--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/spark_xrefs.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,396 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                           S P A R K _ X R E F S                          --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2011-2017, 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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package defines tables used to store information needed for the SPARK
+--  mode. It is used by procedures in Lib.Xref.SPARK_Specific to build the
+--  SPARK-specific cross-reference information before writing it to the ALI
+--  file, and by Get_SPARK_Xrefs/Put_SPARK_Xrefs to read/write the textual
+--  representation that is stored in the ALI file.
+
+with Table;
+with Types;      use Types;
+
+package SPARK_Xrefs is
+
+   --  SPARK cross-reference information can exist in one of two forms. In
+   --  the ALI file, it is represented using a text format that is described
+   --  in this specification. Internally it is stored using three tables:
+   --  SPARK_Xref_Table, SPARK_Scope_Table and SPARK_File_Table, which are
+   --  also defined in this unit.
+
+   --  Lib.Xref.SPARK_Specific is part of the compiler. It extracts SPARK
+   --  cross-reference information from the complete set of cross-references
+   --  generated during compilation.
+
+   --  Get_SPARK_Xrefs reads the text lines in ALI format and populates the
+   --  internal tables with corresponding information.
+
+   --  Put_SPARK_Xrefs reads the internal tables and generates text lines in
+   --  the ALI format.
+
+   ----------------------------
+   -- SPARK Xrefs ALI Format --
+   ----------------------------
+
+   --  SPARK cross-reference information is generated on a unit-by-unit basis
+   --  in the ALI file, using lines that start with the identifying character F
+   --  ("Formal"). These lines are generated if GNATprove_Mode is True.
+
+   --  The SPARK cross-reference information comes after the shared
+   --  cross-reference information, so it can be ignored by tools like
+   --  gnatbind, gnatmake, etc.
+
+   --  -------------------
+   --  -- Scope Section --
+   --  -------------------
+
+   --  A first section defines the scopes in which entities are defined and
+   --  referenced. A scope is a package/subprogram/protected_type/task_type
+   --  declaration/body. Note that a package declaration and body define two
+   --  different scopes. Similarly, a subprogram, protected type and task type
+   --  declaration and body, when both present, define two different scopes.
+
+   --    FD dependency-number filename (-> unit-filename)?
+
+   --      This header precedes scope information for the unit identified by
+   --      dependency number and file name. The dependency number is the index
+   --      into the generated D lines and is ones-origin (e.g. 2 = reference to
+   --      second generated D line).
+
+   --      The list of FD lines should match the list of D lines defined in the
+   --      ALI file, in the same order.
+
+   --      Note that the filename here will reflect the original name if a
+   --      Source_Reference pragma was encountered (since all line number
+   --      references will be with respect to the original file).
+
+   --      Note: the filename is redundant in that it could be deduced from the
+   --      corresponding D line, but it is convenient at least for human
+   --      reading of the SPARK cross-reference information, and means that
+   --      the SPARK cross-reference information can stand on its own without
+   --      needing other parts of the ALI file.
+
+   --      The optional unit filename is given only for subunits.
+
+   --    FS . scope line type col entity (-> spec-file . spec-scope)?
+
+   --      (The ? mark stands for an optional entry in the syntax)
+
+   --      scope is the ones-origin scope number for the current file (e.g. 2 =
+   --      reference to the second FS line in this FD block).
+
+   --      line is the line number of the scope entity. The name of the entity
+   --      starts in column col. Columns are numbered from one, and if
+   --      horizontal tab characters are present, the column number is computed
+   --      assuming standard 1,9,17,.. tab stops. For example, if the entity is
+   --      the first token on the line, and is preceded by space-HT-space, then
+   --      the column would be column 10.
+
+   --      type is a single letter identifying the type of the entity, using
+   --      the same code as in cross-references:
+
+   --        K = package (k = generic package)
+   --        V = function (v = generic function)
+   --        U = procedure (u = generic procedure)
+   --        Y = entry
+
+   --      col is the column number of the scope entity
+
+   --      entity is the name of the scope entity, with casing in the canonical
+   --      casing for the source file where it is defined.
+
+   --      spec-file and spec-scope are respectively the file and scope for the
+   --      spec corresponding to the current body scope, when they differ.
+
+   --  ------------------
+   --  -- Xref Section --
+   --  ------------------
+
+   --  A second section defines cross-references useful for computing global
+   --  variables read/written in each subprogram/package/protected_type/
+   --  task_type.
+
+   --    FX dependency-number filename . entity-number entity
+
+   --      dependency-number and filename identify a file in FD lines
+
+   --      entity-number and entity identify a scope in FS lines
+   --      for the previously identified file.
+
+   --      (filename and entity are just a textual representations of
+   --       dependency-number and entity-number)
+
+   --    F line typ col entity ref*
+
+   --      line is the line number of the referenced entity
+
+   --      typ is the type of the referenced entity, using a code similar to
+   --      the one used for cross-references:
+
+   --        > = IN parameter
+   --        < = OUT parameter
+   --        = = IN OUT parameter
+   --        * = all other cases
+
+   --      col is the column number of the referenced entity
+
+   --      entity is the name of the referenced entity as written in the source
+   --      file where it is defined.
+
+   --  There may be zero or more ref entries on each line
+
+   --    (file |)? ((. scope :)? line type col)*
+
+   --      file is the dependency number of the file with the reference. It and
+   --      the following vertical bar are omitted if the file is the same as
+   --      the previous ref, and the refs for the current file are first (and
+   --      do not need a bar).
+
+   --      scope is the scope number of the scope with the reference. It and
+   --      the following colon are omitted if the scope is the same as the
+   --      previous ref, and the refs for the current scope are first (and do
+   --      not need a colon).
+
+   --      line is the line number of the reference
+
+   --      col is the column number of the reference
+
+   --      type is one of the following, using the same code as in
+   --      cross-references:
+
+   --        m = modification
+   --        r = reference
+   --        c = reference to constant object
+   --        s = subprogram reference in a static call
+
+   --  Special entries for reads and writes to memory reference a special
+   --  variable called "__HEAP". These special entries are present in every
+   --  scope where reads and writes to memory are present. Line and column for
+   --  this special variable are always 0.
+
+   --    Examples: ??? add examples here
+
+   --  -------------------------------
+   --  -- Generated Globals Section --
+   --  -------------------------------
+
+   --  The Generated Globals section is located at the end of the ALI file
+
+   --  All lines with information related to the Generated Globals begin with
+   --  string "GG". This string should therefore not be used in the beginning
+   --  of any line not related to Generated Globals.
+
+   --  The processing (reading and writing) of this section happens in package
+   --  Flow_Generated_Globals (from the SPARK 2014 sources), for further
+   --  information please refer there.
+
+   ----------------
+   -- Xref Table --
+   ----------------
+
+   --  The following table records SPARK cross-references
+
+   type Xref_Index is new Nat;
+   --  Used to index values in this table. Values start at 1 and are assigned
+   --  sequentially as entries are constructed; value 0 is used temporarily
+   --  until a proper value is determined.
+
+   type SPARK_Xref_Record is record
+      Entity_Name : String_Ptr;
+      --  Pointer to entity name in ALI file
+
+      Entity_Line : Nat;
+      --  Line number for the entity referenced
+
+      Etype : Character;
+      --  Indicates type of entity, using code used in ALI file:
+      --    > = IN parameter
+      --    < = OUT parameter
+      --    = = IN OUT parameter
+      --    * = all other cases
+
+      Entity_Col : Nat;
+      --  Column number for the entity referenced
+
+      File_Num : Nat;
+      --  File dependency number for the cross-reference. Note that if no file
+      --  entry is present explicitly, this is just a copy of the reference for
+      --  the current cross-reference section.
+
+      Scope_Num : Nat;
+      --  Scope number for the cross-reference. Note that if no scope entry is
+      --  present explicitly, this is just a copy of the reference for the
+      --  current cross-reference section.
+
+      Line : Nat;
+      --  Line number for the reference
+
+      Rtype : Character;
+      --  Indicates type of the reference, using code used in ALI file:
+      --    r = reference
+      --    c = reference to constant object
+      --    m = modification
+      --    s = call
+
+      Col : Nat;
+      --  Column number for the reference
+   end record;
+
+   package SPARK_Xref_Table is new Table.Table (
+     Table_Component_Type => SPARK_Xref_Record,
+     Table_Index_Type     => Xref_Index,
+     Table_Low_Bound      => 1,
+     Table_Initial        => 2000,
+     Table_Increment      => 300,
+     Table_Name           => "Xref_Table");
+
+   -----------------
+   -- Scope Table --
+   -----------------
+
+   --  This table keeps track of the scopes and the corresponding starting and
+   --  ending indexes (From, To) in the Xref table.
+
+   type Scope_Index is new Nat;
+   --  Used to index values in this table. Values start at 1 and are assigned
+   --  sequentially as entries are constructed; value 0 indicates that no
+   --  entries have been constructed and is also used until a proper value is
+   --  determined.
+
+   type SPARK_Scope_Record is record
+      Scope_Name : String_Ptr;
+      --  Pointer to scope name in ALI file
+
+      File_Num : Nat;
+      --  Set to the file dependency number for the scope
+
+      Scope_Num : Pos;
+      --  Set to the scope number for the scope
+
+      Spec_File_Num : Nat;
+      --  Set to the file dependency number for the scope corresponding to the
+      --  spec of the current scope entity, if different, or else 0.
+
+      Spec_Scope_Num : Nat;
+      --  Set to the scope number for the scope corresponding to the spec of
+      --  the current scope entity, if different, or else 0.
+
+      Line : Nat;
+      --  Line number for the scope
+
+      Stype : Character;
+      --  Indicates type of scope, using code used in ALI file:
+      --    K = package
+      --    T = task
+      --    U = procedure
+      --    V = function
+      --    Y = entry
+
+      Col : Nat;
+      --  Column number for the scope
+
+      From_Xref : Xref_Index;
+      --  Starting index in Xref table for this scope
+
+      To_Xref : Xref_Index;
+      --  Ending index in Xref table for this scope
+
+      --  The following component is only used in-memory, not printed out in
+      --  ALI file.
+
+      Scope_Entity : Entity_Id := Empty;
+      --  Entity (subprogram or package) for the scope
+   end record;
+
+   package SPARK_Scope_Table is new Table.Table (
+     Table_Component_Type => SPARK_Scope_Record,
+     Table_Index_Type     => Scope_Index,
+     Table_Low_Bound      => 1,
+     Table_Initial        => 200,
+     Table_Increment      => 300,
+     Table_Name           => "Scope_Table");
+
+   ----------------
+   -- File Table --
+   ----------------
+
+   --  This table keeps track of the units and the corresponding starting and
+   --  ending indexes (From, To) in the Scope table.
+
+   type File_Index is new Nat;
+   --  Used to index values in this table. Values start at 1 and are assigned
+   --  sequentially as entries are constructed; value 0 indicates that no
+   --  entries have been constructed.
+
+   type SPARK_File_Record is record
+      File_Name : String_Ptr;
+      --  Pointer to file name in ALI file
+
+      Unit_File_Name : String_Ptr;
+      --  Pointer to file name for unit in ALI file, when File_Name refers to a
+      --  subunit; otherwise null.
+
+      File_Num : Nat;
+      --  Dependency number in ALI file
+
+      From_Scope : Scope_Index;
+      --  Starting index in Scope table for this unit
+
+      To_Scope : Scope_Index;
+      --  Ending index in Scope table for this unit
+   end record;
+
+   package SPARK_File_Table is new Table.Table (
+     Table_Component_Type => SPARK_File_Record,
+     Table_Index_Type     => File_Index,
+     Table_Low_Bound      => 1,
+     Table_Initial        => 20,
+     Table_Increment      => 200,
+     Table_Name           => "File_Table");
+
+   ---------------
+   -- Constants --
+   ---------------
+
+   Name_Of_Heap_Variable : constant String := "__HEAP";
+   --  Name of special variable used in effects to denote reads and writes
+   --  through explicit dereference.
+
+   -----------------
+   -- Subprograms --
+   -----------------
+
+   procedure Initialize_SPARK_Tables;
+   --  Reset tables for a new compilation
+
+   procedure dspark;
+   --  Debug routine to dump internal SPARK cross-reference tables. This is a
+   --  raw format dump showing exactly what the tables contain.
+
+   procedure pspark;
+   --  Debugging procedure to output contents of SPARK cross-reference binary
+   --  tables in the format in which they appear in an ALI file.
+
+end SPARK_Xrefs;