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------------------------------------------------------------------------------

--                                                                          --

--                         GNAT COMPILER COMPONENTS                         --

--                                                                          --

--                                  P R J                                   --

--                                                                          --

--                                 S p e c                                  --

--                                                                          --

--          Copyright (C) 2001-2009, 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.      --

--                                                                          --

------------------------------------------------------------------------------

--  The following package declares the data types for GNAT project.

--  These data types may be used by GNAT Project-aware tools.

--  Children of these package implements various services on these data types.

--  See in particular Prj.Pars and Prj.Env.

with Casing; use Casing;

with Namet;  use Namet;

with Osint;

with Scans;  use Scans;

with Types;  use Types;

with GNAT.Dynamic_HTables; use GNAT.Dynamic_HTables;

with GNAT.Dynamic_Tables;

with GNAT.OS_Lib;          use GNAT.OS_Lib;

package Prj is

   All_Other_Names : constant Name_Id := Names_High_Bound;

   --  Name used to replace others as an index of an associative array

   --  attribute in situations where this is allowed.

   Subdirs : String_Ptr := null;

   --  The value after the equal sign in switch --subdirs=...

   --  Contains the relative subdirectory.

   type Library_Support is (None, Static_Only, Full);

   --  Support for Library Project File.

   --  - None: Library Project Files are not supported at all

   --  - Static_Only: Library Project Files are only supported for static

   --    libraries.

   --  - Full: Library Project Files are supported for static and dynamic

   --    (shared) libraries.

   type Yes_No_Unknown is (Yes, No, Unknown);

   --  Tri-state to decide if -lgnarl is needed when linking

   type Project_Qualifier is

     (Unspecified,

      Standard,

      Library,

      Configuration,

      Dry,

      Aggregate,

      Aggregate_Library);

   --  Qualifiers that can prefix the reserved word "project" in a project

   --  file:

   --    Standard:             standard project ...

   --    Library:              library project is ...

   --    Dry:                  abstract project is

   --    Aggregate:            aggregate project is

   --    Aggregate_Library:    aggregate library project is ...

   --    Configuration:        configuration project is ...

   All_Packages : constant String_List_Access;

   --  Default value of parameter Packages of procedures Parse, in Prj.Pars and

   --  Prj.Part, indicating that all packages should be checked.

   type Project_Tree_Data;

   type Project_Tree_Ref is access all Project_Tree_Data;

   --  Reference to a project tree. Several project trees may exist in memory

   --  at the same time.

   No_Project_Tree : constant Project_Tree_Ref;

   procedure Free (Tree : in out Project_Tree_Ref);

   --  Free memory associated with the tree

   Config_Project_File_Extension : String := ".cgpr";

   Project_File_Extension : String := ".gpr";

   --  The standard config and user project file name extensions. They are not

   --  constants, because Canonical_Case_File_Name is called on these variables

   --  in the body of Prj.

   function Empty_File   return File_Name_Type;

   function Empty_String return Name_Id;

   --  Return the id for an empty string ""

   type Path_Information is record

      Name         : Path_Name_Type := No_Path;

      Display_Name : Path_Name_Type := No_Path;

   end record;

   --  Directory names always end with a directory separator

   No_Path_Information : constant Path_Information := (No_Path, No_Path);

   type Project_Data;

   type Project_Id is access all Project_Data;

   No_Project : constant Project_Id := null;

   --  Id of a Project File

   type String_List_Id is new Nat;

   Nil_String : constant String_List_Id := 0;

   type String_Element is record

      Value         : Name_Id        := No_Name;

      Index         : Int            := 0;

      Display_Value : Name_Id        := No_Name;

      Location      : Source_Ptr     := No_Location;

      Flag          : Boolean        := False;

      Next          : String_List_Id := Nil_String;

   end record;

   --  To hold values for string list variables and array elements.

   --  Component Flag may be used for various purposes. For source

   --  directories, it indicates if the directory contains Ada source(s).

   package String_Element_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => String_Element,

      Table_Index_Type     => String_List_Id,

      Table_Low_Bound      => 1,

      Table_Initial        => 200,

      Table_Increment      => 100);

   --  The table for string elements in string lists

   type Variable_Kind is (Undefined, List, Single);

   --  Different kinds of variables

   subtype Defined_Variable_Kind is Variable_Kind range List .. Single;

   --  The defined kinds of variables

   Ignored : constant Variable_Kind;

   --  Used to indicate that a package declaration must be ignored

   --  while processing the project tree (unknown package name).

   type Variable_Value (Kind : Variable_Kind := Undefined) is record

      Project  : Project_Id := No_Project;

      Location : Source_Ptr := No_Location;

      Default  : Boolean    := False;

      case Kind is

         when Undefined =>

            null;

         when List =>

            Values : String_List_Id := Nil_String;

         when Single =>

            Value : Name_Id := No_Name;

            Index : Int     := 0;

      end case;

   end record;

   --  Values for variables and array elements. Default is True if the

   --  current value is the default one for the variable.

   Nil_Variable_Value : constant Variable_Value;

   --  Value of a non existing variable or array element

   type Variable_Id is new Nat;

   No_Variable : constant Variable_Id := 0;

   type Variable is record

      Next  : Variable_Id := No_Variable;

      Name  : Name_Id;

      Value : Variable_Value;

   end record;

   --  To hold the list of variables in a project file and in packages

   package Variable_Element_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => Variable,

      Table_Index_Type     => Variable_Id,

      Table_Low_Bound      => 1,

      Table_Initial        => 200,

      Table_Increment      => 100);

   --  The table of variable in list of variables

   type Array_Element_Id is new Nat;

   No_Array_Element : constant Array_Element_Id := 0;

   type Array_Element is record

      Index                : Name_Id;

      Src_Index            : Int := 0;

      Index_Case_Sensitive : Boolean := True;

      Value                : Variable_Value;

      Next                 : Array_Element_Id := No_Array_Element;

   end record;

   --  Each Array_Element represents an array element and is linked (Next)

   --  to the next array element, if any, in the array.

   package Array_Element_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => Array_Element,

      Table_Index_Type     => Array_Element_Id,

      Table_Low_Bound      => 1,

      Table_Initial        => 200,

      Table_Increment      => 100);

   --  The table that contains all array elements

   type Array_Id is new Nat;

   No_Array : constant Array_Id := 0;

   type Array_Data is record

      Name     : Name_Id          := No_Name;

      Location : Source_Ptr       := No_Location;

      Value    : Array_Element_Id := No_Array_Element;

      Next     : Array_Id         := No_Array;

   end record;

   --  Each Array_Data value represents an array.

   --  Value is the id of the first element.

   --  Next is the id of the next array in the project file or package.

   package Array_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => Array_Data,

      Table_Index_Type     => Array_Id,

      Table_Low_Bound      => 1,

      Table_Initial        => 200,

      Table_Increment      => 100);

   --  The table that contains all arrays

   type Package_Id is new Nat;

   No_Package : constant Package_Id := 0;

   type Declarations is record

      Variables  : Variable_Id := No_Variable;

      Attributes : Variable_Id := No_Variable;

      Arrays     : Array_Id    := No_Array;

      Packages   : Package_Id  := No_Package;

   end record;

   --  Contains the declarations (variables, single and array attributes,

   --  packages) for a project or a package in a project.

   No_Declarations : constant Declarations :=

     (Variables  => No_Variable,

      Attributes => No_Variable,

      Arrays     => No_Array,

      Packages   => No_Package);

   --  Default value of Declarations: indicates that there is no declarations

   type Package_Element is record

      Name   : Name_Id      := No_Name;

      Decl   : Declarations := No_Declarations;

      Parent : Package_Id   := No_Package;

      Next   : Package_Id   := No_Package;

   end record;

   --  A package (includes declarations that may include other packages)

   package Package_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => Package_Element,

      Table_Index_Type     => Package_Id,

      Table_Low_Bound      => 1,

      Table_Initial        => 100,

      Table_Increment      => 100);

   --  The table that contains all packages

   type Language_Data;

   type Language_Ptr is access all Language_Data;

   --  Index of language data

   No_Language_Index : constant Language_Ptr := null;

   --  Constant indicating that there is no language data

   function Get_Language_From_Name

     (Project : Project_Id;

      Name    : String) return Language_Ptr;

   --  Get a language from a project. This might return null if no such

   --  language exists in the project

   Max_Header_Num : constant := 6150;

   type Header_Num is range 0 .. Max_Header_Num;

   --  Size for hash table below. The upper bound is an arbitrary value, the

   --  value here was chosen after testing to determine a good compromise

   --  between speed of access and memory usage.

   function Hash (Name : Name_Id)        return Header_Num;

   function Hash (Name : File_Name_Type) return Header_Num;

   function Hash (Name : Path_Name_Type) return Header_Num;

   function Hash (Project : Project_Id)  return Header_Num;

   --  Used for computing hash values for names put into hash tables

   type Language_Kind is (File_Based, Unit_Based);

   --  Type for the kind of language. All languages are file based, except Ada

   --  which is unit based.

   type Dependency_File_Kind is (None, Makefile, ALI_File);

   --  Type of dependency to be checked: no dependency file, Makefile fragment

   --  or ALI file (for Ada).

   Makefile_Dependency_Suffix : constant String := ".d";

   ALI_Dependency_Suffix      : constant String := ".ali";

   Switches_Dependency_Suffix : constant String := ".cswi";

   Binder_Exchange_Suffix     : constant String := ".bexch";

   --  Suffix for binder exchange files

   Library_Exchange_Suffix     : constant String := ".lexch";

   --  Suffix for library exchange files

   type Name_List_Index is new Nat;

   No_Name_List            : constant Name_List_Index := 0;

   type Name_Node is record

      Name : Name_Id         := No_Name;

      Next : Name_List_Index := No_Name_List;

   end record;

   package Name_List_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => Name_Node,

      Table_Index_Type     => Name_List_Index,

      Table_Low_Bound      => 1,

      Table_Initial        => 10,

      Table_Increment      => 100);

   --  The table for lists of names

   function Length

     (Table : Name_List_Table.Instance;

      List  : Name_List_Index) return Natural;

   --  Return the number of elements in specified list

   type Number_List_Index is new Nat;

   No_Number_List : constant Number_List_Index := 0;

   type Number_Node is record

      Number : Natural           := 0;

      Next   : Number_List_Index := No_Number_List;

   end record;

   package Number_List_Table is new GNAT.Dynamic_Tables

     (Table_Component_Type => Number_Node,

      Table_Index_Type     => Number_List_Index,

      Table_Low_Bound      => 1,

      Table_Initial        => 10,

      Table_Increment      => 100);

   --  The table for lists of numbers

   package Mapping_Files_Htable is new Simple_HTable

     (Header_Num => Header_Num,

      Element    => Path_Name_Type,

      No_Element => No_Path,

      Key        => Path_Name_Type,

      Hash       => Hash,

      Equal      => "=");

   --  A hash table to store the mapping files that are not used

   --  The following record ???

   type Lang_Naming_Data is record

      Dot_Replacement : File_Name_Type := No_File;

      --  The string to replace '.' in the source file name (for Ada)

      Casing : Casing_Type := All_Lower_Case;

      --  The casing of the source file name (for Ada)

      Separate_Suffix : File_Name_Type := No_File;

      --  String to append to unit name for source file name of an Ada subunit

      Spec_Suffix : File_Name_Type := No_File;

      --  The string to append to the unit name for the

      --  source file name of a spec.

      Body_Suffix : File_Name_Type := No_File;

      --  The string to append to the unit name for the

      --  source file name of a body.

   end record;

   No_Lang_Naming_Data : constant Lang_Naming_Data :=

                           (Dot_Replacement => No_File,

                            Casing          => All_Lower_Case,

                            Separate_Suffix => No_File,

                            Spec_Suffix     => No_File,

                            Body_Suffix     => No_File);

   function Is_Standard_GNAT_Naming (Naming : Lang_Naming_Data) return Boolean;

   --  True if the naming scheme is GNAT's default naming scheme. This

   --  is to take into account shortened names like "Ada." (a-), "System." (s-)

   --  and so on.

   type Source_Data;

   type Source_Id is access all Source_Data;

   function Is_Compilable (Source : Source_Id) return Boolean;

   pragma Inline (Is_Compilable);

   --  Return True if we know how to compile Source (i.e. if a compiler is

   --  defined). This doesn't indicate whether the source should be compiled.

   function Object_To_Global_Archive (Source : Source_Id) return Boolean;

   pragma Inline (Object_To_Global_Archive);

   --  Return True if the object file should be put in the global archive.

   --  This is for Ada, when only the closure of a main needs to be

   --  (re)compiled.

   function Other_Part (Source : Source_Id) return Source_Id;

   pragma Inline (Other_Part);

   --  Source ID for the other part, if any: for a spec, indicates its body;

   --  for a body, indicates its spec.

   No_Source : constant Source_Id := null;

   type Path_Syntax_Kind is

     (Canonical,

      --  Unix style

      Host);

      --  Host specific syntax, for example on VMS (the default)

   --  The following record describes the configuration of a language

   type Language_Config is record

      Kind : Language_Kind := File_Based;

      --  Kind of language. All languages are file based, except Ada which is

      --  unit based.

      Naming_Data : Lang_Naming_Data;

      --  The naming data for the languages (prefixes, etc.)

      Include_Compatible_Languages : Name_List_Index := No_Name_List;

      --  List of languages that are "include compatible" with this language. A

      --  language B (for example "C") is "include compatible" with a language

      --  A (for example "C++") if it is expected that sources of language A

      --  may "include" header files from language B.

      Compiler_Driver : File_Name_Type := No_File;

      --  The name of the executable for the compiler of the language

      Compiler_Driver_Path : String_Access := null;

      --  The path name of the executable for the compiler of the language

      Compiler_Leading_Required_Switches : Name_List_Index := No_Name_List;

      --  The list of initial switches that are required as a minimum to invoke

      --  the compiler driver.

      Compiler_Trailing_Required_Switches : Name_List_Index := No_Name_List;

      --  The list of final switches that are required as a minimum to invoke

      --  the compiler driver.

      Multi_Unit_Switches : Name_List_Index := No_Name_List;

      --  The switch(es) to indicate the index of a unit in a multi-source file

      Multi_Unit_Object_Separator : Character := ' ';

      --  The string separating the base name of a source from the index of the

      --  unit in a multi-source file, in the object file name.

      Path_Syntax : Path_Syntax_Kind := Host;

      --  Value may be Canonical (Unix style) or Host (host syntax, for example

      --  on VMS for DEC C).

      Object_File_Suffix : Name_Id := No_Name;

      --  Optional alternate object file suffix

      Object_File_Switches : Name_List_Index := No_Name_List;

      --  Optional object file switches. When this is defined, the switches

      --  are used to specify the object file. The object file name is appended

      --  to the last switch in the list. Example: ("-o", "").

      Compilation_PIC_Option : Name_List_Index := No_Name_List;

      --  The option(s) to compile a source in Position Independent Code for

      --  shared libraries. Specified in the configuration. When not specified,

      --  there is no need for such switch.

      Object_Generated : Boolean := True;

      --  False in no object file is generated

      Objects_Linked : Boolean := True;

      --  False if object files are not use to link executables and build

      --  libraries.

      Runtime_Library_Dir : Name_Id := No_Name;

      --  Path name of the runtime library directory, if any

      Runtime_Source_Dir : Name_Id := No_Name;

      --  Path name of the runtime source directory, if any

      Mapping_File_Switches : Name_List_Index := No_Name_List;

      --  The option(s) to provide a mapping file to the compiler. Specified in

      --  the configuration. When value is No_Name_List, there is no mapping

      --  file.

      Mapping_Spec_Suffix : File_Name_Type := No_File;

      --  Placeholder representing the spec suffix in a mapping file

      Mapping_Body_Suffix : File_Name_Type := No_File;

      --  Placeholder representing the body suffix in a mapping file

      Config_File_Switches : Name_List_Index := No_Name_List;

      --  The option(s) to provide a config file to the compiler. Specified in

      --  the configuration. If value is No_Name_List there is no config file.

      Dependency_Kind : Dependency_File_Kind := None;

      --  The kind of dependency to be checked: none, Makefile fragment or

      --  ALI file (for Ada).

      Dependency_Option : Name_List_Index := No_Name_List;

      --  The option(s) to be used to create the dependency file. When value is

      --  No_Name_List, there is not such option(s).

      Compute_Dependency : Name_List_Index := No_Name_List;

      --  Hold the value of attribute Dependency_Driver, if declared for the

      --  language.

      Include_Option : Name_List_Index := No_Name_List;

      --  Hold the value of attribute Include_Switches, if declared for the

      --  language.

      Include_Path : Name_Id := No_Name;

      --  Name of environment variable declared by attribute Include_Path for

      --  the language.

      Include_Path_File : Name_Id := No_Name;

      --  Name of environment variable declared by attribute Include_Path_File

      --  for the language.

      Objects_Path : Name_Id := No_Name;

      --  Name of environment variable declared by attribute Objects_Path for

      --  the language.

      Objects_Path_File : Name_Id := No_Name;

      --  Name of environment variable declared by attribute Objects_Path_File

      --  for the language.

      Config_Body : Name_Id := No_Name;

      --  The template for a pragma Source_File_Name(_Project) for a specific

      --  file name of a body.

      Config_Body_Index : Name_Id := No_Name;

      --  The template for a pragma Source_File_Name(_Project) for a specific

      --  file name of a body in a multi-source file.

      Config_Body_Pattern : Name_Id := No_Name;

      --  The template for a pragma Source_File_Name(_Project) for a naming

      --  body pattern.

      Config_Spec : Name_Id := No_Name;

      --  The template for a pragma Source_File_Name(_Project) for a specific

      --  file name of a spec.

      Config_Spec_Index : Name_Id := No_Name;

      --  The template for a pragma Source_File_Name(_Project) for a specific

      --  file name of a spec in a multi-source file.

      Config_Spec_Pattern : Name_Id := No_Name;

      --  The template for a pragma Source_File_Name(_Project) for a naming

      --  spec pattern.

      Config_File_Unique : Boolean := False;

      --  Indicate if the config file specified to the compiler needs to be

      --  unique. If it is unique, then all config files are concatenated into

      --  a temp config file.

      Binder_Driver : File_Name_Type := No_File;

      --  The name of the binder driver for the language, if any

      Binder_Driver_Path : Path_Name_Type := No_Path;

      --  The path name of the binder driver

      Binder_Required_Switches : Name_List_Index := No_Name_List;

      --  Hold the value of attribute Binder'Required_Switches for the language

      Binder_Prefix : Name_Id := No_Name;

      --  Hold the value of attribute Binder'Prefix for the language

      Toolchain_Version : Name_Id := No_Name;

      --  Hold the value of attribute Toolchain_Version for the language

      Toolchain_Description : Name_Id := No_Name;

      --  Hold the value of attribute Toolchain_Description for the language

   end record;

   No_Language_Config : constant Language_Config :=

                          (Kind                         => File_Based,

                           Naming_Data                  => No_Lang_Naming_Data,

                           Include_Compatible_Languages => No_Name_List,

                           Compiler_Driver              => No_File,

                           Compiler_Driver_Path         => null,

                           Compiler_Leading_Required_Switches  => No_Name_List,

                           Compiler_Trailing_Required_Switches => No_Name_List,

                           Multi_Unit_Switches          => No_Name_List,

                           Multi_Unit_Object_Separator  => ' ',

                           Path_Syntax                  => Canonical,

                           Object_File_Suffix           => No_Name,

                           Object_File_Switches         => No_Name_List,

                           Compilation_PIC_Option       => No_Name_List,

                           Object_Generated             => True,

                           Objects_Linked               => True,

                           Runtime_Library_Dir          => No_Name,

                           Runtime_Source_Dir           => No_Name,

                           Mapping_File_Switches        => No_Name_List,

                           Mapping_Spec_Suffix          => No_File,

                           Mapping_Body_Suffix          => No_File,

                           Config_File_Switches         => No_Name_List,

                           Dependency_Kind              => None,

                           Dependency_Option            => No_Name_List,

                           Compute_Dependency           => No_Name_List,

                           Include_Option               => No_Name_List,

                           Include_Path                 => No_Name,

                           Include_Path_File            => No_Name,

                           Objects_Path                 => No_Name,

                           Objects_Path_File            => No_Name,

                           Config_Body                  => No_Name,

                           Config_Body_Index            => No_Name,

                           Config_Body_Pattern          => No_Name,

                           Config_Spec                  => No_Name,

                           Config_Spec_Index            => No_Name,

                           Config_Spec_Pattern          => No_Name,

                           Config_File_Unique           => False,

                           Binder_Driver                => No_File,

                           Binder_Driver_Path           => No_Path,

                           Binder_Required_Switches     => No_Name_List,

                           Binder_Prefix                => No_Name,

                           Toolchain_Version            => No_Name,

                           Toolchain_Description        => No_Name);

   --  The following record ???

   type Language_Data is record

      Name          : Name_Id         := No_Name;

      Display_Name  : Name_Id         := No_Name;

      Config        : Language_Config := No_Language_Config;

      First_Source  : Source_Id       := No_Source;

      Mapping_Files : Mapping_Files_Htable.Instance :=

                        Mapping_Files_Htable.Nil;

      Next          : Language_Ptr  := No_Language_Index;

   end record;

   No_Language_Data : constant Language_Data :=

                        (Name          => No_Name,

                         Display_Name  => No_Name,

                         Config        => No_Language_Config,

                         First_Source  => No_Source,

                         Mapping_Files => Mapping_Files_Htable.Nil,

                         Next          => No_Language_Index);

   type Language_List_Element;

   type Language_List is access all Language_List_Element;

   type Language_List_Element is record

      Language : Language_Ptr := No_Language_Index;

      Next     : Language_List;

   end record;

   type Source_Kind is (Spec, Impl, Sep);

   subtype Spec_Or_Body is Source_Kind range Spec .. Impl;

   --  The following declarations declare a structure used to store the Name

   --  and File and Path names of a unit, with a reference to its GNAT Project

   --  File(s). Some units might have neither Spec nor Impl when they were

   --  created for a "separate".

   type File_Names_Data is array (Spec_Or_Body) of Source_Id;

   type Unit_Data is record

      Name       : Name_Id := No_Name;

      File_Names : File_Names_Data;

   end record;

   type Unit_Index is access all Unit_Data;

   No_Unit_Index : constant Unit_Index := null;

   --  Used to indicate a null entry for no unit

   --  Structure to define source data

   type Source_Data is record

      Project : Project_Id := No_Project;

      --  Project of the source

      Source_Dir_Rank : Natural := 0;

      --  The rank of the source directory in list declared with attribute

      --  Source_Dirs. Two source files with the same name cannot appears in

      --  different directory with the same rank. That can happen when the

      --  recursive notation <dir>/** is used in attribute Source_Dirs.

      Language : Language_Ptr := No_Language_Index;

      --  Index of the language. This is an index into

      --  Project_Tree.Languages_Data.

      In_Interfaces : Boolean := True;

      --  False when the source is not included in interfaces, when attribute

      --  Interfaces is declared.

      Declared_In_Interfaces : Boolean := False;

      --  True when source is declared in attribute Interfaces

      Alternate_Languages : Language_List := null;

      --  List of languages a header file may also be, in addition of language

      --  Language_Name.

      Kind : Source_Kind := Spec;

      --  Kind of the source: spec, body or subunit

      Unit : Unit_Index := No_Unit_Index;

      --  Name of the unit, if language is unit based. This is only set for

      --  those files that are part of the compilation set (for instance a

      --  file in an extended project that is overridden will not have this

      --  field set).

      Index : Int := 0;

      --  Index of the source in a multi unit source file (the same Source_Data

      --  is duplicated several times when there are several units in the same

      --  file). Index is 0 if there is either no unit or a single one, and

      --  starts at 1 when there are multiple units

      Locally_Removed : Boolean := False;

      --  True if the source has been "excluded"

      Replaced_By : Source_Id := No_Source;

      --  Missing comment ???

      File : File_Name_Type := No_File;

      --  Canonical file name of the source

      Display_File : File_Name_Type := No_File;

      --  File name of the source, for display purposes

      Path : Path_Information := No_Path_Information;

      --  Path name of the source

      Source_TS : Time_Stamp_Type := Empty_Time_Stamp;

      --  Time stamp of the source file

      Object_Project : Project_Id := No_Project;

      --  Project where the object file is. This might be different from

      --  Project when using extending project files.

      Object : File_Name_Type := No_File;

      --  File name of the object file

      Current_Object_Path : Path_Name_Type := No_Path;

      --  Object path of an existing object file

      Object_Path : Path_Name_Type := No_Path;

      --  Object path of the real object file

      Object_TS : Time_Stamp_Type := Empty_Time_Stamp;

      --  Object file time stamp

      Dep_Name : File_Name_Type := No_File;

      --  Dependency file simple name

      Current_Dep_Path : Path_Name_Type := No_Path;

      --  Path name of an existing dependency file

      Dep_Path : Path_Name_Type := No_Path;

      --  Path name of the real dependency file

      Dep_TS : aliased Osint.File_Attributes := Osint.Unknown_Attributes;

      --  Dependency file time stamp

      Switches : File_Name_Type := No_File;

      --  File name of the switches file. For all languages, this is a file

      --  that ends with the .cswi extension.

      Switches_Path : Path_Name_Type := No_Path;

      --  Path name of the switches file

      Switches_TS : Time_Stamp_Type := Empty_Time_Stamp;

      --  Switches file time stamp

      Naming_Exception : Boolean := False;

      --  True if the source has an exceptional name

      Next_In_Lang : Source_Id := No_Source;

      --  Link to another source of the same language in the same project

   end record;

   No_Source_Data : constant Source_Data :=

                      (Project                => No_Project,

                       Source_Dir_Rank        => 0,

                       Language               => No_Language_Index,

                       In_Interfaces          => True,

                       Declared_In_Interfaces => False,

                       Alternate_Languages    => null,

                       Kind                   => Spec,

                       Unit                   => No_Unit_Index,

                       Index                  => 0,

                       Locally_Removed        => False,

                       Replaced_By            => No_Source,

                       File                   => No_File,

                       Display_File           => No_File,

                       Path                   => No_Path_Information,

                       Source_TS              => Empty_Time_Stamp,

                       Object_Project         => No_Project,

                       Object                 => No_File,

                       Current_Object_Path    => No_Path,

                       Object_Path            => No_Path,

                       Object_TS              => Empty_Time_Stamp,

                       Dep_Name               => No_File,

                       Current_Dep_Path       => No_Path,

                       Dep_Path               => No_Path,

                       Dep_TS                 => Osint.Unknown_Attributes,

                       Switches               => No_File,

                       Switches_Path          => No_Path,

                       Switches_TS            => Empty_Time_Stamp,

                       Naming_Exception       => False,

                       Next_In_Lang           => No_Source);

   package Source_Paths_Htable is new Simple_HTable

     (Header_Num => Header_Num,

      Element    => Source_Id,

      No_Element => No_Source,

      Key        => Path_Name_Type,

      Hash       => Hash,

      Equal      => "=");

   --  Mapping of source paths to source ids

   package Unit_Sources_Htable is new Simple_HTable

     (Header_Num => Header_Num,

      Element    => Source_Id,

      No_Element => No_Source,

      Key        => Name_Id,

      Hash       => Hash,

      Equal      => "=");

   type Verbosity is (Default, Medium, High);

   --  Verbosity when parsing GNAT Project Files

   --    Default is default (very quiet, if no errors).

   --    Medium is more verbose.

   --    High is extremely verbose.

   Current_Verbosity : Verbosity := Default;

   --  The current value of the verbosity the project files are parsed with

   type Lib_Kind is (Static, Dynamic, Relocatable);

   type Policy is (Autonomous, Compliant, Controlled, Restricted, Direct);

   --  Type to specify the symbol policy, when symbol control is supported.

   --  See full explanation about this type in package Symbols.

   --    Autonomous: Create a symbol file without considering any reference

   --    Compliant:  Try to be as compatible as possible with an existing ref

   --    Controlled: Fail if symbols are not the same as those in the reference

   --    Restricted: Restrict the symbols to those in the symbol file

   --    Direct:     The symbol file is used as is

   type Symbol_Record is record

      Symbol_File   : Path_Name_Type := No_Path;

      Reference     : Path_Name_Type := No_Path;