_Op_Add (Loc, Left_Opnd => Sum, Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Temps (J), Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))); end loop; Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats); Set_Character_Literal_Name (Char_Code (Character'Pos ('('))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Pos, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos ('('))))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); for J in 1 .. Dims loop Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Res, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => New_Occurrence_Of (Pos, Loc), High_Bound => Make_Op_Subtract (Loc, Left_Opnd => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Temps (J), Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))), Right_Opnd => Make_Integer_Literal (Loc, 1)))), Expression => New_Occurrence_Of (Temps (J), Loc))); if J < Dims then Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Temps (J), Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))))); Set_Character_Literal_Name (Char_Code (Character'Pos (','))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Pos, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos (','))))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); end if; end loop; Set_Character_Literal_Name (Char_Code (Character'Pos (')'))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Len, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos (')'))))); return Build_Task_Image_Function (Loc, Decls, Stats, Res); end Build_Task_Array_Image; ---------------------------- -- Build_Task_Image_Decls -- ---------------------------- function Build_Task_Image_Decls (Loc : Source_Ptr; Id_Ref : Node_Id; A_Type : Entity_Id; In_Init_Proc : Boolean := False) return List_Id is Decls : constant List_Id := New_List; T_Id : Entity_Id := Empty; Decl : Node_Id; Expr : Node_Id := Empty; Fun : Node_Id := Empty; Is_Dyn : constant Boolean := Nkind (Parent (Id_Ref)) = N_Assignment_Statement and then Nkind (Expression (Parent (Id_Ref))) = N_Allocator; begin -- If Discard_Names or No_Implicit_Heap_Allocations are in effect, -- generate a dummy declaration only. if Restriction_Active (No_Implicit_Heap_Allocations) or else Global_Discard_Names then T_Id := Make_Temporary (Loc, 'J'); Name_Len := 0; return New_List ( Make_Object_Declaration (Loc, Defining_Identifier => T_Id, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); else if Nkind (Id_Ref) = N_Identifier or else Nkind (Id_Ref) = N_Defining_Identifier then -- For a simple variable, the image of the task is built from -- the name of the variable. To avoid possible conflict with the -- anonymous type created for a single protected object, add a -- numeric suffix. T_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (Id_Ref), 'T', 1)); Get_Name_String (Chars (Id_Ref)); Expr := Make_String_Literal (Loc, Strval => String_From_Name_Buffer); elsif Nkind (Id_Ref) = N_Selected_Component then T_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (Selector_Name (Id_Ref)), 'T')); Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn); elsif Nkind (Id_Ref) = N_Indexed_Component then T_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (A_Type), 'N')); Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn); end if; end if; if Present (Fun) then Append (Fun, Decls); Expr := Make_Function_Call (Loc, Name => New_Occurrence_Of (Defining_Entity (Fun), Loc)); if not In_Init_Proc then Set_Uses_Sec_Stack (Defining_Entity (Fun)); end if; end if; Decl := Make_Object_Declaration (Loc, Defining_Identifier => T_Id, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Constant_Present => True, Expression => Expr); Append (Decl, Decls); return Decls; end Build_Task_Image_Decls; ------------------------------- -- Build_Task_Image_Function -- ------------------------------- function Build_Task_Image_Function (Loc : Source_Ptr; Decls : List_Id; Stats : List_Id; Res : Entity_Id) return Node_Id is Spec : Node_Id; begin Append_To (Stats, Make_Simple_Return_Statement (Loc, Expression => New_Occurrence_Of (Res, Loc))); Spec := Make_Function_Specification (Loc, Defining_Unit_Name => Make_Temporary (Loc, 'F'), Result_Definition => New_Occurrence_Of (Standard_String, Loc)); -- Calls to 'Image use the secondary stack, which must be cleaned up -- after the task name is built. return Make_Subprogram_Body (Loc, Specification => Spec, Declarations => Decls, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats)); end Build_Task_Image_Function; ----------------------------- -- Build_Task_Image_Prefix -- ----------------------------- procedure Build_Task_Image_Prefix (Loc : Source_Ptr; Len : out Entity_Id; Res : out Entity_Id; Pos : out Entity_Id; Prefix : Entity_Id; Sum : Node_Id; Decls : List_Id; Stats : List_Id) is begin Len := Make_Temporary (Loc, 'L', Sum); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Len, Object_Definition => New_Occurrence_Of (Standard_Integer, Loc), Expression => Sum)); Res := Make_Temporary (Loc, 'R'); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Res, Object_Definition => Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List ( Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => New_Occurrence_Of (Len, Loc))))))); -- Indicate that the result is an internal temporary, so it does not -- receive a bogus initialization when declaration is expanded. This -- is both efficient, and prevents anomalies in the handling of -- dynamic objects on the secondary stack. Set_Is_Internal (Res); Pos := Make_Temporary (Loc, 'P'); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Pos, Object_Definition => New_Occurrence_Of (Standard_Integer, Loc))); -- Pos := Prefix'Length; Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Prefix, Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1))))); -- Res (1 .. Pos) := Prefix; Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Res, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => New_Occurrence_Of (Pos, Loc))), Expression => New_Occurrence_Of (Prefix, Loc))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); end Build_Task_Image_Prefix; ----------------------------- -- Build_Task_Record_Image -- ----------------------------- function Build_Task_Record_Image (Loc : Source_Ptr; Id_Ref : Node_Id; Dyn : Boolean := False) return Node_Id is Len : Entity_Id; -- Total length of generated name Pos : Entity_Id; -- Index into result Res : Entity_Id; -- String to hold result Pref : constant Entity_Id := Make_Temporary (Loc, 'P'); -- Name of enclosing variable, prefix of resulting name Sum : Node_Id; -- Expression to compute total size of string Sel : Entity_Id; -- Entity for selector name Decls : constant List_Id := New_List; Stats : constant List_Id := New_List; begin -- For a dynamic task, the name comes from the target variable. For a -- static one it is a formal of the enclosing init proc. if Dyn then Get_Name_String (Chars (Entity (Prefix (Id_Ref)))); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Pref, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); else Append_To (Decls, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Pref, Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), Name => Make_Identifier (Loc, Name_uTask_Name))); end if; Sel := Make_Temporary (Loc, 'S'); Get_Name_String (Chars (Selector_Name (Id_Ref))); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Sel, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1)); Sum := Make_Op_Add (Loc, Left_Opnd => Sum, Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Pref, Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))); Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats); Set_Character_Literal_Name (Char_Code (Character'Pos ('.'))); -- Res (Pos) := '.'; Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Pos, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos ('.'))))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); -- Res (Pos .. Len) := Selector; Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Res, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => New_Occurrence_Of (Pos, Loc), High_Bound => New_Occurrence_Of (Len, Loc))), Expression => New_Occurrence_Of (Sel, Loc))); return Build_Task_Image_Function (Loc, Decls, Stats, Res); end Build_Task_Record_Image; --------------------------------------- -- Build_Transient_Object_Statements -- --------------------------------------- procedure Build_Transient_Object_Statements (Obj_Decl : Node_Id; Fin_Call : out Node_Id; Hook_Assign : out Node_Id; Hook_Clear : out Node_Id; Hook_Decl : out Node_Id; Ptr_Decl : out Node_Id; Finalize_Obj : Boolean := True) is Loc : constant Source_Ptr := Sloc (Obj_Decl); Obj_Id : constant Entity_Id := Defining_Entity (Obj_Decl); Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id)); Desig_Typ : Entity_Id; Hook_Expr : Node_Id; Hook_Id : Entity_Id; Obj_Ref : Node_Id; Ptr_Typ : Entity_Id; begin -- Recover the type of the object Desig_Typ := Obj_Typ; if Is_Access_Type (Desig_Typ) then Desig_Typ := Available_View (Designated_Type (Desig_Typ)); end if; -- Create an access type which provides a reference to the transient -- object. Generate: -- type Ptr_Typ is access all Desig_Typ; Ptr_Typ := Make_Temporary (Loc, 'A'); Set_Ekind (Ptr_Typ, E_General_Access_Type); Set_Directly_Designated_Type (Ptr_Typ, Desig_Typ); Ptr_Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Ptr_Typ, Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => True, Subtype_Indication => New_Occurrence_Of (Desig_Typ, Loc))); -- Create a temporary check which acts as a hook to the transient -- object. Generate: -- Hook : Ptr_Typ := null; Hook_Id := Make_Temporary (Loc, 'T'); Set_Ekind (Hook_Id, E_Variable); Set_Etype (Hook_Id, Ptr_Typ); Hook_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Hook_Id, Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc), Expression => Make_Null (Loc)); -- Mark the temporary as a hook. This signals the machinery in -- Build_Finalizer to recognize this special case. Set_Status_Flag_Or_Transient_Decl (Hook_Id, Obj_Decl); -- Hook the transient object to the temporary. Generate: -- Hook := Ptr_Typ (Obj_Id); -- -- Hool := Obj_Id'Unrestricted_Access; if Is_Access_Type (Obj_Typ) then Hook_Expr := Unchecked_Convert_To (Ptr_Typ, New_Occurrence_Of (Obj_Id, Loc)); else Hook_Expr := Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Obj_Id, Loc), Attribute_Name => Name_Unrestricted_Access); end if; Hook_Assign := Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Hook_Id, Loc), Expression => Hook_Expr); -- Crear the hook prior to finalizing the object. Generate: -- Hook := null; Hook_Clear := Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Hook_Id, Loc), Expression => Make_Null (Loc)); -- Finalize the object. Generate: -- [Deep_]Finalize (Obj_Ref[.all]); if Finalize_Obj then Obj_Ref := New_Occurrence_Of (Obj_Id, Loc); if Is_Access_Type (Obj_Typ) then Obj_Ref := Make_Explicit_Dereference (Loc, Obj_Ref); Set_Etype (Obj_Ref, Desig_Typ); end if; Fin_Call := Make_Final_Call (Obj_Ref => Obj_Ref, Typ => Desig_Typ); -- Otherwise finalize the hook. Generate: -- [Deep_]Finalize (Hook.all); else Fin_Call := Make_Final_Call ( Obj_Ref => Make_Explicit_Dereference (Loc, Prefix => New_Occurrence_Of (Hook_Id, Loc)), Typ => Desig_Typ); end if; end Build_Transient_Object_Statements; ----------------------------- -- Check_Float_Op_Overflow -- ----------------------------- procedure Check_Float_Op_Overflow (N : Node_Id) is begin -- Return if no check needed if not Is_Floating_Point_Type (Etype (N)) or else not (Do_Overflow_Check (N) and then Check_Float_Overflow) -- In CodePeer_Mode, rely on the overflow check flag being set instead -- and do not expand the code for float overflow checking. or else CodePeer_Mode then return; end if; -- Otherwise we replace the expression by -- do Tnn : constant ftype := expression; -- constraint_error when not Tnn'Valid; -- in Tnn; declare Loc : constant Source_Ptr := Sloc (N); Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); Typ : constant Entity_Id := Etype (N); begin -- Turn off the Do_Overflow_Check flag, since we are doing that work -- right here. We also set the node as analyzed to prevent infinite -- recursion from repeating the operation in the expansion. Set_Do_Overflow_Check (N, False); Set_Analyzed (N, True); -- Do the rewrite to include the check Rewrite (N, Make_Expression_With_Actions (Loc, Actions => New_List ( Make_Object_Declaration (Loc, Defining_Identifier => Tnn, Object_Definition => New_Occurrence_Of (Typ, Loc), Constant_Present => True, Expression => Relocate_Node (N)), Make_Raise_Constraint_Error (Loc, Condition => Make_Op_Not (Loc, Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Tnn, Loc), Attribute_Name => Name_Valid)), Reason => CE_Overflow_Check_Failed)), Expression => New_Occurrence_Of (Tnn, Loc))); Analyze_And_Resolve (N, Typ); end; end Check_Float_Op_Overflow; ---------------------------------- -- Component_May_Be_Bit_Aligned -- ---------------------------------- function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is UT : Entity_Id; begin -- If no component clause, then everything is fine, since the back end -- never misaligns from byte boundaries by default, even if there is a -- pragma Pack for the record. if No (Comp) or else No (Component_Clause (Comp)) then return False; end if; UT := Underlying_Type (Etype (Comp)); -- It is only array and record types that cause trouble if not Is_Record_Type (UT) and then not Is_Array_Type (UT) then return False; -- If we know that we have a small (64 bits or less) record or small -- bit-packed array, then everything is fine, since the back end can -- handle these cases correctly. elsif Esize (Comp) <= 64 and then (Is_Record_Type (UT) or else Is_Bit_Packed_Array (UT)) then return False; -- Otherwise if the component is not byte aligned, we know we have the -- nasty unaligned case. elsif Normalized_First_Bit (Comp) /= Uint_0 or else Esize (Comp) mod System_Storage_Unit /= Uint_0 then return True; -- If we are large and byte aligned, then OK at this level else return False; end if; end Component_May_Be_Bit_Aligned; ---------------------------------------- -- Containing_Package_With_Ext_Axioms -- ---------------------------------------- function Containing_Package_With_Ext_Axioms (E : Entity_Id) return Entity_Id is begin -- E is the package or generic package which is externally axiomatized if Is_Package_Or_Generic_Package (E) and then Has_Annotate_Pragma_For_External_Axiomatization (E) then return E; end if; -- If E's scope is axiomatized, E is axiomatized if Present (Scope (E)) then declare First_Ax_Parent_Scope : constant Entity_Id := Containing_Package_With_Ext_Axioms (Scope (E)); begin if Present (First_Ax_Parent_Scope) then return First_Ax_Parent_Scope; end if; end; end if; -- Otherwise, if E is a package instance, it is axiomatized if the -- corresponding generic package is axiomatized. if Ekind (E) = E_Package then declare Par : constant Node_Id := Parent (E); Decl : Node_Id; begin if Nkind (Par) = N_Defining_Program_Unit_Name then Decl := Parent (Par); else Decl := Par; end if; if Present (Generic_Parent (Decl)) then return Containing_Package_With_Ext_Axioms (Generic_Parent (Decl)); end if; end; end if; return Empty; end Containing_Package_With_Ext_Axioms; ------------------------------- -- Convert_To_Actual_Subtype -- ------------------------------- procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is Act_ST : Entity_Id; begin Act_ST := Get_Actual_Subtype (Exp); if Act_ST = Etype (Exp) then return; else Rewrite (Exp, Convert_To (Act_ST, Relocate_Node (Exp))); Analyze_And_Resolve (Exp, Act_ST); end if; end Convert_To_Actual_Subtype; ----------------------------------- -- Corresponding_Runtime_Package -- ----------------------------------- function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is function Has_One_Entry_And_No_Queue (T : Entity_Id) return Boolean; -- Return True if protected type T has one entry and the maximum queue -- length is one. -------------------------------- -- Has_One_Entry_And_No_Queue -- -------------------------------- function Has_One_Entry_And_No_Queue (T : Entity_Id) return Boolean is Item : Entity_Id; Is_First : Boolean := True; begin Item := First_Entity (T); while Present (Item) loop if Is_Entry (Item) then -- The protected type has more than one entry if not Is_First then return False; end if; -- The queue length is not one if not Restriction_Active (No_Entry_Queue) and then Get_Max_Queue_Length (Item) /= Uint_1 then return False; end if; Is_First := False; end if; Next_Entity (Item); end loop; return True; end Has_One_Entry_And_No_Queue; -- Local variables Pkg_Id : RTU_Id := RTU_Null; -- Start of processing for Corresponding_Runtime_Package begin pragma Assert (Is_Concurrent_Type (Typ)); if Is_Protected_Type (Typ) then if Has_Entries (Typ) -- A protected type without entries that covers an interface and -- overrides the abstract routines with protected procedures is -- considered equivalent to a protected type with entries in the -- context of dispatching select statements. It is sufficient to -- check for the presence of an interface list in the declaration -- node to recognize this case. or else Present (Interface_List (Parent (Typ))) -- Protected types with interrupt handlers (when not using a -- restricted profile) are also considered equivalent to -- protected types with entries. The types which are used -- (Static_Interrupt_Protection and Dynamic_Interrupt_Protection) -- are derived from Protection_Entries. or else (Has_Attach_Handler (Typ) and then not Restricted_Profile) or else Has_Interrupt_Handler (Typ) then if Abort_Allowed or else Restriction_Active (No_Select_Statements) = False or else not Has_One_Entry_And_No_Queue (Typ) or else (Has_Attach_Handler (Typ) and then not Restricted_Profile) then Pkg_Id := System_Tasking_Protected_Objects_Entries; else Pkg_Id := System_Tasking_Protected_Objects_Single_Entry; end if; else Pkg_Id := System_Tasking_Protected_Objects; end if; end if; return Pkg_Id; end Corresponding_Runtime_Package; ----------------------------------- -- Current_Sem_Unit_Declarations -- ----------------------------------- function Current_Sem_Unit_Declarations return List_Id is U : Node_Id := Unit (Cunit (Current_Sem_Unit)); Decls : List_Id; begin -- If the current unit is a package body, locate the visible -- declarations of the package spec. if Nkind (U) = N_Package_Body then U := Unit (Library_Unit (Cunit (Current_Sem_Unit))); end if; if Nkind (U) = N_Package_Declaration then U := Specification (U); Decls := Visible_Declarations (U); if No (Decls) then Decls := New_List; Set_Visible_Declarations (U, Decls); end if; else Decls := Declarations (U); if No (Decls) then Decls := New_List; Set_Declarations (U, Decls); end if; end if; return Decls; end Current_Sem_Unit_Declarations; ----------------------- -- Duplicate_Subexpr -- ----------------------- function Duplicate_Subexpr (Exp : Node_Id; Name_Req : Boolean := False; Renaming_Req : Boolean := False) return Node_Id is begin Remove_Side_Effects (Exp, Name_Req, Renaming_Req); return New_Copy_Tree (Exp); end Duplicate_Subexpr; --------------------------------- -- Duplicate_Subexpr_No_Checks -- --------------------------------- function Duplicate_Subexpr_No_Checks (Exp : Node_Id; Name_Req : Boolean := False; Renaming_Req : Boolean := False; Related_Id : Entity_Id := Empty; Is_Low_Bound : Boolean := False; Is_High_Bound : Boolean := False) return Node_Id is New_Exp : Node_Id; begin Remove_Side_Effects (Exp => Exp, Name_Req => Name_Req, Renaming_Req => Renaming_Req, Related_Id => Related_Id, Is_Low_Bound => Is_Low_Bound, Is_High_Bound => Is_High_Bound); New_Exp := New_Copy_Tree (Exp); Remove_Checks (New_Exp); return New_Exp; end Duplicate_Subexpr_No_Checks; ----------------------------------- -- Duplicate_Subexpr_Move_Checks -- ----------------------------------- function Duplicate_Subexpr_Move_Checks (Exp : Node_Id; Name_Req : Boolean := False; Renaming_Req : Boolean := False) return Node_Id is New_Exp : Node_Id; begin Remove_Side_Effects (Exp, Name_Req, Renaming_Req); New_Exp := New_Copy_Tree (Exp); Remove_Checks (Exp); return New_Exp; end Duplicate_Subexpr_Move_Checks; ------------------------- -- Enclosing_Init_Proc -- ------------------------- function Enclosing_Init_Proc return Entity_Id is S : Entity_Id; begin S := Current_Scope; while Present (S) and then S /= Standard_Standard loop if Is_Init_Proc (S) then return S; else S := Scope (S); end if; end loop; return Empty; end Enclosing_Init_Proc; -------------------- -- Ensure_Defined -- -------------------- procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is IR : Node_Id; begin -- An itype reference must only be created if this is a local itype, so -- that gigi can elaborate it on the proper objstack. if Is_Itype (Typ) and then Scope (Typ) = Current_Scope then IR := Make_Itype_Reference (Sloc (N)); Set_Itype (IR, Typ); Insert_Action (N, IR); end if; end Ensure_Defined; -------------------- -- Entry_Names_OK -- -------------------- function Entry_Names_OK return Boolean is begin return not Restricted_Profile and then not Global_Discard_Names and then not Restriction_Active (No_Implicit_Heap_Allocations) and then not Restriction_Active (No_Local_Allocators); end Entry_Names_OK; ------------------- -- Evaluate_Name -- ------------------- procedure Evaluate_Name (Nam : Node_Id) is begin -- For an attribute reference or an indexed component, evaluate the -- prefix, which is itself a name, recursively, and then force the -- evaluation of all the subscripts (or attribute expressions). case Nkind (Nam) is when N_Attribute_Reference | N_Indexed_Component => Evaluate_Name (Prefix (Nam)); declare E : Node_Id; begin E := First (Expressions (Nam)); while Present (E) loop Force_Evaluation (E); if Is_Rewrite_Substitution (E) then Set_Do_Range_Check (E, Do_Range_Check (Original_Node (E))); end if; Next (E); end loop; end; -- For an explicit dereference, we simply force the evaluation of -- the name expression. The dereference provides a value that is the -- address for the renamed object, and it is precisely this value -- that we want to preserve. when N_Explicit_Dereference => Force_Evaluation (Prefix (Nam)); -- For a function call, we evaluate the call when N_Function_Call => Force_Evaluation (Nam); -- For a qualified expression, we evaluate the underlying object -- name if any, otherwise we force the evaluation of the underlying -- expression. when N_Qualified_Expression => if Is_Object_Reference (Expression (Nam)) then Evaluate_Name (Expression (Nam)); else Force_Evaluation (Expression (Nam)); end if; -- For a selected component, we simply evaluate the prefix when N_Selected_Component => Evaluate_Name (Prefix (Nam)); -- For a slice, we evaluate the prefix, as for the indexed component -- case and then, if there is a range present, either directly or as -- the constraint of a discrete subtype indication, we evaluate the -- two bounds of this range. when N_Slice => Evaluate_Name (Prefix (Nam)); Evaluate_Slice_Bounds (Nam); -- For a type conversion, the expression of the conversion must be -- the name of an object, and we simply need to evaluate this name. when N_Type_Conversion => Evaluate_Name (Expression (Nam)); -- The remaining cases are direct name, operator symbol and character -- literal. In all these cases, we do nothing, since we want to -- reevaluate each time the renamed object is used. when others => null; end case; end Evaluate_Name; --------------------------- -- Evaluate_Slice_Bounds -- --------------------------- procedure Evaluate_Slice_Bounds (Slice : Node_Id) is DR : constant Node_Id := Discrete_Range (Slice); Constr : Node_Id; Rexpr : Node_Id; begin if Nkind (DR) = N_Range then Force_Evaluation (Low_Bound (DR)); Force_Evaluation (High_Bound (DR)); elsif Nkind (DR) = N_Subtype_Indication then Constr := Constraint (DR); if Nkind (Constr) = N_Range_Constraint then Rexpr := Range_Expression (Constr); Force_Evaluation (Low_Bound (Rexpr)); Force_Evaluation (High_Bound (Rexpr)); end if; end if; end Evaluate_Slice_Bounds; --------------------- -- Evolve_And_Then -- --------------------- procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is begin if No (Cond) then Cond := Cond1; else Cond := Make_And_Then (Sloc (Cond1), Left_Opnd => Cond, Right_Opnd => Cond1); end if; end Evolve_And_Then; -------------------- -- Evolve_Or_Else -- -------------------- procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is begin if No (Cond) then Cond := Cond1; else Cond := Make_Or_Else (Sloc (Cond1), Left_Opnd => Cond, Right_Opnd => Cond1); end if; end Evolve_Or_Else; ----------------------------------------- -- Expand_Static_Predicates_In_Choices -- ----------------------------------------- procedure Expand_Static_Predicates_In_Choices (N : Node_Id) is pragma Assert (Nkind_In (N, N_Case_Statement_Alternative, N_Variant)); Choices : constant List_Id := Discrete_Choices (N); Choice : Node_Id; Next_C : Node_Id; P : Node_Id; C : Node_Id; begin Choice := First (Choices); while Present (Choice) loop Next_C := Next (Choice); -- Check for name of subtype with static predicate if Is_Entity_Name (Choice) and then Is_Type (Entity (Choice)) and then Has_Predicates (Entity (Choice)) then -- Loop through entries in predicate list, converting to choices -- and inserting in the list before the current choice. Note that -- if the list is empty, corresponding to a False predicate, then -- no choices are inserted. P := First (Static_Discrete_Predicate (Entity (Choice))); while Present (P) loop -- If low bound and high bounds are equal, copy simple choice if Expr_Value (Low_Bound (P)) = Expr_Value (High_Bound (P)) then C := New_Copy (Low_Bound (P)); -- Otherwise copy a range else C := New_Copy (P); end if; -- Change Sloc to referencing choice (rather than the Sloc of -- the predicate declaration element itself). Set_Sloc (C, Sloc (Choice)); Insert_Before (Choice, C); Next (P); end loop; -- Delete the predicated entry Remove (Choice); end if; -- Move to next choice to check Choice := Next_C; end loop; Set_Has_SP_Choice (N, False); end Expand_Static_Predicates_In_Choices; ------------------------------ -- Expand_Subtype_From_Expr -- ------------------------------ -- This function is applicable for both static and dynamic allocation of -- objects which are constrained by an initial expression. Basically it -- transforms an unconstrained subtype indication into a constrained one. -- The expression may also be transformed in certain cases in order to -- avoid multiple evaluation. In the static allocation case, the general -- scheme is: -- Val : T := Expr; -- is transformed into -- Val : Constrained_Subtype_Of_T := Maybe_Modified_Expr; -- -- Here are the main cases : -- -- -- Val : T ([Index_Subtype (Expr)]) := Expr; -- -- -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr; -- -- -- subtype T is Type_Of_Expr -- Val : T := Expr; -- -- -- Val : T (constraints taken from Expr) := Expr; -- -- -- type Axxx is access all T; -- Rval : Axxx := Expr'ref; -- Val : T (constraints taken from Rval) := Rval.all; -- ??? note: when the Expression is allocated in the secondary stack -- we could use it directly instead of copying it by declaring -- Val : T (...) renames Rval.all procedure Expand_Subtype_From_Expr (N : Node_Id; Unc_Type : Entity_Id; Subtype_Indic : Node_Id; Exp : Node_Id; Related_Id : Entity_Id := Empty) is Loc : constant Source_Ptr := Sloc (N); Exp_Typ : constant Entity_Id := Etype (Exp); T : Entity_Id; begin -- In general we cannot build the subtype if expansion is disabled, -- because internal entities may not have been defined. However, to -- avoid some cascaded errors, we try to continue when the expression is -- an array (or string), because it is safe to compute the bounds. It is -- in fact required to do so even in a generic context, because there -- may be constants that depend on the bounds of a string literal, both -- standard string types and more generally arrays of characters. -- In GNATprove mode, these extra subtypes are not needed, unless Exp is -- a static expression. In that case, the subtype will be constrained -- while the original type might be unconstrained, so expanding the type -- is necessary both for passing legality checks in GNAT and for precise -- analysis in GNATprove. if GNATprove_Mode and then not Is_Static_Expression (Exp) then return; end if; if not Expander_Active and then (No (Etype (Exp)) or else not Is_String_Type (Etype (Exp))) then return; end if; if Nkind (Exp) = N_Slice then declare Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ)); begin Rewrite (Subtype_Indic, Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Unc_Type, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List (New_Occurrence_Of (Slice_Type, Loc))))); -- This subtype indication may be used later for constraint checks -- we better make sure that if a variable was used as a bound of -- the original slice, its value is frozen. Evaluate_Slice_Bounds (Exp); end; elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then Rewrite (Subtype_Indic, Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Unc_Type, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List ( Make_Literal_Range (Loc, Literal_Typ => Exp_Typ))))); -- If the type of the expression is an internally generated type it -- may not be necessary to create a new subtype. However there are two -- exceptions: references to the current instances, and aliased array -- object declarations for which the back end has to create a template. elsif Is_Constrained (Exp_Typ) and then not Is_Class_Wide_Type (Unc_Type) and then (Nkind (N) /= N_Object_Declaration or else not Is_Entity_Name (Expression (N)) or else not Comes_From_Source (Entity (Expression (N))) or else not Is_Array_Type (Exp_Typ) or else not Aliased_Present (N)) then if Is_Itype (Exp_Typ) then -- Within an initialization procedure, a selected component -- denotes a component of the enclosing record, and it appears as -- an actual in a call to its own initialization procedure. If -- this component depends on the outer discriminant, we must -- generate the proper actual subtype for it. if Nkind (Exp) = N_Selected_Component and then Within_Init_Proc then declare Decl : constant Node_Id := Build_Actual_Subtype_Of_Component (Exp_Typ, Exp); begin if Present (Decl) then Insert_Action (N, Decl); T := Defining_Identifier (Decl); else T := Exp_Typ; end if; end; -- No need to generate a new subtype else T := Exp_Typ; end if; else T := Make_Temporary (Loc, 'T'); Insert_Action (N, Make_Subtype_Declaration (Loc, Defining_Identifier => T, Subtype_Indication => New_Occurrence_Of (Exp_Typ, Loc))); -- This type is marked as an itype even though it has an explicit -- declaration since otherwise Is_Generic_Actual_Type can get -- set, resulting in the generation of spurious errors. (See -- sem_ch8.Analyze_Package_Renaming and sem_type.covers) Set_Is_Itype (T); Set_Associated_Node_For_Itype (T, Exp); end if; Rewrite (Subtype_Indic, New_Occurrence_Of (T, Loc)); -- Nothing needs to be done for private types with unknown discriminants -- if the underlying type is not an unconstrained composite type or it -- is an unchecked union. elsif Is_Private_Type (Unc_Type) and then Has_Unknown_Discriminants (Unc_Type) and then (not Is_Composite_Type (Underlying_Type (Unc_Type)) or else Is_Constrained (Underlying_Type (Unc_Type)) or else Is_Unchecked_Union (Underlying_Type (Unc_Type))) then null; -- Case of derived type with unknown discriminants where the parent type -- also has unknown discriminants. elsif Is_Record_Type (Unc_Type) and then not Is_Class_Wide_Type (Unc_Type) and then Has_Unknown_Discriminants (Unc_Type) and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type)) then -- Nothing to be done if no underlying record view available -- If this is a limited type derived from a type with unknown -- discriminants, do not expand either, so that subsequent expansion -- of the call can add build-in-place parameters to call. if No (Underlying_Record_View (Unc_Type)) or else Is_Limited_Type (Unc_Type) then null; -- Otherwise use the Underlying_Record_View to create the proper -- constrained subtype for an object of a derived type with unknown -- discriminants. else Remove_Side_Effects (Exp); Rewrite (Subtype_Indic, Make_Subtype_From_Expr (Exp, Underlying_Record_View (Unc_Type))); end if; -- Renamings of class-wide interface types require no equivalent -- constrained type declarations because we only need to reference -- the tag component associated with the interface. The same is -- presumably true for class-wide types in general, so this test -- is broadened to include all class-wide renamings, which also -- avoids cases of unbounded recursion in Remove_Side_Effects. -- (Is this really correct, or are there some cases of class-wide -- renamings that require action in this procedure???) elsif Present (N) and then Nkind (N) = N_Object_Renaming_Declaration and then Is_Class_Wide_Type (Unc_Type) then null; -- In Ada 95 nothing to be done if the type of the expression is limited -- because in this case the expression cannot be copied, and its use can -- only be by reference. -- In Ada 2005 the context can be an object declaration whose expression -- is a function that returns in place. If the nominal subtype has -- unknown discriminants, the call still provides constraints on the -- object, and we have to create an actual subtype from it. -- If the type is class-wide, the expression is dynamically tagged and -- we do not create an actual subtype either. Ditto for an interface. -- For now this applies only if the type is immutably limited, and the -- function being called is build-in-place. This will have to be revised -- when build-in-place functions are generalized to other types. elsif Is_Limited_View (Exp_Typ) and then (Is_Class_Wide_Type (Exp_Typ) or else Is_Interface (Exp_Typ) or else not Has_Unknown_Discriminants (Exp_Typ) or else not Is_Composite_Type (Unc_Type)) then null; -- For limited objects initialized with build in place function calls, -- nothing to be done; otherwise we prematurely introduce an N_Reference -- node in the expression initializing the object, which breaks the -- circuitry that detects and adds the additional arguments to the -- called function. elsif Is_Build_In_Place_Function_Call (Exp) then null; else Remove_Side_Effects (Exp); Rewrite (Subtype_Indic, Make_Subtype_From_Expr (Exp, Unc_Type, Related_Id)); end if; end Expand_Subtype_From_Expr; --------------------------------------------- -- Expression_Contains_Primitives_Calls_Of -- --------------------------------------------- function Expression_Contains_Primitives_Calls_Of (Expr : Node_Id; Typ : Entity_Id) return Boolean is U_Typ : constant Entity_Id := Unique_Entity (Typ); Calls_OK : Boolean := False; -- This flag is set to True when expression Expr contains at least one -- call to a nondispatching primitive function of Typ. function Search_Primitive_Calls (N : Node_Id) return Traverse_Result; -- Search for nondispatching calls to primitive functions of type Typ ---------------------------- -- Search_Primitive_Calls -- ---------------------------- function Search_Primitive_Calls (N : Node_Id) return Traverse_Result is Disp_Typ : Entity_Id; Subp : Entity_Id; begin -- Detect a function call that could denote a nondispatching -- primitive of the input type. if Nkind (N) = N_Function_Call and then Is_Entity_Name (Name (N)) then Subp := Entity (Name (N)); -- Do not consider function calls with a controlling argument, as -- those are always dispatching calls. if Is_Dispatching_Operation (Subp) and then No (Controlling_Argument (N)) then Disp_Typ := Find_Dispatching_Type (Subp); -- To qualify as a suitable primitive, the dispatching type of -- the function must be the input type. if Present (Disp_Typ) and then Unique_Entity (Disp_Typ) = U_Typ then Calls_OK := True; -- There is no need to continue the traversal, as one such -- call suffices. return Abandon; end if; end if; end if; return OK; end Search_Primitive_Calls; procedure Search_Calls is new Traverse_Proc (Search_Primitive_Calls); -- Start of processing for Expression_Contains_Primitives_Calls_Of_Type begin Search_Calls (Expr); return Calls_OK; end Expression_Contains_Primitives_Calls_Of; ---------------------- -- Finalize_Address -- ---------------------- function Finalize_Address (Typ : Entity_Id) return Entity_Id is Btyp : constant Entity_Id := Base_Type (Typ); Utyp : Entity_Id := Typ; begin -- Handle protected class-wide or task class-wide types if Is_Class_Wide_Type (Utyp) then if Is_Concurrent_Type (Root_Type (Utyp)) then Utyp := Root_Type (Utyp); elsif Is_Private_Type (Root_Type (Utyp)) and then Present (Full_View (Root_Type (Utyp))) and then Is_Concurrent_Type (Full_View (Root_Type (Utyp))) then Utyp := Full_View (Root_Type (Utyp)); end if; end if; -- Handle private types if Is_Private_Type (Utyp) and then Present (Full_View (Utyp)) then Utyp := Full_View (Utyp); end if; -- Handle protected and task types if Is_Concurrent_Type (Utyp) and then Present (Corresponding_Record_Type (Utyp)) then Utyp := Corresponding_Record_Type (Utyp); end if; Utyp := Underlying_Type (Base_Type (Utyp)); -- Deal with untagged derivation of private views. If the parent is -- now known to be protected, the finalization routine is the one -- defined on the corresponding record of the ancestor (corresponding -- records do not automatically inherit operations, but maybe they -- should???) if Is_Untagged_Derivation (Btyp) then if Is_Protected_Type (Btyp) then Utyp := Corresponding_Record_Type (Root_Type (Btyp)); else Utyp := Underlying_Type (Root_Type (Btyp)); if Is_Protected_Type (Utyp) then Utyp := Corresponding_Record_Type (Utyp); end if; end if; end if; -- If the underlying_type is a subtype, we are dealing with the -- completion of a private type. We need to access the base type and -- generate a conversion to it. if Utyp /= Base_Type (Utyp) then pragma Assert (Is_Private_Type (Typ)); Utyp := Base_Type (Utyp); end if; -- When dealing with an internally built full view for a type with -- unknown discriminants, use the original record type. if Is_Underlying_Record_View (Utyp) then Utyp := Etype (Utyp); end if; return TSS (Utyp, TSS_Finalize_Address); end Finalize_Address; ------------------------ -- Find_Interface_ADT -- ------------------------ function Find_Interface_ADT (T : Entity_Id; Iface : Entity_Id) return Elmt_Id is ADT : Elmt_Id; Typ : Entity_Id := T; begin pragma Assert (Is_Interface (Iface)); -- Handle private types if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then Typ := Full_View (Typ); end if; -- Handle access types if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); end if; -- Handle task and protected types implementing interfaces if Is_Concurrent_Type (Typ) then Typ := Corresponding_Record_Type (Typ); end if; pragma Assert (not Is_Class_Wide_Type (Typ) and then Ekind (Typ) /= E_Incomplete_Type); if Is_Ancestor (Iface, Typ, Use_Full_View => True) then return First_Elmt (Access_Disp_Table (Typ)); else ADT := Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ)))); while Present (ADT) and then Present (Related_Type (Node (ADT))) and then Related_Type (Node (ADT)) /= Iface and then not Is_Ancestor (Iface, Related_Type (Node (ADT)), Use_Full_View => True) loop Next_Elmt (ADT); end loop; pragma Assert (Present (Related_Type (Node (ADT)))); return ADT; end if; end Find_Interface_ADT; ------------------------ -- Find_Interface_Tag -- ------------------------ function Find_Interface_Tag (T : Entity_Id; Iface : Entity_Id) return Entity_Id is AI_Tag : Entity_Id := Empty; Found : Boolean := False; Typ : Entity_Id := T; procedure Find_Tag (Typ : Entity_Id); -- Internal subprogram used to recursively climb to the ancestors -------------- -- Find_Tag -- -------------- procedure Find_Tag (Typ : Entity_Id) is AI_Elmt : Elmt_Id; AI : Node_Id; begin -- This routine does not handle the case in which the interface is an -- ancestor of Typ. That case is handled by the enclosing subprogram. pragma Assert (Typ /= Iface); -- Climb to the root type handling private types if Present (Full_View (Etype (Typ))) then if Full_View (Etype (Typ)) /= Typ then Find_Tag (Full_View (Etype (Typ))); end if; elsif Etype (Typ) /= Typ then Find_Tag (Etype (Typ)); end if; -- Traverse the list of interfaces implemented by the type if not Found and then Present (Interfaces (Typ)) and then not (Is_Empty_Elmt_List (Interfaces (Typ))) then -- Skip the tag associated with the primary table AI_Tag := Next_Tag_Component (First_Tag_Component (Typ)); pragma Assert (Present (AI_Tag)); AI_Elmt := First_Elmt (Interfaces (Typ)); while Present (AI_Elmt) loop AI := Node (AI_Elmt); if AI = Iface or else Is_Ancestor (Iface, AI, Use_Full_View => True) then Found := True; return; end if; AI_Tag := Next_Tag_Component (AI_Tag); Next_Elmt (AI_Elmt); end loop; end if; end Find_Tag; -- Start of processing for Find_Interface_Tag begin pragma Assert (Is_Interface (Iface)); -- Handle access types if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); end if; -- Handle class-wide types if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; -- Handle private types if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then Typ := Full_View (Typ); end if; -- Handle entities from the limited view if Ekind (Typ) = E_Incomplete_Type then pragma Assert (Present (Non_Limited_View (Typ))); Typ := Non_Limited_View (Typ); end if; -- Handle task and protected types implementing interfaces if Is_Concurrent_Type (Typ) then Typ := Corresponding_Record_Type (Typ); end if; -- If the interface is an ancestor of the type, then it shared the -- primary dispatch table. if Is_Ancestor (Iface, Typ, Use_Full_View => True) then return First_Tag_Component (Typ); -- Otherwise we need to search for its associated tag component else Find_Tag (Typ); return AI_Tag; end if; end Find_Interface_Tag; --------------------------- -- Find_Optional_Prim_Op -- --------------------------- function Find_Optional_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is Prim : Elmt_Id; Typ : Entity_Id := T; Op : Entity_Id; begin if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; Typ := Underlying_Type (Typ); -- Loop through primitive operations Prim := First_Elmt (Primitive_Operations (Typ)); while Present (Prim) loop Op := Node (Prim); -- We can retrieve primitive operations by name if it is an internal -- name. For equality we must check that both of its operands have -- the same type, to avoid confusion with user-defined equalities -- than may have a asymmetric signature. exit when Chars (Op) = Name and then (Name /= Name_Op_Eq or else Etype (First_Formal (Op)) = Etype (Last_Formal (Op))); Next_Elmt (Prim); end loop; return Node (Prim); -- Empty if not found end Find_Optional_Prim_Op; --------------------------- -- Find_Optional_Prim_Op -- --------------------------- function Find_Optional_Prim_Op (T : Entity_Id; Name : TSS_Name_Type) return Entity_Id is Inher_Op : Entity_Id := Empty; Own_Op : Entity_Id := Empty; Prim_Elmt : Elmt_Id; Prim_Id : Entity_Id; Typ : Entity_Id := T; begin if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; Typ := Underlying_Type (Typ); -- This search is based on the assertion that the dispatching version -- of the TSS routine always precedes the real primitive. Prim_Elmt := First_Elmt (Primitive_Operations (Typ)); while Present (Prim_Elmt) loop Prim_Id := Node (Prim_Elmt); if Is_TSS (Prim_Id, Name) then if Present (Alias (Prim_Id)) then Inher_Op := Prim_Id; else Own_Op := Prim_Id; end if; end if; Next_Elmt (Prim_Elmt); end loop; if Present (Own_Op) then return Own_Op; elsif Present (Inher_Op) then return Inher_Op; else return Empty; end if; end Find_Optional_Prim_Op; ------------------ -- Find_Prim_Op -- ------------------ function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is Result : constant Entity_Id := Find_Optional_Prim_Op (T, Name); begin if No (Result) then raise Program_Error; end if; return Result; end Find_Prim_Op; ------------------ -- Find_Prim_Op -- ------------------ function Find_Prim_Op (T : Entity_Id; Name : TSS_Name_Type) return Entity_Id is Result : constant Entity_Id := Find_Optional_Prim_Op (T, Name); begin if No (Result) then raise Program_Error; end if; return Result; end Find_Prim_Op; ---------------------------- -- Find_Protection_Object -- ---------------------------- function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is S : Entity_Id; begin S := Scop; while Present (S) loop if Ekind_In (S, E_Entry, E_Entry_Family, E_Function, E_Procedure) and then Present (Protection_Object (S)) then return Protection_Object (S); end if; S := Scope (S); end loop; -- If we do not find a Protection object in the scope chain, then -- something has gone wrong, most likely the object was never created. raise Program_Error; end Find_Protection_Object; -------------------------- -- Find_Protection_Type -- -------------------------- function Find_Protection_Type (Conc_Typ : Entity_Id) return Entity_Id is Comp : Entity_Id; Typ : Entity_Id := Conc_Typ; begin if Is_Concurrent_Type (Typ) then Typ := Corresponding_Record_Type (Typ); end if; -- Since restriction violations are not considered serious errors, the -- expander remains active, but may leave the corresponding record type -- malformed. In such cases, component _object is not available so do -- not look for it. if not Analyzed (Typ) then return Empty; end if; Comp := First_Component (Typ); while Present (Comp) loop if Chars (Comp) = Name_uObject then return Base_Type (Etype (Comp)); end if; Next_Component (Comp); end loop; -- The corresponding record of a protected type should always have an -- _object field. raise Program_Error; end Find_Protection_Type; ----------------------- -- Find_Hook_Context -- ----------------------- function Find_Hook_Context (N : Node_Id) return Node_Id is Par : Node_Id; Top : Node_Id; Wrapped_Node : Node_Id; -- Note: if we are in a transient scope, we want to reuse it as -- the context for actions insertion, if possible. But if N is itself -- part of the stored actions for the current transient scope, -- then we need to insert at the appropriate (inner) location in -- the not as an action on Node_To_Be_Wrapped. In_Cond_Expr : constant Boolean := Within_Case_Or_If_Expression (N); begin -- When the node is inside a case/if expression, the lifetime of any -- temporary controlled object is extended. Find a suitable insertion -- node by locating the topmost case or if expressions. if In_Cond_Expr then Par := N; Top := N; while Present (Par) loop if Nkind_In (Original_Node (Par), N_Case_Expression, N_If_Expression) then Top := Par; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); end loop; -- The topmost case or if expression is now recovered, but it may -- still not be the correct place to add generated code. Climb to -- find a parent that is part of a declarative or statement list, -- and is not a list of actuals in a call. Par := Top; while Present (Par) loop if Is_List_Member (Par) and then not Nkind_In (Par, N_Component_Association, N_Discriminant_Association, N_Parameter_Association, N_Pragma_Argument_Association) and then not Nkind_In (Parent (Par), N_Function_Call, N_Procedure_Call_Statement, N_Entry_Call_Statement) then return Par; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); end loop; return Par; else Par := N; while Present (Par) loop -- Keep climbing past various operators if Nkind (Parent (Par)) in N_Op or else Nkind_In (Parent (Par), N_And_Then, N_Or_Else) then Par := Parent (Par); else exit; end if; end loop; Top := Par; -- The node may be located in a pragma in which case return the -- pragma itself: -- pragma Precondition (... and then Ctrl_Func_Call ...); -- Similar case occurs when the node is related to an object -- declaration or assignment: -- Obj [: Some_Typ] := ... and then Ctrl_Func_Call ...; -- Another case to consider is when the node is part of a return -- statement: -- return ... and then Ctrl_Func_Call ...; -- Another case is when the node acts as a formal in a procedure -- call statement: -- Proc (... and then Ctrl_Func_Call ...); if Scope_Is_Transient then Wrapped_Node := Node_To_Be_Wrapped; else Wrapped_Node := Empty; end if; while Present (Par) loop if Par = Wrapped_Node or else Nkind_In (Par, N_Assignment_Statement, N_Object_Declaration, N_Pragma, N_Procedure_Call_Statement, N_Simple_Return_Statement) then return Par; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); end loop; -- Return the topmost short circuit operator return Top; end if; end Find_Hook_Context; ------------------------------ -- Following_Address_Clause -- ------------------------------ function Following_Address_Clause (D : Node_Id) return Node_Id is Id : constant Entity_Id := Defining_Identifier (D); Result : Node_Id; Par : Node_Id; function Check_Decls (D : Node_Id) return Node_Id; -- This internal function differs from the main function in that it -- gets called to deal with a following package private part, and -- it checks declarations starting with D (the main function checks -- declarations following D). If D is Empty, then Empty is returned. ----------------- -- Check_Decls -- ----------------- function Check_Decls (D : Node_Id) return Node_Id is Decl : Node_Id; begin Decl := D; while Present (Decl) loop if Nkind (Decl) = N_At_Clause and then Chars (Identifier (Decl)) = Chars (Id) then return Decl; elsif Nkind (Decl) = N_Attribute_Definition_Clause and then Chars (Decl) = Name_Address and then Chars (Name (Decl)) = Chars (Id) then return Decl; end if; Next (Decl); end loop; -- Otherwise not found, return Empty return Empty; end Check_Decls; -- Start of processing for Following_Address_Clause begin -- If parser detected no address clause for the identifier in question, -- then the answer is a quick NO, without the need for a search. if not Get_Name_Table_Boolean1 (Chars (Id)) then return Empty; end if; -- Otherwise search current declarative unit Result := Check_Decls (Next (D)); if Present (Result) then return Result; end if; -- Check for possible package private part following Par := Parent (D); if Nkind (Par) = N_Package_Specification and then Visible_Declarations (Par) = List_Containing (D) and then Present (Private_Declarations (Par)) then -- Private part present, check declarations there return Check_Decls (First (Private_Declarations (Par))); else -- No private part, clause not found, return Empty return Empty; end if; end Following_Address_Clause; ---------------------- -- Force_Evaluation -- ---------------------- procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False; Related_Id : Entity_Id := Empty; Is_Low_Bound : Boolean := False; Is_High_Bound : Boolean := False; Mode : Force_Evaluation_Mode := Relaxed) is begin Remove_Side_Effects (Exp => Exp, Name_Req => Name_Req, Variable_Ref => True, Renaming_Req => False, Related_Id => Related_Id, Is_Low_Bound => Is_Low_Bound, Is_High_Bound => Is_High_Bound, Check_Side_Effects => Is_Static_Expression (Exp) or else Mode = Relaxed); end Force_Evaluation; --------------------------------- -- Fully_Qualified_Name_String -- --------------------------------- function Fully_Qualified_Name_String (E : Entity_Id; Append_NUL : Boolean := True) return String_Id is procedure Internal_Full_Qualified_Name (E : Entity_Id); -- Compute recursively the qualified name without NUL at the end, adding -- it to the currently started string being generated ---------------------------------- -- Internal_Full_Qualified_Name -- ---------------------------------- procedure Internal_Full_Qualified_Name (E : Entity_Id) is Ent : Entity_Id; begin -- Deal properly with child units if Nkind (E) = N_Defining_Program_Unit_Name then Ent := Defining_Identifier (E); else Ent := E; end if; -- Compute qualification recursively (only "Standard" has no scope) if Present (Scope (Scope (Ent))) then Internal_Full_Qualified_Name (Scope (Ent)); Store_String_Char (Get_Char_Code ('.')); end if; -- Every entity should have a name except some expanded blocks -- don't bother about those. if Chars (Ent) = No_Name then return; end if; -- Generates the entity name in upper case Get_Decoded_Name_String (Chars (Ent)); Set_All_Upper_Case; Store_String_Chars (Name_Buffer (1 .. Name_Len)); return; end Internal_Full_Qualified_Name; -- Start of processing for Full_Qualified_Name begin Start_String; Internal_Full_Qualified_Name (E); if Append_NUL then Store_String_Char (Get_Char_Code (ASCII.NUL)); end if; return End_String; end Fully_Qualified_Name_String; ------------------------ -- Generate_Poll_Call -- ------------------------ procedure Generate_Poll_Call (N : Node_Id) is begin -- No poll call if polling not active if not Polling_Required then return; -- Otherwise generate require poll call else Insert_Before_And_Analyze (N, Make_Procedure_Call_Statement (Sloc (N), Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N)))); end if; end Generate_Poll_Call; --------------------------------- -- Get_Current_Value_Condition -- --------------------------------- -- Note: the implementation of this procedure is very closely tied to the -- implementation of Set_Current_Value_Condition. In the Get procedure, we -- interpret Current_Value fields set by the Set procedure, so the two -- procedures need to be closely coordinated. procedure Get_Current_Value_Condition (Var : Node_Id; Op : out Node_Kind; Val : out Node_Id) is Loc : constant Source_Ptr := Sloc (Var); Ent : constant Entity_Id := Entity (Var); procedure Process_Current_Value_Condition (N : Node_Id; S : Boolean); -- N is an expression which holds either True (S = True) or False (S = -- False) in the condition. This procedure digs out the expression and -- if it refers to Ent, sets Op and Val appropriately. ------------------------------------- -- Process_Current_Value_Condition -- ------------------------------------- procedure Process_Current_Value_Condition (N : Node_Id; S : Boolean) is Cond : Node_Id; Prev_Cond : Node_Id; Sens : Boolean; begin Cond := N; Sens := S; loop Prev_Cond := Cond; -- Deal with NOT operators, inverting sense while Nkind (Cond) = N_Op_Not loop Cond := Right_Opnd (Cond); Sens := not Sens; end loop; -- Deal with conversions, qualifications, and expressions with -- actions. while Nkind_In (Cond, N_Type_Conversion, N_Qualified_Expression, N_Expression_With_Actions) loop Cond := Expression (Cond); end loop; exit when Cond = Prev_Cond; end loop; -- Deal with AND THEN and AND cases if Nkind_In (Cond, N_And_Then, N_Op_And) then -- Don't ever try to invert a condition that is of the form of an -- AND or AND THEN (since we are not doing sufficiently general -- processing to allow this). if Sens = False then Op := N_Empty; Val := Empty; return; end if; -- Recursively process AND and AND THEN branches Process_Current_Value_Condition (Left_Opnd (Cond), True); if Op /= N_Empty then return; end if; Process_Current_Value_Condition (Right_Opnd (Cond), True); return; -- Case of relational operator elsif Nkind (Cond) in N_Op_Compare then Op := Nkind (Cond); -- Invert sense of test if inverted test if Sens = False then case Op is when N_Op_Eq => Op := N_Op_Ne; when N_Op_Ne => Op := N_Op_Eq; when N_Op_Lt => Op := N_Op_Ge; when N_Op_Gt => Op := N_Op_Le; when N_Op_Le => Op := N_Op_Gt; when N_Op_Ge => Op := N_Op_Lt; when others => raise Program_Error; end case; end if; -- Case of entity op value if Is_Entity_Name (Left_Opnd (Cond)) and then Ent = Entity (Left_Opnd (Cond)) and then Compile_Time_Known_Value (Right_Opnd (Cond)) then Val := Right_Opnd (Cond); -- Case of value op entity elsif Is_Entity_Name (Right_Opnd (Cond)) and then Ent = Entity (Right_Opnd (Cond)) and then Compile_Time_Known_Value (Left_Opnd (Cond)) then Val := Left_Opnd (Cond); -- We are effectively swapping operands case Op is when N_Op_Eq => null; when N_Op_Ne => null; when N_Op_Lt => Op := N_Op_Gt; when N_Op_Gt => Op := N_Op_Lt; when N_Op_Le => Op := N_Op_Ge; when N_Op_Ge => Op := N_Op_Le; when others => raise Program_Error; end case; else Op := N_Empty; end if; return; elsif Nkind_In (Cond, N_Type_Conversion, N_Qualified_Expression, N_Expression_With_Actions) then Cond := Expression (Cond); -- Case of Boolean variable reference, return as though the -- reference had said var = True. else if Is_Entity_Name (Cond) and then Ent = Entity (Cond) then Val := New_Occurrence_Of (Standard_True, Sloc (Cond)); if Sens = False then Op := N_Op_Ne; else Op := N_Op_Eq; end if; end if; end if; end Process_Current_Value_Condition; -- Start of processing for Get_Current_Value_Condition begin Op := N_Empty; Val := Empty; -- Immediate return, nothing doing, if this is not an object if Ekind (Ent) not in Object_Kind then return; end if; -- Otherwise examine current value declare CV : constant Node_Id := Current_Value (Ent); Sens : Boolean; Stm : Node_Id; begin -- If statement. Condition is known true in THEN section, known False -- in any ELSIF or ELSE part, and unknown outside the IF statement. if Nkind (CV) = N_If_Statement then -- Before start of IF statement if Loc < Sloc (CV) then return; -- After end of IF statement elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then return; end if; -- At this stage we know that we are within the IF statement, but -- unfortunately, the tree does not record the SLOC of the ELSE so -- we cannot use a simple SLOC comparison to distinguish between -- the then/else statements, so we have to climb the tree. declare N : Node_Id; begin N := Parent (Var); while Parent (N) /= CV loop N := Parent (N); -- If we fall off the top of the tree, then that's odd, but -- perhaps it could occur in some error situation, and the -- safest response is simply to assume that the outcome of -- the condition is unknown. No point in bombing during an -- attempt to optimize things. if No (N) then return; end if; end loop; -- Now we have N pointing to a node whose parent is the IF -- statement in question, so now we can tell if we are within -- the THEN statements. if Is_List_Member (N) and then List_Containing (N) = Then_Statements (CV) then Sens := True; -- If the variable reference does not come from source, we -- cannot reliably tell whether it appears in the else part. -- In particular, if it appears in generated code for a node -- that requires finalization, it may be attached to a list -- that has not been yet inserted into the code. For now, -- treat it as unknown. elsif not Comes_From_Source (N) then return; -- Otherwise we must be in ELSIF or ELSE part else Sens := False; end if; end; -- ELSIF part. Condition is known true within the referenced -- ELSIF, known False in any subsequent ELSIF or ELSE part, -- and unknown before the ELSE part or after the IF statement. elsif Nkind (CV) = N_Elsif_Part then -- if the Elsif_Part had condition_actions, the elsif has been -- rewritten as a nested if, and the original elsif_part is -- detached from the tree, so there is no way to obtain useful -- information on the current value of the variable. -- Can this be improved ??? if No (Parent (CV)) then return; end if; Stm := Parent (CV); -- If the tree has been otherwise rewritten there is nothing -- else to be done either. if Nkind (Stm) /= N_If_Statement then return; end if; -- Before start of ELSIF part if Loc < Sloc (CV) then return; -- After end of IF statement elsif Loc >= Sloc (Stm) + Text_Ptr (UI_To_Int (End_Span (Stm))) then return; end if; -- Again we lack the SLOC of the ELSE, so we need to climb the -- tree to see if we are within the ELSIF part in question. declare N : Node_Id; begin N := Parent (Var); while Parent (N) /= Stm loop N := Parent (N); -- If we fall off the top of the tree, then that's odd, but -- perhaps it could occur in some error situation, and the -- safest response is simply to assume that the outcome of -- the condition is unknown. No point in bombing during an -- attempt to optimize things. if No (N) then return; end if; end loop; -- Now we have N pointing to a node whose parent is the IF -- statement in question, so see if is the ELSIF part we want. -- the THEN statements. if N = CV then Sens := True; -- Otherwise we must be in subsequent ELSIF or ELSE part else Sens := False; end if; end; -- Iteration scheme of while loop. The condition is known to be -- true within the body of the loop. elsif Nkind (CV) = N_Iteration_Scheme then declare Loop_Stmt : constant Node_Id := Parent (CV); begin -- Before start of body of loop if Loc < Sloc (Loop_Stmt) then return; -- After end of LOOP statement elsif Loc >= Sloc (End_Label (Loop_Stmt)) then return; -- We are within the body of the loop else Sens := True; end if; end; -- All other cases of Current_Value settings else return; end if; -- If we fall through here, then we have a reportable condition, Sens -- is True if the condition is true and False if it needs inverting. Process_Current_Value_Condition (Condition (CV), Sens); end; end Get_Current_Value_Condition; --------------------- -- Get_Stream_Size -- --------------------- function Get_Stream_Size (E : Entity_Id) return Uint is begin -- If we have a Stream_Size clause for this type use it if Has_Stream_Size_Clause (E) then return Static_Integer (Expression (Stream_Size_Clause (E))); -- Otherwise the Stream_Size if the size of the type else return Esize (E); end if; end Get_Stream_Size; --------------------------- -- Has_Access_Constraint -- --------------------------- function Has_Access_Constraint (E : Entity_Id) return Boolean is Disc : Entity_Id; T : constant Entity_Id := Etype (E); begin if Has_Per_Object_Constraint (E) and then Has_Discriminants (T) then Disc := First_Discriminant (T); while Present (Disc) loop if Is_Access_Type (Etype (Disc)) then return True; end if; Next_Discriminant (Disc); end loop; return False; else return False; end if; end Has_Access_Constraint; ----------------------------------------------------- -- Has_Annotate_Pragma_For_External_Axiomatization -- ----------------------------------------------------- function Has_Annotate_Pragma_For_External_Axiomatization (E : Entity_Id) return Boolean is function Is_Annotate_Pragma_For_External_Axiomatization (N : Node_Id) return Boolean; -- Returns whether N is -- pragma Annotate (GNATprove, External_Axiomatization); ---------------------------------------------------- -- Is_Annotate_Pragma_For_External_Axiomatization -- ---------------------------------------------------- -- The general form of pragma Annotate is -- pragma Annotate (IDENTIFIER [, IDENTIFIER {, ARG}]); -- ARG ::= NAME | EXPRESSION -- The first two arguments are by convention intended to refer to an -- external tool and a tool-specific function. These arguments are -- not analyzed. -- The following is used to annotate a package specification which -- GNATprove should treat specially, because the axiomatization of -- this unit is given by the user instead of being automatically -- generated. -- pragma Annotate (GNATprove, External_Axiomatization); function Is_Annotate_Pragma_For_External_Axiomatization (N : Node_Id) return Boolean is Name_GNATprove : constant String := "gnatprove"; Name_External_Axiomatization : constant String := "external_axiomatization"; -- Special names begin if Nkind (N) = N_Pragma and then Get_Pragma_Id (N) = Pragma_Annotate and then List_Length (Pragma_Argument_Associations (N)) = 2 then declare Arg1 : constant Node_Id := First (Pragma_Argument_Associations (N)); Arg2 : constant Node_Id := Next (Arg1); Nam1 : Name_Id; Nam2 : Name_Id; begin -- Fill in Name_Buffer with Name_GNATprove first, and then with -- Name_External_Axiomatization so that Name_Find returns the -- corresponding name. This takes care of all possible casings. Name_Len := 0; Add_Str_To_Name_Buffer (Name_GNATprove); Nam1 := Name_Find; Name_Len := 0; Add_Str_To_Name_Buffer (Name_External_Axiomatization); Nam2 := Name_Find; return Chars (Get_Pragma_Arg (Arg1)) = Nam1 and then Chars (Get_Pragma_Arg (Arg2)) = Nam2; end; else return False; end if; end Is_Annotate_Pragma_For_External_Axiomatization; -- Local variables Decl : Node_Id; Vis_Decls : List_Id; N : Node_Id; -- Start of processing for Has_Annotate_Pragma_For_External_Axiomatization begin if Nkind (Parent (E)) = N_Defining_Program_Unit_Name then Decl := Parent (Parent (E)); else Decl := Parent (E); end if; Vis_Decls := Visible_Declarations (Decl); N := First (Vis_Decls); while Present (N) loop -- Skip declarations generated by the frontend. Skip all pragmas -- that are not the desired Annotate pragma. Stop the search on -- the first non-pragma source declaration. if Comes_From_Source (N) then if Nkind (N) = N_Pragma then if Is_Annotate_Pragma_For_External_Axiomatization (N) then return True; end if; else return False; end if; end if; Next (N); end loop; return False; end Has_Annotate_Pragma_For_External_Axiomatization; -------------------- -- Homonym_Number -- -------------------- function Homonym_Number (Subp : Entity_Id) return Pos is Hom : Entity_Id := Homonym (Subp); Count : Pos := 1; begin while Present (Hom) loop if Scope (Hom) = Scope (Subp) then Count := Count + 1; end if; Hom := Homonym (Hom); end loop; return Count; end Homonym_Number; ----------------------------------- -- In_Library_Level_Package_Body -- ----------------------------------- function In_Library_Level_Package_Body (Id : Entity_Id) return Boolean is begin -- First determine whether the entity appears at the library level, then -- look at the containing unit. if Is_Library_Level_Entity (Id) then declare Container : constant Node_Id := Cunit (Get_Source_Unit (Id)); begin return Nkind (Unit (Container)) = N_Package_Body; end; end if; return False; end In_Library_Level_Package_Body; ------------------------------ -- In_Unconditional_Context -- ------------------------------ function In_Unconditional_Context (Node : Node_Id) return Boolean is P : Node_Id; begin P := Node; while Present (P) loop case Nkind (P) is when N_Subprogram_Body => return True; when N_If_Statement => return False; when N_Loop_Statement => return False; when N_Case_Statement => return False; when others => P := Parent (P); end case; end loop; return False; end In_Unconditional_Context; ------------------- -- Insert_Action -- ------------------- procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id; Spec_Expr_OK : Boolean := False) is begin if Present (Ins_Action) then Insert_Actions (Assoc_Node => Assoc_Node, Ins_Actions => New_List (Ins_Action), Spec_Expr_OK => Spec_Expr_OK); end if; end Insert_Action; -- Version with check(s) suppressed procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id; Spec_Expr_OK : Boolean := False) is begin Insert_Actions (Assoc_Node => Assoc_Node, Ins_Actions => New_List (Ins_Action), Suppress => Suppress, Spec_Expr_OK => Spec_Expr_OK); end Insert_Action; ------------------------- -- Insert_Action_After -- ------------------------- procedure Insert_Action_After (Assoc_Node : Node_Id; Ins_Action : Node_Id) is begin Insert_Actions_After (Assoc_Node, New_List (Ins_Action)); end Insert_Action_After; -------------------- -- Insert_Actions -- -------------------- procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id; Spec_Expr_OK : Boolean := False) is N : Node_Id; P : Node_Id; Wrapped_Node : Node_Id := Empty; begin if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then return; end if; -- Insert the action when the context is "Handling of Default and Per- -- Object Expressions" only when requested by the caller. if Spec_Expr_OK then null; -- Ignore insert of actions from inside default expression (or other -- similar "spec expression") in the special spec-expression analyze -- mode. Any insertions at this point have no relevance, since we are -- only doing the analyze to freeze the types of any static expressions. -- See section "Handling of Default and Per-Object Expressions" in the -- spec of package Sem for further details. elsif In_Spec_Expression then return; end if; -- If the action derives from stuff inside a record, then the actions -- are attached to the current scope, to be inserted and analyzed on -- exit from the scope. The reason for this is that we may also be -- generating freeze actions at the same time, and they must eventually -- be elaborated in the correct order. if Is_Record_Type (Current_Scope) and then not Is_Frozen (Current_Scope) then if No (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions) then Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions := Ins_Actions; else Append_List (Ins_Actions, Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions); end if; return; end if; -- We now intend to climb up the tree to find the right point to -- insert the actions. We start at Assoc_Node, unless this node is a -- subexpression in which case we start with its parent. We do this for -- two reasons. First it speeds things up. Second, if Assoc_Node is -- itself one of the special nodes like N_And_Then, then we assume that -- an initial request to insert actions for such a node does not expect -- the actions to get deposited in the node for later handling when the -- node is expanded, since clearly the node is being dealt with by the -- caller. Note that in the subexpression case, N is always the child we -- came from. -- N_Raise_xxx_Error is an annoying special case, it is a statement -- if it has type Standard_Void_Type, and a subexpression otherwise. -- Procedure calls, and similarly procedure attribute references, are -- also statements. if Nkind (Assoc_Node) in N_Subexpr and then (Nkind (Assoc_Node) not in N_Raise_xxx_Error or else Etype (Assoc_Node) /= Standard_Void_Type) and then Nkind (Assoc_Node) /= N_Procedure_Call_Statement and then (Nkind (Assoc_Node) /= N_Attribute_Reference or else not Is_Procedure_Attribute_Name (Attribute_Name (Assoc_Node))) then N := Assoc_Node; P := Parent (Assoc_Node); -- Nonsubexpression case. Note that N is initially Empty in this case -- (N is only guaranteed non-Empty in the subexpr case). else N := Empty; P := Assoc_Node; end if; -- Capture root of the transient scope if Scope_Is_Transient then Wrapped_Node := Node_To_Be_Wrapped; end if; loop pragma Assert (Present (P)); -- Make sure that inserted actions stay in the transient scope if Present (Wrapped_Node) and then N = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); return; end if; case Nkind (P) is -- Case of right operand of AND THEN or OR ELSE. Put the actions -- in the Actions field of the right operand. They will be moved -- out further when the AND THEN or OR ELSE operator is expanded. -- Nothing special needs to be done for the left operand since -- in that case the actions are executed unconditionally. when N_Short_Circuit => if N = Right_Opnd (P) then -- We are now going to either append the actions to the -- actions field of the short-circuit operation. We will -- also analyze the actions now. -- This analysis is really too early, the proper thing would -- be to just park them there now, and only analyze them if -- we find we really need them, and to it at the proper -- final insertion point. However attempting to this proved -- tricky, so for now we just kill current values before and -- after the analyze call to make sure we avoid peculiar -- optimizations from this out of order insertion. Kill_Current_Values; -- If P has already been expanded, we can't park new actions -- on it, so we need to expand them immediately, introducing -- an Expression_With_Actions. N can't be an expression -- with actions, or else then the actions would have been -- inserted at an inner level. if Analyzed (P) then pragma Assert (Nkind (N) /= N_Expression_With_Actions); Rewrite (N, Make_Expression_With_Actions (Sloc (N), Actions => Ins_Actions, Expression => Relocate_Node (N))); Analyze_And_Resolve (N); elsif Present (Actions (P)) then Insert_List_After_And_Analyze (Last (Actions (P)), Ins_Actions); else Set_Actions (P, Ins_Actions); Analyze_List (Actions (P)); end if; Kill_Current_Values; return; end if; -- Then or Else dependent expression of an if expression. Add -- actions to Then_Actions or Else_Actions field as appropriate. -- The actions will be moved further out when the if is expanded. when N_If_Expression => declare ThenX : constant Node_Id := Next (First (Expressions (P))); ElseX : constant Node_Id := Next (ThenX); begin -- If the enclosing expression is already analyzed, as -- is the case for nested elaboration checks, insert the -- conditional further out. if Analyzed (P) then null; -- Actions belong to the then expression, temporarily place -- them as Then_Actions of the if expression. They will be -- moved to the proper place later when the if expression -- is expanded. elsif N = ThenX then if Present (Then_Actions (P)) then Insert_List_After_And_Analyze (Last (Then_Actions (P)), Ins_Actions); else Set_Then_Actions (P, Ins_Actions); Analyze_List (Then_Actions (P)); end if; return; -- Actions belong to the else expression, temporarily place -- them as Else_Actions of the if expression. They will be -- moved to the proper place later when the if expression -- is expanded. elsif N = ElseX then if Present (Else_Actions (P)) then Insert_List_After_And_Analyze (Last (Else_Actions (P)), Ins_Actions); else Set_Else_Actions (P, Ins_Actions); Analyze_List (Else_Actions (P)); end if; return; -- Actions belong to the condition. In this case they are -- unconditionally executed, and so we can continue the -- search for the proper insert point. else null; end if; end; -- Alternative of case expression, we place the action in the -- Actions field of the case expression alternative, this will -- be handled when the case expression is expanded. when N_Case_Expression_Alternative => if Present (Actions (P)) then Insert_List_After_And_Analyze (Last (Actions (P)), Ins_Actions); else Set_Actions (P, Ins_Actions); Analyze_List (Actions (P)); end if; return; -- Case of appearing within an Expressions_With_Actions node. When -- the new actions come from the expression of the expression with -- actions, they must be added to the existing actions. The other -- alternative is when the new actions are related to one of the -- existing actions of the expression with actions, and should -- never reach here: if actions are inserted on a statement -- within the Actions of an expression with actions, or on some -- subexpression of such a statement, then the outermost proper -- insertion point is right before the statement, and we should -- never climb up as far as the N_Expression_With_Actions itself. when N_Expression_With_Actions => if N = Expression (P) then if Is_Empty_List (Actions (P)) then Append_List_To (Actions (P), Ins_Actions); Analyze_List (Actions (P)); else Insert_List_After_And_Analyze (Last (Actions (P)), Ins_Actions); end if; return; else raise Program_Error; end if; -- Case of appearing in the condition of a while expression or -- elsif. We insert the actions into the Condition_Actions field. -- They will be moved further out when the while loop or elsif -- is analyzed. when N_Elsif_Part | N_Iteration_Scheme => if N = Condition (P) then if Present (Condition_Actions (P)) then Insert_List_After_And_Analyze (Last (Condition_Actions (P)), Ins_Actions); else Set_Condition_Actions (P, Ins_Actions); -- Set the parent of the insert actions explicitly. This -- is not a syntactic field, but we need the parent field -- set, in particular so that freeze can understand that -- it is dealing with condition actions, and properly -- insert the freezing actions. Set_Parent (Ins_Actions, P); Analyze_List (Condition_Actions (P)); end if; return; end if; -- Statements, declarations, pragmas, representation clauses when -- Statements N_Procedure_Call_Statement | N_Statement_Other_Than_Procedure_Call -- Pragmas | N_Pragma -- Representation_Clause | N_At_Clause | N_Attribute_Definition_Clause | N_Enumeration_Representation_Clause | N_Record_Representation_Clause -- Declarations | N_Abstract_Subprogram_Declaration | N_Entry_Body | N_Exception_Declaration | N_Exception_Renaming_Declaration | N_Expression_Function | N_Formal_Abstract_Subprogram_Declaration | N_Formal_Concrete_Subprogram_Declaration | N_Formal_Object_Declaration | N_Formal_Type_Declaration | N_Full_Type_Declaration | N_Function_Instantiation | N_Generic_Function_Renaming_Declaration | N_Generic_Package_Declaration | N_Generic_Package_Renaming_Declaration | N_Generic_Procedure_Renaming_Declaration | N_Generic_Subprogram_Declaration | N_Implicit_Label_Declaration | N_Incomplete_Type_Declaration | N_Number_Declaration | N_Object_Declaration | N_Object_Renaming_Declaration | N_Package_Body | N_Package_Body_Stub | N_Package_Declaration | N_Package_Instantiation | N_Package_Renaming_Declaration | N_Private_Extension_Declaration | N_Private_Type_Declaration | N_Procedure_Instantiation | N_Protected_Body | N_Protected_Body_Stub | N_Single_Task_Declaration | N_Subprogram_Body | N_Subprogram_Body_Stub | N_Subprogram_Declaration | N_Subprogram_Renaming_Declaration | N_Subtype_Declaration | N_Task_Body | N_Task_Body_Stub -- Use clauses can appear in lists of declarations | N_Use_Package_Clause | N_Use_Type_Clause -- Freeze entity behaves like a declaration or statement | N_Freeze_Entity | N_Freeze_Generic_Entity => -- Do not insert here if the item is not a list member (this -- happens for example with a triggering statement, and the -- proper approach is to insert before the entire select). if not Is_List_Member (P) then null; -- Do not insert if parent of P is an N_Component_Association -- node (i.e. we are in the context of an N_Aggregate or -- N_Extension_Aggregate node. In this case we want to insert -- before the entire aggregate. elsif Nkind (Parent (P)) = N_Component_Association then null; -- Do not insert if the parent of P is either an N_Variant node -- or an N_Record_Definition node, meaning in either case that -- P is a member of a component list, and that therefore the -- actions should be inserted outside the complete record -- declaration. elsif Nkind_In (Parent (P), N_Variant, N_Record_Definition) then null; -- Do not insert freeze nodes within the loop generated for -- an aggregate, because they may be elaborated too late for -- subsequent use in the back end: within a package spec the -- loop is part of the elaboration procedure and is only -- elaborated during the second pass. -- If the loop comes from source, or the entity is local to the -- loop itself it must remain within. elsif Nkind (Parent (P)) = N_Loop_Statement and then not Comes_From_Source (Parent (P)) and then Nkind (First (Ins_Actions)) = N_Freeze_Entity and then Scope (Entity (First (Ins_Actions))) /= Current_Scope then null; -- Otherwise we can go ahead and do the insertion elsif P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); return; else Insert_List_Before_And_Analyze (P, Ins_Actions); return; end if; -- the expansion of Task and protected type declarations can -- create declarations for temporaries which, like other actions -- are inserted and analyzed before the current declaraation. -- However, the current scope is the synchronized type, and -- for unnesting it is critical that the proper scope for these -- generated entities be the enclosing one. when N_Task_Type_Declaration | N_Protected_Type_Declaration => Push_Scope (Scope (Current_Scope)); Insert_List_Before_And_Analyze (P, Ins_Actions); Pop_Scope; return; -- A special case, N_Raise_xxx_Error can act either as a statement -- or a subexpression. We tell the difference by looking at the -- Etype. It is set to Standard_Void_Type in the statement case. when N_Raise_xxx_Error => if Etype (P) = Standard_Void_Type then if P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); else Insert_List_Before_And_Analyze (P, Ins_Actions); end if; return; -- In the subexpression case, keep climbing else null; end if; -- If a component association appears within a loop created for -- an array aggregate, attach the actions to the association so -- they can be subsequently inserted within the loop. For other -- component associations insert outside of the aggregate. For -- an association that will generate a loop, its Loop_Actions -- attribute is already initialized (see exp_aggr.adb). -- The list of Loop_Actions can in turn generate additional ones, -- that are inserted before the associated node. If the associated -- node is outside the aggregate, the new actions are collected -- at the end of the Loop_Actions, to respect the order in which -- they are to be elaborated. when N_Component_Association | N_Iterated_Component_Association => if Nkind (Parent (P)) = N_Aggregate and then Present (Loop_Actions (P)) then if Is_Empty_List (Loop_Actions (P)) then Set_Loop_Actions (P, Ins_Actions); Analyze_List (Ins_Actions); else declare Decl : Node_Id; begin -- Check whether these actions were generated by a -- declaration that is part of the Loop_Actions for -- the component_association. Decl := Assoc_Node; while Present (Decl) loop exit when Parent (Decl) = P and then Is_List_Member (Decl) and then List_Containing (Decl) = Loop_Actions (P); Decl := Parent (Decl); end loop; if Present (Decl) then Insert_List_Before_And_Analyze (Decl, Ins_Actions); else Insert_List_After_And_Analyze (Last (Loop_Actions (P)), Ins_Actions); end if; end; end if; return; else null; end if; -- Special case: an attribute denoting a procedure call when N_Attribute_Reference => if Is_Procedure_Attribute_Name (Attribute_Name (P)) then if P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); else Insert_List_Before_And_Analyze (P, Ins_Actions); end if; return; -- In the subexpression case, keep climbing else null; end if; -- Special case: a marker when N_Call_Marker | N_Variable_Reference_Marker => if Is_List_Member (P) then Insert_List_Before_And_Analyze (P, Ins_Actions); return; end if; -- A contract node should not belong to the tree when N_Contract => raise Program_Error; -- For all other node types, keep climbing tree when N_Abortable_Part | N_Accept_Alternative | N_Access_Definition | N_Access_Function_Definition | N_Access_Procedure_Definition | N_Access_To_Object_Definition | N_Aggregate | N_Allocator | N_Aspect_Specification | N_Case_Expression | N_Case_Statement_Alternative | N_Character_Literal | N_Compilation_Unit | N_Compilation_Unit_Aux | N_Component_Clause | N_Component_Declaration | N_Component_Definition | N_Component_List | N_Constrained_Array_Definition | N_Decimal_Fixed_Point_Definition | N_Defining_Character_Literal | N_Defining_Identifier | N_Defining_Operator_Symbol | N_Defining_Program_Unit_Name | N_Delay_Alternative | N_Delta_Aggregate | N_Delta_Constraint | N_Derived_Type_Definition | N_Designator | N_Digits_Constraint | N_Discriminant_Association | N_Discriminant_Specification | N_Empty | N_Entry_Body_Formal_Part | N_Entry_Call_Alternative | N_Entry_Declaration | N_Entry_Index_Specification | N_Enumeration_Type_Definition | N_Error | N_Exception_Handler | N_Expanded_Name | N_Explicit_Dereference | N_Extension_Aggregate | N_Floating_Point_Definition | N_Formal_Decimal_Fixed_Point_Definition | N_Formal_Derived_Type_Definition | N_Formal_Discrete_Type_Definition | N_Formal_Floating_Point_Definition | N_Formal_Modular_Type_Definition | N_Formal_Ordinary_Fixed_Point_Definition | N_Formal_Package_Declaration | N_Formal_Private_Type_Definition | N_Formal_Incomplete_Type_Definition | N_Formal_Signed_Integer_Type_Definition | N_Function_Call | N_Function_Specification | N_Generic_Association | N_Handled_Sequence_Of_Statements | N_Identifier | N_In | N_Index_Or_Discriminant_Constraint | N_Indexed_Component | N_Integer_Literal | N_Iterator_Specification | N_Itype_Reference | N_Label | N_Loop_Parameter_Specification | N_Mod_Clause | N_Modular_Type_Definition | N_Not_In | N_Null | N_Op_Abs | N_Op_Add | N_Op_And | N_Op_Concat | N_Op_Divide | N_Op_Eq | N_Op_Expon | N_Op_Ge | N_Op_Gt | N_Op_Le | N_Op_Lt | N_Op_Minus | N_Op_Mod | N_Op_Multiply | N_Op_Ne | N_Op_Not | N_Op_Or | N_Op_Plus | N_Op_Rem | N_Op_Rotate_Left | N_Op_Rotate_Right | N_Op_Shift_Left | N_Op_Shift_Right | N_Op_Shift_Right_Arithmetic | N_Op_Subtract | N_Op_Xor | N_Operator_Symbol | N_Ordinary_Fixed_Point_Definition | N_Others_Choice | N_Package_Specification | N_Parameter_Association | N_Parameter_Specification | N_Pop_Constraint_Error_Label | N_Pop_Program_Error_Label | N_Pop_Storage_Error_Label | N_Pragma_Argument_Association | N_Procedure_Specification | N_Protected_Definition | N_Push_Constraint_Error_Label | N_Push_Program_Error_Label | N_Push_Storage_Error_Label | N_Qualified_Expression | N_Quantified_Expression | N_Raise_Expression | N_Range | N_Range_Constraint | N_Real_Literal | N_Real_Range_Specification | N_Record_Definition | N_Reference | N_SCIL_Dispatch_Table_Tag_Init | N_SCIL_Dispatching_Call | N_SCIL_Membership_Test | N_Selected_Component | N_Signed_Integer_Type_Definition | N_Single_Protected_Declaration | N_Slice | N_String_Literal | N_Subtype_Indication | N_Subunit | N_Target_Name | N_Task_Definition | N_Terminate_Alternative | N_Triggering_Alternative | N_Type_Conversion | N_Unchecked_Expression | N_Unchecked_Type_Conversion | N_Unconstrained_Array_Definition | N_Unused_At_End | N_Unused_At_Start | N_Variant | N_Variant_Part | N_Validate_Unchecked_Conversion | N_With_Clause => null; end case; -- If we fall through above tests, keep climbing tree N := P; if Nkind (Parent (N)) = N_Subunit then -- This is the proper body corresponding to a stub. Insertion must -- be done at the point of the stub, which is in the declarative -- part of the parent unit. P := Corresponding_Stub (Parent (N)); else P := Parent (N); end if; end loop; end Insert_Actions; -- Version with check(s) suppressed procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id; Suppress : Check_Id; Spec_Expr_OK : Boolean := False) is begin if Suppress = All_Checks then declare Sva : constant Suppress_Array := Scope_Suppress.Suppress; begin Scope_Suppress.Suppress := (others => True); Insert_Actions (Assoc_Node, Ins_Actions, Spec_Expr_OK); Scope_Suppress.Suppress := Sva; end; else declare Svg : constant Boolean := Scope_Suppress.Suppress (Suppress); begin Scope_Suppress.Suppress (Suppress) := True; Insert_Actions (Assoc_Node, Ins_Actions, Spec_Expr_OK); Scope_Suppress.Suppress (Suppress) := Svg; end; end if; end Insert_Actions; -------------------------- -- Insert_Actions_After -- -------------------------- procedure Insert_Actions_After (Assoc_Node : Node_Id; Ins_Actions : List_Id) is begin if Scope_Is_Transient and then Assoc_Node = Node_To_Be_Wrapped then Store_After_Actions_In_Scope (Ins_Actions); else Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions); end if; end Insert_Actions_After; ------------------------ -- Insert_Declaration -- ------------------------ procedure Insert_Declaration (N : Node_Id; Decl : Node_Id) is P : Node_Id; begin pragma Assert (Nkind (N) in N_Subexpr); -- Climb until we find a procedure or a package P := N; loop pragma Assert (Present (Parent (P))); P := Parent (P); if Is_List_Member (P) then exit when Nkind_In (Parent (P), N_Package_Specification, N_Subprogram_Body); -- Special handling for handled sequence of statements, we must -- insert in the statements not the exception handlers! if Nkind (Parent (P)) = N_Handled_Sequence_Of_Statements then P := First (Statements (Parent (P))); exit; end if; end if; end loop; -- Now do the insertion Insert_Before (P, Decl); Analyze (Decl); end Insert_Declaration; --------------------------------- -- Insert_Library_Level_Action -- --------------------------------- procedure Insert_Library_Level_Action (N : Node_Id) is Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit)); begin Push_Scope (Cunit_Entity (Current_Sem_Unit)); -- And not Main_Unit as previously. If the main unit is a body, -- the scope needed to analyze the actions is the entity of the -- corresponding declaration. if No (Actions (Aux)) then Set_Actions (Aux, New_List (N)); else Append (N, Actions (Aux)); end if; Analyze (N); Pop_Scope; end Insert_Library_Level_Action; ---------------------------------- -- Insert_Library_Level_Actions -- ---------------------------------- procedure Insert_Library_Level_Actions (L : List_Id) is Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit)); begin if Is_Non_Empty_List (L) then Push_Scope (Cunit_Entity (Main_Unit)); -- ??? should this be Current_Sem_Unit instead of Main_Unit? if No (Actions (Aux)) then Set_Actions (Aux, L); Analyze_List (L); else Insert_List_After_And_Analyze (Last (Actions (Aux)), L); end if; Pop_Scope; end if; end Insert_Library_Level_Actions; ---------------------- -- Inside_Init_Proc -- ---------------------- function Inside_Init_Proc return Boolean is Proc : constant Entity_Id := Enclosing_Init_Proc; begin return Proc /= Empty; end Inside_Init_Proc; ---------------------------- -- Is_All_Null_Statements -- ---------------------------- function Is_All_Null_Statements (L : List_Id) return Boolean is Stm : Node_Id; begin Stm := First (L); while Present (Stm) loop if Nkind (Stm) /= N_Null_Statement then return False; end if; Next (Stm); end loop; return True; end Is_All_Null_Statements; -------------------------------------------------- -- Is_Displacement_Of_Object_Or_Function_Result -- -------------------------------------------------- function Is_Displacement_Of_Object_Or_Function_Result (Obj_Id : Entity_Id) return Boolean is function Is_Controlled_Function_Call (N : Node_Id) return Boolean; -- Determine whether node N denotes a controlled function call function Is_Controlled_Indexing (N : Node_Id) return Boolean; -- Determine whether node N denotes a generalized indexing form which -- involves a controlled result. function Is_Displace_Call (N : Node_Id) return Boolean; -- Determine whether node N denotes a call to Ada.Tags.Displace function Is_Source_Object (N : Node_Id) return Boolean; -- Determine whether a particular node denotes a source object function Strip (N : Node_Id) return Node_Id; -- Examine arbitrary node N by stripping various indirections and return -- the "real" node. --------------------------------- -- Is_Controlled_Function_Call -- --------------------------------- function Is_Controlled_Function_Call (N : Node_Id) return Boolean is Expr : Node_Id; begin -- When a function call appears in Object.Operation format, the -- original representation has several possible forms depending on -- the availability and form of actual parameters: -- Obj.Func N_Selected_Component -- Obj.Func (Actual) N_Indexed_Component -- Obj.Func (Formal => Actual) N_Function_Call, whose Name is an -- N_Selected_Component Expr := Original_Node (N); loop if Nkind (Expr) = N_Function_Call then Expr := Name (Expr); -- "Obj.Func (Actual)" case elsif Nkind (Expr) = N_Indexed_Component then Expr := Prefix (Expr); -- "Obj.Func" or "Obj.Func (Formal => Actual) case elsif Nkind (Expr) = N_Selected_Component then Expr := Selector_Name (Expr); else exit; end if; end loop; return Nkind (Expr) in N_Has_Entity and then Present (Entity (Expr)) and then Ekind (Entity (Expr)) = E_Function and then Needs_Finalization (Etype (Entity (Expr))); end Is_Controlled_Function_Call; ---------------------------- -- Is_Controlled_Indexing -- ---------------------------- function Is_Controlled_Indexing (N : Node_Id) return Boolean is Expr : constant Node_Id := Original_Node (N); begin return Nkind (Expr) = N_Indexed_Component and then Present (Generalized_Indexing (Expr)) and then Needs_Finalization (Etype (Expr)); end Is_Controlled_Indexing; ---------------------- -- Is_Displace_Call -- ---------------------- function Is_Displace_Call (N : Node_Id) return Boolean is Call : constant Node_Id := Strip (N); begin return Present (Call) and then Nkind (Call) = N_Function_Call and then Nkind (Name (Call)) in N_Has_Entity and then Is_RTE (Entity (Name (Call)), RE_Displace); end Is_Displace_Call; ---------------------- -- Is_Source_Object -- ---------------------- function Is_Source_Object (N : Node_Id) return Boolean is Obj : constant Node_Id := Strip (N); begin return Present (Obj) and then Comes_From_Source (Obj) and then Nkind (Obj) in N_Has_Entity and then Is_Object (Entity (Obj)); end Is_Source_Object; ----------- -- Strip -- ----------- function Strip (N : Node_Id) return Node_Id is Result : Node_Id; begin Result := N; loop if Nkind (Result) = N_Explicit_Dereference then Result := Prefix (Result); elsif Nkind_In (Result, N_Type_Conversion, N_Unchecked_Type_Conversion) then Result := Expression (Result); else exit; end if; end loop; return Result; end Strip; -- Local variables Obj_Decl : constant Node_Id := Declaration_Node (Obj_Id); Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id)); Orig_Decl : constant Node_Id := Original_Node (Obj_Decl); Orig_Expr : Node_Id; -- Start of processing for Is_Displacement_Of_Object_Or_Function_Result begin -- Case 1: -- Obj : CW_Type := Function_Call (...); -- is rewritten into: -- Temp : ... := Function_Call (...)'reference; -- Obj : CW_Type renames (... Ada.Tags.Displace (Temp)); -- where the return type of the function and the class-wide type require -- dispatch table pointer displacement. -- Case 2: -- Obj : CW_Type := Container (...); -- is rewritten into: -- Temp : ... := Function_Call (Container, ...)'reference; -- Obj : CW_Type renames (... Ada.Tags.Displace (Temp)); -- where the container element type and the class-wide type require -- dispatch table pointer dispacement. -- Case 3: -- Obj : CW_Type := Src_Obj; -- is rewritten into: -- Obj : CW_Type renames (... Ada.Tags.Displace (Src_Obj)); -- where the type of the source object and the class-wide type require -- dispatch table pointer displacement. if Nkind (Obj_Decl) = N_Object_Renaming_Declaration and then Is_Class_Wide_Type (Obj_Typ) and then Is_Displace_Call (Renamed_Object (Obj_Id)) and then Nkind (Orig_Decl) = N_Object_Declaration and then Comes_From_Source (Orig_Decl) then Orig_Expr := Expression (Orig_Decl); return Is_Controlled_Function_Call (Orig_Expr) or else Is_Controlled_Indexing (Orig_Expr) or else Is_Source_Object (Orig_Expr); end if; return False; end Is_Displacement_Of_Object_Or_Function_Result; ------------------------------ -- Is_Finalizable_Transient -- ------------------------------ function Is_Finalizable_Transient (Decl : Node_Id; Rel_Node : Node_Id) return Boolean is Obj_Id : constant Entity_Id := Defining_Identifier (Decl); Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id)); function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean; -- Determine whether transient object Trans_Id is initialized either -- by a function call which returns an access type or simply renames -- another pointer. function Initialized_By_Aliased_BIP_Func_Call (Trans_Id : Entity_Id) return Boolean; -- Determine whether transient object Trans_Id is initialized by a -- build-in-place function call where the BIPalloc parameter is of -- value 1 and BIPaccess is not null. This case creates an aliasing -- between the returned value and the value denoted by BIPaccess. function Is_Aliased (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean; -- Determine whether transient object Trans_Id has been renamed or -- aliased through 'reference in the statement list starting from -- First_Stmt. function Is_Allocated (Trans_Id : Entity_Id) return Boolean; -- Determine whether transient object Trans_Id is allocated on the heap function Is_Iterated_Container (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean; -- Determine whether transient object Trans_Id denotes a container which -- is in the process of being iterated in the statement list starting -- from First_Stmt. --------------------------- -- Initialized_By_Access -- --------------------------- function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean is Expr : constant Node_Id := Expression (Parent (Trans_Id)); begin return Present (Expr) and then Nkind (Expr) /= N_Reference and then Is_Access_Type (Etype (Expr)); end Initialized_By_Access; ------------------------------------------ -- Initialized_By_Aliased_BIP_Func_Call -- ------------------------------------------ function Initialized_By_Aliased_BIP_Func_Call (Trans_Id : Entity_Id) return Boolean is Call : Node_Id := Expression (Parent (Trans_Id)); begin -- Build-in-place calls usually appear in 'reference format if Nkind (Call) = N_Reference then Call := Prefix (Call); end if; Call := Unqual_Conv (Call); if Is_Build_In_Place_Function_Call (Call) then declare Access_Nam : Name_Id := No_Name; Access_OK : Boolean := False; Actual : Node_Id; Alloc_Nam : Name_Id := No_Name; Alloc_OK : Boolean := False; Formal : Node_Id; Func_Id : Entity_Id; Param : Node_Id; begin -- Examine all parameter associations of the function call Param := First (Parameter_Associations (Call)); while Present (Param) loop if Nkind (Param) = N_Parameter_Association and then Nkind (Selector_Name (Param)) = N_Identifier then Actual := Explicit_Actual_Parameter (Param); Formal := Selector_Name (Param); -- Construct the names of formals BIPaccess and BIPalloc -- using the function name retrieved from an arbitrary -- formal. if Access_Nam = No_Name and then Alloc_Nam = No_Name and then Present (Entity (Formal)) then Func_Id := Scope (Entity (Formal)); Access_Nam := New_External_Name (Chars (Func_Id), BIP_Formal_Suffix (BIP_Object_Access)); Alloc_Nam := New_External_Name (Chars (Func_Id), BIP_Formal_Suffix (BIP_Alloc_Form)); end if; -- A match for BIPaccess => Temp has been found if Chars (Formal) = Access_Nam and then Nkind (Actual) /= N_Null then Access_OK := True; end if; -- A match for BIPalloc => 1 has been found if Chars (Formal) = Alloc_Nam and then Nkind (Actual) = N_Integer_Literal and then Intval (Actual) = Uint_1 then Alloc_OK := True; end if; end if; Next (Param); end loop; return Access_OK and Alloc_OK; end; end if; return False; end Initialized_By_Aliased_BIP_Func_Call; ---------------- -- Is_Aliased -- ---------------- function Is_Aliased (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean is function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id; -- Given an object renaming declaration, retrieve the entity of the -- renamed name. Return Empty if the renamed name is anything other -- than a variable or a constant. ------------------------- -- Find_Renamed_Object -- ------------------------- function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id is Ren_Obj : Node_Id := Empty; function Find_Object (N : Node_Id) return Traverse_Result; -- Try to detect an object which is either a constant or a -- variable. ----------------- -- Find_Object -- ----------------- function Find_Object (N : Node_Id) return Traverse_Result is begin -- Stop the search once a constant or a variable has been -- detected. if Nkind (N) = N_Identifier and then Present (Entity (N)) and then Ekind_In (Entity (N), E_Constant, E_Variable) then Ren_Obj := Entity (N); return Abandon; end if; return OK; end Find_Object; procedure Search is new Traverse_Proc (Find_Object); -- Local variables Typ : constant Entity_Id := Etype (Defining_Identifier (Ren_Decl)); -- Start of processing for Find_Renamed_Object begin -- Actions related to dispatching calls may appear as renamings of -- tags. Do not process this type of renaming because it does not -- use the actual value of the object. if not Is_RTE (Typ, RE_Tag_Ptr) then Search (Name (Ren_Decl)); end if; return Ren_Obj; end Find_Renamed_Object; -- Local variables Expr : Node_Id; Ren_Obj : Entity_Id; Stmt : Node_Id; -- Start of processing for Is_Aliased begin -- A controlled transient object is not considered aliased when it -- appears inside an expression_with_actions node even when there are -- explicit aliases of it: -- do -- Trans_Id : Ctrl_Typ ...; -- transient object -- Alias : ... := Trans_Id; -- object is aliased -- Val : constant Boolean := -- ... Alias ...; -- aliasing ends -- -- object safe to finalize -- in Val end; -- Expansion ensures that all aliases are encapsulated in the actions -- list and do not leak to the expression by forcing the evaluation -- of the expression. if Nkind (Rel_Node) = N_Expression_With_Actions then return False; -- Otherwise examine the statements after the controlled transient -- object and look for various forms of aliasing. else Stmt := First_Stmt; while Present (Stmt) loop if Nkind (Stmt) = N_Object_Declaration then Expr := Expression (Stmt); -- Aliasing of the form: -- Obj : ... := Trans_Id'reference; if Present (Expr) and then Nkind (Expr) = N_Reference and then Nkind (Prefix (Expr)) = N_Identifier and then Entity (Prefix (Expr)) = Trans_Id then return True; end if; elsif Nkind (Stmt) = N_Object_Renaming_Declaration then Ren_Obj := Find_Renamed_Object (Stmt); -- Aliasing of the form: -- Obj : ... renames ... Trans_Id ...; if Present (Ren_Obj) and then Ren_Obj = Trans_Id then return True; end if; end if; Next (Stmt); end loop; return False; end if; end Is_Aliased; ------------------ -- Is_Allocated -- ------------------ function Is_Allocated (Trans_Id : Entity_Id) return Boolean is Expr : constant Node_Id := Expression (Parent (Trans_Id)); begin return Is_Access_Type (Etype (Trans_Id)) and then Present (Expr) and then Nkind (Expr) = N_Allocator; end Is_Allocated; --------------------------- -- Is_Iterated_Container -- --------------------------- function Is_Iterated_Container (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean is Aspect : Node_Id; Call : Node_Id; Iter : Entity_Id; Param : Node_Id; Stmt : Node_Id; Typ : Entity_Id; begin -- It is not possible to iterate over containers in non-Ada 2012 code if Ada_Version < Ada_2012 then return False; end if; Typ := Etype (Trans_Id); -- Handle access type created for secondary stack use if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); end if; -- Look for aspect Default_Iterator. It may be part of a type -- declaration for a container, or inherited from a base type -- or parent type. Aspect := Find_Value_Of_Aspect (Typ, Aspect_Default_Iterator); if Present (Aspect) then Iter := Entity (Aspect); -- Examine the statements following the container object and -- look for a call to the default iterate routine where the -- first parameter is the transient. Such a call appears as: -- It : Access_To_CW_Iterator := -- Iterate (Tran_Id.all, ...)'reference; Stmt := First_Stmt; while Present (Stmt) loop -- Detect an object declaration which is initialized by a -- secondary stack function call. if Nkind (Stmt) = N_Object_Declaration and then Present (Expression (Stmt)) and then Nkind (Expression (Stmt)) = N_Reference and then Nkind (Prefix (Expression (Stmt))) = N_Function_Call then Call := Prefix (Expression (Stmt)); -- The call must invoke the default iterate routine of -- the container and the transient object must appear as -- the first actual parameter. Skip any calls whose names -- are not entities. if Is_Entity_Name (Name (Call)) and then Entity (Name (Call)) = Iter and then Present (Parameter_Associations (Call)) then Param := First (Parameter_Associations (Call)); if Nkind (Param) = N_Explicit_Dereference and then Entity (Prefix (Param)) = Trans_Id then return True; end if; end if; end if; Next (Stmt); end loop; end if; return False; end Is_Iterated_Container; -- Local variables Desig : Entity_Id := Obj_Typ; -- Start of processing for Is_Finalizable_Transient begin -- Handle access types if Is_Access_Type (Desig) then Desig := Available_View (Designated_Type (Desig)); end if; return Ekind_In (Obj_Id, E_Constant, E_Variable) and then Needs_Finalization (Desig) and then Requires_Transient_Scope (Desig) and then Nkind (Rel_Node) /= N_Simple_Return_Statement -- Do not consider a transient object that was already processed and then not Is_Finalized_Transient (Obj_Id) -- Do not consider renamed or 'reference-d transient objects because -- the act of renaming extends the object's lifetime. and then not Is_Aliased (Obj_Id, Decl) -- Do not consider transient objects allocated on the heap since -- they are attached to a finalization master. and then not Is_Allocated (Obj_Id) -- If the transient object is a pointer, check that it is not -- initialized by a function that returns a pointer or acts as a -- renaming of another pointer. and then (not Is_Access_Type (Obj_Typ) or else not Initialized_By_Access (Obj_Id)) -- Do not consider transient objects which act as indirect aliases -- of build-in-place function results. and then not Initialized_By_Aliased_BIP_Func_Call (Obj_Id) -- Do not consider conversions of tags to class-wide types and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id) -- Do not consider iterators because those are treated as normal -- controlled objects and are processed by the usual finalization -- machinery. This avoids the double finalization of an iterator. and then not Is_Iterator (Desig) -- Do not consider containers in the context of iterator loops. Such -- transient objects must exist for as long as the loop is around, -- otherwise any operation carried out by the iterator will fail. and then not Is_Iterated_Container (Obj_Id, Decl); end Is_Finalizable_Transient; --------------------------------- -- Is_Fully_Repped_Tagged_Type -- --------------------------------- function Is_Fully_Repped_Tagged_Type (T : Entity_Id) return Boolean is U : constant Entity_Id := Underlying_Type (T); Comp : Entity_Id; begin if No (U) or else not Is_Tagged_Type (U) then return False; elsif Has_Discriminants (U) then return False; elsif not Has_Specified_Layout (U) then return False; end if; -- Here we have a tagged type, see if it has any component (other than -- tag and parent) with no component_clause. If so, we return False. Comp := First_Component (U); while Present (Comp) loop if not Is_Tag (Comp) and then Chars (Comp) /= Name_uParent and then No (Component_Clause (Comp)) then return False; else Next_Component (Comp); end if; end loop; -- All components have clauses return True; end Is_Fully_Repped_Tagged_Type; ---------------------------------- -- Is_Library_Level_Tagged_Type -- ---------------------------------- function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is begin return Is_Tagged_Type (Typ) and then Is_Library_Level_Entity (Typ); end Is_Library_Level_Tagged_Type; -------------------------- -- Is_Non_BIP_Func_Call -- -------------------------- function Is_Non_BIP_Func_Call (Expr : Node_Id) return Boolean is begin -- The expected call is of the format -- -- Func_Call'reference return Nkind (Expr) = N_Reference and then Nkind (Prefix (Expr)) = N_Function_Call and then not Is_Build_In_Place_Function_Call (Prefix (Expr)); end Is_Non_BIP_Func_Call; ---------------------------------- -- Is_Possibly_Unaligned_Object -- ---------------------------------- function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is T : constant Entity_Id := Etype (N); begin -- If renamed object, apply test to underlying object if Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N))); end if; -- Tagged and controlled types and aliased types are always aligned, as -- are concurrent types. if Is_Aliased (T) or else Has_Controlled_Component (T) or else Is_Concurrent_Type (T) or else Is_Tagged_Type (T) or else Is_Controlled (T) then return False; end if; -- If this is an element of a packed array, may be unaligned if Is_Ref_To_Bit_Packed_Array (N) then return True; end if; -- Case of indexed component reference: test whether prefix is unaligned if Nkind (N) = N_Indexed_Component then return Is_Possibly_Unaligned_Object (Prefix (N)); -- Case of selected component reference elsif Nkind (N) = N_Selected_Component then declare P : constant Node_Id := Prefix (N); C : constant Entity_Id := Entity (Selector_Name (N)); M : Nat; S : Nat; begin -- If component reference is for an array with nonstatic bounds, -- then it is always aligned: we can only process unaligned arrays -- with static bounds (more precisely compile time known bounds). if Is_Array_Type (T) and then not Compile_Time_Known_Bounds (T) then return False; end if; -- If component is aliased, it is definitely properly aligned if Is_Aliased (C) then return False; end if; -- If component is for a type implemented as a scalar, and the -- record is packed, and the component is other than the first -- component of the record, then the component may be unaligned. if Is_Packed (Etype (P)) and then Represented_As_Scalar (Etype (C)) and then First_Entity (Scope (C)) /= C then return True; end if; -- Compute maximum possible alignment for T -- If alignment is known, then that settles things if Known_Alignment (T) then M := UI_To_Int (Alignment (T)); -- If alignment is not known, tentatively set max alignment else M := Ttypes.Maximum_Alignment; -- We can reduce this if the Esize is known since the default -- alignment will never be more than the smallest power of 2 -- that does not exceed this Esize value. if Known_Esize (T) then S := UI_To_Int (Esize (T)); while (M / 2) >= S loop M := M / 2; end loop; end if; end if; -- The following code is historical, it used to be present but it -- is too cautious, because the front-end does not know the proper -- default alignments for the target. Also, if the alignment is -- not known, the front end can't know in any case. If a copy is -- needed, the back-end will take care of it. This whole section -- including this comment can be removed later ??? -- If the component reference is for a record that has a specified -- alignment, and we either know it is too small, or cannot tell, -- then the component may be unaligned. -- What is the following commented out code ??? -- if Known_Alignment (Etype (P)) -- and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment -- and then M > Alignment (Etype (P)) -- then -- return True; -- end if; -- Case of component clause present which may specify an -- unaligned position. if Present (Component_Clause (C)) then -- Otherwise we can do a test to make sure that the actual -- start position in the record, and the length, are both -- consistent with the required alignment. If not, we know -- that we are unaligned. declare Align_In_Bits : constant Nat := M * System_Storage_Unit; Comp : Entity_Id; begin Comp := C; -- For a component inherited in a record extension, the -- clause is inherited but position and size are not set. if Is_Base_Type (Etype (P)) and then Is_Tagged_Type (Etype (P)) and then Present (Original_Record_Component (Comp)) then Comp := Original_Record_Component (Comp); end if; if Component_Bit_Offset (Comp) mod Align_In_Bits /= 0 or else Esize (Comp) mod Align_In_Bits /= 0 then return True; end if; end; end if; -- Otherwise, for a component reference, test prefix return Is_Possibly_Unaligned_Object (P); end; -- If not a component reference, must be aligned else return False; end if; end Is_Possibly_Unaligned_Object; --------------------------------- -- Is_Possibly_Unaligned_Slice -- --------------------------------- function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is begin -- Go to renamed object if Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N))); end if; -- The reference must be a slice if Nkind (N) /= N_Slice then return False; end if; -- If it is a slice, then look at the array type being sliced declare Sarr : constant Node_Id := Prefix (N); -- Prefix of the slice, i.e. the array being sliced Styp : constant Entity_Id := Etype (Prefix (N)); -- Type of the array being sliced Pref : Node_Id; Ptyp : Entity_Id; begin -- The problems arise if the array object that is being sliced -- is a component of a record or array, and we cannot guarantee -- the alignment of the array within its containing object. -- To investigate this, we look at successive prefixes to see -- if we have a worrisome indexed or selected component. Pref := Sarr; loop -- Case of array is part of an indexed component reference if Nkind (Pref) = N_Indexed_Component then Ptyp := Etype (Prefix (Pref)); -- The only problematic case is when the array is packed, in -- which case we really know nothing about the alignment of -- individual components. if Is_Bit_Packed_Array (Ptyp) then return True; end if; -- Case of array is part of a selected component reference elsif Nkind (Pref) = N_Selected_Component then Ptyp := Etype (Prefix (Pref)); -- We are definitely in trouble if the record in question -- has an alignment, and either we know this alignment is -- inconsistent with the alignment of the slice, or we don't -- know what the alignment of the slice should be. But this -- really matters only if the target has strict alignment. if Target_Strict_Alignment and then Known_Alignment (Ptyp) and then (Unknown_Alignment (Styp) or else Alignment (Styp) > Alignment (Ptyp)) then return True; end if; -- We are in potential trouble if the record type is packed. -- We could special case when we know that the array is the -- first component, but that's not such a simple case ??? if Is_Packed (Ptyp) then return True; end if; -- We are in trouble if there is a component clause, and -- either we do not know the alignment of the slice, or -- the alignment of the slice is inconsistent with the -- bit position specified by the component clause. declare Field : constant Entity_Id := Entity (Selector_Name (Pref)); begin if Present (Component_Clause (Field)) and then (Unknown_Alignment (Styp) or else (Component_Bit_Offset (Field) mod (System_Storage_Unit * Alignment (Styp))) /= 0) then return True; end if; end; -- For cases other than selected or indexed components we know we -- are OK, since no issues arise over alignment. else return False; end if; -- We processed an indexed component or selected component -- reference that looked safe, so keep checking prefixes. Pref := Prefix (Pref); end loop; end; end Is_Possibly_Unaligned_Slice; ------------------------------- -- Is_Related_To_Func_Return -- ------------------------------- function Is_Related_To_Func_Return (Id : Entity_Id) return Boolean is Expr : constant Node_Id := Related_Expression (Id); begin return Present (Expr) and then Nkind (Expr) = N_Explicit_Dereference and then Nkind (Parent (Expr)) = N_Simple_Return_Statement; end Is_Related_To_Func_Return; -------------------------------- -- Is_Ref_To_Bit_Packed_Array -- -------------------------------- function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is Result : Boolean; Expr : Node_Id; begin if Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N))); end if; if Nkind_In (N, N_Indexed_Component, N_Selected_Component) then if Is_Bit_Packed_Array (Etype (Prefix (N))) then Result := True; else Result := Is_Ref_To_Bit_Packed_Array (Prefix (N)); end if; if Result and then Nkind (N) = N_Indexed_Component then Expr := First (Expressions (N)); while Present (Expr) loop Force_Evaluation (Expr); Next (Expr); end loop; end if; return Result; else return False; end if; end Is_Ref_To_Bit_Packed_Array; -------------------------------- -- Is_Ref_To_Bit_Packed_Slice -- -------------------------------- function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is begin if Nkind (N) = N_Type_Conversion then return Is_Ref_To_Bit_Packed_Slice (Expression (N)); elsif Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N))); elsif Nkind (N) = N_Slice and then Is_Bit_Packed_Array (Etype (Prefix (N))) then return True; elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then return Is_Ref_To_Bit_Packed_Slice (Prefix (N)); else return False; end if; end Is_Ref_To_Bit_Packed_Slice; ----------------------- -- Is_Renamed_Object -- ----------------------- function Is_Renamed_Object (N : Node_Id) return Boolean is Pnod : constant Node_Id := Parent (N); Kind : constant Node_Kind := Nkind (Pnod); begin if Kind = N_Object_Renaming_Declaration then return True; elsif Nkind_In (Kind, N_Indexed_Component, N_Selected_Component) then return Is_Renamed_Object (Pnod); else return False; end if; end Is_Renamed_Object; -------------------------------------- -- Is_Secondary_Stack_BIP_Func_Call -- -------------------------------------- function Is_Secondary_Stack_BIP_Func_Call (Expr : Node_Id) return Boolean is Alloc_Nam : Name_Id := No_Name; Actual : Node_Id; Call : Node_Id := Expr; Formal : Node_Id; Param : Node_Id; begin -- Build-in-place calls usually appear in 'reference format. Note that -- the accessibility check machinery may add an extra 'reference due to -- side effect removal. while Nkind (Call) = N_Reference loop Call := Prefix (Call); end loop; Call := Unqual_Conv (Call); if Is_Build_In_Place_Function_Call (Call) then -- Examine all parameter associations of the function call Param := First (Parameter_Associations (Call)); while Present (Param) loop if Nkind (Param) = N_Parameter_Association then Formal := Selector_Name (Param); Actual := Explicit_Actual_Parameter (Param); -- Construct the name of formal BIPalloc. It is much easier to -- extract the name of the function using an arbitrary formal's -- scope rather than the Name field of Call. if Alloc_Nam = No_Name and then Present (Entity (Formal)) then Alloc_Nam := New_External_Name (Chars (Scope (Entity (Formal))), BIP_Formal_Suffix (BIP_Alloc_Form)); end if; -- A match for BIPalloc => 2 has been found if Chars (Formal) = Alloc_Nam and then Nkind (Actual) = N_Integer_Literal and then Intval (Actual) = Uint_2 then return True; end if; end if; Next (Param); end loop; end if; return False; end Is_Secondary_Stack_BIP_Func_Call; ------------------------------------- -- Is_Tag_To_Class_Wide_Conversion -- ------------------------------------- function Is_Tag_To_Class_Wide_Conversion (Obj_Id : Entity_Id) return Boolean is Expr : constant Node_Id := Expression (Parent (Obj_Id)); begin return Is_Class_Wide_Type (Etype (Obj_Id)) and then Present (Expr) and then Nkind (Expr) = N_Unchecked_Type_Conversion and then Etype (Expression (Expr)) = RTE (RE_Tag); end Is_Tag_To_Class_Wide_Conversion; ---------------------------- -- Is_Untagged_Derivation -- ---------------------------- function Is_Untagged_Derivation (T : Entity_Id) return Boolean is begin return (not Is_Tagged_Type (T) and then Is_Derived_Type (T)) or else (Is_Private_Type (T) and then Present (Full_View (T)) and then not Is_Tagged_Type (Full_View (T)) and then Is_Derived_Type (Full_View (T)) and then Etype (Full_View (T)) /= T); end Is_Untagged_Derivation; ------------------------------------ -- Is_Untagged_Private_Derivation -- ------------------------------------ function Is_Untagged_Private_Derivation (Priv_Typ : Entity_Id; Full_Typ : Entity_Id) return Boolean is begin return Present (Priv_Typ) and then Is_Untagged_Derivation (Priv_Typ) and then Is_Private_Type (Etype (Priv_Typ)) and then Present (Full_Typ) and then Is_Itype (Full_Typ); end Is_Untagged_Private_Derivation; ------------------------------ -- Is_Verifiable_DIC_Pragma -- ------------------------------ function Is_Verifiable_DIC_Pragma (Prag : Node_Id) return Boolean is Args : constant List_Id := Pragma_Argument_Associations (Prag); begin -- To qualify as verifiable, a DIC pragma must have a non-null argument return Present (Args) and then Nkind (Get_Pragma_Arg (First (Args))) /= N_Null; end Is_Verifiable_DIC_Pragma; --------------------------- -- Is_Volatile_Reference -- --------------------------- function Is_Volatile_Reference (N : Node_Id) return Boolean is begin -- Only source references are to be treated as volatile, internally -- generated stuff cannot have volatile external effects. if not Comes_From_Source (N) then return False; -- Never true for reference to a type elsif Is_Entity_Name (N) and then Is_Type (Entity (N)) then return False; -- Never true for a compile time known constant elsif Compile_Time_Known_Value (N) then return False; -- True if object reference with volatile type elsif Is_Volatile_Object (N) then return True; -- True if reference to volatile entity elsif Is_Entity_Name (N) then return Treat_As_Volatile (Entity (N)); -- True for slice of volatile array elsif Nkind (N) = N_Slice then return Is_Volatile_Reference (Prefix (N)); -- True if volatile component elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then if (Is_Entity_Name (Prefix (N)) and then Has_Volatile_Components (Entity (Prefix (N)))) or else (Present (Etype (Prefix (N))) and then Has_Volatile_Components (Etype (Prefix (N)))) then return True; else return Is_Volatile_Reference (Prefix (N)); end if; -- Otherwise false else return False; end if; end Is_Volatile_Reference; -------------------- -- Kill_Dead_Code -- -------------------- procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is W : Boolean := Warn; -- Set False if warnings suppressed begin if Present (N) then Remove_Warning_Messages (N); -- Update the internal structures of the ABE mechanism in case the -- dead node is an elaboration scenario. Kill_Elaboration_Scenario (N); -- Generate warning if appropriate if W then -- We suppress the warning if this code is under control of an -- if statement, whose condition is a simple identifier, and -- either we are in an instance, or warnings off is set for this -- identifier. The reason for killing it in the instance case is -- that it is common and reasonable for code to be deleted in -- instances for various reasons. -- Could we use Is_Statically_Unevaluated here??? if Nkind (Parent (N)) = N_If_Statement then declare C : constant Node_Id := Condition (Parent (N)); begin if Nkind (C) = N_Identifier and then (In_Instance or else (Present (Entity (C)) and then Has_Warnings_Off (Entity (C)))) then W := False; end if; end; end if; -- Generate warning if not suppressed if W then Error_Msg_F ("?t?this code can never be executed and has been deleted!", N); end if; end if; -- Recurse into block statements and bodies to process declarations -- and statements. if Nkind (N) = N_Block_Statement or else Nkind (N) = N_Subprogram_Body or else Nkind (N) = N_Package_Body then Kill_Dead_Code (Declarations (N), False); Kill_Dead_Code (Statements (Handled_Statement_Sequence (N))); if Nkind (N) = N_Subprogram_Body then Set_Is_Eliminated (Defining_Entity (N)); end if; elsif Nkind (N) = N_Package_Declaration then Kill_Dead_Code (Visible_Declarations (Specification (N))); Kill_Dead_Code (Private_Declarations (Specification (N))); -- ??? After this point, Delete_Tree has been called on all -- declarations in Specification (N), so references to entities -- therein look suspicious. declare E : Entity_Id := First_Entity (Defining_Entity (N)); begin while Present (E) loop if Ekind (E) = E_Operator then Set_Is_Eliminated (E); end if; Next_Entity (E); end loop; end; -- Recurse into composite statement to kill individual statements in -- particular instantiations. elsif Nkind (N) = N_If_Statement then Kill_Dead_Code (Then_Statements (N)); Kill_Dead_Code (Elsif_Parts (N)); Kill_Dead_Code (Else_Statements (N)); elsif Nkind (N) = N_Loop_Statement then Kill_Dead_Code (Statements (N)); elsif Nkind (N) = N_Case_Statement then declare Alt : Node_Id; begin Alt := First (Alternatives (N)); while Present (Alt) loop Kill_Dead_Code (Statements (Alt)); Next (Alt); end loop; end; elsif Nkind (N) = N_Case_Statement_Alternative then Kill_Dead_Code (Statements (N)); -- Deal with dead instances caused by deleting instantiations elsif Nkind (N) in N_Generic_Instantiation then Remove_Dead_Instance (N); end if; end if; end Kill_Dead_Code; -- Case where argument is a list of nodes to be killed procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is N : Node_Id; W : Boolean; begin W := Warn; if Is_Non_Empty_List (L) then N := First (L); while Present (N) loop Kill_Dead_Code (N, W); W := False; Next (N); end loop; end if; end Kill_Dead_Code; ------------------------ -- Known_Non_Negative -- ------------------------ function Known_Non_Negative (Opnd : Node_Id) return Boolean is begin if Is_OK_Static_Expression (Opnd) and then Expr_Value (Opnd) >= 0 then return True; else declare Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd)); begin return Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0; end; end if; end Known_Non_Negative; ----------------------------- -- Make_CW_Equivalent_Type -- ----------------------------- -- Create a record type used as an equivalent of any member of the class -- which takes its size from exp. -- Generate the following code: -- type Equiv_T is record -- _parent : T (List of discriminant constraints taken from Exp); -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8); -- end Equiv_T; -- -- ??? Note that this type does not guarantee same alignment as all -- derived types -- -- Note: for the freezing circuitry, this looks like a record extension, -- and so we need to make sure that the scalar storage order is the same -- as that of the parent type. (This does not change anything for the -- representation of the extension part.) function Make_CW_Equivalent_Type (T : Entity_Id; E : Node_Id) return Entity_Id is Loc : constant Source_Ptr := Sloc (E); Root_Typ : constant Entity_Id := Root_Type (T); Root_Utyp : constant Entity_Id := Underlying_Type (Root_Typ); List_Def : constant List_Id := Empty_List; Comp_List : constant List_Id := New_List; Equiv_Type : Entity_Id; Range_Type : Entity_Id; Str_Type : Entity_Id; Constr_Root : Entity_Id; Sizexpr : Node_Id; begin -- If the root type is already constrained, there are no discriminants -- in the expression. if not Has_Discriminants (Root_Typ) or else Is_Constrained (Root_Typ) then Constr_Root := Root_Typ; -- At this point in the expansion, nonlimited view of the type -- must be available, otherwise the error will be reported later. if From_Limited_With (Constr_Root) and then Present (Non_Limited_View (Constr_Root)) then Constr_Root := Non_Limited_View (Constr_Root); end if; else Constr_Root := Make_Temporary (Loc, 'R'); -- subtype cstr__n is T (List of discr constraints taken from Exp) Append_To (List_Def, Make_Subtype_Declaration (Loc, Defining_Identifier => Constr_Root, Subtype_Indication => Make_Subtype_From_Expr (E, Root_Typ))); end if; -- Generate the range subtype declaration Range_Type := Make_Temporary (Loc, 'G'); if not Is_Interface (Root_Typ) then -- subtype rg__xx is -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit Sizexpr := Make_Op_Subtract (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)), Attribute_Name => Name_Size), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Constr_Root, Loc), Attribute_Name => Name_Object_Size)); else -- subtype rg__xx is -- Storage_Offset range 1 .. Expr'size / Storage_Unit Sizexpr := Make_Attribute_Reference (Loc, Prefix => OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)), Attribute_Name => Name_Size); end if; Set_Paren_Count (Sizexpr, 1); Append_To (List_Def, Make_Subtype_Declaration (Loc, Defining_Identifier => Range_Type, Subtype_Indication => Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (RTE (RE_Storage_Offset), Loc), Constraint => Make_Range_Constraint (Loc, Range_Expression => Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => Make_Op_Divide (Loc, Left_Opnd => Sizexpr, Right_Opnd => Make_Integer_Literal (Loc, Intval => System_Storage_Unit))))))); -- subtype str__nn is Storage_Array (rg__x); Str_Type := Make_Temporary (Loc, 'S'); Append_To (List_Def, Make_Subtype_Declaration (Loc, Defining_Identifier => Str_Type, Subtype_Indication => Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (RTE (RE_Storage_Array), Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List (New_Occurrence_Of (Range_Type, Loc)))))); -- type Equiv_T is record -- [ _parent : Tnn; ] -- E : Str_Type; -- end Equiv_T; Equiv_Type := Make_Temporary (Loc, 'T'); Set_Ekind (Equiv_Type, E_Record_Type); Set_Parent_Subtype (Equiv_Type, Constr_Root); -- Set Is_Class_Wide_Equivalent_Type very early to trigger the special -- treatment for this type. In particular, even though _parent's type -- is a controlled type or contains controlled components, we do not -- want to set Has_Controlled_Component on it to avoid making it gain -- an unwanted _controller component. Set_Is_Class_Wide_Equivalent_Type (Equiv_Type); -- A class-wide equivalent type does not require initialization Set_Suppress_Initialization (Equiv_Type); if not Is_Interface (Root_Typ) then Append_To (Comp_List, Make_Component_Declaration (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_uParent), Component_Definition => Make_Component_Definition (Loc, Aliased_Present => False, Subtype_Indication => New_Occurrence_Of (Constr_Root, Loc)))); Set_Reverse_Storage_Order (Equiv_Type, Reverse_Storage_Order (Base_Type (Root_Utyp))); Set_Reverse_Bit_Order (Equiv_Type, Reverse_Bit_Order (Base_Type (Root_Utyp))); end if; Append_To (Comp_List, Make_Component_Declaration (Loc, Defining_Identifier => Make_Temporary (Loc, 'C'), Component_Definition => Make_Component_Definition (Loc, Aliased_Present => False, Subtype_Indication => New_Occurrence_Of (Str_Type, Loc)))); Append_To (List_Def, Make_Full_Type_Declaration (Loc, Defining_Identifier => Equiv_Type, Type_Definition => Make_Record_Definition (Loc, Component_List => Make_Component_List (Loc, Component_Items => Comp_List, Variant_Part => Empty)))); -- Suppress all checks during the analysis of the expanded code to avoid -- the generation of spurious warnings under ZFP run-time. Insert_Actions (E, List_Def, Suppress => All_Checks); return Equiv_Type; end Make_CW_Equivalent_Type; ------------------------- -- Make_Invariant_Call -- ------------------------- function Make_Invariant_Call (Expr : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Expr); Typ : constant Entity_Id := Base_Type (Etype (Expr)); Proc_Id : Entity_Id; begin pragma Assert (Has_Invariants (Typ)); Proc_Id := Invariant_Procedure (Typ); pragma Assert (Present (Proc_Id)); -- Ignore the invariant if that policy is in effect if Invariants_Ignored (Typ) then return Make_Null_Statement (Loc); else return Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Id, Loc), Parameter_Associations => New_List (Relocate_Node (Expr))); end if; end Make_Invariant_Call; ------------------------ -- Make_Literal_Range -- ------------------------ function Make_Literal_Range (Loc : Source_Ptr; Literal_Typ : Entity_Id) return Node_Id is Lo : constant Node_Id := New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ)); Index : constant Entity_Id := Etype (Lo); Length_Expr : constant Node_Id := Make_Op_Subtract (Loc, Left_Opnd => Make_Integer_Literal (Loc, Intval => String_Literal_Length (Literal_Typ)), Right_Opnd => Make_Integer_Literal (Loc, 1)); Hi : Node_Id; begin Set_Analyzed (Lo, False); if Is_Integer_Type (Index) then Hi := Make_Op_Add (Loc, Left_Opnd => New_Copy_Tree (Lo), Right_Opnd => Length_Expr); else Hi := Make_Attribute_Reference (Loc, Attribute_Name => Name_Val, Prefix => New_Occurrence_Of (Index, Loc), Expressions => New_List ( Make_Op_Add (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Pos, Prefix => New_Occurrence_Of (Index, Loc), Expressions => New_List (New_Copy_Tree (Lo))), Right_Opnd => Length_Expr))); end if; return Make_Range (Loc, Low_Bound => Lo, High_Bound => Hi); end Make_Literal_Range; -------------------------- -- Make_Non_Empty_Check -- -------------------------- function Make_Non_Empty_Check (Loc : Source_Ptr; N : Node_Id) return Node_Id is begin return Make_Op_Ne (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => Duplicate_Subexpr_No_Checks (N, Name_Req => True)), Right_Opnd => Make_Integer_Literal (Loc, 0)); end Make_Non_Empty_Check; ------------------------- -- Make_Predicate_Call -- ------------------------- -- WARNING: This routine manages Ghost regions. Return statements must be -- replaced by gotos which jump to the end of the routine and restore the -- Ghost mode. function Make_Predicate_Call (Typ : Entity_Id; Expr : Node_Id; Mem : Boolean := False) return Node_Id is Loc : constant Source_Ptr := Sloc (Expr); Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; Saved_IGR : constant Node_Id := Ignored_Ghost_Region; -- Save the Ghost-related attributes to restore on exit Call : Node_Id; Func_Id : Entity_Id; begin Func_Id := Predicate_Function (Typ); pragma Assert (Present (Func_Id)); -- The related type may be subject to pragma Ghost. Set the mode now to -- ensure that the call is properly marked as Ghost. Set_Ghost_Mode (Typ); -- Call special membership version if requested and available if Mem and then Present (Predicate_Function_M (Typ)) then Func_Id := Predicate_Function_M (Typ); end if; -- Case of calling normal predicate function -- If the type is tagged, the expression may be class-wide, in which -- case it has to be converted to its root type, given that the -- generated predicate function is not dispatching. The conversion is -- type-safe and does not need validation, which matters when private -- extensions are involved. if Is_Tagged_Type (Typ) then Call := Make_Function_Call (Loc, Name => New_Occurrence_Of (Func_Id, Loc), Parameter_Associations => New_List (OK_Convert_To (Typ, Relocate_Node (Expr)))); else Call := Make_Function_Call (Loc, Name => New_Occurrence_Of (Func_Id, Loc), Parameter_Associations => New_List (Relocate_Node (Expr))); end if; Restore_Ghost_Region (Saved_GM, Saved_IGR); return Call; end Make_Predicate_Call; -------------------------- -- Make_Predicate_Check -- -------------------------- function Make_Predicate_Check (Typ : Entity_Id; Expr : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Expr); procedure Add_Failure_Expression (Args : List_Id); -- Add the failure expression of pragma Predicate_Failure (if any) to -- list Args. ---------------------------- -- Add_Failure_Expression -- ---------------------------- procedure Add_Failure_Expression (Args : List_Id) is function Failure_Expression return Node_Id; pragma Inline (Failure_Expression); -- Find aspect or pragma Predicate_Failure that applies to type Typ -- and return its expression. Return Empty if no such annotation is -- available. function Is_OK_PF_Aspect (Asp : Node_Id) return Boolean; pragma Inline (Is_OK_PF_Aspect); -- Determine whether aspect Asp is a suitable Predicate_Failure -- aspect that applies to type Typ. function Is_OK_PF_Pragma (Prag : Node_Id) return Boolean; pragma Inline (Is_OK_PF_Pragma); -- Determine whether pragma Prag is a suitable Predicate_Failure -- pragma that applies to type Typ. procedure Replace_Subtype_Reference (N : Node_Id); -- Replace the current instance of type Typ denoted by N with -- expression Expr. ------------------------ -- Failure_Expression -- ------------------------ function Failure_Expression return Node_Id is Item : Node_Id; begin -- The management of the rep item chain involves "inheritance" of -- parent type chains. If a parent [sub]type is already subject to -- pragma Predicate_Failure, then the pragma will also appear in -- the chain of the child [sub]type, which in turn may possess a -- pragma of its own. Avoid order-dependent issues by inspecting -- the rep item chain directly. Note that routine Get_Pragma may -- return a parent pragma. Item := First_Rep_Item (Typ); while Present (Item) loop -- Predicate_Failure appears as an aspect if Nkind (Item) = N_Aspect_Specification and then Is_OK_PF_Aspect (Item) then return Expression (Item); -- Predicate_Failure appears as a pragma elsif Nkind (Item) = N_Pragma and then Is_OK_PF_Pragma (Item) then return Get_Pragma_Arg (Next (First (Pragma_Argument_Associations (Item)))); end if; Item := Next_Rep_Item (Item); end loop; return Empty; end Failure_Expression; --------------------- -- Is_OK_PF_Aspect -- --------------------- function Is_OK_PF_Aspect (Asp : Node_Id) return Boolean is begin -- To qualify, the aspect must apply to the type subjected to the -- predicate check. return Chars (Identifier (Asp)) = Name_Predicate_Failure and then Present (Entity (Asp)) and then Entity (Asp) = Typ; end Is_OK_PF_Aspect; --------------------- -- Is_OK_PF_Pragma -- --------------------- function Is_OK_PF_Pragma (Prag : Node_Id) return Boolean is Args : constant List_Id := Pragma_Argument_Associations (Prag); Typ_Arg : Node_Id; begin -- Nothing to do when the pragma does not denote Predicate_Failure if Pragma_Name (Prag) /= Name_Predicate_Failure then return False; -- Nothing to do when the pragma lacks arguments, in which case it -- is illegal. elsif No (Args) or else Is_Empty_List (Args) then return False; end if; Typ_Arg := Get_Pragma_Arg (First (Args)); -- To qualify, the local name argument of the pragma must denote -- the type subjected to the predicate check. return Is_Entity_Name (Typ_Arg) and then Present (Entity (Typ_Arg)) and then Entity (Typ_Arg) = Typ; end Is_OK_PF_Pragma; -------------------------------- -- Replace_Subtype_Reference -- -------------------------------- procedure Replace_Subtype_Reference (N : Node_Id) is begin Rewrite (N, New_Copy_Tree (Expr)); -- We want to treat the node as if it comes from source, so that -- ASIS will not ignore it. Set_Comes_From_Source (N, True); end Replace_Subtype_Reference; procedure Replace_Subtype_References is new Replace_Type_References_Generic (Replace_Subtype_Reference); -- Local variables PF_Expr : constant Node_Id := Failure_Expression; Expr : Node_Id; -- Start of processing for Add_Failure_Expression begin if Present (PF_Expr) then -- Replace any occurrences of the current instance of the type -- with the object subjected to the predicate check. Expr := New_Copy_Tree (PF_Expr); Replace_Subtype_References (Expr, Typ); -- The failure expression appears as the third argument of the -- Check pragma. Append_To (Args, Make_Pragma_Argument_Association (Loc, Expression => Expr)); end if; end Add_Failure_Expression; -- Local variables Args : List_Id; Nam : Name_Id; -- Start of processing for Make_Predicate_Check begin -- If predicate checks are suppressed, then return a null statement. For -- this call, we check only the scope setting. If the caller wants to -- check a specific entity's setting, they must do it manually. if Predicate_Checks_Suppressed (Empty) then return Make_Null_Statement (Loc); end if; -- Do not generate a check within an internal subprogram (stream -- functions and the like, including predicate functions). if Within_Internal_Subprogram then return Make_Null_Statement (Loc); end if; -- Compute proper name to use, we need to get this right so that the -- right set of check policies apply to the Check pragma we are making. if Has_Dynamic_Predicate_Aspect (Typ) then Nam := Name_Dynamic_Predicate; elsif Has_Static_Predicate_Aspect (Typ) then Nam := Name_Static_Predicate; else Nam := Name_Predicate; end if; Args := New_List ( Make_Pragma_Argument_Association (Loc, Expression => Make_Identifier (Loc, Nam)), Make_Pragma_Argument_Association (Loc, Expression => Make_Predicate_Call (Typ, Expr))); -- If the subtype is subject to pragma Predicate_Failure, add the -- failure expression as an additional parameter. Add_Failure_Expression (Args); return Make_Pragma (Loc, Chars => Name_Check, Pragma_Argument_Associations => Args); end Make_Predicate_Check; ---------------------------- -- Make_Subtype_From_Expr -- ---------------------------- -- 1. If Expr is an unconstrained array expression, creates -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n)) -- 2. If Expr is a unconstrained discriminated type expression, creates -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n) -- 3. If Expr is class-wide, creates an implicit class-wide subtype function Make_Subtype_From_Expr (E : Node_Id; Unc_Typ : Entity_Id; Related_Id : Entity_Id := Empty) return Node_Id is List_Constr : constant List_Id := New_List; Loc : constant Source_Ptr := Sloc (E); D : Entity_Id; Full_Exp : Node_Id; Full_Subtyp : Entity_Id; High_Bound : Entity_Id; Index_Typ : Entity_Id; Low_Bound : Entity_Id; Priv_Subtyp : Entity_Id; Utyp : Entity_Id; begin if Is_Private_Type (Unc_Typ) and then Has_Unknown_Discriminants (Unc_Typ) then -- The caller requests a unique external name for both the private -- and the full subtype. if Present (Related_Id) then Full_Subtyp := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Related_Id), 'C')); Priv_Subtyp := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Related_Id), 'P')); else Full_Subtyp := Make_Temporary (Loc, 'C'); Priv_Subtyp := Make_Temporary (Loc, 'P'); end if; -- Prepare the subtype completion. Use the base type to find the -- underlying type because the type may be a generic actual or an -- explicit subtype. Utyp := Underlying_Type (Base_Type (Unc_Typ)); Full_Exp := Unchecked_Convert_To (Utyp, Duplicate_Subexpr_No_Checks (E)); Set_Parent (Full_Exp, Parent (E)); Insert_Action (E, Make_Subtype_Declaration (Loc, Defining_Identifier => Full_Subtyp, Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp))); -- Define the dummy private subtype Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ))); Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ)); Set_Scope (Priv_Subtyp, Full_Subtyp); Set_Is_Constrained (Priv_Subtyp); Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ)); Set_Is_Itype (Priv_Subtyp); Set_Associated_Node_For_Itype (Priv_Subtyp, E); if Is_Tagged_Type (Priv_Subtyp) then Set_Class_Wide_Type (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ)); Set_Direct_Primitive_Operations (Priv_Subtyp, Direct_Primitive_Operations (Unc_Typ)); end if; Set_Full_View (Priv_Subtyp, Full_Subtyp); return New_Occurrence_Of (Priv_Subtyp, Loc); elsif Is_Array_Type (Unc_Typ) then Index_Typ := First_Index (Unc_Typ); for J in 1 .. Number_Dimensions (Unc_Typ) loop -- Capture the bounds of each index constraint in case the context -- is an object declaration of an unconstrained type initialized -- by a function call: -- Obj : Unconstr_Typ := Func_Call; -- This scenario requires secondary scope management and the index -- constraint cannot depend on the temporary used to capture the -- result of the function call. -- SS_Mark; -- Temp : Unconstr_Typ_Ptr := Func_Call'reference; -- subtype S is Unconstr_Typ (Temp.all'First .. Temp.all'Last); -- Obj : S := Temp.all; -- SS_Release; -- Temp is gone at this point, bounds of S are -- -- non existent. -- Generate: -- Low_Bound : constant Base_Type (Index_Typ) := E'First (J); Low_Bound := Make_Temporary (Loc, 'B'); Insert_Action (E, Make_Object_Declaration (Loc, Defining_Identifier => Low_Bound, Object_Definition => New_Occurrence_Of (Base_Type (Etype (Index_Typ)), Loc), Constant_Present => True, Expression => Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (E), Attribute_Name => Name_First, Expressions => New_List ( Make_Integer_Literal (Loc, J))))); -- Generate: -- High_Bound : constant Base_Type (Index_Typ) := E'Last (J); High_Bound := Make_Temporary (Loc, 'B'); Insert_Action (E, Make_Object_Declaration (Loc, Defining_Identifier => High_Bound, Object_Definition => New_Occurrence_Of (Base_Type (Etype (Index_Typ)), Loc), Constant_Present => True, Expression => Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (E), Attribute_Name => Name_Last, Expressions => New_List ( Make_Integer_Literal (Loc, J))))); Append_To (List_Constr, Make_Range (Loc, Low_Bound => New_Occurrence_Of (Low_Bound, Loc), High_Bound => New_Occurrence_Of (High_Bound, Loc))); Index_Typ := Next_Index (Index_Typ); end loop; elsif Is_Class_Wide_Type (Unc_Typ) then declare CW_Subtype : Entity_Id; EQ_Typ : Entity_Id := Empty; begin -- A class-wide equivalent type is not needed on VM targets -- because the VM back-ends handle the class-wide object -- initialization itself (and doesn't need or want the -- additional intermediate type to handle the assignment). if Expander_Active and then Tagged_Type_Expansion then -- If this is the class-wide type of a completion that is a -- record subtype, set the type of the class-wide type to be -- the full base type, for use in the expanded code for the -- equivalent type. Should this be done earlier when the -- completion is analyzed ??? if Is_Private_Type (Etype (Unc_Typ)) and then Ekind (Full_View (Etype (Unc_Typ))) = E_Record_Subtype then Set_Etype (Unc_Typ, Base_Type (Full_View (Etype (Unc_Typ)))); end if; EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E); end if; CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E); Set_Equivalent_Type (CW_Subtype, EQ_Typ); Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ)); return New_Occurrence_Of (CW_Subtype, Loc); end; -- Indefinite record type with discriminants else D := First_Discriminant (Unc_Typ); while Present (D) loop Append_To (List_Constr, Make_Selected_Component (Loc, Prefix => Duplicate_Subexpr_No_Checks (E), Selector_Name => New_Occurrence_Of (D, Loc))); Next_Discriminant (D); end loop; end if; return Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Unc_Typ, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => List_Constr)); end Make_Subtype_From_Expr; --------------- -- Map_Types -- --------------- procedure Map_Types (Parent_Type : Entity_Id; Derived_Type : Entity_Id) is -- NOTE: Most of the routines in Map_Types are intentionally unnested to -- avoid deep indentation of code. -- NOTE: Routines which deal with discriminant mapping operate on the -- [underlying/record] full view of various types because those views -- contain all discriminants and stored constraints. procedure Add_Primitive (Prim : Entity_Id; Par_Typ : Entity_Id); -- Subsidiary to Map_Primitives. Find a primitive in the inheritance or -- overriding chain starting from Prim whose dispatching type is parent -- type Par_Typ and add a mapping between the result and primitive Prim. function Ancestor_Primitive (Subp : Entity_Id) return Entity_Id; -- Subsidiary to Map_Primitives. Return the next ancestor primitive in -- the inheritance or overriding chain of subprogram Subp. Return Empty -- if no such primitive is available. function Build_Chain (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id) return Elist_Id; -- Subsidiary to Map_Discriminants. Recreate the derivation chain from -- parent type Par_Typ leading down towards derived type Deriv_Typ. The -- list has the form: -- -- head tail -- v v -- -> -> -> Deriv_Typ -- -- Note that Par_Typ is not part of the resulting derivation chain function Discriminated_View (Typ : Entity_Id) return Entity_Id; -- Return the view of type Typ which could potentially contains either -- the discriminants or stored constraints of the type. function Find_Discriminant_Value (Discr : Entity_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Typ_Elmt : Elmt_Id) return Node_Or_Entity_Id; -- Subsidiary to Map_Discriminants. Find the value of discriminant Discr -- in the derivation chain starting from parent type Par_Typ leading to -- derived type Deriv_Typ. The returned value is one of the following: -- -- * An entity which is either a discriminant or a nondiscriminant -- name, and renames/constraints Discr. -- -- * An expression which constraints Discr -- -- Typ_Elmt is an element of the derivation chain created by routine -- Build_Chain and denotes the current ancestor being examined. procedure Map_Discriminants (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id); -- Map each discriminant of type Par_Typ to a meaningful constraint -- from the point of view of type Deriv_Typ. procedure Map_Primitives (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id); -- Map each primitive of type Par_Typ to a corresponding primitive of -- type Deriv_Typ. ------------------- -- Add_Primitive -- ------------------- procedure Add_Primitive (Prim : Entity_Id; Par_Typ : Entity_Id) is Par_Prim : Entity_Id; begin -- Inspect the inheritance chain through the Alias attribute and the -- overriding chain through the Overridden_Operation looking for an -- ancestor primitive with the appropriate dispatching type. Par_Prim := Prim; while Present (Par_Prim) loop exit when Find_Dispatching_Type (Par_Prim) = Par_Typ; Par_Prim := Ancestor_Primitive (Par_Prim); end loop; -- Create a mapping of the form: -- parent type primitive -> derived type primitive if Present (Par_Prim) then Type_Map.Set (Par_Prim, Prim); end if; end Add_Primitive; ------------------------ -- Ancestor_Primitive -- ------------------------ function Ancestor_Primitive (Subp : Entity_Id) return Entity_Id is Inher_Prim : constant Entity_Id := Alias (Subp); Over_Prim : constant Entity_Id := Overridden_Operation (Subp); begin -- The current subprogram overrides an ancestor primitive if Present (Over_Prim) then return Over_Prim; -- The current subprogram is an internally generated alias of an -- inherited ancestor primitive. elsif Present (Inher_Prim) then return Inher_Prim; -- Otherwise the current subprogram is the root of the inheritance or -- overriding chain. else return Empty; end if; end Ancestor_Primitive; ----------------- -- Build_Chain -- ----------------- function Build_Chain (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id) return Elist_Id is Anc_Typ : Entity_Id; Chain : Elist_Id; Curr_Typ : Entity_Id; begin Chain := New_Elmt_List; -- Add the derived type to the derivation chain Prepend_Elmt (Deriv_Typ, Chain); -- Examine all ancestors starting from the derived type climbing -- towards parent type Par_Typ. Curr_Typ := Deriv_Typ; loop -- Handle the case where the current type is a record which -- derives from a subtype. -- subtype Sub_Typ is Par_Typ ... -- type Deriv_Typ is Sub_Typ ... if Ekind (Curr_Typ) = E_Record_Type and then Present (Parent_Subtype (Curr_Typ)) then Anc_Typ := Parent_Subtype (Curr_Typ); -- Handle the case where the current type is a record subtype of -- another subtype. -- subtype Sub_Typ1 is Par_Typ ... -- subtype Sub_Typ2 is Sub_Typ1 ... elsif Ekind (Curr_Typ) = E_Record_Subtype and then Present (Cloned_Subtype (Curr_Typ)) then Anc_Typ := Cloned_Subtype (Curr_Typ); -- Otherwise use the direct parent type else Anc_Typ := Etype (Curr_Typ); end if; -- Use the first subtype when dealing with itypes if Is_Itype (Anc_Typ) then Anc_Typ := First_Subtype (Anc_Typ); end if; -- Work with the view which contains the discriminants and stored -- constraints. Anc_Typ := Discriminated_View (Anc_Typ); -- Stop the climb when either the parent type has been reached or -- there are no more ancestors left to examine. exit when Anc_Typ = Curr_Typ or else Anc_Typ = Par_Typ; Prepend_Unique_Elmt (Anc_Typ, Chain); Curr_Typ := Anc_Typ; end loop; return Chain; end Build_Chain; ------------------------ -- Discriminated_View -- ------------------------ function Discriminated_View (Typ : Entity_Id) return Entity_Id is T : Entity_Id; begin T := Typ; -- Use the [underlying] full view when dealing with private types -- because the view contains all inherited discriminants or stored -- constraints. if Is_Private_Type (T) then if Present (Underlying_Full_View (T)) then T := Underlying_Full_View (T); elsif Present (Full_View (T)) then T := Full_View (T); end if; end if; -- Use the underlying record view when the type is an extenstion of -- a parent type with unknown discriminants because the view contains -- all inherited discriminants or stored constraints. if Ekind (T) = E_Record_Type and then Present (Underlying_Record_View (T)) then T := Underlying_Record_View (T); end if; return T; end Discriminated_View; ----------------------------- -- Find_Discriminant_Value -- ----------------------------- function Find_Discriminant_Value (Discr : Entity_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Typ_Elmt : Elmt_Id) return Node_Or_Entity_Id is Discr_Pos : constant Uint := Discriminant_Number (Discr); Typ : constant Entity_Id := Node (Typ_Elmt); function Find_Constraint_Value (Constr : Node_Or_Entity_Id) return Node_Or_Entity_Id; -- Given constraint Constr, find what it denotes. This is either: -- -- * An entity which is either a discriminant or a name -- -- * An expression --------------------------- -- Find_Constraint_Value -- --------------------------- function Find_Constraint_Value (Constr : Node_Or_Entity_Id) return Node_Or_Entity_Id is begin if Nkind (Constr) in N_Entity then -- The constraint denotes a discriminant of the curren type -- which renames the ancestor discriminant: -- vv -- type Typ (D1 : ...; DN : ...) is -- new Anc (Discr => D1) with ... -- ^^ if Ekind (Constr) = E_Discriminant then -- The discriminant belongs to derived type Deriv_Typ. This -- is the final value for the ancestor discriminant as the -- derivations chain has been fully exhausted. if Typ = Deriv_Typ then return Constr; -- Otherwise the discriminant may be renamed or constrained -- at a lower level. Continue looking down the derivation -- chain. else return Find_Discriminant_Value (Discr => Constr, Par_Typ => Par_Typ, Deriv_Typ => Deriv_Typ, Typ_Elmt => Next_Elmt (Typ_Elmt)); end if; -- Otherwise the constraint denotes a reference to some name -- which results in a Girder discriminant: -- vvvv -- Name : ...; -- type Typ (D1 : ...; DN : ...) is -- new Anc (Discr => Name) with ... -- ^^^^ -- Return the name as this is the proper constraint of the -- discriminant. else return Constr; end if; -- The constraint denotes a reference to a name elsif Is_Entity_Name (Constr) then return Find_Constraint_Value (Entity (Constr)); -- Otherwise the current constraint is an expression which yields -- a Girder discriminant: -- type Typ (D1 : ...; DN : ...) is -- new Anc (Discr => ) with ... -- ^^^^^^^^^^ -- Return the expression as this is the proper constraint of the -- discriminant. else return Constr; end if; end Find_Constraint_Value; -- Local variables Constrs : constant Elist_Id := Stored_Constraint (Typ); Constr_Elmt : Elmt_Id; Pos : Uint; Typ_Discr : Entity_Id; -- Start of processing for Find_Discriminant_Value begin -- The algorithm for finding the value of a discriminant works as -- follows. First, it recreates the derivation chain from Par_Typ -- to Deriv_Typ as a list: -- Par_Typ (shown for completeness) -- v -- Ancestor_N <-- head of chain -- v -- Ancestor_1 -- v -- Deriv_Typ <-- tail of chain -- The algorithm then traces the fate of a parent discriminant down -- the derivation chain. At each derivation level, the discriminant -- may be either inherited or constrained. -- 1) Discriminant is inherited: there are two cases, depending on -- which type is inheriting. -- 1.1) Deriv_Typ is inheriting: -- type Ancestor (D_1 : ...) is tagged ... -- type Deriv_Typ is new Ancestor ... -- In this case the inherited discriminant is the final value of -- the parent discriminant because the end of the derivation chain -- has been reached. -- 1.2) Some other type is inheriting: -- type Ancestor_1 (D_1 : ...) is tagged ... -- type Ancestor_2 is new Ancestor_1 ... -- In this case the algorithm continues to trace the fate of the -- inherited discriminant down the derivation chain because it may -- be further inherited or constrained. -- 2) Discriminant is constrained: there are three cases, depending -- on what the constraint is. -- 2.1) The constraint is another discriminant (aka renaming): -- type Ancestor_1 (D_1 : ...) is tagged ... -- type Ancestor_2 (D_2 : ...) is new Ancestor_1 (D_1 => D_2) ... -- In this case the constraining discriminant becomes the one to -- track down the derivation chain. The algorithm already knows -- that D_2 constrains D_1, therefore if the algorithm finds the -- value of D_2, then this would also be the value for D_1. -- 2.2) The constraint is a name (aka Girder): -- Name : ... -- type Ancestor_1 (D_1 : ...) is tagged ... -- type Ancestor_2 is new Ancestor_1 (D_1 => Name) ... -- In this case the name is the final value of D_1 because the -- discriminant cannot be further constrained. -- 2.3) The constraint is an expression (aka Girder): -- type Ancestor_1 (D_1 : ...) is tagged ... -- type Ancestor_2 is new Ancestor_1 (D_1 => 1 + 2) ... -- Similar to 2.2, the expression is the final value of D_1 Pos := Uint_1; -- When a derived type constrains its parent type, all constaints -- appear in the Stored_Constraint list. Examine the list looking -- for a positional match. if Present (Constrs) then Constr_Elmt := First_Elmt (Constrs); while Present (Constr_Elmt) loop -- The position of the current constraint matches that of the -- ancestor discriminant. if Pos = Discr_Pos then return Find_Constraint_Value (Node (Constr_Elmt)); end if; Next_Elmt (Constr_Elmt); Pos := Pos + 1; end loop; -- Otherwise the derived type does not constraint its parent type in -- which case it inherits the parent discriminants. else Typ_Discr := First_Discriminant (Typ); while Present (Typ_Discr) loop -- The position of the current discriminant matches that of the -- ancestor discriminant. if Pos = Discr_Pos then return Find_Constraint_Value (Typ_Discr); end if; Next_Discriminant (Typ_Discr); Pos := Pos + 1; end loop; end if; -- A discriminant must always have a corresponding value. This is -- either another discriminant, a name, or an expression. If this -- point is reached, them most likely the derivation chain employs -- the wrong views of types. pragma Assert (False); return Empty; end Find_Discriminant_Value; ----------------------- -- Map_Discriminants -- ----------------------- procedure Map_Discriminants (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id) is Deriv_Chain : constant Elist_Id := Build_Chain (Par_Typ, Deriv_Typ); Discr : Entity_Id; Discr_Val : Node_Or_Entity_Id; begin -- Examine each discriminant of parent type Par_Typ and find a -- suitable value for it from the point of view of derived type -- Deriv_Typ. if Has_Discriminants (Par_Typ) then Discr := First_Discriminant (Par_Typ); while Present (Discr) loop Discr_Val := Find_Discriminant_Value (Discr => Discr, Par_Typ => Par_Typ, Deriv_Typ => Deriv_Typ, Typ_Elmt => First_Elmt (Deriv_Chain)); -- Create a mapping of the form: -- parent type discriminant -> value Type_Map.Set (Discr, Discr_Val); Next_Discriminant (Discr); end loop; end if; end Map_Discriminants; -------------------- -- Map_Primitives -- -------------------- procedure Map_Primitives (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id) is Deriv_Prim : Entity_Id; Par_Prim : Entity_Id; Par_Prims : Elist_Id; Prim_Elmt : Elmt_Id; begin -- Inspect the primitives of the derived type and determine whether -- they relate to the primitives of the parent type. If there is a -- meaningful relation, create a mapping of the form: -- parent type primitive -> perived type primitive if Present (Direct_Primitive_Operations (Deriv_Typ)) then Prim_Elmt := First_Elmt (Direct_Primitive_Operations (Deriv_Typ)); while Present (Prim_Elmt) loop Deriv_Prim := Node (Prim_Elmt); if Is_Subprogram (Deriv_Prim) and then Find_Dispatching_Type (Deriv_Prim) = Deriv_Typ then Add_Primitive (Deriv_Prim, Par_Typ); end if; Next_Elmt (Prim_Elmt); end loop; end if; -- If the parent operation is an interface operation, the overriding -- indicator is not present. Instead, we get from the interface -- operation the primitive of the current type that implements it. if Is_Interface (Par_Typ) then Par_Prims := Collect_Primitive_Operations (Par_Typ); if Present (Par_Prims) then Prim_Elmt := First_Elmt (Par_Prims); while Present (Prim_Elmt) loop Par_Prim := Node (Prim_Elmt); Deriv_Prim := Find_Primitive_Covering_Interface (Deriv_Typ, Par_Prim); if Present (Deriv_Prim) then Type_Map.Set (Par_Prim, Deriv_Prim); end if; Next_Elmt (Prim_Elmt); end loop; end if; end if; end Map_Primitives; -- Start of processing for Map_Types begin -- Nothing to do if there are no types to work with if No (Parent_Type) or else No (Derived_Type) then return; -- Nothing to do if the mapping already exists elsif Type_Map.Get (Parent_Type) = Derived_Type then return; -- Nothing to do if both types are not tagged. Note that untagged types -- do not have primitive operations and their discriminants are already -- handled by gigi. elsif not Is_Tagged_Type (Parent_Type) or else not Is_Tagged_Type (Derived_Type) then return; end if; -- Create a mapping of the form -- parent type -> derived type -- to prevent any subsequent attempts to produce the same relations Type_Map.Set (Parent_Type, Derived_Type); -- Create mappings of the form -- parent type discriminant -> derived type discriminant -- -- parent type discriminant -> constraint -- Note that mapping of discriminants breaks privacy because it needs to -- work with those views which contains the discriminants and any stored -- constraints. Map_Discriminants (Par_Typ => Discriminated_View (Parent_Type), Deriv_Typ => Discriminated_View (Derived_Type)); -- Create mappings of the form -- parent type primitive -> derived type primitive Map_Primitives (Par_Typ => Parent_Type, Deriv_Typ => Derived_Type); end Map_Types; ---------------------------- -- Matching_Standard_Type -- ---------------------------- function Matching_Standard_Type (Typ : Entity_Id) return Entity_Id is pragma Assert (Is_Scalar_Type (Typ)); Siz : constant Uint := Esize (Typ); begin -- Floating-point cases if Is_Floating_Point_Type (Typ) then if Siz <= Esize (Standard_Short_Float) then return Standard_Short_Float; elsif Siz <= Esize (Standard_Float) then return Standard_Float; elsif Siz <= Esize (Standard_Long_Float) then return Standard_Long_Float; elsif Siz <= Esize (Standard_Long_Long_Float) then return Standard_Long_Long_Float; else raise Program_Error; end if; -- Integer cases (includes fixed-point types) -- Unsigned integer cases (includes normal enumeration types) elsif Is_Unsigned_Type (Typ) then if Siz <= Esize (Standard_Short_Short_Unsigned) then return Standard_Short_Short_Unsigned; elsif Siz <= Esize (Standard_Short_Unsigned) then return Standard_Short_Unsigned; elsif Siz <= Esize (Standard_Unsigned) then return Standard_Unsigned; elsif Siz <= Esize (Standard_Long_Unsigned) then return Standard_Long_Unsigned; elsif Siz <= Esize (Standard_Long_Long_Unsigned) then return Standard_Long_Long_Unsigned; else raise Program_Error; end if; -- Signed integer cases else if Siz <= Esize (Standard_Short_Short_Integer) then return Standard_Short_Short_Integer; elsif Siz <= Esize (Standard_Short_Integer) then return Standard_Short_Integer; elsif Siz <= Esize (Standard_Integer) then return Standard_Integer; elsif Siz <= Esize (Standard_Long_Integer) then return Standard_Long_Integer; elsif Siz <= Esize (Standard_Long_Long_Integer) then return Standard_Long_Long_Integer; else raise Program_Error; end if; end if; end Matching_Standard_Type; ----------------------------- -- May_Generate_Large_Temp -- ----------------------------- -- At the current time, the only types that we return False for (i.e. where -- we decide we know they cannot generate large temps) are ones where we -- know the size is 256 bits or less at compile time, and we are still not -- doing a thorough job on arrays and records ??? function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is begin if not Size_Known_At_Compile_Time (Typ) then return False; elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then return False; elsif Is_Array_Type (Typ) and then Present (Packed_Array_Impl_Type (Typ)) then return May_Generate_Large_Temp (Packed_Array_Impl_Type (Typ)); -- We could do more here to find other small types ??? else return True; end if; end May_Generate_Large_Temp; -------------------------------------------- -- Needs_Conditional_Null_Excluding_Check -- -------------------------------------------- function Needs_Conditional_Null_Excluding_Check (Typ : Entity_Id) return Boolean is begin return Is_Array_Type (Typ) and then Can_Never_Be_Null (Component_Type (Typ)); end Needs_Conditional_Null_Excluding_Check; ---------------------------- -- Needs_Constant_Address -- ---------------------------- function Needs_Constant_Address (Decl : Node_Id; Typ : Entity_Id) return Boolean is begin -- If we have no initialization of any kind, then we don't need to place -- any restrictions on the address clause, because the object will be -- elaborated after the address clause is evaluated. This happens if the -- declaration has no initial expression, or the type has no implicit -- initialization, or the object is imported. -- The same holds for all initialized scalar types and all access types. -- Packed bit arrays of size up to 64 are represented using a modular -- type with an initialization (to zero) and can be processed like other -- initialized scalar types. -- If the type is controlled, code to attach the object to a -- finalization chain is generated at the point of declaration, and -- therefore the elaboration of the object cannot be delayed: the -- address expression must be a constant. if No (Expression (Decl)) and then not Needs_Finalization (Typ) and then (not Has_Non_Null_Base_Init_Proc (Typ) or else Is_Imported (Defining_Identifier (Decl))) then return False; elsif (Present (Expression (Decl)) and then Is_Scalar_Type (Typ)) or else Is_Access_Type (Typ) or else (Is_Bit_Packed_Array (Typ) and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ))) then return False; else -- Otherwise, we require the address clause to be constant because -- the call to the initialization procedure (or the attach code) has -- to happen at the point of the declaration. -- Actually the IP call has been moved to the freeze actions anyway, -- so maybe we can relax this restriction??? return True; end if; end Needs_Constant_Address; ---------------------------- -- New_Class_Wide_Subtype -- ---------------------------- function New_Class_Wide_Subtype (CW_Typ : Entity_Id; N : Node_Id) return Entity_Id is Res : constant Entity_Id := Create_Itype (E_Void, N); -- Capture relevant attributes of the class-wide subtype which must be -- restored after the copy. Res_Chars : constant Name_Id := Chars (Res); Res_Is_CGE : constant Boolean := Is_Checked_Ghost_Entity (Res); Res_Is_IGE : constant Boolean := Is_Ignored_Ghost_Entity (Res); Res_Is_IGN : constant Boolean := Is_Ignored_Ghost_Node (Res); Res_Scope : constant Entity_Id := Scope (Res); begin Copy_Node (CW_Typ, Res); -- Restore the relevant attributes of the class-wide subtype Set_Chars (Res, Res_Chars); Set_Is_Checked_Ghost_Entity (Res, Res_Is_CGE); Set_Is_Ignored_Ghost_Entity (Res, Res_Is_IGE); Set_Is_Ignored_Ghost_Node (Res, Res_Is_IGN); Set_Scope (Res, Res_Scope); -- Decorate the class-wide subtype Set_Associated_Node_For_Itype (Res, N); Set_Comes_From_Source (Res, False); Set_Ekind (Res, E_Class_Wide_Subtype); Set_Etype (Res, Base_Type (CW_Typ)); Set_Freeze_Node (Res, Empty); Set_Is_Frozen (Res, False); Set_Is_Itype (Res); Set_Is_Public (Res, False); Set_Next_Entity (Res, Empty); Set_Prev_Entity (Res, Empty); Set_Sloc (Res, Sloc (N)); Set_Public_Status (Res); return Res; end New_Class_Wide_Subtype; -------------------------------- -- Non_Limited_Designated_Type -- --------------------------------- function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is Desig : constant Entity_Id := Designated_Type (T); begin if Has_Non_Limited_View (Desig) then return Non_Limited_View (Desig); else return Desig; end if; end Non_Limited_Designated_Type; ----------------------------------- -- OK_To_Do_Constant_Replacement -- ----------------------------------- function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is ES : constant Entity_Id := Scope (E); CS : Entity_Id; begin -- Do not replace statically allocated objects, because they may be -- modified outside the current scope. if Is_Statically_Allocated (E) then return False; -- Do not replace aliased or volatile objects, since we don't know what -- else might change the value. elsif Is_Aliased (E) or else Treat_As_Volatile (E) then return False; -- Debug flag -gnatdM disconnects this optimization elsif Debug_Flag_MM then return False; -- Otherwise check scopes else CS := Current_Scope; loop -- If we are in right scope, replacement is safe if CS = ES then return True; -- Packages do not affect the determination of safety elsif Ekind (CS) = E_Package then exit when CS = Standard_Standard; CS := Scope (CS); -- Blocks do not affect the determination of safety elsif Ekind (CS) = E_Block then CS := Scope (CS); -- Loops do not affect the determination of safety. Note that we -- kill all current values on entry to a loop, so we are just -- talking about processing within a loop here. elsif Ekind (CS) = E_Loop then CS := Scope (CS); -- Otherwise, the reference is dubious, and we cannot be sure that -- it is safe to do the replacement. else exit; end if; end loop; return False; end if; end OK_To_Do_Constant_Replacement; ------------------------------------ -- Possible_Bit_Aligned_Component -- ------------------------------------ function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is begin -- Do not process an unanalyzed node because it is not yet decorated and -- most checks performed below will fail. if not Analyzed (N) then return False; end if; -- There are never alignment issues in CodePeer mode if CodePeer_Mode then return False; end if; case Nkind (N) is -- Case of indexed component when N_Indexed_Component => declare P : constant Node_Id := Prefix (N); Ptyp : constant Entity_Id := Etype (P); begin -- If we know the component size and it is not larger than 64, -- then we are definitely OK. The back end does the assignment -- of misaligned small objects correctly. if Known_Static_Component_Size (Ptyp) and then Component_Size (Ptyp) <= 64 then return False; -- Otherwise, we need to test the prefix, to see if we are -- indexing from a possibly unaligned component. else return Possible_Bit_Aligned_Component (P); end if; end; -- Case of selected component when N_Selected_Component => declare P : constant Node_Id := Prefix (N); Comp : constant Entity_Id := Entity (Selector_Name (N)); begin -- This is the crucial test: if the component itself causes -- trouble, then we can stop and return True. if Component_May_Be_Bit_Aligned (Comp) then return True; -- Otherwise, we need to test the prefix, to see if we are -- selecting from a possibly unaligned component. else return Possible_Bit_Aligned_Component (P); end if; end; -- For a slice, test the prefix, if that is possibly misaligned, -- then for sure the slice is. when N_Slice => return Possible_Bit_Aligned_Component (Prefix (N)); -- For an unchecked conversion, check whether the expression may -- be bit aligned. when N_Unchecked_Type_Conversion => return Possible_Bit_Aligned_Component (Expression (N)); -- If we have none of the above, it means that we have fallen off the -- top testing prefixes recursively, and we now have a stand alone -- object, where we don't have a problem, unless this is a renaming, -- in which case we need to look into the renamed object. when others => if Is_Entity_Name (N) and then Present (Renamed_Object (Entity (N))) then return Possible_Bit_Aligned_Component (Renamed_Object (Entity (N))); else return False; end if; end case; end Possible_Bit_Aligned_Component; ----------------------------------------------- -- Process_Statements_For_Controlled_Objects -- ----------------------------------------------- procedure Process_Statements_For_Controlled_Objects (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); function Are_Wrapped (L : List_Id) return Boolean; -- Determine whether list L contains only one statement which is a block function Wrap_Statements_In_Block (L : List_Id; Scop : Entity_Id := Current_Scope) return Node_Id; -- Given a list of statements L, wrap it in a block statement and return -- the generated node. Scop is either the current scope or the scope of -- the context (if applicable). ----------------- -- Are_Wrapped -- ----------------- function Are_Wrapped (L : List_Id) return Boolean is Stmt : constant Node_Id := First (L); begin return Present (Stmt) and then No (Next (Stmt)) and then Nkind (Stmt) = N_Block_Statement; end Are_Wrapped; ------------------------------ -- Wrap_Statements_In_Block -- ------------------------------ function Wrap_Statements_In_Block (L : List_Id; Scop : Entity_Id := Current_Scope) return Node_Id is Block_Id : Entity_Id; Block_Nod : Node_Id; Iter_Loop : Entity_Id; begin Block_Nod := Make_Block_Statement (Loc, Declarations => No_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => L)); -- Create a label for the block in case the block needs to manage the -- secondary stack. A label allows for flag Uses_Sec_Stack to be set. Add_Block_Identifier (Block_Nod, Block_Id); -- When wrapping the statements of an iterator loop, check whether -- the loop requires secondary stack management and if so, propagate -- the appropriate flags to the block. This ensures that the cursor -- is properly cleaned up at each iteration of the loop. Iter_Loop := Find_Enclosing_Iterator_Loop (Scop); if Present (Iter_Loop) then Set_Uses_Sec_Stack (Block_Id, Uses_Sec_Stack (Iter_Loop)); -- Secondary stack reclamation is suppressed when the associated -- iterator loop contains a return statement which uses the stack. Set_Sec_Stack_Needed_For_Return (Block_Id, Sec_Stack_Needed_For_Return (Iter_Loop)); end if; return Block_Nod; end Wrap_Statements_In_Block; -- Local variables Block : Node_Id; -- Start of processing for Process_Statements_For_Controlled_Objects begin -- Whenever a non-handled statement list is wrapped in a block, the -- block must be explicitly analyzed to redecorate all entities in the -- list and ensure that a finalizer is properly built. case Nkind (N) is when N_Conditional_Entry_Call | N_Elsif_Part | N_If_Statement | N_Selective_Accept => -- Check the "then statements" for elsif parts and if statements if Nkind_In (N, N_Elsif_Part, N_If_Statement) and then not Is_Empty_List (Then_Statements (N)) and then not Are_Wrapped (Then_Statements (N)) and then Requires_Cleanup_Actions (L => Then_Statements (N), Lib_Level => False, Nested_Constructs => False) then Block := Wrap_Statements_In_Block (Then_Statements (N)); Set_Then_Statements (N, New_List (Block)); Analyze (Block); end if; -- Check the "else statements" for conditional entry calls, if -- statements and selective accepts. if Nkind_In (N, N_Conditional_Entry_Call, N_If_Statement, N_Selective_Accept) and then not Is_Empty_List (Else_Statements (N)) and then not Are_Wrapped (Else_Statements (N)) and then Requires_Cleanup_Actions (L => Else_Statements (N), Lib_Level => False, Nested_Constructs => False) then Block := Wrap_Statements_In_Block (Else_Statements (N)); Set_Else_Statements (N, New_List (Block)); Analyze (Block); end if; when N_Abortable_Part | N_Accept_Alternative | N_Case_Statement_Alternative | N_Delay_Alternative | N_Entry_Call_Alternative | N_Exception_Handler | N_Loop_Statement | N_Triggering_Alternative => if not Is_Empty_List (Statements (N)) and then not Are_Wrapped (Statements (N)) and then Requires_Cleanup_Actions (L => Statements (N), Lib_Level => False, Nested_Constructs => False) then if Nkind (N) = N_Loop_Statement and then Present (Identifier (N)) then Block := Wrap_Statements_In_Block (L => Statements (N), Scop => Entity (Identifier (N))); else Block := Wrap_Statements_In_Block (Statements (N)); end if; Set_Statements (N, New_List (Block)); Analyze (Block); end if; -- Could be e.g. a loop that was transformed into a block or null -- statement. Do nothing for terminate alternatives. when N_Block_Statement | N_Null_Statement | N_Terminate_Alternative => null; when others => raise Program_Error; end case; end Process_Statements_For_Controlled_Objects; ------------------ -- Power_Of_Two -- ------------------ function Power_Of_Two (N : Node_Id) return Nat is Typ : constant Entity_Id := Etype (N); pragma Assert (Is_Integer_Type (Typ)); Siz : constant Nat := UI_To_Int (Esize (Typ)); Val : Uint; begin if not Compile_Time_Known_Value (N) then return 0; else Val := Expr_Value (N); for J in 1 .. Siz - 1 loop if Val = Uint_2 ** J then return J; end if; end loop; return 0; end if; end Power_Of_Two; ---------------------- -- Remove_Init_Call -- ---------------------- function Remove_Init_Call (Var : Entity_Id; Rep_Clause : Node_Id) return Node_Id is Par : constant Node_Id := Parent (Var); Typ : constant Entity_Id := Etype (Var); Init_Proc : Entity_Id; -- Initialization procedure for Typ function Find_Init_Call_In_List (From : Node_Id) return Node_Id; -- Look for init call for Var starting at From and scanning the -- enclosing list until Rep_Clause or the end of the list is reached. ---------------------------- -- Find_Init_Call_In_List -- ---------------------------- function Find_Init_Call_In_List (From : Node_Id) return Node_Id is Init_Call : Node_Id; begin Init_Call := From; while Present (Init_Call) and then Init_Call /= Rep_Clause loop if Nkind (Init_Call) = N_Procedure_Call_Statement and then Is_Entity_Name (Name (Init_Call)) and then Entity (Name (Init_Call)) = Init_Proc then return Init_Call; end if; Next (Init_Call); end loop; return Empty; end Find_Init_Call_In_List; Init_Call : Node_Id; -- Start of processing for Find_Init_Call begin if Present (Initialization_Statements (Var)) then Init_Call := Initialization_Statements (Var); Set_Initialization_Statements (Var, Empty); elsif not Has_Non_Null_Base_Init_Proc (Typ) then -- No init proc for the type, so obviously no call to be found return Empty; else -- We might be able to handle other cases below by just properly -- setting Initialization_Statements at the point where the init proc -- call is generated??? Init_Proc := Base_Init_Proc (Typ); -- First scan the list containing the declaration of Var Init_Call := Find_Init_Call_In_List (From => Next (Par)); -- If not found, also look on Var's freeze actions list, if any, -- since the init call may have been moved there (case of an address -- clause applying to Var). if No (Init_Call) and then Present (Freeze_Node (Var)) then Init_Call := Find_Init_Call_In_List (First (Actions (Freeze_Node (Var)))); end if; -- If the initialization call has actuals that use the secondary -- stack, the call may have been wrapped into a temporary block, in -- which case the block itself has to be removed. if No (Init_Call) and then Nkind (Next (Par)) = N_Block_Statement then declare Blk : constant Node_Id := Next (Par); begin if Present (Find_Init_Call_In_List (First (Statements (Handled_Statement_Sequence (Blk))))) then Init_Call := Blk; end if; end; end if; end if; if Present (Init_Call) then Remove (Init_Call); end if; return Init_Call; end Remove_Init_Call; ------------------------- -- Remove_Side_Effects -- ------------------------- procedure Remove_Side_Effects (Exp : Node_Id; Name_Req : Boolean := False; Renaming_Req : Boolean := False; Variable_Ref : Boolean := False; Related_Id : Entity_Id := Empty; Is_Low_Bound : Boolean := False; Is_High_Bound : Boolean := False; Check_Side_Effects : Boolean := True) is function Build_Temporary (Loc : Source_Ptr; Id : Character; Related_Nod : Node_Id := Empty) return Entity_Id; -- Create an external symbol of the form xxx_FIRST/_LAST if Related_Nod -- is present (xxx is taken from the Chars field of Related_Nod), -- otherwise it generates an internal temporary. The created temporary -- entity is marked as internal. --------------------- -- Build_Temporary -- --------------------- function Build_Temporary (Loc : Source_Ptr; Id : Character; Related_Nod : Node_Id := Empty) return Entity_Id is Temp_Id : Entity_Id; Temp_Nam : Name_Id; begin -- The context requires an external symbol if Present (Related_Id) then if Is_Low_Bound then Temp_Nam := New_External_Name (Chars (Related_Id), "_FIRST"); else pragma Assert (Is_High_Bound); Temp_Nam := New_External_Name (Chars (Related_Id), "_LAST"); end if; Temp_Id := Make_Defining_Identifier (Loc, Temp_Nam); -- Otherwise generate an internal temporary else Temp_Id := Make_Temporary (Loc, Id, Related_Nod); end if; Set_Is_Internal (Temp_Id); return Temp_Id; end Build_Temporary; -- Local variables Loc : constant Source_Ptr := Sloc (Exp); Exp_Type : constant Entity_Id := Etype (Exp); Svg_Suppress : constant Suppress_Record := Scope_Suppress; Def_Id : Entity_Id; E : Node_Id; New_Exp : Node_Id; Ptr_Typ_Decl : Node_Id; Ref_Type : Entity_Id; Res : Node_Id; -- Start of processing for Remove_Side_Effects begin -- Handle cases in which there is nothing to do. In GNATprove mode, -- removal of side effects is useful for the light expansion of -- renamings. This removal should only occur when not inside a -- generic and not doing a preanalysis. if not Expander_Active and (Inside_A_Generic or not Full_Analysis or not GNATprove_Mode) then return; -- Cannot generate temporaries if the invocation to remove side effects -- was issued too early and the type of the expression is not resolved -- (this happens because routines Duplicate_Subexpr_XX implicitly invoke -- Remove_Side_Effects). elsif No (Exp_Type) or else Ekind (Exp_Type) = E_Access_Attribute_Type then return; -- Nothing to do if prior expansion determined that a function call does -- not require side effect removal. elsif Nkind (Exp) = N_Function_Call and then No_Side_Effect_Removal (Exp) then return; -- No action needed for side-effect free expressions elsif Check_Side_Effects and then Side_Effect_Free (Exp, Name_Req, Variable_Ref) then return; -- Generating C code we cannot remove side effect of function returning -- class-wide types since there is no secondary stack (required to use -- 'reference). elsif Modify_Tree_For_C and then Nkind (Exp) = N_Function_Call and then Is_Class_Wide_Type (Etype (Exp)) then return; end if; -- The remaining processing is done with all checks suppressed -- Note: from now on, don't use return statements, instead do a goto -- Leave, to ensure that we properly restore Scope_Suppress.Suppress. Scope_Suppress.Suppress := (others => True); -- If this is an elementary or a small not-by-reference record type, and -- we need to capture the value, just make a constant; this is cheap and -- objects of both kinds of types can be bit aligned, so it might not be -- possible to generate a reference to them. Likewise if this is not a -- name reference, except for a type conversion, because we would enter -- an infinite recursion with Checks.Apply_Predicate_Check if the target -- type has predicates (and type conversions need a specific treatment -- anyway, see below). Also do it if we have a volatile reference and -- Name_Req is not set (see comments for Side_Effect_Free). if (Is_Elementary_Type (Exp_Type) or else (Is_Record_Type (Exp_Type) and then Known_Static_RM_Size (Exp_Type) and then RM_Size (Exp_Type) <= 64 and then not Has_Discriminants (Exp_Type) and then not Is_By_Reference_Type (Exp_Type))) and then (Variable_Ref or else (not Is_Name_Reference (Exp) and then Nkind (Exp) /= N_Type_Conversion) or else (not Name_Req and then Is_Volatile_Reference (Exp))) then Def_Id := Build_Temporary (Loc, 'R', Exp); Set_Etype (Def_Id, Exp_Type); Res := New_Occurrence_Of (Def_Id, Loc); -- If the expression is a packed reference, it must be reanalyzed and -- expanded, depending on context. This is the case for actuals where -- a constraint check may capture the actual before expansion of the -- call is complete. if Nkind (Exp) = N_Indexed_Component and then Is_Packed (Etype (Prefix (Exp))) then Set_Analyzed (Exp, False); Set_Analyzed (Prefix (Exp), False); end if; -- Generate: -- Rnn : Exp_Type renames Expr; -- In GNATprove mode, we prefer to use renamings for intermediate -- variables to definition of constants, due to the implicit move -- operation that such a constant definition causes as part of the -- support in GNATprove for ownership pointers. Hence, we generate -- a renaming for a reference to an object of a nonscalar type. if Renaming_Req or else (GNATprove_Mode and then Is_Object_Reference (Exp) and then not Is_Scalar_Type (Exp_Type)) then E := Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc), Name => Relocate_Node (Exp)); -- Generate: -- Rnn : constant Exp_Type := Expr; else E := Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Occurrence_Of (Exp_Type, Loc), Constant_Present => True, Expression => Relocate_Node (Exp)); Set_Assignment_OK (E); end if; Insert_Action (Exp, E); -- If the expression has the form v.all then we can just capture the -- pointer, and then do an explicit dereference on the result, but -- this is not right if this is a volatile reference. elsif Nkind (Exp) = N_Explicit_Dereference and then not Is_Volatile_Reference (Exp) then Def_Id := Build_Temporary (Loc, 'R', Exp); Res := Make_Explicit_Dereference (Loc, New_Occurrence_Of (Def_Id, Loc)); Insert_Action (Exp, Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Occurrence_Of (Etype (Prefix (Exp)), Loc), Constant_Present => True, Expression => Relocate_Node (Prefix (Exp)))); -- Similar processing for an unchecked conversion of an expression of -- the form v.all, where we want the same kind of treatment. elsif Nkind (Exp) = N_Unchecked_Type_Conversion and then Nkind (Expression (Exp)) = N_Explicit_Dereference then Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref); goto Leave; -- If this is a type conversion, leave the type conversion and remove -- the side effects in the expression. This is important in several -- circumstances: for change of representations, and also when this is a -- view conversion to a smaller object, where gigi can end up creating -- its own temporary of the wrong size. elsif Nkind (Exp) = N_Type_Conversion then Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref); -- Generating C code the type conversion of an access to constrained -- array type into an access to unconstrained array type involves -- initializing a fat pointer and the expression must be free of -- side effects to safely compute its bounds. if Modify_Tree_For_C and then Is_Access_Type (Etype (Exp)) and then Is_Array_Type (Designated_Type (Etype (Exp))) and then not Is_Constrained (Designated_Type (Etype (Exp))) then Def_Id := Build_Temporary (Loc, 'R', Exp); Set_Etype (Def_Id, Exp_Type); Res := New_Occurrence_Of (Def_Id, Loc); Insert_Action (Exp, Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Occurrence_Of (Exp_Type, Loc), Constant_Present => True, Expression => Relocate_Node (Exp))); else goto Leave; end if; -- If this is an unchecked conversion that Gigi can't handle, make -- a copy or a use a renaming to capture the value. elsif Nkind (Exp) = N_Unchecked_Type_Conversion and then not Safe_Unchecked_Type_Conversion (Exp) then if CW_Or_Has_Controlled_Part (Exp_Type) then -- Use a renaming to capture the expression, rather than create -- a controlled temporary. Def_Id := Build_Temporary (Loc, 'R', Exp); Res := New_Occurrence_Of (Def_Id, Loc); Insert_Action (Exp, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc), Name => Relocate_Node (Exp))); else Def_Id := Build_Temporary (Loc, 'R', Exp); Set_Etype (Def_Id, Exp_Type); Res := New_Occurrence_Of (Def_Id, Loc); E := Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Occurrence_Of (Exp_Type, Loc), Constant_Present => not Is_Variable (Exp), Expression => Relocate_Node (Exp)); Set_Assignment_OK (E); Insert_Action (Exp, E); end if; -- For expressions that denote names, we can use a renaming scheme. -- This is needed for correctness in the case of a volatile object of -- a nonvolatile type because the Make_Reference call of the "default" -- approach would generate an illegal access value (an access value -- cannot designate such an object - see Analyze_Reference). elsif Is_Name_Reference (Exp) -- We skip using this scheme if we have an object of a volatile -- type and we do not have Name_Req set true (see comments for -- Side_Effect_Free). and then (Name_Req or else not Treat_As_Volatile (Exp_Type)) then Def_Id := Build_Temporary (Loc, 'R', Exp); Res := New_Occurrence_Of (Def_Id, Loc); Insert_Action (Exp, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc), Name => Relocate_Node (Exp))); -- If this is a packed reference, or a selected component with -- a nonstandard representation, a reference to the temporary -- will be replaced by a copy of the original expression (see -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be -- elaborated by gigi, and is of course not to be replaced in-line -- by the expression it renames, which would defeat the purpose of -- removing the side effect. if Nkind_In (Exp, N_Selected_Component, N_Indexed_Component) and then Has_Non_Standard_Rep (Etype (Prefix (Exp))) then null; else Set_Is_Renaming_Of_Object (Def_Id, False); end if; -- Avoid generating a variable-sized temporary, by generating the -- reference just for the function call. The transformation could be -- refined to apply only when the array component is constrained by a -- discriminant??? elsif Nkind (Exp) = N_Selected_Component and then Nkind (Prefix (Exp)) = N_Function_Call and then Is_Array_Type (Exp_Type) then Remove_Side_Effects (Prefix (Exp), Name_Req, Variable_Ref); goto Leave; -- Otherwise we generate a reference to the expression else -- An expression which is in SPARK mode is considered side effect -- free if the resulting value is captured by a variable or a -- constant. if GNATprove_Mode and then Nkind (Parent (Exp)) = N_Object_Declaration then goto Leave; -- When generating C code we cannot consider side effect free object -- declarations that have discriminants and are initialized by means -- of a function call since on this target there is no secondary -- stack to store the return value and the expander may generate an -- extra call to the function to compute the discriminant value. In -- addition, for targets that have secondary stack, the expansion of -- functions with side effects involves the generation of an access -- type to capture the return value stored in the secondary stack; -- by contrast when generating C code such expansion generates an -- internal object declaration (no access type involved) which must -- be identified here to avoid entering into a never-ending loop -- generating internal object declarations. elsif Modify_Tree_For_C and then Nkind (Parent (Exp)) = N_Object_Declaration and then (Nkind (Exp) /= N_Function_Call or else not Has_Discriminants (Exp_Type) or else Is_Internal_Name (Chars (Defining_Identifier (Parent (Exp))))) then goto Leave; end if; -- Special processing for function calls that return a limited type. -- We need to build a declaration that will enable build-in-place -- expansion of the call. This is not done if the context is already -- an object declaration, to prevent infinite recursion. -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have -- to accommodate functions returning limited objects by reference. if Ada_Version >= Ada_2005 and then Nkind (Exp) = N_Function_Call and then Is_Limited_View (Etype (Exp)) and then Nkind (Parent (Exp)) /= N_Object_Declaration then declare Obj : constant Entity_Id := Make_Temporary (Loc, 'F', Exp); Decl : Node_Id; begin Decl := Make_Object_Declaration (Loc, Defining_Identifier => Obj, Object_Definition => New_Occurrence_Of (Exp_Type, Loc), Expression => Relocate_Node (Exp)); Insert_Action (Exp, Decl); Set_Etype (Obj, Exp_Type); Rewrite (Exp, New_Occurrence_Of (Obj, Loc)); goto Leave; end; end if; Def_Id := Build_Temporary (Loc, 'R', Exp); -- The regular expansion of functions with side effects involves the -- generation of an access type to capture the return value found on -- the secondary stack. Since SPARK (and why) cannot process access -- types, use a different approach which ignores the secondary stack -- and "copies" the returned object. -- When generating C code, no need for a 'reference since the -- secondary stack is not supported. if GNATprove_Mode or Modify_Tree_For_C then Res := New_Occurrence_Of (Def_Id, Loc); Ref_Type := Exp_Type; -- Regular expansion utilizing an access type and 'reference else Res := Make_Explicit_Dereference (Loc, Prefix => New_Occurrence_Of (Def_Id, Loc)); -- Generate: -- type Ann is access all ; Ref_Type := Make_Temporary (Loc, 'A'); Ptr_Typ_Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Ref_Type, Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => True, Subtype_Indication => New_Occurrence_Of (Exp_Type, Loc))); Insert_Action (Exp, Ptr_Typ_Decl); end if; E := Exp; if Nkind (E) = N_Explicit_Dereference then New_Exp := Relocate_Node (Prefix (E)); else E := Relocate_Node (E); -- Do not generate a 'reference in SPARK mode or C generation -- since the access type is not created in the first place. if GNATprove_Mode or Modify_Tree_For_C then New_Exp := E; -- Otherwise generate reference, marking the value as non-null -- since we know it cannot be null and we don't want a check. else New_Exp := Make_Reference (Loc, E); Set_Is_Known_Non_Null (Def_Id); end if; end if; if Is_Delayed_Aggregate (E) then -- The expansion of nested aggregates is delayed until the -- enclosing aggregate is expanded. As aggregates are often -- qualified, the predicate applies to qualified expressions as -- well, indicating that the enclosing aggregate has not been -- expanded yet. At this point the aggregate is part of a -- stand-alone declaration, and must be fully expanded. if Nkind (E) = N_Qualified_Expression then Set_Expansion_Delayed (Expression (E), False); Set_Analyzed (Expression (E), False); else Set_Expansion_Delayed (E, False); end if; Set_Analyzed (E, False); end if; -- Generating C code of object declarations that have discriminants -- and are initialized by means of a function call we propagate the -- discriminants of the parent type to the internally built object. -- This is needed to avoid generating an extra call to the called -- function. -- For example, if we generate here the following declaration, it -- will be expanded later adding an extra call to evaluate the value -- of the discriminant (needed to compute the size of the object). -- -- type Rec (D : Integer) is ... -- Obj : constant Rec := SomeFunc; if Modify_Tree_For_C and then Nkind (Parent (Exp)) = N_Object_Declaration and then Has_Discriminants (Exp_Type) and then Nkind (Exp) = N_Function_Call then Insert_Action (Exp, Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Copy_Tree (Object_Definition (Parent (Exp))), Constant_Present => True, Expression => New_Exp)); else Insert_Action (Exp, Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Occurrence_Of (Ref_Type, Loc), Constant_Present => True, Expression => New_Exp)); end if; end if; -- Preserve the Assignment_OK flag in all copies, since at least one -- copy may be used in a context where this flag must be set (otherwise -- why would the flag be set in the first place). Set_Assignment_OK (Res, Assignment_OK (Exp)); -- Preserve the Do_Range_Check flag in all copies Set_Do_Range_Check (Res, Do_Range_Check (Exp)); -- Finally rewrite the original expression and we are done Rewrite (Exp, Res); Analyze_And_Resolve (Exp, Exp_Type); <> Scope_Suppress := Svg_Suppress; end Remove_Side_Effects; ------------------------ -- Replace_References -- ------------------------ procedure Replace_References (Expr : Node_Id; Par_Typ : Entity_Id; Deriv_Typ : Entity_Id; Par_Obj : Entity_Id := Empty; Deriv_Obj : Entity_Id := Empty) is function Is_Deriv_Obj_Ref (Ref : Node_Id) return Boolean; -- Determine whether node Ref denotes some component of Deriv_Obj function Replace_Ref (Ref : Node_Id) return Traverse_Result; -- Substitute a reference to an entity with the corresponding value -- stored in table Type_Map. function Type_Of_Formal (Call : Node_Id; Actual : Node_Id) return Entity_Id; -- Find the type of the formal parameter which corresponds to actual -- parameter Actual in subprogram call Call. ---------------------- -- Is_Deriv_Obj_Ref -- ---------------------- function Is_Deriv_Obj_Ref (Ref : Node_Id) return Boolean is Par : constant Node_Id := Parent (Ref); begin -- Detect the folowing selected component form: -- Deriv_Obj.(something) return Nkind (Par) = N_Selected_Component and then Is_Entity_Name (Prefix (Par)) and then Entity (Prefix (Par)) = Deriv_Obj; end Is_Deriv_Obj_Ref; ----------------- -- Replace_Ref -- ----------------- function Replace_Ref (Ref : Node_Id) return Traverse_Result is procedure Remove_Controlling_Arguments (From_Arg : Node_Id); -- Reset the Controlling_Argument of all function calls that -- encapsulate node From_Arg. ---------------------------------- -- Remove_Controlling_Arguments -- ---------------------------------- procedure Remove_Controlling_Arguments (From_Arg : Node_Id) is Par : Node_Id; begin Par := From_Arg; while Present (Par) loop if Nkind (Par) = N_Function_Call and then Present (Controlling_Argument (Par)) then Set_Controlling_Argument (Par, Empty); -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then exit; end if; Par := Parent (Par); end loop; end Remove_Controlling_Arguments; -- Local variables Context : constant Node_Id := Parent (Ref); Loc : constant Source_Ptr := Sloc (Ref); Ref_Id : Entity_Id; Result : Traverse_Result; New_Ref : Node_Id; -- The new reference which is intended to substitute the old one Old_Ref : Node_Id; -- The reference designated for replacement. In certain cases this -- may be a node other than Ref. Val : Node_Or_Entity_Id; -- The corresponding value of Ref from the type map -- Start of processing for Replace_Ref begin -- Assume that the input reference is to be replaced and that the -- traversal should examine the children of the reference. Old_Ref := Ref; Result := OK; -- The input denotes a meaningful reference if Nkind (Ref) in N_Has_Entity and then Present (Entity (Ref)) then Ref_Id := Entity (Ref); Val := Type_Map.Get (Ref_Id); -- The reference has a corresponding value in the type map, a -- substitution is possible. if Present (Val) then -- The reference denotes a discriminant if Ekind (Ref_Id) = E_Discriminant then if Nkind (Val) in N_Entity then -- The value denotes another discriminant. Replace as -- follows: -- _object.Discr -> _object.Val if Ekind (Val) = E_Discriminant then New_Ref := New_Occurrence_Of (Val, Loc); -- Otherwise the value denotes the entity of a name which -- constraints the discriminant. Replace as follows: -- _object.Discr -> Val else pragma Assert (Is_Deriv_Obj_Ref (Old_Ref)); New_Ref := New_Occurrence_Of (Val, Loc); Old_Ref := Parent (Old_Ref); end if; -- Otherwise the value denotes an arbitrary expression which -- constraints the discriminant. Replace as follows: -- _object.Discr -> Val else pragma Assert (Is_Deriv_Obj_Ref (Old_Ref)); New_Ref := New_Copy_Tree (Val); Old_Ref := Parent (Old_Ref); end if; -- Otherwise the reference denotes a primitive. Replace as -- follows: -- Primitive -> Val else pragma Assert (Nkind (Val) in N_Entity); New_Ref := New_Occurrence_Of (Val, Loc); end if; -- The reference mentions the _object parameter of the parent -- type's DIC or type invariant procedure. Replace as follows: -- _object -> _object elsif Present (Par_Obj) and then Present (Deriv_Obj) and then Ref_Id = Par_Obj then New_Ref := New_Occurrence_Of (Deriv_Obj, Loc); -- The type of the _object parameter is class-wide when the -- expression comes from an assertion pragma that applies to -- an abstract parent type or an interface. The class-wide type -- facilitates the preanalysis of the expression by treating -- calls to abstract primitives that mention the current -- instance of the type as dispatching. Once the calls are -- remapped to invoke overriding or inherited primitives, the -- calls no longer need to be dispatching. Examine all function -- calls that encapsulate the _object parameter and reset their -- Controlling_Argument attribute. if Is_Class_Wide_Type (Etype (Par_Obj)) and then Is_Abstract_Type (Root_Type (Etype (Par_Obj))) then Remove_Controlling_Arguments (Old_Ref); end if; -- The reference to _object acts as an actual parameter in a -- subprogram call which may be invoking a primitive of the -- parent type: -- Primitive (... _object ...); -- The parent type primitive may not be overridden nor -- inherited when it is declared after the derived type -- definition: -- type Parent is tagged private; -- type Child is new Parent with private; -- procedure Primitive (Obj : Parent); -- In this scenario the _object parameter is converted to the -- parent type. Due to complications with partial/full views -- and view swaps, the parent type is taken from the formal -- parameter of the subprogram being called. if Nkind_In (Context, N_Function_Call, N_Procedure_Call_Statement) and then No (Type_Map.Get (Entity (Name (Context)))) then New_Ref := Convert_To (Type_Of_Formal (Context, Old_Ref), New_Ref); -- Do not process the generated type conversion because -- both the parent type and the derived type are in the -- Type_Map table. This will clobber the type conversion -- by resetting its subtype mark. Result := Skip; end if; -- Otherwise there is nothing to replace else New_Ref := Empty; end if; if Present (New_Ref) then Rewrite (Old_Ref, New_Ref); -- Update the return type when the context of the reference -- acts as the name of a function call. Note that the update -- should not be performed when the reference appears as an -- actual in the call. if Nkind (Context) = N_Function_Call and then Name (Context) = Old_Ref then Set_Etype (Context, Etype (Val)); end if; end if; end if; -- Reanalyze the reference due to potential replacements if Nkind (Old_Ref) in N_Has_Etype then Set_Analyzed (Old_Ref, False); end if; return Result; end Replace_Ref; procedure Replace_Refs is new Traverse_Proc (Replace_Ref); -------------------- -- Type_Of_Formal -- -------------------- function Type_Of_Formal (Call : Node_Id; Actual : Node_Id) return Entity_Id is A : Node_Id; F : Entity_Id; begin -- Examine the list of actual and formal parameters in parallel A := First (Parameter_Associations (Call)); F := First_Formal (Entity (Name (Call))); while Present (A) and then Present (F) loop if A = Actual then return Etype (F); end if; Next (A); Next_Formal (F); end loop; -- The actual parameter must always have a corresponding formal pragma Assert (False); return Empty; end Type_Of_Formal; -- Start of processing for Replace_References begin -- Map the attributes of the parent type to the proper corresponding -- attributes of the derived type. Map_Types (Parent_Type => Par_Typ, Derived_Type => Deriv_Typ); -- Inspect the input expression and perform substitutions where -- necessary. Replace_Refs (Expr); end Replace_References; ----------------------------- -- Replace_Type_References -- ----------------------------- procedure Replace_Type_References (Expr : Node_Id; Typ : Entity_Id; Obj_Id : Entity_Id) is procedure Replace_Type_Ref (N : Node_Id); -- Substitute a single reference of the current instance of type Typ -- with a reference to Obj_Id. ---------------------- -- Replace_Type_Ref -- ---------------------- procedure Replace_Type_Ref (N : Node_Id) is begin -- Decorate the reference to Typ even though it may be rewritten -- further down. This is done for two reasons: -- * ASIS has all necessary semantic information in the original -- tree. -- * Routines which examine properties of the Original_Node have -- some semantic information. if Nkind (N) = N_Identifier then Set_Entity (N, Typ); Set_Etype (N, Typ); elsif Nkind (N) = N_Selected_Component then Analyze (Prefix (N)); Set_Entity (Selector_Name (N), Typ); Set_Etype (Selector_Name (N), Typ); end if; -- Perform the following substitution: -- Typ --> _object Rewrite (N, New_Occurrence_Of (Obj_Id, Sloc (N))); Set_Comes_From_Source (N, True); end Replace_Type_Ref; procedure Replace_Type_Refs is new Replace_Type_References_Generic (Replace_Type_Ref); -- Start of processing for Replace_Type_References begin Replace_Type_Refs (Expr, Typ); end Replace_Type_References; --------------------------- -- Represented_As_Scalar -- --------------------------- function Represented_As_Scalar (T : Entity_Id) return Boolean is UT : constant Entity_Id := Underlying_Type (T); begin return Is_Scalar_Type (UT) or else (Is_Bit_Packed_Array (UT) and then Is_Scalar_Type (Packed_Array_Impl_Type (UT))); end Represented_As_Scalar; ------------------------------ -- Requires_Cleanup_Actions -- ------------------------------ function Requires_Cleanup_Actions (N : Node_Id; Lib_Level : Boolean) return Boolean is At_Lib_Level : constant Boolean := Lib_Level and then Nkind_In (N, N_Package_Body, N_Package_Specification); -- N is at the library level if the top-most context is a package and -- the path taken to reach N does not include nonpackage constructs. begin case Nkind (N) is when N_Accept_Statement | N_Block_Statement | N_Entry_Body | N_Package_Body | N_Protected_Body | N_Subprogram_Body | N_Task_Body => return Requires_Cleanup_Actions (L => Declarations (N), Lib_Level => At_Lib_Level, Nested_Constructs => True) or else (Present (Handled_Statement_Sequence (N)) and then Requires_Cleanup_Actions (L => Statements (Handled_Statement_Sequence (N)), Lib_Level => At_Lib_Level, Nested_Constructs => True)); -- Extended return statements are the same as the above, except that -- there is no Declarations field. We do not want to clean up the -- Return_Object_Declarations. when N_Extended_Return_Statement => return Present (Handled_Statement_Sequence (N)) and then Requires_Cleanup_Actions (L => Statements (Handled_Statement_Sequence (N)), Lib_Level => At_Lib_Level, Nested_Constructs => True); when N_Package_Specification => return Requires_Cleanup_Actions (L => Visible_Declarations (N), Lib_Level => At_Lib_Level, Nested_Constructs => True) or else Requires_Cleanup_Actions (L => Private_Declarations (N), Lib_Level => At_Lib_Level, Nested_Constructs => True); when others => raise Program_Error; end case; end Requires_Cleanup_Actions; ------------------------------ -- Requires_Cleanup_Actions -- ------------------------------ function Requires_Cleanup_Actions (L : List_Id; Lib_Level : Boolean; Nested_Constructs : Boolean) return Boolean is Decl : Node_Id; Expr : Node_Id; Obj_Id : Entity_Id; Obj_Typ : Entity_Id; Pack_Id : Entity_Id; Typ : Entity_Id; begin if No (L) or else Is_Empty_List (L) then return False; end if; Decl := First (L); while Present (Decl) loop -- Library-level tagged types if Nkind (Decl) = N_Full_Type_Declaration then Typ := Defining_Identifier (Decl); -- Ignored Ghost types do not need any cleanup actions because -- they will not appear in the final tree. if Is_Ignored_Ghost_Entity (Typ) then null; elsif Is_Tagged_Type (Typ) and then Is_Library_Level_Entity (Typ) and then Convention (Typ) = Convention_Ada and then Present (Access_Disp_Table (Typ)) and then RTE_Available (RE_Unregister_Tag) and then not Is_Abstract_Type (Typ) and then not No_Run_Time_Mode then return True; end if; -- Regular object declarations elsif Nkind (Decl) = N_Object_Declaration then Obj_Id := Defining_Identifier (Decl); Obj_Typ := Base_Type (Etype (Obj_Id)); Expr := Expression (Decl); -- Bypass any form of processing for objects which have their -- finalization disabled. This applies only to objects at the -- library level. if Lib_Level and then Finalize_Storage_Only (Obj_Typ) then null; -- Finalization of transient objects are treated separately in -- order to handle sensitive cases. These include: -- * Aggregate expansion -- * If, case, and expression with actions expansion -- * Transient scopes -- If one of those contexts has marked the transient object as -- ignored, do not generate finalization actions for it. elsif Is_Finalized_Transient (Obj_Id) or else Is_Ignored_Transient (Obj_Id) then null; -- Ignored Ghost objects do not need any cleanup actions because -- they will not appear in the final tree. elsif Is_Ignored_Ghost_Entity (Obj_Id) then null; -- The object is of the form: -- Obj : [constant] Typ [:= Expr]; -- -- Do not process tag-to-class-wide conversions because they do -- not yield an object. Do not process the incomplete view of a -- deferred constant. Note that an object initialized by means -- of a build-in-place function call may appear as a deferred -- constant after expansion activities. These kinds of objects -- must be finalized. elsif not Is_Imported (Obj_Id) and then Needs_Finalization (Obj_Typ) and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id) and then not (Ekind (Obj_Id) = E_Constant and then not Has_Completion (Obj_Id) and then No (BIP_Initialization_Call (Obj_Id))) then return True; -- The object is of the form: -- Obj : Access_Typ := Non_BIP_Function_Call'reference; -- -- Obj : Access_Typ := -- BIP_Function_Call (BIPalloc => 2, ...)'reference; elsif Is_Access_Type (Obj_Typ) and then Needs_Finalization (Available_View (Designated_Type (Obj_Typ))) and then Present (Expr) and then (Is_Secondary_Stack_BIP_Func_Call (Expr) or else (Is_Non_BIP_Func_Call (Expr) and then not Is_Related_To_Func_Return (Obj_Id))) then return True; -- Processing for "hook" objects generated for transient objects -- declared inside an Expression_With_Actions. elsif Is_Access_Type (Obj_Typ) and then Present (Status_Flag_Or_Transient_Decl (Obj_Id)) and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) = N_Object_Declaration then return True; -- Processing for intermediate results of if expressions where -- one of the alternatives uses a controlled function call. elsif Is_Access_Type (Obj_Typ) and then Present (Status_Flag_Or_Transient_Decl (Obj_Id)) and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) = N_Defining_Identifier and then Present (Expr) and then Nkind (Expr) = N_Null then return True; -- Simple protected objects which use type System.Tasking. -- Protected_Objects.Protection to manage their locks should be -- treated as controlled since they require manual cleanup. elsif Ekind (Obj_Id) = E_Variable and then (Is_Simple_Protected_Type (Obj_Typ) or else Has_Simple_Protected_Object (Obj_Typ)) then return True; end if; -- Specific cases of object renamings elsif Nkind (Decl) = N_Object_Renaming_Declaration then Obj_Id := Defining_Identifier (Decl); Obj_Typ := Base_Type (Etype (Obj_Id)); -- Bypass any form of processing for objects which have their -- finalization disabled. This applies only to objects at the -- library level. if Lib_Level and then Finalize_Storage_Only (Obj_Typ) then null; -- Ignored Ghost object renamings do not need any cleanup actions -- because they will not appear in the final tree. elsif Is_Ignored_Ghost_Entity (Obj_Id) then null; -- Return object of a build-in-place function. This case is -- recognized and marked by the expansion of an extended return -- statement (see Expand_N_Extended_Return_Statement). elsif Needs_Finalization (Obj_Typ) and then Is_Return_Object (Obj_Id) and then Present (Status_Flag_Or_Transient_Decl (Obj_Id)) then return True; -- Detect a case where a source object has been initialized by -- a controlled function call or another object which was later -- rewritten as a class-wide conversion of Ada.Tags.Displace. -- Obj1 : CW_Type := Src_Obj; -- Obj2 : CW_Type := Function_Call (...); -- Obj1 : CW_Type renames (... Ada.Tags.Displace (Src_Obj)); -- Tmp : ... := Function_Call (...)'reference; -- Obj2 : CW_Type renames (... Ada.Tags.Displace (Tmp)); elsif Is_Displacement_Of_Object_Or_Function_Result (Obj_Id) then return True; end if; -- Inspect the freeze node of an access-to-controlled type and look -- for a delayed finalization master. This case arises when the -- freeze actions are inserted at a later time than the expansion of -- the context. Since Build_Finalizer is never called on a single -- construct twice, the master will be ultimately left out and never -- finalized. This is also needed for freeze actions of designated -- types themselves, since in some cases the finalization master is -- associated with a designated type's freeze node rather than that -- of the access type (see handling for freeze actions in -- Build_Finalization_Master). elsif Nkind (Decl) = N_Freeze_Entity and then Present (Actions (Decl)) then Typ := Entity (Decl); -- Freeze nodes for ignored Ghost types do not need cleanup -- actions because they will never appear in the final tree. if Is_Ignored_Ghost_Entity (Typ) then null; elsif ((Is_Access_Type (Typ) and then not Is_Access_Subprogram_Type (Typ) and then Needs_Finalization (Available_View (Designated_Type (Typ)))) or else (Is_Type (Typ) and then Needs_Finalization (Typ))) and then Requires_Cleanup_Actions (Actions (Decl), Lib_Level, Nested_Constructs) then return True; end if; -- Nested package declarations elsif Nested_Constructs and then Nkind (Decl) = N_Package_Declaration then Pack_Id := Defining_Entity (Decl); -- Do not inspect an ignored Ghost package because all code found -- within will not appear in the final tree. if Is_Ignored_Ghost_Entity (Pack_Id) then null; elsif Ekind (Pack_Id) /= E_Generic_Package and then Requires_Cleanup_Actions (Specification (Decl), Lib_Level) then return True; end if; -- Nested package bodies elsif Nested_Constructs and then Nkind (Decl) = N_Package_Body then -- Do not inspect an ignored Ghost package body because all code -- found within will not appear in the final tree. if Is_Ignored_Ghost_Entity (Defining_Entity (Decl)) then null; elsif Ekind (Corresponding_Spec (Decl)) /= E_Generic_Package and then Requires_Cleanup_Actions (Decl, Lib_Level) then return True; end if; elsif Nkind (Decl) = N_Block_Statement and then -- Handle a rare case caused by a controlled transient object -- created as part of a record init proc. The variable is wrapped -- in a block, but the block is not associated with a transient -- scope. (Inside_Init_Proc -- Handle the case where the original context has been wrapped in -- a block to avoid interference between exception handlers and -- At_End handlers. Treat the block as transparent and process its -- contents. or else Is_Finalization_Wrapper (Decl)) then if Requires_Cleanup_Actions (Decl, Lib_Level) then return True; end if; end if; Next (Decl); end loop; return False; end Requires_Cleanup_Actions; ------------------------------------ -- Safe_Unchecked_Type_Conversion -- ------------------------------------ -- Note: this function knows quite a bit about the exact requirements of -- Gigi with respect to unchecked type conversions, and its code must be -- coordinated with any changes in Gigi in this area. -- The above requirements should be documented in Sinfo ??? function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is Otyp : Entity_Id; Ityp : Entity_Id; Oalign : Uint; Ialign : Uint; Pexp : constant Node_Id := Parent (Exp); begin -- If the expression is the RHS of an assignment or object declaration -- we are always OK because there will always be a target. -- Object renaming declarations, (generated for view conversions of -- actuals in inlined calls), like object declarations, provide an -- explicit type, and are safe as well. if (Nkind (Pexp) = N_Assignment_Statement and then Expression (Pexp) = Exp) or else Nkind_In (Pexp, N_Object_Declaration, N_Object_Renaming_Declaration) then return True; -- If the expression is the prefix of an N_Selected_Component we should -- also be OK because GCC knows to look inside the conversion except if -- the type is discriminated. We assume that we are OK anyway if the -- type is not set yet or if it is controlled since we can't afford to -- introduce a temporary in this case. elsif Nkind (Pexp) = N_Selected_Component and then Prefix (Pexp) = Exp then if No (Etype (Pexp)) then return True; else return not Has_Discriminants (Etype (Pexp)) or else Is_Constrained (Etype (Pexp)); end if; end if; -- Set the output type, this comes from Etype if it is set, otherwise we -- take it from the subtype mark, which we assume was already fully -- analyzed. if Present (Etype (Exp)) then Otyp := Etype (Exp); else Otyp := Entity (Subtype_Mark (Exp)); end if; -- The input type always comes from the expression, and we assume this -- is indeed always analyzed, so we can simply get the Etype. Ityp := Etype (Expression (Exp)); -- Initialize alignments to unknown so far Oalign := No_Uint; Ialign := No_Uint; -- Replace a concurrent type by its corresponding record type and each -- type by its underlying type and do the tests on those. The original -- type may be a private type whose completion is a concurrent type, so -- find the underlying type first. if Present (Underlying_Type (Otyp)) then Otyp := Underlying_Type (Otyp); end if; if Present (Underlying_Type (Ityp)) then Ityp := Underlying_Type (Ityp); end if; if Is_Concurrent_Type (Otyp) then Otyp := Corresponding_Record_Type (Otyp); end if; if Is_Concurrent_Type (Ityp) then Ityp := Corresponding_Record_Type (Ityp); end if; -- If the base types are the same, we know there is no problem since -- this conversion will be a noop. if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then return True; -- Same if this is an upwards conversion of an untagged type, and there -- are no constraints involved (could be more general???) elsif Etype (Ityp) = Otyp and then not Is_Tagged_Type (Ityp) and then not Has_Discriminants (Ityp) and then No (First_Rep_Item (Base_Type (Ityp))) then return True; -- If the expression has an access type (object or subprogram) we assume -- that the conversion is safe, because the size of the target is safe, -- even if it is a record (which might be treated as having unknown size -- at this point). elsif Is_Access_Type (Ityp) then return True; -- If the size of output type is known at compile time, there is never -- a problem. Note that unconstrained records are considered to be of -- known size, but we can't consider them that way here, because we are -- talking about the actual size of the object. -- We also make sure that in addition to the size being known, we do not -- have a case which might generate an embarrassingly large temp in -- stack checking mode. elsif Size_Known_At_Compile_Time (Otyp) and then (not Stack_Checking_Enabled or else not May_Generate_Large_Temp (Otyp)) and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp)) then return True; -- If either type is tagged, then we know the alignment is OK so Gigi -- will be able to use pointer punning. elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then return True; -- If either type is a limited record type, we cannot do a copy, so say -- safe since there's nothing else we can do. elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then return True; -- Conversions to and from packed array types are always ignored and -- hence are safe. elsif Is_Packed_Array_Impl_Type (Otyp) or else Is_Packed_Array_Impl_Type (Ityp) then return True; end if; -- The only other cases known to be safe is if the input type's -- alignment is known to be at least the maximum alignment for the -- target or if both alignments are known and the output type's -- alignment is no stricter than the input's. We can use the component -- type alignment for an array if a type is an unpacked array type. if Present (Alignment_Clause (Otyp)) then Oalign := Expr_Value (Expression (Alignment_Clause (Otyp))); elsif Is_Array_Type (Otyp) and then Present (Alignment_Clause (Component_Type (Otyp))) then Oalign := Expr_Value (Expression (Alignment_Clause (Component_Type (Otyp)))); end if; if Present (Alignment_Clause (Ityp)) then Ialign := Expr_Value (Expression (Alignment_Clause (Ityp))); elsif Is_Array_Type (Ityp) and then Present (Alignment_Clause (Component_Type (Ityp))) then Ialign := Expr_Value (Expression (Alignment_Clause (Component_Type (Ityp)))); end if; if Ialign /= No_Uint and then Ialign > Maximum_Alignment then return True; elsif Ialign /= No_Uint and then Oalign /= No_Uint and then Ialign <= Oalign then return True; -- Otherwise, Gigi cannot handle this and we must make a temporary else return False; end if; end Safe_Unchecked_Type_Conversion; --------------------------------- -- Set_Current_Value_Condition -- --------------------------------- -- Note: the implementation of this procedure is very closely tied to the -- implementation of Get_Current_Value_Condition. Here we set required -- Current_Value fields, and in Get_Current_Value_Condition, we interpret -- them, so they must have a consistent view. procedure Set_Current_Value_Condition (Cnode : Node_Id) is procedure Set_Entity_Current_Value (N : Node_Id); -- If N is an entity reference, where the entity is of an appropriate -- kind, then set the current value of this entity to Cnode, unless -- there is already a definite value set there. procedure Set_Expression_Current_Value (N : Node_Id); -- If N is of an appropriate form, sets an appropriate entry in current -- value fields of relevant entities. Multiple entities can be affected -- in the case of an AND or AND THEN. ------------------------------ -- Set_Entity_Current_Value -- ------------------------------ procedure Set_Entity_Current_Value (N : Node_Id) is begin if Is_Entity_Name (N) then declare Ent : constant Entity_Id := Entity (N); begin -- Don't capture if not safe to do so if not Safe_To_Capture_Value (N, Ent, Cond => True) then return; end if; -- Here we have a case where the Current_Value field may need -- to be set. We set it if it is not already set to a compile -- time expression value. -- Note that this represents a decision that one condition -- blots out another previous one. That's certainly right if -- they occur at the same level. If the second one is nested, -- then the decision is neither right nor wrong (it would be -- equally OK to leave the outer one in place, or take the new -- inner one. Really we should record both, but our data -- structures are not that elaborate. if Nkind (Current_Value (Ent)) not in N_Subexpr then Set_Current_Value (Ent, Cnode); end if; end; end if; end Set_Entity_Current_Value; ---------------------------------- -- Set_Expression_Current_Value -- ---------------------------------- procedure Set_Expression_Current_Value (N : Node_Id) is Cond : Node_Id; begin Cond := N; -- Loop to deal with (ignore for now) any NOT operators present. The -- presence of NOT operators will be handled properly when we call -- Get_Current_Value_Condition. while Nkind (Cond) = N_Op_Not loop Cond := Right_Opnd (Cond); end loop; -- For an AND or AND THEN, recursively process operands if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then Set_Expression_Current_Value (Left_Opnd (Cond)); Set_Expression_Current_Value (Right_Opnd (Cond)); return; end if; -- Check possible relational operator if Nkind (Cond) in N_Op_Compare then if Compile_Time_Known_Value (Right_Opnd (Cond)) then Set_Entity_Current_Value (Left_Opnd (Cond)); elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then Set_Entity_Current_Value (Right_Opnd (Cond)); end if; elsif Nkind_In (Cond, N_Type_Conversion, N_Qualified_Expression, N_Expression_With_Actions) then Set_Expression_Current_Value (Expression (Cond)); -- Check possible boolean variable reference else Set_Entity_Current_Value (Cond); end if; end Set_Expression_Current_Value; -- Start of processing for Set_Current_Value_Condition begin Set_Expression_Current_Value (Condition (Cnode)); end Set_Current_Value_Condition; -------------------------- -- Set_Elaboration_Flag -- -------------------------- procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); Ent : constant Entity_Id := Elaboration_Entity (Spec_Id); Asn : Node_Id; begin if Present (Ent) then -- Nothing to do if at the compilation unit level, because in this -- case the flag is set by the binder generated elaboration routine. if Nkind (Parent (N)) = N_Compilation_Unit then null; -- Here we do need to generate an assignment statement else Check_Restriction (No_Elaboration_Code, N); Asn := Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Ent, Loc), Expression => Make_Integer_Literal (Loc, Uint_1)); -- Mark the assignment statement as elaboration code. This allows -- the early call region mechanism (see Sem_Elab) to properly -- ignore such assignments even though they are nonpreelaborable -- code. Set_Is_Elaboration_Code (Asn); if Nkind (Parent (N)) = N_Subunit then Insert_After (Corresponding_Stub (Parent (N)), Asn); else Insert_After (N, Asn); end if; Analyze (Asn); -- 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. Set_Current_Value (Ent, Empty); -- If the subprogram is in the current declarative part and -- 'access has been applied to it, generate an elaboration -- check at the beginning of the declarations of the body. if Nkind (N) = N_Subprogram_Body and then Address_Taken (Spec_Id) and then Ekind_In (Scope (Spec_Id), E_Block, E_Procedure, E_Function) then declare Loc : constant Source_Ptr := Sloc (N); Decls : constant List_Id := Declarations (N); Chk : Node_Id; begin -- No need to generate this check if first entry in the -- declaration list is a raise of Program_Error now. if Present (Decls) and then Nkind (First (Decls)) = N_Raise_Program_Error then return; end if; -- Otherwise generate the check Chk := Make_Raise_Program_Error (Loc, Condition => Make_Op_Eq (Loc, Left_Opnd => New_Occurrence_Of (Ent, Loc), Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), Reason => PE_Access_Before_Elaboration); if No (Decls) then Set_Declarations (N, New_List (Chk)); else Prepend (Chk, Decls); end if; Analyze (Chk); end; end if; end if; end if; end Set_Elaboration_Flag; ---------------------------- -- Set_Renamed_Subprogram -- ---------------------------- procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is begin -- If input node is an identifier, we can just reset it if Nkind (N) = N_Identifier then Set_Chars (N, Chars (E)); Set_Entity (N, E); -- Otherwise we have to do a rewrite, preserving Comes_From_Source else declare CS : constant Boolean := Comes_From_Source (N); begin Rewrite (N, Make_Identifier (Sloc (N), Chars (E))); Set_Entity (N, E); Set_Comes_From_Source (N, CS); Set_Analyzed (N, True); end; end if; end Set_Renamed_Subprogram; ---------------------- -- Side_Effect_Free -- ---------------------- function Side_Effect_Free (N : Node_Id; Name_Req : Boolean := False; Variable_Ref : Boolean := False) return Boolean is Typ : constant Entity_Id := Etype (N); -- Result type of the expression function Safe_Prefixed_Reference (N : Node_Id) return Boolean; -- The argument N is a construct where the Prefix is dereferenced if it -- is an access type and the result is a variable. The call returns True -- if the construct is side effect free (not considering side effects in -- other than the prefix which are to be tested by the caller). function Within_In_Parameter (N : Node_Id) return Boolean; -- Determines if N is a subcomponent of a composite in-parameter. If so, -- N is not side-effect free when the actual is global and modifiable -- indirectly from within a subprogram, because it may be passed by -- reference. The front-end must be conservative here and assume that -- this may happen with any array or record type. On the other hand, we -- cannot create temporaries for all expressions for which this -- condition is true, for various reasons that might require clearing up -- ??? For example, discriminant references that appear out of place, or -- spurious type errors with class-wide expressions. As a result, we -- limit the transformation to loop bounds, which is so far the only -- case that requires it. ----------------------------- -- Safe_Prefixed_Reference -- ----------------------------- function Safe_Prefixed_Reference (N : Node_Id) return Boolean is begin -- If prefix is not side effect free, definitely not safe if not Side_Effect_Free (Prefix (N), Name_Req, Variable_Ref) then return False; -- If the prefix is of an access type that is not access-to-constant, -- then this construct is a variable reference, which means it is to -- be considered to have side effects if Variable_Ref is set True. elsif Is_Access_Type (Etype (Prefix (N))) and then not Is_Access_Constant (Etype (Prefix (N))) and then Variable_Ref then -- Exception is a prefix that is the result of a previous removal -- of side effects. return Is_Entity_Name (Prefix (N)) and then not Comes_From_Source (Prefix (N)) and then Ekind (Entity (Prefix (N))) = E_Constant and then Is_Internal_Name (Chars (Entity (Prefix (N)))); -- If the prefix is an explicit dereference then this construct is a -- variable reference, which means it is to be considered to have -- side effects if Variable_Ref is True. -- We do NOT exclude dereferences of access-to-constant types because -- we handle them as constant view of variables. elsif Nkind (Prefix (N)) = N_Explicit_Dereference and then Variable_Ref then return False; -- Note: The following test is the simplest way of solving a complex -- problem uncovered by the following test (Side effect on loop bound -- that is a subcomponent of a global variable: -- with Text_Io; use Text_Io; -- procedure Tloop is -- type X is -- record -- V : Natural := 4; -- S : String (1..5) := (others => 'a'); -- end record; -- X1 : X; -- procedure Modi; -- generic -- with procedure Action; -- procedure Loop_G (Arg : X; Msg : String) -- procedure Loop_G (Arg : X; Msg : String) is -- begin -- Put_Line ("begin loop_g " & Msg & " will loop till: " -- & Natural'Image (Arg.V)); -- for Index in 1 .. Arg.V loop -- Text_Io.Put_Line -- (Natural'Image (Index) & " " & Arg.S (Index)); -- if Index > 2 then -- Modi; -- end if; -- end loop; -- Put_Line ("end loop_g " & Msg); -- end; -- procedure Loop1 is new Loop_G (Modi); -- procedure Modi is -- begin -- X1.V := 1; -- Loop1 (X1, "from modi"); -- end; -- -- begin -- Loop1 (X1, "initial"); -- end; -- The output of the above program should be: -- begin loop_g initial will loop till: 4 -- 1 a -- 2 a -- 3 a -- begin loop_g from modi will loop till: 1 -- 1 a -- end loop_g from modi -- 4 a -- begin loop_g from modi will loop till: 1 -- 1 a -- end loop_g from modi -- end loop_g initial -- If a loop bound is a subcomponent of a global variable, a -- modification of that variable within the loop may incorrectly -- affect the execution of the loop. elsif Nkind (Parent (Parent (N))) = N_Loop_Parameter_Specification and then Within_In_Parameter (Prefix (N)) and then Variable_Ref then return False; -- All other cases are side effect free else return True; end if; end Safe_Prefixed_Reference; ------------------------- -- Within_In_Parameter -- ------------------------- function Within_In_Parameter (N : Node_Id) return Boolean is begin if not Comes_From_Source (N) then return False; elsif Is_Entity_Name (N) then return Ekind (Entity (N)) = E_In_Parameter; elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then return Within_In_Parameter (Prefix (N)); else return False; end if; end Within_In_Parameter; -- Start of processing for Side_Effect_Free begin -- If volatile reference, always consider it to have side effects if Is_Volatile_Reference (N) then return False; end if; -- Note on checks that could raise Constraint_Error. Strictly, if we -- take advantage of 11.6, these checks do not count as side effects. -- However, we would prefer to consider that they are side effects, -- since the back end CSE does not work very well on expressions which -- can raise Constraint_Error. On the other hand if we don't consider -- them to be side effect free, then we get some awkward expansions -- in -gnato mode, resulting in code insertions at a point where we -- do not have a clear model for performing the insertions. -- Special handling for entity names if Is_Entity_Name (N) then -- A type reference is always side effect free if Is_Type (Entity (N)) then return True; -- Variables are considered to be a side effect if Variable_Ref -- is set or if we have a volatile reference and Name_Req is off. -- If Name_Req is True then we can't help returning a name which -- effectively allows multiple references in any case. elsif Is_Variable (N, Use_Original_Node => False) then return not Variable_Ref and then (not Is_Volatile_Reference (N) or else Name_Req); -- Any other entity (e.g. a subtype name) is definitely side -- effect free. else return True; end if; -- A value known at compile time is always side effect free elsif Compile_Time_Known_Value (N) then return True; -- A variable renaming is not side-effect free, because the renaming -- will function like a macro in the front-end in some cases, and an -- assignment can modify the component designated by N, so we need to -- create a temporary for it. -- The guard testing for Entity being present is needed at least in -- the case of rewritten predicate expressions, and may well also be -- appropriate elsewhere. Obviously we can't go testing the entity -- field if it does not exist, so it's reasonable to say that this is -- not the renaming case if it does not exist. elsif Is_Entity_Name (Original_Node (N)) and then Present (Entity (Original_Node (N))) and then Is_Renaming_Of_Object (Entity (Original_Node (N))) and then Ekind (Entity (Original_Node (N))) /= E_Constant then declare RO : constant Node_Id := Renamed_Object (Entity (Original_Node (N))); begin -- If the renamed object is an indexed component, or an -- explicit dereference, then the designated object could -- be modified by an assignment. if Nkind_In (RO, N_Indexed_Component, N_Explicit_Dereference) then return False; -- A selected component must have a safe prefix elsif Nkind (RO) = N_Selected_Component then return Safe_Prefixed_Reference (RO); -- In all other cases, designated object cannot be changed so -- we are side effect free. else return True; end if; end; -- Remove_Side_Effects generates an object renaming declaration to -- capture the expression of a class-wide expression. In VM targets -- the frontend performs no expansion for dispatching calls to -- class- wide types since they are handled by the VM. Hence, we must -- locate here if this node corresponds to a previous invocation of -- Remove_Side_Effects to avoid a never ending loop in the frontend. elsif not Tagged_Type_Expansion and then not Comes_From_Source (N) and then Nkind (Parent (N)) = N_Object_Renaming_Declaration and then Is_Class_Wide_Type (Typ) then return True; -- Generating C the type conversion of an access to constrained array -- type into an access to unconstrained array type involves initializing -- a fat pointer and the expression cannot be assumed to be free of side -- effects since it must referenced several times to compute its bounds. elsif Modify_Tree_For_C and then Nkind (N) = N_Type_Conversion and then Is_Access_Type (Typ) and then Is_Array_Type (Designated_Type (Typ)) and then not Is_Constrained (Designated_Type (Typ)) then return False; end if; -- For other than entity names and compile time known values, -- check the node kind for special processing. case Nkind (N) is -- An attribute reference is side effect free if its expressions -- are side effect free and its prefix is side effect free or -- is an entity reference. -- Is this right? what about x'first where x is a variable??? when N_Attribute_Reference => Attribute_Reference : declare function Side_Effect_Free_Attribute (Attribute_Name : Name_Id) return Boolean; -- Returns True if evaluation of the given attribute is -- considered side-effect free (independent of prefix and -- arguments). -------------------------------- -- Side_Effect_Free_Attribute -- -------------------------------- function Side_Effect_Free_Attribute (Attribute_Name : Name_Id) return Boolean is begin case Attribute_Name is when Name_Input => return False; when Name_Image | Name_Img | Name_Wide_Image | Name_Wide_Wide_Image => -- CodePeer doesn't want to see replicated copies of -- 'Image calls. return not CodePeer_Mode; when others => return True; end case; end Side_Effect_Free_Attribute; -- Start of processing for Attribute_Reference begin return Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref) and then Side_Effect_Free_Attribute (Attribute_Name (N)) and then (Is_Entity_Name (Prefix (N)) or else Side_Effect_Free (Prefix (N), Name_Req, Variable_Ref)); end Attribute_Reference; -- A binary operator is side effect free if and both operands are -- side effect free. For this purpose binary operators include -- membership tests and short circuit forms. when N_Binary_Op | N_Membership_Test | N_Short_Circuit => return Side_Effect_Free (Left_Opnd (N), Name_Req, Variable_Ref) and then Side_Effect_Free (Right_Opnd (N), Name_Req, Variable_Ref); -- An explicit dereference is side effect free only if it is -- a side effect free prefixed reference. when N_Explicit_Dereference => return Safe_Prefixed_Reference (N); -- An expression with action is side effect free if its expression -- is side effect free and it has no actions. when N_Expression_With_Actions => return Is_Empty_List (Actions (N)) and then Side_Effect_Free (Expression (N), Name_Req, Variable_Ref); -- A call to _rep_to_pos is side effect free, since we generate -- this pure function call ourselves. Moreover it is critically -- important to make this exception, since otherwise we can have -- discriminants in array components which don't look side effect -- free in the case of an array whose index type is an enumeration -- type with an enumeration rep clause. -- All other function calls are not side effect free when N_Function_Call => return Nkind (Name (N)) = N_Identifier and then Is_TSS (Name (N), TSS_Rep_To_Pos) and then Side_Effect_Free (First (Parameter_Associations (N)), Name_Req, Variable_Ref); -- An IF expression is side effect free if it's of a scalar type, and -- all its components are all side effect free (conditions and then -- actions and else actions). We restrict to scalar types, since it -- is annoying to deal with things like (if A then B else C)'First -- where the type involved is a string type. when N_If_Expression => return Is_Scalar_Type (Typ) and then Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref); -- An indexed component is side effect free if it is a side -- effect free prefixed reference and all the indexing -- expressions are side effect free. when N_Indexed_Component => return Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref) and then Safe_Prefixed_Reference (N); -- A type qualification, type conversion, or unchecked expression is -- side effect free if the expression is side effect free. when N_Qualified_Expression | N_Type_Conversion | N_Unchecked_Expression => return Side_Effect_Free (Expression (N), Name_Req, Variable_Ref); -- A selected component is side effect free only if it is a side -- effect free prefixed reference. when N_Selected_Component => return Safe_Prefixed_Reference (N); -- A range is side effect free if the bounds are side effect free when N_Range => return Side_Effect_Free (Low_Bound (N), Name_Req, Variable_Ref) and then Side_Effect_Free (High_Bound (N), Name_Req, Variable_Ref); -- A slice is side effect free if it is a side effect free -- prefixed reference and the bounds are side effect free. when N_Slice => return Side_Effect_Free (Discrete_Range (N), Name_Req, Variable_Ref) and then Safe_Prefixed_Reference (N); -- A unary operator is side effect free if the operand -- is side effect free. when N_Unary_Op => return Side_Effect_Free (Right_Opnd (N), Name_Req, Variable_Ref); -- An unchecked type conversion is side effect free only if it -- is safe and its argument is side effect free. when N_Unchecked_Type_Conversion => return Safe_Unchecked_Type_Conversion (N) and then Side_Effect_Free (Expression (N), Name_Req, Variable_Ref); -- A literal is side effect free when N_Character_Literal | N_Integer_Literal | N_Real_Literal | N_String_Literal => return True; -- We consider that anything else has side effects. This is a bit -- crude, but we are pretty close for most common cases, and we -- are certainly correct (i.e. we never return True when the -- answer should be False). when others => return False; end case; end Side_Effect_Free; -- A list is side effect free if all elements of the list are side -- effect free. function Side_Effect_Free (L : List_Id; Name_Req : Boolean := False; Variable_Ref : Boolean := False) return Boolean is N : Node_Id; begin if L = No_List or else L = Error_List then return True; else N := First (L); while Present (N) loop if not Side_Effect_Free (N, Name_Req, Variable_Ref) then return False; else Next (N); end if; end loop; return True; end if; end Side_Effect_Free; ---------------------------------- -- Silly_Boolean_Array_Not_Test -- ---------------------------------- -- This procedure implements an odd and silly test. We explicitly check -- for the case where the 'First of the component type is equal to the -- 'Last of this component type, and if this is the case, we make sure -- that constraint error is raised. The reason is that the NOT is bound -- to cause CE in this case, and we will not otherwise catch it. -- No such check is required for AND and OR, since for both these cases -- False op False = False, and True op True = True. For the XOR case, -- see Silly_Boolean_Array_Xor_Test. -- Believe it or not, this was reported as a bug. Note that nearly always, -- the test will evaluate statically to False, so the code will be -- statically removed, and no extra overhead caused. procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); CT : constant Entity_Id := Component_Type (T); begin -- The check we install is -- constraint_error when -- component_type'first = component_type'last -- and then array_type'Length /= 0) -- We need the last guard because we don't want to raise CE for empty -- arrays since no out of range values result. (Empty arrays with a -- component type of True .. True -- very useful -- even the ACATS -- does not test that marginal case). Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Make_And_Then (Loc, Left_Opnd => Make_Op_Eq (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_First), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_Last)), Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))), Reason => CE_Range_Check_Failed)); end Silly_Boolean_Array_Not_Test; ---------------------------------- -- Silly_Boolean_Array_Xor_Test -- ---------------------------------- -- This procedure implements an odd and silly test. We explicitly check -- for the XOR case where the component type is True .. True, since this -- will raise constraint error. A special check is required since CE -- will not be generated otherwise (cf Expand_Packed_Not). -- No such check is required for AND and OR, since for both these cases -- False op False = False, and True op True = True, and no check is -- required for the case of False .. False, since False xor False = False. -- See also Silly_Boolean_Array_Not_Test procedure Silly_Boolean_Array_Xor_Test (N : Node_Id; R : Node_Id; T : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); CT : constant Entity_Id := Component_Type (T); begin -- The check we install is -- constraint_error when -- Boolean (component_type'First) -- and then Boolean (component_type'Last) -- and then array_type'Length /= 0) -- We need the last guard because we don't want to raise CE for empty -- arrays since no out of range values result (Empty arrays with a -- component type of True .. True -- very useful -- even the ACATS -- does not test that marginal case). Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Make_And_Then (Loc, Left_Opnd => Make_And_Then (Loc, Left_Opnd => Convert_To (Standard_Boolean, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_First)), Right_Opnd => Convert_To (Standard_Boolean, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_Last))), Right_Opnd => Make_Non_Empty_Check (Loc, R)), Reason => CE_Range_Check_Failed)); end Silly_Boolean_Array_Xor_Test; -------------------------- -- Target_Has_Fixed_Ops -- -------------------------- Integer_Sized_Small : Ureal; -- Set to 2.0 ** -(Integer'Size - 1) the first time that this function is -- called (we don't want to compute it more than once). Long_Integer_Sized_Small : Ureal; -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this function -- is called (we don't want to compute it more than once) First_Time_For_THFO : Boolean := True; -- Set to False after first call (if Fractional_Fixed_Ops_On_Target) function Target_Has_Fixed_Ops (Left_Typ : Entity_Id; Right_Typ : Entity_Id; Result_Typ : Entity_Id) return Boolean is function Is_Fractional_Type (Typ : Entity_Id) return Boolean; -- Return True if the given type is a fixed-point type with a small -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have -- an absolute value less than 1.0. This is currently limited to -- fixed-point types that map to Integer or Long_Integer. ------------------------ -- Is_Fractional_Type -- ------------------------ function Is_Fractional_Type (Typ : Entity_Id) return Boolean is begin if Esize (Typ) = Standard_Integer_Size then return Small_Value (Typ) = Integer_Sized_Small; elsif Esize (Typ) = Standard_Long_Integer_Size then return Small_Value (Typ) = Long_Integer_Sized_Small; else return False; end if; end Is_Fractional_Type; -- Start of processing for Target_Has_Fixed_Ops begin -- Return False if Fractional_Fixed_Ops_On_Target is false if not Fractional_Fixed_Ops_On_Target then return False; end if; -- Here the target has Fractional_Fixed_Ops, if first time, compute -- standard constants used by Is_Fractional_Type. if First_Time_For_THFO then First_Time_For_THFO := False; Integer_Sized_Small := UR_From_Components (Num => Uint_1, Den => UI_From_Int (Standard_Integer_Size - 1), Rbase => 2); Long_Integer_Sized_Small := UR_From_Components (Num => Uint_1, Den => UI_From_Int (Standard_Long_Integer_Size - 1), Rbase => 2); end if; -- Return True if target supports fixed-by-fixed multiply/divide for -- fractional fixed-point types (see Is_Fractional_Type) and the operand -- and result types are equivalent fractional types. return Is_Fractional_Type (Base_Type (Left_Typ)) and then Is_Fractional_Type (Base_Type (Right_Typ)) and then Is_Fractional_Type (Base_Type (Result_Typ)) and then Esize (Left_Typ) = Esize (Right_Typ) and then Esize (Left_Typ) = Esize (Result_Typ); end Target_Has_Fixed_Ops; ------------------- -- Type_Map_Hash -- ------------------- function Type_Map_Hash (Id : Entity_Id) return Type_Map_Header is begin return Type_Map_Header (Id mod Type_Map_Size); end Type_Map_Hash; ------------------------------------------ -- Type_May_Have_Bit_Aligned_Components -- ------------------------------------------ function Type_May_Have_Bit_Aligned_Components (Typ : Entity_Id) return Boolean is begin -- Array type, check component type if Is_Array_Type (Typ) then return Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)); -- Record type, check components elsif Is_Record_Type (Typ) then declare E : Entity_Id; begin E := First_Component_Or_Discriminant (Typ); while Present (E) loop -- This is the crucial test: if the component itself causes -- trouble, then we can stop and return True. if Component_May_Be_Bit_Aligned (E) then return True; end if; -- Otherwise, we need to test its type, to see if it may -- itself contain a troublesome component. if Type_May_Have_Bit_Aligned_Components (Etype (E)) then return True; end if; Next_Component_Or_Discriminant (E); end loop; return False; end; -- Type other than array or record is always OK else return False; end if; end Type_May_Have_Bit_Aligned_Components; ------------------------------- -- Update_Primitives_Mapping -- ------------------------------- procedure Update_Primitives_Mapping (Inher_Id : Entity_Id; Subp_Id : Entity_Id) is begin Map_Types (Parent_Type => Find_Dispatching_Type (Inher_Id), Derived_Type => Find_Dispatching_Type (Subp_Id)); end Update_Primitives_Mapping; ---------------------------------- -- Within_Case_Or_If_Expression -- ---------------------------------- function Within_Case_Or_If_Expression (N : Node_Id) return Boolean is Par : Node_Id; begin -- Locate an enclosing case or if expression. Note that these constructs -- can be expanded into Expression_With_Actions, hence the test of the -- original node. Par := Parent (N); while Present (Par) loop if Nkind_In (Original_Node (Par), N_Case_Expression, N_If_Expression) then return True; -- Prevent the search from going too far elsif Is_Body_Or_Package_Declaration (Par) then return False; end if; Par := Parent (Par); end loop; return False; end Within_Case_Or_If_Expression; -------------------------------- -- Within_Internal_Subprogram -- -------------------------------- function Within_Internal_Subprogram return Boolean is S : Entity_Id; begin S := Current_Scope; while Present (S) and then not Is_Subprogram (S) loop S := Scope (S); end loop; return Present (S) and then Get_TSS_Name (S) /= TSS_Null and then not Is_Predicate_Function (S) and then not Is_Predicate_Function_M (S); end Within_Internal_Subprogram; end Exp_Util;