path: root/gcc/ada/makegpr.adb

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                              M A K E G P R                               --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 2004-2008, 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 Csets;
with Gnatvsn;
with Hostparm; use Hostparm;
with Makeutl;  use Makeutl;
with MLib.Tgt; use MLib.Tgt;
with Namet;    use Namet;
with Output;   use Output;
with Opt;      use Opt;
with Osint;    use Osint;
with Prj;      use Prj;
with Prj.Ext;  use Prj.Ext;
with Prj.Pars;
with Prj.Util; use Prj.Util;
with Snames;   use Snames;
with Table;
with Types;    use Types;

with Ada.Command_Line;           use Ada.Command_Line;
with Ada.Strings.Fixed;          use Ada.Strings.Fixed;
with Ada.Text_IO;                use Ada.Text_IO;
with Ada.Unchecked_Deallocation;

with GNAT.Directory_Operations;  use GNAT.Directory_Operations;
with GNAT.Dynamic_Tables;
with GNAT.Expect;                use GNAT.Expect;
with GNAT.HTable;
with GNAT.OS_Lib;                use GNAT.OS_Lib;
with GNAT.Regpat;                use GNAT.Regpat;

with System;
with System.Case_Util;           use System.Case_Util;

package body Makegpr is

   On_Windows : constant Boolean := Directory_Separator = '\';
   --  True when on Windows. Used in Check_Compilation_Needed when processing
   --  C/C++ dependency files for backslash handling.

   Max_In_Archives : constant := 50;
   --  The maximum number of arguments for a single invocation of the
   --  Archive Indexer (ar).

   No_Argument : aliased Argument_List := (1 .. 0 => null);
   --  Null argument list representing case of no arguments

   FD : Process_Descriptor;
   --  The process descriptor used when invoking a non GNU compiler with -M
   --  and getting the output with GNAT.Expect.

   Line_Matcher : constant Pattern_Matcher := Compile ("^.*?\n", Single_Line);
   --  Pattern for GNAT.Expect for the invocation of a non GNU compiler with -M

   Name_Ide              : Name_Id;
   Name_Compiler_Command : Name_Id;
   --  Names of package IDE and its attribute Compiler_Command.
   --  Set up by Initialize.

   Unique_Compile : Boolean := False;
   --  True when switch -u is used on the command line

   type Source_Index_Rec is record
      Project : Project_Id;
      Id      : Other_Source_Id;
      Found   : Boolean := False;
   end record;
   --  Used as Source_Indexes component to check if archive needs to be rebuilt

   type Source_Index_Array is array (Positive range <>) of Source_Index_Rec;
   type Source_Indexes_Ref is access Source_Index_Array;

   procedure Free is new Ada.Unchecked_Deallocation
     (Source_Index_Array, Source_Indexes_Ref);

   Initial_Source_Index_Count : constant Positive := 20;
   Source_Indexes : Source_Indexes_Ref :=
     new Source_Index_Array (1 .. Initial_Source_Index_Count);
   --  A list of the Other_Source_Ids of a project file, with an indication
   --  that they have been found in the archive dependency file.

   Last_Source : Natural := 0;
   --  The index of the last valid component of Source_Indexes

   Compiler_Names : array (First_Language_Indexes) of String_Access;
   --  The names of the compilers to be used. Set up by Get_Compiler.
   --  Used to display the commands spawned.

   Gnatmake_String       : constant String_Access := new String'("gnatmake");
   GCC_String            : constant String_Access := new String'("gcc");
   G_Plus_Plus_String    : constant String_Access := new String'("g++");

   Default_Compiler_Names : constant array
     (First_Language_Indexes range
        Ada_Language_Index .. C_Plus_Plus_Language_Index)
     of String_Access :=
       (Ada_Language_Index         => Gnatmake_String,
        C_Language_Index           => GCC_String,
        C_Plus_Plus_Language_Index => G_Plus_Plus_String);

   Compiler_Paths : array (First_Language_Indexes) of String_Access;
   --  The path names of the compiler to be used. Set up by Get_Compiler.
   --  Used to spawn compiling/linking processes.

   Compiler_Is_Gcc : array (First_Language_Indexes) of Boolean;
   --  An indication that a compiler is a GCC compiler, to be able to use
   --  specific GCC switches.

   Archive_Builder_Path : String_Access := null;
   --  The path name of the archive builder (ar). To be used when spawning
   --  ar commands.

   Archive_Indexer_Path : String_Access := null;
   --  The path name of the archive indexer (ranlib), if it exists

   Copyright_Output : Boolean := False;
   Usage_Output     : Boolean := False;
   --  Flags to avoid multiple displays of Copyright notice and of Usage

   Output_File_Name           : String_Access := null;
   --  The name given after a switch -o

   Output_File_Name_Expected  : Boolean := False;
   --  True when last switch was -o

   Project_File_Name          : String_Access := null;
   --  The name of the project file specified with switch -P

   Project_File_Name_Expected : Boolean := False;
   --  True when last switch was -P

   Naming_String   : aliased String := "naming";
   Builder_String  : aliased String := "builder";
   Compiler_String : aliased String := "compiler";
   Binder_String   : aliased String := "binder";
   Linker_String   : aliased String := "linker";
   --  Name of packages to be checked when parsing/processing project files

   List_Of_Packages : aliased String_List :=
     (Naming_String   'Access,
      Builder_String  'Access,
      Compiler_String 'Access,
      Binder_String   'Access,
      Linker_String   'Access);
   Packages_To_Check : constant String_List_Access := List_Of_Packages'Access;
   --  List of the packages to be checked when parsing/processing project files

   Project_Tree : constant Project_Tree_Ref := new Project_Tree_Data;

   Main_Project : Project_Id;
   --  The project id of the main project

   type Processor is (None, Linker, Compiler);
   Current_Processor : Processor := None;
   --  This variable changes when switches -*args are used

   Current_Language  : Language_Index := Ada_Language_Index;
   --  The compiler language to consider when Processor is Compiler

   package Comp_Opts is new GNAT.Dynamic_Tables
     (Table_Component_Type => String_Access,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 20,
      Table_Increment      => 100);
   Options : array (First_Language_Indexes) of Comp_Opts.Instance;
   --  Tables to store compiling options for the different compilers

   package Linker_Options is new Table.Table
     (Table_Component_Type => String_Access,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 20,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Linker_Options");
   --  Table to store the linking options

   package Library_Opts is new Table.Table
     (Table_Component_Type => String_Access,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 20,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Library_Opts");
   --  Table to store the linking options

   package Ada_Mains is new Table.Table
     (Table_Component_Type => String_Access,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 20,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Ada_Mains");
   --  Table to store the Ada mains, either specified on the command line
   --  or found in attribute Main of the main project file.

   package Other_Mains is new Table.Table
     (Table_Component_Type => Other_Source,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 20,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Other_Mains");
   --  Table to store the mains of languages other than Ada, either specified
   --  on the command line or found in attribute Main of the main project file.

   package Sources_Compiled is new GNAT.HTable.Simple_HTable
     (Header_Num => Header_Num,
      Element    => Boolean,
      No_Element => False,
      Key        => File_Name_Type,
      Hash       => Hash,
      Equal      => "=");

   package Saved_Switches is new Table.Table
     (Table_Component_Type => String_Access,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 10,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Saved_Switches");
   --  Table to store the switches to be passed to gnatmake

   Initial_Argument_Count : constant Positive := 20;
   type Boolean_Array is array (Positive range <>) of Boolean;
   type Booleans is access Boolean_Array;

   procedure Free is new Ada.Unchecked_Deallocation (Boolean_Array, Booleans);

   Arguments : Argument_List_Access :=
     new Argument_List (1 .. Initial_Argument_Count);
   --  Used to store lists of arguments to be used when spawning a process

   Arguments_Displayed : Booleans :=
     new Boolean_Array (1 .. Initial_Argument_Count);
   --  For each argument in Arguments, indicate if the argument should be
   --  displayed when procedure Display_Command is called.

   Last_Argument : Natural := 0;
   --  Index of the last valid argument in Arguments

   package Cache_Args is new Table.Table
     (Table_Component_Type => String_Access,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 200,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Cache_Args");
   --  A table to cache arguments, to avoid multiple allocation of the same
   --  strings. It is not possible to use a hash table, because String is
   --  an unconstrained type.

   --  Various switches used when spawning processes:

   Dash_B_String     : aliased  String := "-B";
   Dash_B            : constant String_Access := Dash_B_String'Access;
   Dash_c_String     : aliased  String := "-c";
   Dash_c            : constant String_Access := Dash_c_String'Access;
   Dash_cargs_String : aliased  String := "-cargs";
   Dash_cargs        : constant String_Access := Dash_cargs_String'Access;
   Dash_d_String     : aliased  String := "-d";
   Dash_d            : constant String_Access := Dash_d_String'Access;
   Dash_eL_String    : aliased  String := "-eL";
   Dash_eL           : constant String_Access := Dash_eL_String'Access;
   Dash_f_String     : aliased  String := "-f";
   Dash_f            : constant String_Access := Dash_f_String'Access;
   Dash_k_String     : aliased  String := "-k";
   Dash_k            : constant String_Access := Dash_k_String'Access;
   Dash_largs_String : aliased  String := "-largs";
   Dash_largs        : constant String_Access := Dash_largs_String'Access;
   Dash_M_String     : aliased  String := "-M";
   Dash_M            : constant String_Access := Dash_M_String'Access;
   Dash_margs_String : aliased  String := "-margs";
   Dash_margs        : constant String_Access := Dash_margs_String'Access;
   Dash_o_String     : aliased  String := "-o";
   Dash_o            : constant String_Access := Dash_o_String'Access;
   Dash_P_String     : aliased  String := "-P";
   Dash_P            : constant String_Access := Dash_P_String'Access;
   Dash_q_String     : aliased  String := "-q";
   Dash_q            : constant String_Access := Dash_q_String'Access;
   Dash_u_String     : aliased  String := "-u";
   Dash_u            : constant String_Access := Dash_u_String'Access;
   Dash_v_String     : aliased  String := "-v";
   Dash_v            : constant String_Access := Dash_v_String'Access;
   Dash_vP1_String   : aliased  String := "-vP1";
   Dash_vP1          : constant String_Access := Dash_vP1_String'Access;
   Dash_vP2_String   : aliased  String := "-vP2";
   Dash_vP2          : constant String_Access := Dash_vP2_String'Access;
   Dash_x_String     : aliased  String := "-x";
   Dash_x            : constant String_Access := Dash_x_String'Access;
   r_String          : aliased  String := "r";
   r                 : constant String_Access := r_String'Access;

   CPATH : constant String := "CPATH";
   --  The environment variable to set when compiler is a GCC compiler
   --  to indicate the include directory path.

   Current_Include_Paths : array (First_Language_Indexes) of String_Access;
   --  A cache for the paths of included directories, to avoid setting
   --  env var CPATH unnecessarily.

   C_Plus_Plus_Is_Used : Boolean := False;
   --  True when there are sources in C++

   Link_Options_Switches : Argument_List_Access := null;
   --  The link options coming from the attributes Linker'Linker_Options in
   --  project files imported, directly or indirectly, by the main project.

   Total_Number_Of_Errors : Natural := 0;
   --  Used when Keep_Going is True (switch -k) to keep the total number
   --  of compilation/linking errors, to report at the end of execution.

   Need_To_Rebuild_Global_Archive : Boolean := False;

   Error_Header : constant String := "*** ERROR: ";
   --  The beginning of error message, when Keep_Going is True

   Need_To_Relink : Boolean := False;
   --  True when an executable of a language other than Ada need to be linked

   Global_Archive_Exists : Boolean := False;
   --  True if there is a non empty global archive, to prevent creation
   --  of such archives.

   Path_Option : String_Access;
   --  The path option switch, when supported

   Project_Of_Current_Object_Directory : Project_Id := No_Project;
   --  The object directory of the project for the last compilation. Avoid
   --  calling Change_Dir if the current working directory is already this
   --  directory.

   package Lib_Path is new Table.Table
     (Table_Component_Type => Character,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 200,
      Table_Increment      => 100,
      Table_Name           => "Makegpr.Lib_Path");
   --  A table to compute the path to put in the path option switch, when it
   --  is supported.

   procedure Add_Archives (For_Gnatmake : Boolean);
   --  Add to Arguments the list of archives for linking an executable

   procedure Add_Argument (Arg : String_Access; Display : Boolean);
   procedure Add_Argument (Arg : String; Display : Boolean);
   --  Add an argument to Arguments. Reallocate if necessary

   procedure Add_Arguments (Args : Argument_List; Display : Boolean);
   --  Add a list of arguments to Arguments. Reallocate if necessary

   procedure Add_Option (Arg : String);
   --  Add a switch for the Ada, C or C++ compiler, or for the linker.
   --  The table where this option is stored depends on the values of
   --  Current_Processor and Current_Language.

   procedure Add_Search_Directories
     (Data     : Project_Data;
      Language : First_Language_Indexes);
   --  Either add to the Arguments the necessary -I switches needed to
   --  compile, or, when compiler is gcc/g++, set up the C*INCLUDE_PATH
   --  environment variable, if necessary.

   procedure Add_Source_Id (Project : Project_Id; Id : Other_Source_Id);
   --  Add a source id to Source_Indexes, with Found set to False

   procedure Add_Switches
     (Data      : Project_Data;
      Proc      : Processor;
      Language  : Language_Index;
      File_Name : File_Name_Type);
   --  Add to Arguments the switches, if any, for a source (attribute Switches)
   --  or language (attribute Default_Switches), coming from package Compiler
   --  or Linker (depending on Proc) of a specified project file.

   procedure Build_Global_Archive;
   --  Build the archive for the main project

   procedure Build_Library (Project : Project_Id; Unconditionally : Boolean);
   --  Build the library for a library project. If Unconditionally is
   --  False, first check if the library is up to date, and build it only
   --  if it is not.

   procedure Check (Option : String);
   --  Check that a switch coming from a project file is not the concatenation
   --  of several valid switch, for example "-g -v". If it is, issue a warning.

   procedure Check_Archive_Builder;
   --  Check if the archive builder (ar) is there

   procedure Check_Compilation_Needed
     (Source          : Other_Source;
      Need_To_Compile : out Boolean);
   --  Check if a source of a language other than Ada needs to be compiled or
   --  recompiled.

   procedure Check_For_C_Plus_Plus;
   --  Check if C++ is used in at least one project

   procedure Compile
     (Source_Id    : Other_Source_Id;
      Data         : Project_Data;
      Local_Errors : in out Boolean);
   --  Compile one non-Ada source

   procedure Compile_Individual_Sources;
   --  Compile the sources specified on the command line, when in
   --  Unique_Compile mode.

   procedure Compile_Link_With_Gnatmake (Mains_Specified : Boolean);
   --  Compile/Link with gnatmake when there are Ada sources in the main
   --  project. Arguments may already contain options to be used by
   --  gnatmake. Used for both Ada mains and mains of other languages.
   --  When Compile_Only is True, do not use the linking options

   procedure Compile_Sources;
   --  Compile the sources of languages other than Ada, if necessary

   procedure Copyright;
   --  Output the Copyright notice

   procedure Create_Archive_Dependency_File
     (Name         : String;
      First_Source : Other_Source_Id);
   --  Create the archive dependency file for a library project

   procedure Create_Global_Archive_Dependency_File (Name : String);
   --  Create the archive dependency file for the main project

   procedure Display_Command
     (Name    : String;
      Path    : String_Access;
      CPATH   : String_Access := null;
      Ellipse : Boolean := False);
   --  Display the command for a spawned process, if in Verbose_Mode or not in
   --  Quiet_Output. In non verbose mode, when Ellipse is True, display "..."
   --  in place of the first argument that has Display set to False.

   procedure Get_Compiler (For_Language : First_Language_Indexes);
   --  Find the compiler name and path name for a specified programming
   --  language, if not already done. Results are in the corresponding elements
   --  of arrays Compiler_Names and Compiler_Paths. Name of compiler is found
   --  in package IDE of the main project, or defaulted. Fail if compiler
   --  cannot be found on the path. For the Ada language, gnatmake, rather than
   --  the Ada compiler is returned.

   procedure Get_Imported_Directories
     (Project : Project_Id;
      Data    : in out Project_Data);
   --  Find the necessary switches -I to be used when compiling sources of
   --  languages other than Ada, in a specified project file. Cache the result
   --  in component Imported_Directories_Switches of the project data. For
   --  gcc/g++ compilers, get the value of the C*_INCLUDE_PATH, instead.

   procedure Initialize;
   --  Do the necessary package initialization and process the command line
   --  arguments.

   function Is_Included_In_Global_Archive
     (Object_Name : File_Name_Type;
      Project     : Project_Id) return Boolean;
   --  Return True if the object Object_Name is not overridden by a source
   --  in a project extending project Project.

   procedure Link_Executables;
   --  Link executables

   procedure Report_Error (S1 : String; S2 : String := ""; S3 : String := "");
   --  Report an error. If Keep_Going is False, just call Osint.Fail. If
   --  Keep_Going is True, display the error and increase the total number of
   --  errors.

   procedure Report_Total_Errors (Kind : String);
   --  If Total_Number_Of_Errors is not zero, report it, and fail

   procedure Scan_Arg (Arg : String);
   --  Process one command line argument

   function Strip_CR_LF (Text : String) return String;
   --  Remove characters ASCII.CR and ASCII.LF from a String

   procedure Usage;
   --  Display the usage

   ------------------
   -- Add_Archives --
   ------------------

   procedure Add_Archives (For_Gnatmake : Boolean) is
      Last_Arg : constant Natural := Last_Argument;
      --  The position of the last argument before adding the archives. Used to
      --  reverse the order of the arguments added when processing the
      --  archives.

      procedure Recursive_Add_Archives (Project : Project_Id);
      --  Recursive procedure to add the archive of a project file, if any,
      --  then call itself for the project imported.

      ----------------------------
      -- Recursive_Add_Archives --
      ----------------------------

      procedure Recursive_Add_Archives (Project : Project_Id) is
         Data     : Project_Data;
         Imported : Project_List;
         Prj      : Project_Id;

         procedure Add_Archive_Path;
         --  For a library project or the main project, add the archive
         --  path to the arguments.

         ----------------------
         -- Add_Archive_Path --
         ----------------------

         procedure Add_Archive_Path is
            Increment : Positive;
            Prev_Last : Positive;

         begin
            if Data.Library then

               --  If it is a library project file, nothing to do if gnatmake
               --  will be invoked, because gnatmake will take care of it, even
               --  if the library is not an Ada library.

               if not For_Gnatmake then
                  if Data.Library_Kind = Static then
                     Add_Argument
                       (Get_Name_String (Data.Display_Library_Dir) &
                        Directory_Separator &
                        "lib" & Get_Name_String (Data.Library_Name) &
                        '.' & Archive_Ext,
                        Verbose_Mode);

                  else
                     --  As we first insert in the reverse order,
                     --  -L<dir> is put after -l<lib>

                     Add_Argument
                       ("-l" & Get_Name_String (Data.Library_Name),
                        Verbose_Mode);

                     Get_Name_String (Data.Display_Library_Dir);

                     Add_Argument
                       ("-L" & Name_Buffer (1 .. Name_Len),
                        Verbose_Mode);

                     --  If there is a run path option, prepend this directory
                     --  to the library path. It is probable that the order of
                     --  the directories in the path option is not important,
                     --  but just in case put the directories in the same order
                     --  as the libraries.

                     if Path_Option /= null then

                        --  If it is not the first directory, make room at the
                        --  beginning of the table, including for a path
                        --  separator.

                        if Lib_Path.Last > 0 then
                           Increment := Name_Len + 1;
                           Prev_Last := Lib_Path.Last;
                           Lib_Path.Set_Last (Prev_Last + Increment);

                           for Index in reverse 1 .. Prev_Last loop
                              Lib_Path.Table (Index + Increment) :=
                                Lib_Path.Table (Index);
                           end loop;

                           Lib_Path.Table (Increment) := Path_Separator;

                        else
                           --  If it is the first directory, just set
                           --  Last to the length of the directory.

                           Lib_Path.Set_Last (Name_Len);
                        end if;

                        --  Put the directory at the beginning of the
                        --  table.

                        for Index in 1 .. Name_Len loop
                           Lib_Path.Table (Index) := Name_Buffer (Index);
                        end loop;
                     end if;
                  end if;
               end if;

            --  For a non-library project, the only archive needed is the one
            --  for the main project, if there is one.

            elsif Project = Main_Project and then Global_Archive_Exists then
               Add_Argument
                 (Get_Name_String (Data.Display_Object_Dir) &
                  Directory_Separator &
                  "lib" & Get_Name_String (Data.Display_Name)
                  & '.' & Archive_Ext,
                  Verbose_Mode);
            end if;
         end Add_Archive_Path;

      begin
         --  Nothing to do when there is no project specified

         if Project /= No_Project then
            Data := Project_Tree.Projects.Table (Project);

            --  Nothing to do if the project has already been processed

            if not Data.Seen then

               --  Mark the project as processed, to avoid processing it again

               Project_Tree.Projects.Table (Project).Seen := True;

               Recursive_Add_Archives (Data.Extends);

               Imported := Data.Imported_Projects;

               --  Call itself recursively for all imported projects

               while Imported /= Empty_Project_List loop
                  Prj := Project_Tree.Project_Lists.Table
                           (Imported).Project;

                  if Prj /= No_Project then
                     while Project_Tree.Projects.Table
                             (Prj).Extended_By /= No_Project
                     loop
                        Prj := Project_Tree.Projects.Table
                                 (Prj).Extended_By;
                     end loop;

                     Recursive_Add_Archives (Prj);
                  end if;

                  Imported := Project_Tree.Project_Lists.Table
                                (Imported).Next;
               end loop;

               --  If there is sources of language other than Ada in this
               --  project, add the path of the archive to Arguments.

               if Project = Main_Project
                 or else Data.Other_Sources_Present
               then
                  Add_Archive_Path;
               end if;
            end if;
         end if;
      end Recursive_Add_Archives;

   --  Start of processing for Add_Archives

   begin
      --  First, mark all projects as not processed

      for Project in Project_Table.First ..
                     Project_Table.Last (Project_Tree.Projects)
      loop
         Project_Tree.Projects.Table (Project).Seen := False;
      end loop;

      --  Take care of the run path option

      if Path_Option = null then
         Path_Option := MLib.Linker_Library_Path_Option;
      end if;

      Lib_Path.Set_Last (0);

      --  Add archives in the reverse order

      Recursive_Add_Archives (Main_Project);

      --  And reverse the order

      declare
         First : Positive;
         Last  : Natural;
         Temp  : String_Access;

      begin
         First := Last_Arg + 1;
         Last  := Last_Argument;
         while First < Last loop
            Temp := Arguments (First);
            Arguments (First) := Arguments (Last);
            Arguments (Last)  := Temp;
            First := First + 1;
            Last := Last - 1;
         end loop;
      end;
   end Add_Archives;

   ------------------
   -- Add_Argument --
   ------------------

   procedure Add_Argument (Arg : String_Access; Display : Boolean) is
   begin
      --  Nothing to do if no argument is specified or if argument is empty

      if Arg /= null or else Arg'Length = 0 then

         --  Reallocate arrays if necessary

         if Last_Argument = Arguments'Last then
            declare
               New_Arguments : constant Argument_List_Access :=
                                 new Argument_List
                                   (1 .. Last_Argument +
                                           Initial_Argument_Count);

               New_Arguments_Displayed : constant Booleans :=
                                           new Boolean_Array
                                             (1 .. Last_Argument +
                                                     Initial_Argument_Count);

            begin
               New_Arguments (Arguments'Range) := Arguments.all;

               --  To avoid deallocating the strings, nullify all components
               --  of Arguments before calling Free.

               Arguments.all := (others => null);

               Free (Arguments);
               Arguments := New_Arguments;

               New_Arguments_Displayed (Arguments_Displayed'Range) :=
                 Arguments_Displayed.all;
               Free (Arguments_Displayed);
               Arguments_Displayed := New_Arguments_Displayed;
            end;
         end if;

         --  Add the argument and its display indication

         Last_Argument := Last_Argument + 1;
         Arguments (Last_Argument) := Arg;
         Arguments_Displayed (Last_Argument) := Display;
      end if;
   end Add_Argument;

   procedure Add_Argument (Arg : String; Display : Boolean) is
      Argument : String_Access := null;

   begin
      --  Nothing to do if argument is empty

      if Arg'Length > 0 then

         --  Check if the argument is already in the Cache_Args table.
         --  If it is already there, reuse the allocated value.

         for Index in 1 .. Cache_Args.Last loop
            if Cache_Args.Table (Index).all = Arg then
               Argument := Cache_Args.Table (Index);
               exit;
            end if;
         end loop;

         --  If the argument is not in the cache, create a new entry in the
         --  cache.

         if Argument = null then
            Argument := new String'(Arg);
            Cache_Args.Increment_Last;
            Cache_Args.Table (Cache_Args.Last) := Argument;
         end if;

         --  And add the argument

         Add_Argument (Argument, Display);
      end if;
   end Add_Argument;

   -------------------
   -- Add_Arguments --
   -------------------

   procedure Add_Arguments (Args : Argument_List; Display : Boolean) is
   begin
      --  Reallocate the arrays, if necessary

      if Last_Argument + Args'Length > Arguments'Last then
         declare
            New_Arguments : constant Argument_List_Access :=
                              new Argument_List
                                    (1 .. Last_Argument + Args'Length +
                                          Initial_Argument_Count);

            New_Arguments_Displayed : constant Booleans :=
                                        new Boolean_Array
                                              (1 .. Last_Argument +
                                                    Args'Length +
                                                    Initial_Argument_Count);

         begin
            New_Arguments (1 .. Last_Argument) :=
              Arguments (1 .. Last_Argument);

            --  To avoid deallocating the strings, nullify all components
            --  of Arguments before calling Free.

            Arguments.all := (others => null);
            Free (Arguments);

            Arguments := New_Arguments;
            New_Arguments_Displayed (1 .. Last_Argument) :=
              Arguments_Displayed (1 .. Last_Argument);
            Free (Arguments_Displayed);
            Arguments_Displayed := New_Arguments_Displayed;
         end;
      end if;

      --  Add the new arguments and the display indications

      Arguments (Last_Argument + 1 .. Last_Argument + Args'Length) := Args;
      Arguments_Displayed (Last_Argument + 1 .. Last_Argument + Args'Length) :=
        (others => Display);
      Last_Argument := Last_Argument + Args'Length;
   end Add_Arguments;

   ----------------
   -- Add_Option --
   ----------------

   procedure Add_Option (Arg : String) is
      Option : constant String_Access := new String'(Arg);

   begin
      case Current_Processor is
         when None =>
            null;

         when Linker =>

            --  Add option to the linker table

            Linker_Options.Increment_Last;
            Linker_Options.Table (Linker_Options.Last) := Option;

         when Compiler =>

            --  Add option to the compiler option table, depending on the
            --  value of Current_Language.

            Comp_Opts.Increment_Last (Options (Current_Language));
            Options (Current_Language).Table
              (Comp_Opts.Last (Options (Current_Language))) := Option;

      end case;
   end Add_Option;

   -------------------
   -- Add_Source_Id --
   -------------------

   procedure Add_Source_Id (Project : Project_Id; Id : Other_Source_Id) is
   begin
      --  Reallocate the array, if necessary

      if Last_Source = Source_Indexes'Last then
         declare
            New_Indexes : constant Source_Indexes_Ref :=
                            new Source_Index_Array
                              (1 .. Source_Indexes'Last +
                                      Initial_Source_Index_Count);
         begin
            New_Indexes (Source_Indexes'Range) := Source_Indexes.all;
            Free (Source_Indexes);
            Source_Indexes := New_Indexes;
         end;
      end if;

      Last_Source := Last_Source + 1;
      Source_Indexes (Last_Source) := (Project, Id, False);
   end Add_Source_Id;

   ----------------------------
   -- Add_Search_Directories --
   ----------------------------

   procedure Add_Search_Directories
     (Data     : Project_Data;
      Language : First_Language_Indexes)
   is
   begin
      --  If a GNU compiler is used, set the CPATH environment variable,
      --  if it does not already has the correct value.

      if Compiler_Is_Gcc (Language) then
         if Current_Include_Paths (Language) /= Data.Include_Path then
            Current_Include_Paths (Language) := Data.Include_Path;
            Setenv (CPATH, Data.Include_Path.all);
         end if;

      else
         Add_Arguments (Data.Imported_Directories_Switches.all, Verbose_Mode);
      end if;
   end Add_Search_Directories;

   ------------------
   -- Add_Switches --
   ------------------

   procedure Add_Switches
     (Data      : Project_Data;
      Proc      : Processor;
      Language  : Language_Index;
      File_Name : File_Name_Type)
   is
      Switches       : Variable_Value;
      --  The switches, if any, for the file/language

      Pkg            : Package_Id;
      --  The id of the package where to look for the switches

      Defaults       : Array_Element_Id;
      --  The Default_Switches associative array

      Switches_Array : Array_Element_Id;
      --  The Switches associative array

      Element_Id     : String_List_Id;
      Element        : String_Element;

   begin
      --  First, choose the proper package

      case Proc is
         when None =>
            raise Program_Error;

         when Linker =>
            Pkg := Value_Of (Name_Linker, Data.Decl.Packages, Project_Tree);

         when Compiler =>
            Pkg := Value_Of (Name_Compiler, Data.Decl.Packages, Project_Tree);
      end case;

      if Pkg /= No_Package then

         --  Get the Switches ("file name"), if they exist

         Switches_Array := Prj.Util.Value_Of
           (Name      => Name_Switches,
            In_Arrays => Project_Tree.Packages.Table
                          (Pkg).Decl.Arrays,
            In_Tree   => Project_Tree);

         Switches :=
           Prj.Util.Value_Of
             (Index     => Name_Id (File_Name),
              Src_Index => 0,
              In_Array  => Switches_Array,
              In_Tree   => Project_Tree);

         --  Otherwise, get the Default_Switches ("language"), if they exist

         if Switches = Nil_Variable_Value then
            Defaults := Prj.Util.Value_Of
              (Name      => Name_Default_Switches,
               In_Arrays => Project_Tree.Packages.Table
                              (Pkg).Decl.Arrays,
               In_Tree   => Project_Tree);
            Switches := Prj.Util.Value_Of
              (Index     => Language_Names.Table (Language),
               Src_Index => 0,
               In_Array  => Defaults,
               In_Tree   => Project_Tree);
         end if;

         --  If there are switches, add them to Arguments

         if Switches /= Nil_Variable_Value then
            Element_Id := Switches.Values;
            while Element_Id /= Nil_String loop
               Element := Project_Tree.String_Elements.Table
                            (Element_Id);

               if Element.Value /= No_Name then
                  Get_Name_String (Element.Value);

                  if not Quiet_Output then

                     --  When not in quiet output (no -q), check that the
                     --  switch is not the concatenation of several valid
                     --  switches, such as "-g -v". If it is, issue a warning.

                     Check (Option => Name_Buffer (1 .. Name_Len));
                  end if;

                  Add_Argument (Name_Buffer (1 .. Name_Len), True);
               end if;

               Element_Id := Element.Next;
            end loop;
         end if;
      end if;
   end Add_Switches;

   --------------------------
   -- Build_Global_Archive --
   --------------------------

   procedure Build_Global_Archive is
      Data      : Project_Data := Project_Tree.Projects.Table (Main_Project);
      Source_Id : Other_Source_Id;
      S_Id      : Other_Source_Id;
      Source    : Other_Source;
      Success   : Boolean;

      Archive_Name : constant String :=
                       "lib"
                         & Get_Name_String (Data.Display_Name)
                         & '.'
                         & Archive_Ext;
      --  The name of the archive file for this project

      Archive_Dep_Name : constant String :=
                           "lib"
                             & Get_Name_String (Data.Display_Name)
                             & ".deps";
      --  The name of the archive dependency file for this project

      Need_To_Rebuild : Boolean := Need_To_Rebuild_Global_Archive;
      --  When True, archive will be rebuilt

      File                : Prj.Util.Text_File;
      Object_Path         : Path_Name_Type;
      Time_Stamp          : Time_Stamp_Type;
      Saved_Last_Argument : Natural;
      First_Object        : Natural;

      Discard : Boolean;
      pragma Warnings (Off, Discard);

   begin
      Check_Archive_Builder;

      if Project_Of_Current_Object_Directory /= Main_Project then
         Project_Of_Current_Object_Directory := Main_Project;
         Change_Dir (Get_Name_String (Data.Object_Directory));

         if Verbose_Mode then
            Write_Str  ("Changing to object directory of """);
            Write_Name (Data.Display_Name);
            Write_Str  (""": """);
            Write_Name (Data.Display_Object_Dir);
            Write_Line ("""");
         end if;
      end if;

      if not Need_To_Rebuild then
         if Verbose_Mode then
            Write_Str  ("   Checking ");
            Write_Line (Archive_Name);
         end if;

         --  If the archive does not exist, of course it needs to be built

         if not Is_Regular_File (Archive_Name) then
            Need_To_Rebuild := True;

            if Verbose_Mode then
               Write_Line ("      -> archive does not exist");
            end if;

         --  Archive does exist

         else
            --  Check the archive dependency file

            Open (File, Archive_Dep_Name);

            --  If the archive dependency file does not exist, we need to
            --  rebuild the archive and to create its dependency file.

            if not Is_Valid (File) then
               Need_To_Rebuild := True;

               if Verbose_Mode then
                  Write_Str  ("      -> archive dependency file ");
                  Write_Str  (Archive_Dep_Name);
                  Write_Line (" does not exist");
               end if;

            else
               --  Put all sources of language other than Ada in Source_Indexes

               declare
                  Local_Data : Project_Data;

               begin
                  Last_Source := 0;

                  for Proj in Project_Table.First ..
                    Project_Table.Last (Project_Tree.Projects)
                  loop
                     Local_Data := Project_Tree.Projects.Table (Proj);

                     if not Local_Data.Library then
                        Source_Id := Local_Data.First_Other_Source;
                        while Source_Id /= No_Other_Source loop
                           Add_Source_Id (Proj, Source_Id);
                           Source_Id := Project_Tree.Other_Sources.Table
                             (Source_Id).Next;
                        end loop;
                     end if;
                  end loop;
               end;

               --  Read the dependency file, line by line

               while not End_Of_File (File) loop
                  Get_Line (File, Name_Buffer, Name_Len);

                  --  First line is the path of the object file

                  Object_Path := Name_Find;
                  Source_Id := No_Other_Source;

                  --  Check if this object file is for a source of this project

                  for S in 1 .. Last_Source loop
                     S_Id := Source_Indexes (S).Id;
                     Source := Project_Tree.Other_Sources.Table (S_Id);

                     if (not Source_Indexes (S).Found)
                       and then Source.Object_Path = Object_Path
                     then
                        --  We have found the object file: get the source data,
                        --  and mark it as found.

                        Source_Id := S_Id;
                        Source_Indexes (S).Found := True;
                        exit;
                     end if;
                  end loop;

                  --  If it is not for a source of this project, then the
                  --  archive needs to be rebuilt.

                  if Source_Id = No_Other_Source then
                     Need_To_Rebuild := True;
                     if Verbose_Mode then
                        Write_Str  ("      -> ");
                        Write_Str  (Get_Name_String (Object_Path));
                        Write_Line (" is not an object of any project");
                     end if;

                     exit;
                  end if;

                  --  The second line is the time stamp of the object file. If
                  --  there is no next line, then the dependency file is
                  --  truncated, and the archive need to be rebuilt.

                  if End_Of_File (File) then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> archive dependency file ");
                        Write_Line (" is truncated");
                     end if;

                     exit;
                  end if;

                  Get_Line (File, Name_Buffer, Name_Len);

                  --  If the line has the wrong number of characters, then
                  --  the dependency file is incorrectly formatted, and the
                  --  archive needs to be rebuilt.

                  if Name_Len /= Time_Stamp_Length then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> archive dependency file ");
                        Write_Line (" is incorrectly formatted (time stamp)");
                     end if;

                     exit;
                  end if;

                  Time_Stamp := Time_Stamp_Type (Name_Buffer (1 .. Name_Len));

                  --  If the time stamp in the dependency file is different
                  --  from the time stamp of the object file, then the archive
                  --  needs to be rebuilt.

                  if Time_Stamp /= Source.Object_TS then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> time stamp of ");
                        Write_Str  (Get_Name_String (Object_Path));
                        Write_Str  (" is incorrect in the archive");
                        Write_Line (" dependency file");
                     end if;

                     exit;
                  end if;
               end loop;

               Close (File);
            end if;
         end if;
      end if;

      if not Need_To_Rebuild then
         if Verbose_Mode then
            Write_Line  ("      -> up to date");
         end if;

         --  No need to create a global archive, if there is no object
         --  file to put into.

         Global_Archive_Exists := Last_Source /= 0;

      --  Archive needs to be rebuilt

      else
         --  If archive already exists, first delete it

         --  Comment needed on why we discard result???

         if Is_Regular_File (Archive_Name) then
            Delete_File (Archive_Name, Discard);
         end if;

         Last_Argument := 0;

         --  Start with the options found in MLib.Tgt (usually just "rc")

         Add_Arguments (Archive_Builder_Options.all, True);

         --  Followed by the archive name

         Add_Argument (Archive_Name, True);

         First_Object := Last_Argument;

         --  Followed by all the object files of the non library projects

         for Proj in Project_Table.First ..
                     Project_Table.Last (Project_Tree.Projects)
         loop
            Data := Project_Tree.Projects.Table (Proj);

            if not Data.Library then
               Source_Id := Data.First_Other_Source;
               while Source_Id /= No_Other_Source loop
                  Source :=
                    Project_Tree.Other_Sources.Table (Source_Id);

                  --  Only include object file name that have not been
                  --  overridden in extending projects.

                  if Is_Included_In_Global_Archive
                       (Source.Object_Name, Proj)
                  then
                     Add_Argument
                       (Get_Name_String (Source.Object_Path),
                        Verbose_Mode or (First_Object = Last_Argument));
                  end if;

                  Source_Id := Source.Next;
               end loop;
            end if;
         end loop;

         --  No need to create a global archive, if there is no object
         --  file to put into.

         Global_Archive_Exists := Last_Argument > First_Object;

         if Global_Archive_Exists then

            --  If the archive is built, then linking will need to occur
            --  unconditionally.

            Need_To_Relink := True;

            --  Spawn the archive builder (ar)

            Saved_Last_Argument := Last_Argument;
            Last_Argument := First_Object + Max_In_Archives;
            loop
               if Last_Argument > Saved_Last_Argument then
                  Last_Argument := Saved_Last_Argument;
               end if;

               Display_Command
                 (Archive_Builder,
                  Archive_Builder_Path,
                  Ellipse => True);

               Spawn
                 (Archive_Builder_Path.all,
                  Arguments (1 .. Last_Argument),
                  Success);

               exit when not Success
                 or else Last_Argument = Saved_Last_Argument;

               Arguments (1) := r;
               Arguments (3 .. Saved_Last_Argument - Last_Argument + 2) :=
                 Arguments (Last_Argument + 1 .. Saved_Last_Argument);
               Saved_Last_Argument := Saved_Last_Argument - Last_Argument + 2;
            end loop;

            --  If the archive was built, run the archive indexer (ranlib)
            --  if there is one.

            if Success then

               if Archive_Indexer_Path /= null then
                  Last_Argument := 0;
                  Add_Argument (Archive_Name, True);

                  Display_Command (Archive_Indexer, Archive_Indexer_Path);

                  Spawn
                    (Archive_Indexer_Path.all, Arguments (1 .. 1), Success);

                  if not Success then

                     --  Running ranlib failed, delete the dependency file,
                     --  if it exists.

                     if Is_Regular_File (Archive_Dep_Name) then
                        Delete_File (Archive_Dep_Name, Success);
                     end if;

                     --  And report the error

                     Report_Error
                       ("running" & Archive_Indexer & " for project """,
                        Get_Name_String (Data.Display_Name),
                        """ failed");
                     return;
                  end if;
               end if;

               --  The archive was correctly built, create its dependency file

               Create_Global_Archive_Dependency_File (Archive_Dep_Name);

            --  Building the archive failed, delete dependency file if one
            --  exists.

            else
               if Is_Regular_File (Archive_Dep_Name) then
                  Delete_File (Archive_Dep_Name, Success);
               end if;

               --  And report the error

               Report_Error
                 ("building archive for project """,
                  Get_Name_String (Data.Display_Name),
                  """ failed");
            end if;
         end if;
      end if;
   end Build_Global_Archive;

   -------------------
   -- Build_Library --
   -------------------

   procedure Build_Library (Project : Project_Id; Unconditionally : Boolean) is
      Data      : constant Project_Data :=
                    Project_Tree.Projects.Table (Project);
      Source_Id : Other_Source_Id;
      Source    : Other_Source;

      Archive_Name : constant String :=
                       "lib" & Get_Name_String (Data.Library_Name)
                       & '.' & Archive_Ext;
      --  The name of the archive file for this project

      Archive_Dep_Name : constant String :=
                           "lib" & Get_Name_String (Data.Library_Name)
                           & ".deps";
      --  The name of the archive dependency file for this project

      Need_To_Rebuild : Boolean := Unconditionally;
      --  When True, archive will be rebuilt

      File : Prj.Util.Text_File;

      Object_Name : File_Name_Type;
      Time_Stamp  : Time_Stamp_Type;
      Driver_Name : Name_Id := No_Name;

      Lib_Opts    : Argument_List_Access := No_Argument'Access;

   begin
      --  Nothing to do if the project is externally built

      if Data.Externally_Built then
         return;
      end if;

      Check_Archive_Builder;

      --  If Unconditionally is False, check if the archive need to be built

      if not Need_To_Rebuild then
         if Verbose_Mode then
            Write_Str  ("   Checking ");
            Write_Line (Archive_Name);
         end if;

         --  If the archive does not exist, of course it needs to be built

         if not Is_Regular_File (Archive_Name) then
            Need_To_Rebuild := True;

            if Verbose_Mode then
               Write_Line ("      -> archive does not exist");
            end if;

         --  Archive does exist

         else
            --  Check the archive dependency file

            Open (File, Archive_Dep_Name);

            --  If the archive dependency file does not exist, we need to
            --  rebuild the archive and to create its dependency file.

            if not Is_Valid (File) then
               Need_To_Rebuild := True;

               if Verbose_Mode then
                  Write_Str  ("      -> archive dependency file ");
                  Write_Str  (Archive_Dep_Name);
                  Write_Line (" does not exist");
               end if;

            else
               --  Put all sources of language other than Ada in Source_Indexes

               Last_Source := 0;

               Source_Id := Data.First_Other_Source;
               while Source_Id /= No_Other_Source loop
                  Add_Source_Id (Project, Source_Id);
                  Source_Id :=
                    Project_Tree.Other_Sources.Table (Source_Id).Next;
               end loop;

               --  Read the dependency file, line by line

               while not End_Of_File (File) loop
                  Get_Line (File, Name_Buffer, Name_Len);

                  --  First line is the name of an object file

                  Object_Name := Name_Find;
                  Source_Id := No_Other_Source;

                  --  Check if this object file is for a source of this project

                  for S in 1 .. Last_Source loop
                     if (not Source_Indexes (S).Found)
                       and then
                         Project_Tree.Other_Sources.Table
                           (Source_Indexes (S).Id).Object_Name = Object_Name
                     then
                        --  We have found the object file: get the source
                        --  data, and mark it as found.

                        Source_Id := Source_Indexes (S).Id;
                        Source := Project_Tree.Other_Sources.Table
                                    (Source_Id);
                        Source_Indexes (S).Found := True;
                        exit;
                     end if;
                  end loop;

                  --  If it is not for a source of this project, then the
                  --  archive needs to be rebuilt.

                  if Source_Id = No_Other_Source then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> ");
                        Write_Str  (Get_Name_String (Object_Name));
                        Write_Line (" is not an object of the project");
                     end if;

                     exit;
                  end if;

                  --  The second line is the time stamp of the object file.
                  --  If there is no next line, then the dependency file is
                  --  truncated, and the archive need to be rebuilt.

                  if End_Of_File (File) then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> archive dependency file ");
                        Write_Line (" is truncated");
                     end if;

                     exit;
                  end if;

                  Get_Line (File, Name_Buffer, Name_Len);

                  --  If the line has the wrong number of character, then
                  --  the dependency file is incorrectly formatted, and the
                  --  archive needs to be rebuilt.

                  if Name_Len /= Time_Stamp_Length then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> archive dependency file ");
                        Write_Line (" is incorrectly formatted (time stamp)");
                     end if;

                     exit;
                  end if;

                  Time_Stamp := Time_Stamp_Type (Name_Buffer (1 .. Name_Len));

                  --  If the time stamp in the dependency file is different
                  --  from the time stamp of the object file, then the archive
                  --  needs to be rebuilt.

                  if Time_Stamp /= Source.Object_TS then
                     Need_To_Rebuild := True;

                     if Verbose_Mode then
                        Write_Str  ("      -> time stamp of ");
                        Write_Str  (Get_Name_String (Object_Name));
                        Write_Str  (" is incorrect in the archive");
                        Write_Line (" dependency file");
                     end if;

                     exit;
                  end if;
               end loop;

               Close (File);

               if not Need_To_Rebuild then

                  --  Now, check if all object files of the project have been
                  --  accounted for. If any of them is not in the dependency
                  --  file, the archive needs to be rebuilt.

                  for Index in 1 .. Last_Source loop
                     if not Source_Indexes (Index).Found then
                        Need_To_Rebuild := True;

                        if Verbose_Mode then
                           Source_Id := Source_Indexes (Index).Id;
                           Source := Project_Tree.Other_Sources.Table
                                       (Source_Id);
                           Write_Str  ("      -> ");
                           Write_Str  (Get_Name_String (Source.Object_Name));
                           Write_Str  (" is not in the archive ");
                           Write_Line ("dependency file");
                        end if;

                        exit;
                     end if;
                  end loop;
               end if;

               if (not Need_To_Rebuild) and Verbose_Mode then
                  Write_Line ("      -> up to date");
               end if;
            end if;
         end if;
      end if;

      --  Build the library if necessary

      if Need_To_Rebuild then

         --  If a library is built, then linking will need to occur
         --  unconditionally.

         Need_To_Relink := True;

         Last_Argument := 0;

         --  If there are sources in Ada, then gnatmake will build the library,
         --  so nothing to do.

         if not Data.Langs (Ada_Language_Index) then

            --  Get all the object files of the project

            Source_Id := Data.First_Other_Source;
            while Source_Id /= No_Other_Source loop
               Source := Project_Tree.Other_Sources.Table (Source_Id);
               Add_Argument
                 (Get_Name_String (Source.Object_Name), Verbose_Mode);
               Source_Id := Source.Next;
            end loop;

            --  If it is a library, it need to be built it the same way Ada
            --  libraries are built.

            if Data.Library_Kind = Static then
               MLib.Build_Library
                 (Ofiles      => Arguments (1 .. Last_Argument),
                  Output_File => Get_Name_String (Data.Library_Name),
                  Output_Dir  => Get_Name_String (Data.Display_Library_Dir));

            else
               --  Link with g++ if C++ is one of the languages, otherwise
               --  building the library may fail with unresolved symbols.

               if C_Plus_Plus_Is_Used then
                  if Compiler_Names (C_Plus_Plus_Language_Index) = null then
                     Get_Compiler (C_Plus_Plus_Language_Index);
                  end if;

                  if Compiler_Is_Gcc (C_Plus_Plus_Language_Index) then
                     Name_Len := 0;
                     Add_Str_To_Name_Buffer
                       (Compiler_Names (C_Plus_Plus_Language_Index).all);
                     Driver_Name := Name_Find;
                  end if;
               end if;

               --  If Library_Options is specified, add these options

               declare
                  Library_Options : constant Variable_Value :=
                                      Value_Of
                                        (Name_Library_Options,
                                         Data.Decl.Attributes,
                                         Project_Tree);

               begin
                  if not Library_Options.Default then
                     declare
                        Current : String_List_Id;
                        Element : String_Element;

                     begin
                        Current := Library_Options.Values;
                        while Current /= Nil_String loop
                           Element :=
                             Project_Tree.String_Elements.Table (Current);
                           Get_Name_String (Element.Value);

                           if Name_Len /= 0 then
                              Library_Opts.Increment_Last;
                              Library_Opts.Table (Library_Opts.Last) :=
                                new String'(Name_Buffer (1 .. Name_Len));
                           end if;

                           Current := Element.Next;
                        end loop;
                     end;
                  end if;

                  Lib_Opts :=
                    new Argument_List'(Argument_List
                       (Library_Opts.Table (1 .. Library_Opts.Last)));
               end;

               MLib.Tgt.Build_Dynamic_Library
                 (Ofiles       => Arguments (1 .. Last_Argument),
                  Options      => Lib_Opts.all,
                  Interfaces   => No_Argument,
                  Lib_Filename => Get_Name_String (Data.Library_Name),
                  Lib_Dir      => Get_Name_String (Data.Library_Dir),
                  Symbol_Data  => No_Symbols,
                  Driver_Name  => Driver_Name,
                  Lib_Version  => "",
                  Auto_Init    => False);
            end if;
         end if;

         --  Create fake empty archive, so we can check its time stamp later

         declare
            Archive : Ada.Text_IO.File_Type;
         begin
            Create (Archive, Out_File, Archive_Name);
            Close (Archive);
         end;

         Create_Archive_Dependency_File
           (Archive_Dep_Name, Data.First_Other_Source);
      end if;
   end Build_Library;

   -----------
   -- Check --
   -----------

   procedure Check (Option : String) is
      First : Positive := Option'First;
      Last  : Natural;

   begin
      for Index in Option'First + 1 .. Option'Last - 1 loop
         if Option (Index) = ' ' and then Option (Index + 1) = '-' then
            Write_Str ("warning: switch """);
            Write_Str (Option);
            Write_Str (""" is suspicious; consider using ");

            Last := First;
            while Last <= Option'Last loop
               if Option (Last) = ' ' then
                  if First /= Option'First then
                     Write_Str (", ");
                  end if;

                  Write_Char ('"');
                  Write_Str (Option (First .. Last - 1));
                  Write_Char ('"');

                  while Last <= Option'Last and then Option (Last) = ' ' loop
                     Last := Last + 1;
                  end loop;

                  First := Last;

               else
                  if Last = Option'Last then
                     if First /= Option'First then
                        Write_Str (", ");
                     end if;

                     Write_Char ('"');
                     Write_Str (Option (First .. Last));
                     Write_Char ('"');
                  end if;

                  Last := Last + 1;
               end if;
            end loop;

            Write_Line (" instead");
            exit;
         end if;
      end loop;
   end Check;

   ---------------------------
   -- Check_Archive_Builder --
   ---------------------------

   procedure Check_Archive_Builder is
   begin
      --  First, make sure that the archive builder (ar) is on the path

      if Archive_Builder_Path = null then
         Archive_Builder_Path := Locate_Exec_On_Path (Archive_Builder);

         if Archive_Builder_Path = null then
            Osint.Fail
              ("unable to locate archive builder """,
               Archive_Builder,
               """");
         end if;

         --  If there is an archive indexer (ranlib), try to locate it on the
         --  path. Don't fail if it is not found.

         if Archive_Indexer /= "" then
            Archive_Indexer_Path := Locate_Exec_On_Path (Archive_Indexer);
         end if;
      end if;
   end Check_Archive_Builder;

   ------------------------------
   -- Check_Compilation_Needed --
   ------------------------------

   procedure Check_Compilation_Needed
     (Source          : Other_Source;
      Need_To_Compile : out Boolean)
   is
      Source_Name   : constant String := Get_Name_String (Source.File_Name);
      Source_Path   : constant String := Get_Name_String (Source.Path_Name);
      Object_Name   : constant String := Get_Name_String (Source.Object_Name);
      C_Object_Name : String := Object_Name;
      Dep_Name      : constant String := Get_Name_String (Source.Dep_Name);
      C_Source_Path : constant String :=
                        Normalize_Pathname
                          (Name           => Source_Path,
                           Resolve_Links  => False,
                           Case_Sensitive => False);

      Source_In_Dependencies : Boolean := False;
      --  Set True if source was found in dependency file of its object file

      Dep_File : Prj.Util.Text_File;
      Start    : Natural;
      Finish   : Natural;

      Looping : Boolean := False;
      --  Set to True at the end of the first Big_Loop

   begin
      Canonical_Case_File_Name (C_Object_Name);

      --  Assume the worst, so that statement "return;" may be used if there
      --  is any problem.

      Need_To_Compile := True;

      if Verbose_Mode then
         Write_Str  ("   Checking ");
         Write_Str  (Source_Name);
         Write_Line (" ... ");
      end if;

      --  If object file does not exist, of course source need to be compiled

      if Source.Object_TS = Empty_Time_Stamp then
         if Verbose_Mode then
            Write_Str  ("      -> object file ");
            Write_Str  (Object_Name);
            Write_Line (" does not exist");
         end if;

         return;
      end if;

      --  If the object file has been created before the last modification
      --  of the source, the source need to be recompiled.

      if Source.Object_TS < Source.Source_TS then
         if Verbose_Mode then
            Write_Str  ("      -> object file ");
            Write_Str  (Object_Name);
            Write_Line (" has time stamp earlier than source");
         end if;

         return;
      end if;

      --  If there is no dependency file, then the source needs to be
      --  recompiled and the dependency file need to be created.

      if Source.Dep_TS = Empty_Time_Stamp then
         if Verbose_Mode then
            Write_Str  ("      -> dependency file ");
            Write_Str  (Dep_Name);
            Write_Line (" does not exist");
         end if;

         return;
      end if;

      --  The source needs to be recompiled if the source has been modified
      --  after the dependency file has been created.

      if Source.Dep_TS < Source.Source_TS then
         if Verbose_Mode then
            Write_Str  ("      -> dependency file ");
            Write_Str  (Dep_Name);
            Write_Line (" has time stamp earlier than source");
         end if;

         return;
      end if;

      --  Look for all dependencies

      Open (Dep_File, Dep_Name);

      --  If dependency file cannot be open, we need to recompile the source

      if not Is_Valid (Dep_File) then
         if Verbose_Mode then
            Write_Str  ("      -> could not open dependency file ");
            Write_Line (Dep_Name);
         end if;

         return;
      end if;

      --  Loop Big_Loop is executed several times only when the dependency file
      --  contains several times
      --     <object file>: <source1> ...
      --  When there is only one of such occurrence, Big_Loop is exited
      --  successfully at the beginning of the second loop.

      Big_Loop :
      loop
         declare
            End_Of_File_Reached : Boolean := False;

         begin
            loop
               if End_Of_File (Dep_File) then
                  End_Of_File_Reached := True;
                  exit;
               end if;

               Get_Line (Dep_File, Name_Buffer, Name_Len);

               exit when Name_Len > 0 and then Name_Buffer (1) /= '#';
            end loop;

            --  If dependency file contains only empty lines or comments, then
            --  dependencies are unknown, and the source needs to be
            --  recompiled.

            if End_Of_File_Reached then
               --  If we have reached the end of file after the first loop,
               --  there is nothing else to do.

               exit Big_Loop when Looping;

               if Verbose_Mode then
                  Write_Str  ("      -> dependency file ");
                  Write_Str  (Dep_Name);
                  Write_Line (" is empty");
               end if;

               Close (Dep_File);
               return;
            end if;
         end;

         Start  := 1;
         Finish := Index (Name_Buffer (1 .. Name_Len), ": ");

         if Finish /= 0 then
            Canonical_Case_File_Name (Name_Buffer (1 .. Finish - 1));
         end if;

         --  First line must start with name of object file, followed by colon

         if Finish = 0 or else
            Name_Buffer (1 .. Finish - 1) /= C_Object_Name
         then
            if Verbose_Mode then
               Write_Str  ("      -> dependency file ");
               Write_Str  (Dep_Name);
               Write_Line (" has wrong format");
            end if;

            Close (Dep_File);
            return;

         else
            Start := Finish + 2;

            --  Process each line

            Line_Loop : loop
               declare
                  Line : String  := Name_Buffer (1 .. Name_Len);
                  Last : Natural := Name_Len;

               begin
                  Name_Loop : loop

                     --  Find the beginning of the next source path name

                     while Start < Last and then Line (Start) = ' ' loop
                        Start := Start + 1;
                     end loop;

                     --  Go to next line when there is a continuation character
                     --  \ at the end of the line.

                     exit Name_Loop when Start = Last
                       and then Line (Start) = '\';

                     --  We should not be at the end of the line, without
                     --  a continuation character \.

                     if Start = Last then
                        if Verbose_Mode then
                           Write_Str  ("      -> dependency file ");
                           Write_Str  (Dep_Name);
                           Write_Line (" has wrong format");
                        end if;

                        Close (Dep_File);
                        return;
                     end if;

                     --  Look for the end of the source path name

                     Finish := Start;
                     while Finish < Last loop
                        if Line (Finish) = '\' then

                           --  On Windows, a '\' is part of the path name,
                           --  except when it is followed by another '\' or by
                           --  a space. On other platforms, when we are getting
                           --  a '\' that is not the last character of the
                           --  line, the next character is part of the path
                           --  name, even if it is a space.

                           if On_Windows
                             and then Line (Finish + 1) /= '\'
                             and then Line (Finish + 1) /= ' '
                           then
                              Finish := Finish + 1;

                           else
                              Line (Finish .. Last - 1) :=
                                Line (Finish + 1 .. Last);
                              Last := Last - 1;
                           end if;

                        else
                           --  A space that is not preceded by '\' indicates
                           --  the end of the path name.

                           exit when Line (Finish + 1) = ' ';

                           Finish := Finish + 1;
                        end if;
                     end loop;

                     --  Check this source

                     declare
                        Src_Name : constant String :=
                                     Normalize_Pathname
                                       (Name           =>
                                                       Line (Start .. Finish),
                                        Resolve_Links  => False,
                                        Case_Sensitive => False);
                        Src_TS   : Time_Stamp_Type;

                     begin
                        --  If it is original source, set
                        --  Source_In_Dependencies.

                        if Src_Name = C_Source_Path then
                           Source_In_Dependencies := True;
                        end if;

                        Name_Len := 0;
                        Add_Str_To_Name_Buffer (Src_Name);
                        Src_TS := File_Stamp (File_Name_Type'(Name_Find));

                        --  If the source does not exist, we need to recompile

                        if Src_TS = Empty_Time_Stamp then
                           if Verbose_Mode then
                              Write_Str  ("      -> source ");
                              Write_Str  (Src_Name);
                              Write_Line (" does not exist");
                           end if;

                           Close (Dep_File);
                           return;

                           --  If the source has been modified after the object
                           --  file, we need to recompile.

                        elsif Src_TS > Source.Object_TS then
                           if Verbose_Mode then
                              Write_Str  ("      -> source ");
                              Write_Str  (Src_Name);
                              Write_Line
                                (" has time stamp later than object file");
                           end if;

                           Close (Dep_File);
                           return;
                        end if;
                     end;

                     --  If the source path name ends the line, we are done

                     exit Line_Loop when Finish = Last;

                     --  Go get the next source on the line

                     Start := Finish + 1;
                  end loop Name_Loop;
               end;

               --  If we are here, we had a continuation character \ at the end
               --  of the line, so we continue with the next line.

               Get_Line (Dep_File, Name_Buffer, Name_Len);
               Start := 1;
            end loop Line_Loop;
         end if;

         --  Set Looping at the end of the first loop
         Looping := True;
      end loop Big_Loop;

      Close (Dep_File);

      --  If the original sources were not in the dependency file, then we
      --  need to recompile. It may mean that we are using a different source
      --  (different variant) for this object file.

      if not Source_In_Dependencies then
         if Verbose_Mode then
            Write_Str  ("      -> source ");
            Write_Str  (Source_Path);
            Write_Line (" is not in the dependencies");
         end if;

         return;
      end if;

      --  If we are here, then everything is OK, no need to recompile

      if Verbose_Mode then
         Write_Line ("      -> up to date");
      end if;

      Need_To_Compile := False;
   end Check_Compilation_Needed;

   ---------------------------
   -- Check_For_C_Plus_Plus --
   ---------------------------

   procedure Check_For_C_Plus_Plus is
   begin
      C_Plus_Plus_Is_Used := False;

      for Project in Project_Table.First ..
                     Project_Table.Last (Project_Tree.Projects)
      loop
         if
           Project_Tree.Projects.Table (Project).Langs
                                           (C_Plus_Plus_Language_Index)
         then
            C_Plus_Plus_Is_Used := True;
            exit;
         end if;
      end loop;
   end Check_For_C_Plus_Plus;

   -------------
   -- Compile --
   -------------

   procedure Compile
     (Source_Id    : Other_Source_Id;
      Data         : Project_Data;
      Local_Errors : in out Boolean)
   is
      Source  : Other_Source :=
                  Project_Tree.Other_Sources.Table (Source_Id);
      Success : Boolean;
      CPATH   : String_Access := null;

   begin
      --  If the compiler is not known yet, get its path name

      if Compiler_Names (Source.Language) = null then
         Get_Compiler (Source.Language);
      end if;

      --  For non GCC compilers, get the dependency file, first calling the
      --  compiler with the switch -M.

      if not Compiler_Is_Gcc (Source.Language) then
         Last_Argument := 0;

         --  Add the source name, preceded by -M

         Add_Argument (Dash_M, True);
         Add_Argument (Get_Name_String (Source.Path_Name), True);

         --  Add the compiling switches for this source found in
         --  package Compiler of the project file, if they exist.

         Add_Switches
           (Data, Compiler, Source.Language, Source.File_Name);

         --  Add the compiling switches for the language specified
         --  on the command line, if any.

         for
           J in 1 .. Comp_Opts.Last (Options (Source.Language))
         loop
            Add_Argument (Options (Source.Language).Table (J), True);
         end loop;

         --  Finally, add imported directory switches for this project file

         Add_Search_Directories (Data, Source.Language);

         --  And invoke the compiler using GNAT.Expect

         Display_Command
           (Compiler_Names (Source.Language).all,
            Compiler_Paths (Source.Language));

         begin
            Non_Blocking_Spawn
              (FD,
               Compiler_Paths (Source.Language).all,
               Arguments (1 .. Last_Argument),
               Buffer_Size => 0,
               Err_To_Out => True);

            declare
               Dep_File : Ada.Text_IO.File_Type;
               Result   : Expect_Match;

               Status : Integer;
               pragma Warnings (Off, Status);

            begin
               --  Create the dependency file

               Create (Dep_File, Out_File, Get_Name_String (Source.Dep_Name));

               loop
                  Expect (FD, Result, Line_Matcher);

                  exit when Result = Expect_Timeout;

                  declare
                     S : constant String := Strip_CR_LF (Expect_Out (FD));

                  begin
                     --  Each line of the output is put in the dependency
                     --  file, including errors. If there are errors, the
                     --  syntax of the dependency file will be incorrect and
                     --  recompilation will occur automatically the next time
                     --  the dependencies are checked.

                     Put_Line (Dep_File, S);
                  end;
               end loop;

               --  If we are here, it means we had a timeout, so the
               --  dependency file may be incomplete. It is safer to
               --  delete it, otherwise the dependencies may be wrong.

               Close (FD, Status);
               Close (Dep_File);
               Delete_File (Get_Name_String (Source.Dep_Name), Success);

            exception
               when Process_Died =>

                  --  This is the normal outcome. Just close the file

                  Close (FD, Status);
                  Close (Dep_File);

               when others =>

                  --  Something wrong happened. It is safer to delete the
                  --  dependency file, otherwise the dependencies may be wrong.

                  Close (FD, Status);

                  if Is_Open (Dep_File) then
                     Close (Dep_File);
                  end if;

                  Delete_File (Get_Name_String (Source.Dep_Name), Success);
            end;

         exception
               --  If we cannot spawn the compiler, then the dependencies are
               --  not updated. It is safer then to delete the dependency file,
               --  otherwise the dependencies may be wrong.

            when Invalid_Process =>
               Delete_File (Get_Name_String (Source.Dep_Name), Success);
         end;
      end if;

      Last_Argument := 0;

      --  For GCC compilers, make sure the language is always specified to
      --  to the GCC driver, in case the extension is not recognized by the
      --  GCC driver as a source of the language.

      if Compiler_Is_Gcc (Source.Language) then
         Add_Argument (Dash_x, Verbose_Mode);
         Add_Argument
           (Get_Name_String (Language_Names.Table (Source.Language)),
            Verbose_Mode);
      end if;

      Add_Argument (Dash_c, True);

      --  Add the compiling switches for this source found in package Compiler
      --  of the project file, if they exist.

      Add_Switches
        (Data, Compiler, Source.Language, Source.File_Name);

      --  Specify the source to be compiled

      Add_Argument (Get_Name_String (Source.Path_Name), True);

      --  If non static library project, compile with the PIC option if there
      --  is one (when there is no PIC option, MLib.Tgt.PIC_Option returns an
      --  empty string, and Add_Argument with an empty string has no effect).

      if Data.Library and then Data.Library_Kind /= Static then
         Add_Argument (PIC_Option, True);
      end if;

      --  Indicate the name of the object

      Add_Argument (Dash_o, True);
      Add_Argument (Get_Name_String (Source.Object_Name), True);

      --  When compiler is GCC, use the magic switch that creates the
      --  dependency file in the correct format.

      if Compiler_Is_Gcc (Source.Language) then
         Add_Argument
           ("-Wp,-MD," & Get_Name_String (Source.Dep_Name),
            Verbose_Mode);
      end if;

      --  Add the compiling switches for the language specified on the command
      --  line, if any.

      for J in 1 .. Comp_Opts.Last (Options (Source.Language)) loop
         Add_Argument (Options (Source.Language).Table (J), True);
      end loop;

      --  Finally, add the imported directory switches for this project file
      --  (or, for gcc compilers, set up the CPATH env var if needed).

      Add_Search_Directories (Data, Source.Language);

      --  Set CPATH, if compiler is GCC

      if Compiler_Is_Gcc (Source.Language) then
         CPATH := Current_Include_Paths (Source.Language);
      end if;

      --  And invoke the compiler

      Display_Command
        (Name  => Compiler_Names (Source.Language).all,
         Path  => Compiler_Paths (Source.Language),
         CPATH => CPATH);

      Spawn
        (Compiler_Paths (Source.Language).all,
         Arguments (1 .. Last_Argument),
         Success);

      --  Case of successful compilation

      if Success then

         --  Update the time stamp of the object file

         Source.Object_TS := File_Stamp (Source.Object_Name);

         --  Do some sanity checks

         if Source.Object_TS = Empty_Time_Stamp then
            Local_Errors := True;
            Report_Error
              ("object file ",
               Get_Name_String (Source.Object_Name),
               " has not been created");

         elsif Source.Object_TS < Source.Source_TS then
            Local_Errors := True;
            Report_Error
              ("object file ",
               Get_Name_String (Source.Object_Name),
               " has not been modified");

         else
            --  Everything looks fine, update the Other_Sources table

            Project_Tree.Other_Sources.Table (Source_Id) := Source;
         end if;

      --  Compilation failed

      else
         Local_Errors := True;
         Report_Error
           ("compilation of ",
            Get_Name_String (Source.Path_Name),
            " failed");
      end if;
   end Compile;

   --------------------------------
   -- Compile_Individual_Sources --
   --------------------------------

   procedure Compile_Individual_Sources is
      Data         : Project_Data :=
                       Project_Tree.Projects.Table (Main_Project);
      Source_Id    : Other_Source_Id;
      Source       : Other_Source;
      Source_Name  : File_Name_Type;
      Project_Name : String := Get_Name_String (Data.Name);
      Dummy        : Boolean := False;

      Ada_Is_A_Language : constant Boolean :=
                            Data.Langs (Ada_Language_Index);

   begin
      Ada_Mains.Init;
      To_Mixed (Project_Name);
      Compile_Only := True;

      Get_Imported_Directories (Main_Project, Data);
      Project_Tree.Projects.Table (Main_Project) := Data;

      --  Compilation will occur in the object directory

      if Project_Of_Current_Object_Directory /= Main_Project then
         Project_Of_Current_Object_Directory := Main_Project;
         Change_Dir (Get_Name_String (Data.Object_Directory));

         if Verbose_Mode then
            Write_Str  ("Changing to object directory of """);
            Write_Name (Data.Name);
            Write_Str  (""": """);
            Write_Name (Data.Display_Object_Dir);
            Write_Line ("""");
         end if;
      end if;

      if not Data.Other_Sources_Present then
         if Ada_Is_A_Language then
            Mains.Reset;

            loop
               declare
                  Main : constant String := Mains.Next_Main;
               begin
                  exit when Main'Length = 0;
                  Ada_Mains.Increment_Last;
                  Ada_Mains.Table (Ada_Mains.Last) := new String'(Main);
               end;
            end loop;

         else
            Osint.Fail ("project ", Project_Name, " contains no source");
         end if;

      else
         Mains.Reset;

         loop
            declare
               Main : constant String := Mains.Next_Main;
            begin
               Name_Len := Main'Length;
               exit when Name_Len = 0;
               Name_Buffer (1 .. Name_Len) := Main;
               Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
               Source_Name := Name_Find;

               if not Sources_Compiled.Get (Source_Name) then
                  Sources_Compiled.Set (Source_Name, True);

                  Source_Id := Data.First_Other_Source;
                  while Source_Id /= No_Other_Source loop
                     Source := Project_Tree.Other_Sources.Table (Source_Id);
                     exit when Source.File_Name = Source_Name;
                     Source_Id := Source.Next;
                  end loop;

                  if Source_Id = No_Other_Source then
                     if Ada_Is_A_Language then
                        Ada_Mains.Increment_Last;
                        Ada_Mains.Table (Ada_Mains.Last) := new String'(Main);

                     else
                        Report_Error
                          (Main,
                           " is not a valid source of project ",
                           Project_Name);
                     end if;

                  else
                     Compile (Source_Id, Data, Dummy);
                  end if;
               end if;
            end;
         end loop;
      end if;

      if Ada_Mains.Last > 0 then

         --  Invoke gnatmake for all Ada sources

         Last_Argument := 0;
         Add_Argument (Dash_u, True);

         for Index in 1 .. Ada_Mains.Last loop
            Add_Argument (Ada_Mains.Table (Index), True);
         end loop;

         Compile_Link_With_Gnatmake (Mains_Specified => False);
      end if;
   end Compile_Individual_Sources;

   --------------------------------
   -- Compile_Link_With_Gnatmake --
   --------------------------------

   procedure Compile_Link_With_Gnatmake (Mains_Specified : Boolean) is
      Data    : constant Project_Data :=
                  Project_Tree.Projects.Table (Main_Project);
      Success : Boolean;

   begin
      --  Array Arguments may already contain some arguments, so we don't
      --  set Last_Argument to 0.

      --  Get the gnatmake to invoke

      Get_Compiler (Ada_Language_Index);

      --  Specify the project file

      Add_Argument (Dash_P, True);
      Add_Argument (Get_Name_String (Data.Display_Path_Name), True);

      --  Add the saved switches, if any

      for Index in 1 .. Saved_Switches.Last loop
         Add_Argument (Saved_Switches.Table (Index), True);
      end loop;

      --  If Mains_Specified is True, find the mains in package Mains

      if Mains_Specified then
         Mains.Reset;

         loop
            declare
               Main : constant String := Mains.Next_Main;
            begin
               exit when Main'Length = 0;
               Add_Argument (Main, True);
            end;
         end loop;
      end if;

      --  Specify output file name, if any was specified on the command line

      if Output_File_Name /= null then
         Add_Argument (Dash_o, True);
         Add_Argument (Output_File_Name, True);
      end if;

      --  Transmit some switches to gnatmake

      --  -c

      if Compile_Only then
         Add_Argument (Dash_c, True);
      end if;

      --  -d

      if Display_Compilation_Progress then
         Add_Argument (Dash_d, True);
      end if;

      --  -eL

      if Follow_Links_For_Files then
         Add_Argument (Dash_eL, True);
      end if;

      --  -k

      if Keep_Going then
         Add_Argument (Dash_k, True);
      end if;

      --  -f

      if Force_Compilations then
         Add_Argument (Dash_f, True);
      end if;

      --  -v

      if Verbose_Mode then
         Add_Argument (Dash_v, True);
      end if;

      --  -q

      if Quiet_Output then
         Add_Argument (Dash_q, True);
      end if;

      --  -vP1 and -vP2

      case Current_Verbosity is
         when Default =>
            null;

         when Medium =>
            Add_Argument (Dash_vP1, True);

         when High =>
            Add_Argument (Dash_vP2, True);
      end case;

      --  If there are compiling options for Ada, transmit them to gnatmake

      if Comp_Opts.Last (Options (Ada_Language_Index)) /= 0 then
         Add_Argument (Dash_cargs, True);

         for Arg in 1 .. Comp_Opts.Last (Options (Ada_Language_Index)) loop
            Add_Argument (Options (Ada_Language_Index).Table (Arg), True);
         end loop;
      end if;

      if not Compile_Only then

         --  Linking options

         if Linker_Options.Last /= 0 then
            Add_Argument (Dash_largs, True);
         else
            Add_Argument (Dash_largs, Verbose_Mode);
         end if;

         --  Add the archives

         Add_Archives (For_Gnatmake => True);

         --  If there are linking options from the command line,
         --  transmit them to gnatmake.

         for Arg in 1 .. Linker_Options.Last loop
            Add_Argument (Linker_Options.Table (Arg), True);
         end loop;
      end if;

      --  And invoke gnatmake

      Display_Command
        (Compiler_Names (Ada_Language_Index).all,
         Compiler_Paths (Ada_Language_Index));

      Spawn
        (Compiler_Paths (Ada_Language_Index).all,
         Arguments (1 .. Last_Argument),
         Success);

      --  Report an error if call to gnatmake failed

      if not Success then
         Report_Error
           ("invocation of ",
            Compiler_Names (Ada_Language_Index).all,
            " failed");
      end if;
   end Compile_Link_With_Gnatmake;

   ---------------------
   -- Compile_Sources --
   ---------------------

   procedure Compile_Sources is
      Data         : Project_Data;
      Source_Id    : Other_Source_Id;
      Source       : Other_Source;

      Local_Errors : Boolean := False;
      --  Set to True when there is a compilation error. Used only when
      --  Keep_Going is True, to inhibit the building of the archive.

      Need_To_Compile : Boolean;
      --  Set to True when a source needs to be compiled/recompiled

      Need_To_Rebuild_Archive : Boolean := Force_Compilations;
      --  True when the archive needs to be built/rebuilt unconditionally

      Total_Number_Of_Sources : Int := 0;

      Current_Source_Number : Int := 0;

   begin
      --  First, get the number of sources

      for Project in Project_Table.First ..
                     Project_Table.Last (Project_Tree.Projects)
      loop
         Data := Project_Tree.Projects.Table (Project);

         if not Data.Virtual and then Data.Other_Sources_Present then
            Source_Id := Data.First_Other_Source;
            while Source_Id /= No_Other_Source loop
               Source := Project_Tree.Other_Sources.Table (Source_Id);
               Total_Number_Of_Sources := Total_Number_Of_Sources + 1;
               Source_Id := Source.Next;
            end loop;
         end if;
      end loop;

      --  Loop through project files

      for Project in Project_Table.First ..
                     Project_Table.Last (Project_Tree.Projects)
      loop
         Local_Errors := False;
         Data := Project_Tree.Projects.Table (Project);

         --  Nothing to do when no sources of language other than Ada

         if (not Data.Virtual) and then Data.Other_Sources_Present then

            --  If the imported directory switches are unknown, compute them

            if not Data.Include_Data_Set then
               Get_Imported_Directories (Project, Data);
               Data.Include_Data_Set := True;
               Project_Tree.Projects.Table (Project) := Data;
            end if;

            Need_To_Rebuild_Archive := Force_Compilations;

            --  Compilation will occur in the object directory

            if Project_Of_Current_Object_Directory /= Project then
               Project_Of_Current_Object_Directory := Project;
               Change_Dir (Get_Name_String (Data.Object_Directory));

               if Verbose_Mode then
                  Write_Str  ("Changing to object directory of """);
                  Write_Name (Data.Display_Name);
                  Write_Str  (""": """);
                  Write_Name (Data.Display_Object_Dir);
                  Write_Line ("""");
               end if;
            end if;

            --  Process each source one by one

            Source_Id := Data.First_Other_Source;
            while Source_Id /= No_Other_Source loop
               Source := Project_Tree.Other_Sources.Table (Source_Id);
               Current_Source_Number := Current_Source_Number + 1;
               Need_To_Compile := Force_Compilations;

               --  Check if compilation is needed

               if not Need_To_Compile then
                  Check_Compilation_Needed (Source, Need_To_Compile);
               end if;

               --  Proceed, if compilation is needed

               if Need_To_Compile then

                  --  If a source is compiled/recompiled, of course the
                  --  archive will need to be built/rebuilt.

                  Need_To_Rebuild_Archive := True;
                  Compile (Source_Id, Data, Local_Errors);
               end if;

               if Display_Compilation_Progress then
                  Write_Str ("completed ");
                  Write_Int (Current_Source_Number);
                  Write_Str (" out of ");
                  Write_Int (Total_Number_Of_Sources);
                  Write_Str (" (");
                  Write_Int
                    ((Current_Source_Number * 100) / Total_Number_Of_Sources);
                  Write_Str ("%)...");
                  Write_Eol;
               end if;

               --  Next source, if any

               Source_Id := Source.Next;
            end loop;

            if Need_To_Rebuild_Archive and then (not Data.Library) then
               Need_To_Rebuild_Global_Archive := True;
            end if;

            --  If there was no compilation error and -c was not used,
            --  build / rebuild the archive if necessary.

            if not Local_Errors
              and then Data.Library
              and then not Data.Langs (Ada_Language_Index)
              and then not Compile_Only
            then
               Build_Library (Project, Need_To_Rebuild_Archive);
            end if;
         end if;
      end loop;
   end Compile_Sources;

   ---------------
   -- Copyright --
   ---------------

   procedure Copyright is
   begin
      --  Only output the Copyright notice once

      if not Copyright_Output then
         Copyright_Output := True;
         Write_Eol;
         Write_Str ("GPRMAKE ");
         Write_Str (Gnatvsn.Gnat_Version_String);
         Write_Str (" Copyright 2004-");
         Write_Str (Gnatvsn.Current_Year);
         Write_Str (" Free Software Foundation, Inc.");
         Write_Eol;
      end if;
   end Copyright;

   ------------------------------------
   -- Create_Archive_Dependency_File --
   ------------------------------------

   procedure Create_Archive_Dependency_File
     (Name         : String;
      First_Source : Other_Source_Id)
   is
      Source_Id : Other_Source_Id;
      Source    : Other_Source;
      Dep_File  : Ada.Text_IO.File_Type;

   begin
      --  Create the file in Append mode, to avoid automatic insertion of
      --  an end of line if file is empty.

      Create (Dep_File, Append_File, Name);

      Source_Id := First_Source;
      while Source_Id /= No_Other_Source loop
         Source := Project_Tree.Other_Sources.Table (Source_Id);
         Put_Line (Dep_File, Get_Name_String (Source.Object_Name));
         Put_Line (Dep_File, String (Source.Object_TS));
         Source_Id := Source.Next;
      end loop;

      Close (Dep_File);

   exception
      when others =>
         if Is_Open (Dep_File) then
            Close (Dep_File);
         end if;
   end Create_Archive_Dependency_File;

   -------------------------------------------
   -- Create_Global_Archive_Dependency_File --
   -------------------------------------------

   procedure Create_Global_Archive_Dependency_File (Name : String) is
      Source_Id : Other_Source_Id;
      Source    : Other_Source;
      Dep_File  : Ada.Text_IO.File_Type;

   begin
      --  Create the file in Append mode, to avoid automatic insertion of
      --  an end of line if file is empty.

      Create (Dep_File, Append_File, Name);

      --  Get all the object files of non-Ada sources in non-library projects

      for Project in Project_Table.First ..
                     Project_Table.Last (Project_Tree.Projects)
      loop
         if not Project_Tree.Projects.Table (Project).Library then
            Source_Id :=
              Project_Tree.Projects.Table (Project).First_Other_Source;
            while Source_Id /= No_Other_Source loop
               Source := Project_Tree.Other_Sources.Table (Source_Id);

               --  Put only those object files that are in the global archive

               if Is_Included_In_Global_Archive
                    (Source.Object_Name, Project)
               then
                  Put_Line (Dep_File, Get_Name_String (Source.Object_Path));
                  Put_Line (Dep_File, String (Source.Object_TS));
               end if;

               Source_Id := Source.Next;
            end loop;
         end if;
      end loop;

      Close (Dep_File);

   exception
      when others =>
         if Is_Open (Dep_File) then
            Close (Dep_File);
         end if;
   end Create_Global_Archive_Dependency_File;

   ---------------------
   -- Display_Command --
   ---------------------

   procedure Display_Command
     (Name    : String;
      Path    : String_Access;
      CPATH   : String_Access := null;
      Ellipse : Boolean := False)
   is
      Display_Ellipse : Boolean := Ellipse;

   begin
      --  Only display the command in Verbose Mode (-v) or when
      --  not in Quiet Output (no -q).

      if Verbose_Mode or (not Quiet_Output) then

         --  In Verbose Mode output the full path of the spawned process

         if Verbose_Mode then
            if CPATH /= null then
               Write_Str  ("CPATH = ");
               Write_Line (CPATH.all);
            end if;

            Write_Str (Path.all);

         else
            Write_Str (Name);
         end if;

         --  Display only the arguments for which the display flag is set
         --  (in Verbose Mode, the display flag is set for all arguments)

         for Arg in 1 .. Last_Argument loop
            if Arguments_Displayed (Arg) then
               Write_Char (' ');
               Write_Str (Arguments (Arg).all);

            elsif Display_Ellipse then
               Write_Str (" ...");
               Display_Ellipse := False;
            end if;
         end loop;

         Write_Eol;
      end if;
   end Display_Command;

   ------------------
   -- Get_Compiler --
   ------------------

   procedure Get_Compiler (For_Language : First_Language_Indexes) is
      Data : constant Project_Data :=
               Project_Tree.Projects.Table (Main_Project);

      Ide : constant Package_Id :=
        Value_Of
          (Name_Ide,
           In_Packages => Data.Decl.Packages,
           In_Tree     => Project_Tree);
      --  The id of the package IDE in the project file

      Compiler : constant Variable_Value :=
        Value_Of
          (Name                    => Language_Names.Table (For_Language),
           Index                   => 0,
           Attribute_Or_Array_Name => Name_Compiler_Command,
           In_Package              => Ide,
           In_Tree                 => Project_Tree);
      --  The value of Compiler_Command ("language") in package IDE, if defined

   begin
      --  No need to do it again if the compiler is known for this language

      if Compiler_Names (For_Language) = null then

         --  If compiler command is not defined for this language in package
         --  IDE, use the default compiler for this language.

         if Compiler = Nil_Variable_Value then
            if For_Language in Default_Compiler_Names'Range then
               Compiler_Names (For_Language) :=
                 Default_Compiler_Names (For_Language);

            else
               Osint.Fail
                 ("unknown compiler name for language """,
                  Get_Name_String (Language_Names.Table (For_Language)),
                  """");
            end if;

         else
            Compiler_Names (For_Language) :=
              new String'(Get_Name_String (Compiler.Value));
         end if;

         --  Check we have a GCC compiler (name ends with "gcc" or "g++")

         declare
            Comp_Name : constant String := Compiler_Names (For_Language).all;
            Last3     : String (1 .. 3);
         begin
            if Comp_Name'Length >= 3 then
               Last3 := Comp_Name (Comp_Name'Last - 2 .. Comp_Name'Last);
               Compiler_Is_Gcc (For_Language) :=
                 (Last3 = "gcc") or (Last3 = "g++");
            else
               Compiler_Is_Gcc (For_Language) := False;
            end if;
         end;

         --  Locate the compiler on the path

         Compiler_Paths (For_Language) :=
           Locate_Exec_On_Path (Compiler_Names (For_Language).all);

         --  Fail if compiler cannot be found

         if Compiler_Paths (For_Language) = null then
            if For_Language = Ada_Language_Index then
               Osint.Fail
                 ("unable to locate """,
                  Compiler_Names (For_Language).all,
                  """");

            else
               Osint.Fail
                 ("unable to locate " &
                  Get_Name_String (Language_Names.Table (For_Language)),
                  " compiler """, Compiler_Names (For_Language).all & '"');
            end if;
         end if;
      end if;
   end Get_Compiler;

   ------------------------------
   -- Get_Imported_Directories --
   ------------------------------

   procedure Get_Imported_Directories
     (Project : Project_Id;
      Data    : in out Project_Data)
   is
      Imported_Projects : Project_List := Data.Imported_Projects;

      Path_Length : Natural := 0;
      Position    : Natural := 0;

      procedure Add (Source_Dirs : String_List_Id);
      --  Add a list of source directories

      procedure Recursive_Get_Dirs (Prj : Project_Id);
      --  Recursive procedure to get the source directories of this project
      --  file and of the project files it imports, in the correct order.

      ---------
      -- Add --
      ---------

      procedure Add (Source_Dirs : String_List_Id) is
         Element_Id : String_List_Id;
         Element    : String_Element;
         Add_Arg    : Boolean := True;

      begin
         --  Add each source directory path name, preceded by "-I" to Arguments

         Element_Id := Source_Dirs;
         while Element_Id /= Nil_String loop
            Element := Project_Tree.String_Elements.Table (Element_Id);

            if Element.Value /= No_Name then
               Get_Name_String (Element.Display_Value);

               if Name_Len > 0 then

                  --  Remove a trailing directory separator: this may cause
                  --  problems on Windows.

                  if Name_Len > 1
                    and then Name_Buffer (Name_Len) = Directory_Separator
                  then
                     Name_Len := Name_Len - 1;
                  end if;

                  declare
                     Arg : constant String :=
                             "-I" & Name_Buffer (1 .. Name_Len);
                  begin
                     --  Check if directory is already in the list. If it is,
                     --  no need to put it there again.

                     Add_Arg := True;

                     for Index in 1 .. Last_Argument loop
                        if Arguments (Index).all = Arg then
                           Add_Arg := False;
                           exit;
                        end if;
                     end loop;

                     if Add_Arg then
                        if Path_Length /= 0 then
                           Path_Length := Path_Length + 1;
                        end if;

                        Path_Length := Path_Length + Name_Len;

                        Add_Argument (Arg, True);
                     end if;
                  end;
               end if;
            end if;

            Element_Id := Element.Next;
         end loop;
      end Add;

      ------------------------
      -- Recursive_Get_Dirs --
      ------------------------

      procedure Recursive_Get_Dirs (Prj : Project_Id) is
         Data     : Project_Data;
         Imported : Project_List;

      begin
         --  Nothing to do if project is undefined

         if Prj /= No_Project then
            Data := Project_Tree.Projects.Table (Prj);

            --  Nothing to do if project has already been processed

            if not Data.Seen then

               --  Mark the project as processed, to avoid multiple processing
               --  of the same project.

               Project_Tree.Projects.Table (Prj).Seen := True;

               --  Add the source directories of this project

               if not Data.Virtual then
                  Add (Data.Source_Dirs);
               end if;

               Recursive_Get_Dirs (Data.Extends);

               --  Call itself for all imported projects, if any

               Imported := Data.Imported_Projects;
               while Imported /= Empty_Project_List loop
                  Recursive_Get_Dirs
                    (Project_Tree.Project_Lists.Table (Imported).Project);
                  Imported :=
                    Project_Tree.Project_Lists.Table (Imported).Next;
               end loop;
            end if;
         end if;
      end Recursive_Get_Dirs;

   --  Start of processing for Get_Imported_Directories

   begin
      --  First, mark all project as not processed

      for J in Project_Table.First ..
               Project_Table.Last (Project_Tree.Projects)
      loop
         Project_Tree.Projects.Table (J).Seen := False;
      end loop;

      --  Empty Arguments

      Last_Argument := 0;

      --  Process this project individually, project data are already known

      Project_Tree.Projects.Table (Project).Seen := True;

      Add (Data.Source_Dirs);

      Recursive_Get_Dirs (Data.Extends);

      while Imported_Projects /= Empty_Project_List loop
         Recursive_Get_Dirs
           (Project_Tree.Project_Lists.Table
              (Imported_Projects).Project);
         Imported_Projects := Project_Tree.Project_Lists.Table
                                (Imported_Projects).Next;
      end loop;

      Data.Imported_Directories_Switches :=
        new Argument_List'(Arguments (1 .. Last_Argument));

      --  Create the Include_Path, from the Arguments

      Data.Include_Path := new String (1 .. Path_Length);
      Data.Include_Path (1 .. Arguments (1)'Length - 2) :=
        Arguments (1)(Arguments (1)'First + 2 .. Arguments (1)'Last);
      Position := Arguments (1)'Length - 2;

      for Arg in 2 .. Last_Argument loop
         Position := Position + 1;
         Data.Include_Path (Position) := Path_Separator;
         Data.Include_Path
           (Position + 1 .. Position + Arguments (Arg)'Length - 2) :=
           Arguments (Arg)(Arguments (Arg)'First + 2 .. Arguments (Arg)'Last);
         Position := Position + Arguments (Arg)'Length - 2;
      end loop;

      Last_Argument := 0;
   end Get_Imported_Directories;

   -------------
   -- Gprmake --
   -------------

   procedure Gprmake is
   begin
      Makegpr.Initialize;

      if Verbose_Mode then
         Write_Eol;
         Write_Str ("Parsing project file """);
         Write_Str (Project_File_Name.all);
         Write_Str (""".");
         Write_Eol;
      end if;

      --  Parse and process project files for other languages (not for Ada)

      Prj.Pars.Parse
        (Project           => Main_Project,
         In_Tree           => Project_Tree,
         Project_File_Name => Project_File_Name.all,
         Packages_To_Check => Packages_To_Check);

      --  Fail if parsing/processing was unsuccessful

      if Main_Project = No_Project then
         Osint.Fail ("""", Project_File_Name.all, """ processing failed");
      end if;

      if Verbose_Mode then
         Write_Eol;
         Write_Str ("Parsing of project file """);
         Write_Str (Project_File_Name.all);
         Write_Str (""" is finished.");
         Write_Eol;
      end if;

      --  If -f was specified, we will certainly need to link (except when
      --  -u or -c were specified, of course).

      Need_To_Relink := Force_Compilations;

      if Unique_Compile then
         if Mains.Number_Of_Mains = 0 then
            Osint.Fail
              ("No source specified to compile in 'unique compile' mode");
         else
            Compile_Individual_Sources;
            Report_Total_Errors ("compilation");
         end if;

      else
         declare
            Data : constant Prj.Project_Data :=
                     Project_Tree.Projects.Table (Main_Project);
         begin
            if Data.Library and then Mains.Number_Of_Mains /= 0 then
               Osint.Fail
                 ("Cannot specify mains on the command line " &
                  "for a Library Project");
            end if;

            --  First check for C++, to link libraries with g++,
            --  rather than gcc.

            Check_For_C_Plus_Plus;

            --  Compile sources and build archives for library project,
            --  if necessary.

            Compile_Sources;

            --  When Keep_Going is True, if we had some errors, fail now,
            --  reporting the number of compilation errors.
            --  Do not attempt to link.

            Report_Total_Errors ("compilation");

            --  If -c was not specified, link the executables,
            --  if there are any.

            if not Compile_Only
              and then not Data.Library
              and then Data.Object_Directory /= No_Path
            then
               Build_Global_Archive;
               Link_Executables;
            end if;

            --  When Keep_Going is True, if we had some errors, fail, reporting
            --  the number of linking errors.

            Report_Total_Errors ("linking");
         end;
      end if;
   end Gprmake;

   ----------------
   -- Initialize --
   ----------------

   procedure Initialize is
   begin
      Set_Mode (Ada_Only);

      --  Do some necessary package initializations

      Csets.Initialize;
      Namet.Initialize;
      Snames.Initialize;
      Prj.Initialize (Project_Tree);
      Mains.Delete;

      --  Add the directory where gprmake is invoked in front of the path,
      --  if gprmake is invoked from a bin directory or with directory
      --  information. Only do this if the platform is not VMS, where the
      --  notion of path does not really exist.

      --  Below code shares nasty code duplication with make.adb code???

      if not OpenVMS then
         declare
            Prefix  : constant String := Executable_Prefix_Path;
            Command : constant String := Command_Name;

         begin
            if Prefix'Length > 0 then
               declare
                  PATH : constant String :=
                           Prefix & Directory_Separator & "bin" &
                           Path_Separator &
                           Getenv ("PATH").all;
               begin
                  Setenv ("PATH", PATH);
               end;

            else
               for Index in reverse Command'Range loop
                  if Command (Index) = Directory_Separator then
                     declare
                        Absolute_Dir : constant String :=
                                         Normalize_Pathname
                                           (Command (Command'First .. Index));
                        PATH         : constant String :=
                                         Absolute_Dir &
                                         Path_Separator &
                                         Getenv ("PATH").all;
                     begin
                        Setenv ("PATH", PATH);
                     end;

                     exit;
                  end if;
               end loop;
            end if;
         end;
      end if;

      --  Set Name_Ide and Name_Compiler_Command

      Name_Len := 0;
      Add_Str_To_Name_Buffer ("ide");
      Name_Ide := Name_Find;

      Name_Len := 0;
      Add_Str_To_Name_Buffer ("compiler_command");
      Name_Compiler_Command := Name_Find;

      --  Make sure the Saved_Switches table is empty

      Saved_Switches.Set_Last (0);

      --  Get the command line arguments

      Scan_Args : for Next_Arg in 1 .. Argument_Count loop
         Scan_Arg (Argument (Next_Arg));
      end loop Scan_Args;

      --  Fail if command line ended with "-P"

      if Project_File_Name_Expected then
         Osint.Fail ("project file name missing after -P");

      --  Or if it ended with "-o"

      elsif Output_File_Name_Expected then
         Osint.Fail ("output file name missing after -o");
      end if;

      --  If no project file was specified, display the usage and fail

      if Project_File_Name = null then
         Usage;
         Exit_Program (E_Success);
      end if;

      --  To be able of finding libgnat.a in MLib.Tgt, we need to have the
      --  default search dirs established in Osint.

      Osint.Add_Default_Search_Dirs;
   end Initialize;

   -----------------------------------
   -- Is_Included_In_Global_Archive --
   -----------------------------------

   function Is_Included_In_Global_Archive
     (Object_Name : File_Name_Type;
      Project     : Project_Id) return Boolean
   is
      Data   : Project_Data := Project_Tree.Projects.Table (Project);
      Source : Other_Source_Id;

   begin
      while Data.Extended_By /= No_Project loop
         Data := Project_Tree.Projects.Table (Data.Extended_By);

         Source := Data.First_Other_Source;
         while Source /= No_Other_Source loop
            if Project_Tree.Other_Sources.Table (Source).Object_Name =
                 Object_Name
            then
               return False;
            else
               Source :=
                 Project_Tree.Other_Sources.Table (Source).Next;
            end if;
         end loop;
      end loop;

      return True;
   end Is_Included_In_Global_Archive;

   ----------------------
   -- Link_Executables --
   ----------------------

   procedure Link_Executables is
      Data : constant Project_Data :=
               Project_Tree.Projects.Table (Main_Project);

      Mains_Specified : constant Boolean := Mains.Number_Of_Mains /= 0;
      --  True if main sources were specified on the command line

      Object_Dir : constant String :=
                     Get_Name_String (Data.Display_Object_Dir);
      --  Path of the object directory of the main project

      Source_Id : Other_Source_Id;
      Source    : Other_Source;
      Success   : Boolean;

      Linker_Name : String_Access;
      Linker_Path : String_Access;
      --  The linker name and path, when linking is not done by gnatlink

      Link_Done   : Boolean := False;
      --  Set to True when the linker is invoked directly (not through
      --  gnatmake) to be able to report if mains were up to date at the end
      --  of execution.

      procedure Add_C_Plus_Plus_Link_For_Gnatmake;
      --  Add the --LINK= switch for gnatlink, depending on the C++ compiler

      procedure Check_Time_Stamps (Exec_Time_Stamp : Time_Stamp_Type);
      --  Check if there is an archive that is more recent than the executable
      --  to decide if we need to relink.

      procedure Choose_C_Plus_Plus_Link_Process;
      --  If the C++ compiler is not g++, create the correct script to link

      procedure Link_Foreign
        (Main    : String;
         Main_Id : File_Name_Type;
         Source  : Other_Source);
      --  Link a non-Ada main, when there is no Ada code

      ---------------------------------------
      -- Add_C_Plus_Plus_Link_For_Gnatmake --
      ---------------------------------------

      procedure Add_C_Plus_Plus_Link_For_Gnatmake is
      begin
         Add_Argument
           ("--LINK=" & Compiler_Names (C_Plus_Plus_Language_Index).all,
            Verbose_Mode);
      end Add_C_Plus_Plus_Link_For_Gnatmake;

      -----------------------
      -- Check_Time_Stamps --
      -----------------------

      procedure Check_Time_Stamps (Exec_Time_Stamp : Time_Stamp_Type) is
         Prj_Data : Project_Data;

      begin
         for Prj in Project_Table.First ..
                    Project_Table.Last (Project_Tree.Projects)
         loop
            Prj_Data := Project_Tree.Projects.Table (Prj);

            --  There is an archive only in project
            --  files with sources other than Ada
            --  sources.

            if Data.Other_Sources_Present then
               declare
                  Archive_Path : constant String := Get_Name_String
                    (Prj_Data.Display_Object_Dir) & Directory_Separator
                    & "lib" & Get_Name_String (Prj_Data.Display_Name)
                    & '.' & Archive_Ext;
                  Archive_TS   : Time_Stamp_Type;
               begin
                  Name_Len := 0;
                  Add_Str_To_Name_Buffer (Archive_Path);
                  Archive_TS := File_Stamp (File_Name_Type'(Name_Find));

                  --  If the archive is later than the
                  --  executable, we need to relink.

                  if Archive_TS /=  Empty_Time_Stamp
                    and then
                      Exec_Time_Stamp < Archive_TS
                  then
                     Need_To_Relink := True;

                     if Verbose_Mode then
                        Write_Str ("      -> ");
                        Write_Str (Archive_Path);
                        Write_Str (" has time stamp ");
                        Write_Str ("later than ");
                        Write_Line ("executable");
                     end if;

                     exit;
                  end if;
               end;
            end if;
         end loop;
      end Check_Time_Stamps;

      -------------------------------------
      -- Choose_C_Plus_Plus_Link_Process --
      -------------------------------------

      procedure Choose_C_Plus_Plus_Link_Process is
      begin
         if Compiler_Names (C_Plus_Plus_Language_Index) = null then
            Get_Compiler (C_Plus_Plus_Language_Index);
         end if;
      end Choose_C_Plus_Plus_Link_Process;

      ------------------
      -- Link_Foreign --
      ------------------

      procedure Link_Foreign
        (Main    : String;
         Main_Id : File_Name_Type;
         Source  : Other_Source)
      is
         Executable_Name : constant String :=
                             Get_Name_String
                               (Executable_Of
                                    (Project  => Main_Project,
                                     In_Tree  => Project_Tree,
                                     Main     => Main_Id,
                                     Index    => 0,
                                     Ada_Main => False));
         --  File name of the executable

         Executable_Path : constant String :=
                             Get_Name_String
                               (Data.Display_Exec_Dir) &
                                Directory_Separator & Executable_Name;
         --  Path name of the executable

         Exec_Time_Stamp : Time_Stamp_Type;

      begin
         --  Now, check if the executable is up to date. It is considered
         --  up to date if its time stamp is not earlier that the time stamp
         --  of any archive. Only do that if we don't know if we need to link.

         if not Need_To_Relink then

            --  Get the time stamp of the executable

            Name_Len := 0;
            Add_Str_To_Name_Buffer (Executable_Path);
            Exec_Time_Stamp := File_Stamp (File_Name_Type'(Name_Find));

            if Verbose_Mode then
               Write_Str  ("   Checking executable ");
               Write_Line (Executable_Name);
            end if;

            --  If executable does not exist, we need to link

            if Exec_Time_Stamp = Empty_Time_Stamp then
               Need_To_Relink := True;

               if Verbose_Mode then
                  Write_Line ("      -> not found");
               end if;

            --  Otherwise, get the time stamps of each archive. If one of
            --  them is found later than the executable, we need to relink.

            else
               Check_Time_Stamps (Exec_Time_Stamp);
            end if;

            --  If Need_To_Relink is False, we are done

            if Verbose_Mode and (not Need_To_Relink) then
               Write_Line ("      -> up to date");
            end if;
         end if;

         --  Prepare to link

         if Need_To_Relink then
            Link_Done := True;

            Last_Argument := 0;

            --  Specify the executable path name

            Add_Argument (Dash_o, True);
            Add_Argument
              (Get_Name_String (Data.Display_Exec_Dir) &
               Directory_Separator &
               Get_Name_String
                 (Executable_Of
                    (Project  => Main_Project,
                     In_Tree  => Project_Tree,
                     Main     => Main_Id,
                     Index    => 0,
                     Ada_Main => False)),
               True);

            --  Specify the object file of the main source

            Add_Argument
              (Object_Dir & Directory_Separator &
               Get_Name_String (Source.Object_Name),
               True);

            --  Add all the archives, in a correct order

            Add_Archives (For_Gnatmake => False);

            --  Add the switches specified in package Linker of
            --  the main project.

            Add_Switches
              (Data      => Data,
               Proc      => Linker,
               Language  => Source.Language,
               File_Name => Main_Id);

            --  Add the switches specified in attribute
            --  Linker_Options of packages Linker.

            if Link_Options_Switches = null then
               Link_Options_Switches :=
                 new Argument_List'
                   (Linker_Options_Switches (Main_Project, Project_Tree));
            end if;

            Add_Arguments (Link_Options_Switches.all, True);

            --  Add the linking options specified on the
            --  command line.

            for Arg in 1 .. Linker_Options.Last loop
               Add_Argument (Linker_Options.Table (Arg), True);
            end loop;

            --  If there are shared libraries and the run path
            --  option is supported, add the run path switch.

            if Lib_Path.Last > 0 then
               Add_Argument
                 (Path_Option.all &
                  String (Lib_Path.Table (1 .. Lib_Path.Last)),
                  Verbose_Mode);
            end if;

            --  And invoke the linker

            Display_Command (Linker_Name.all, Linker_Path);
            Spawn
              (Linker_Path.all,
               Arguments (1 .. Last_Argument),
               Success);

            if not Success then
               Report_Error ("could not link ", Main);
            end if;
         end if;
      end Link_Foreign;

   --  Start of processing of Link_Executables

   begin
      --  If no mains specified, get mains from attribute Main, if it exists

      if not Mains_Specified then
         declare
            Element_Id : String_List_Id;
            Element    : String_Element;

         begin
            Element_Id := Data.Mains;
            while Element_Id /= Nil_String loop
               Element := Project_Tree.String_Elements.Table (Element_Id);

               if Element.Value /= No_Name then
                  Mains.Add_Main (Get_Name_String (Element.Value));
               end if;

               Element_Id := Element.Next;
            end loop;
         end;
      end if;

      if Mains.Number_Of_Mains = 0 then

         --  If the attribute Main is an empty list or not specified,
         --  there is nothing to do.

         if Verbose_Mode then
            Write_Line ("No main to link");
         end if;
         return;
      end if;

      --  Check if -o was used for several mains

      if Output_File_Name /= null and then Mains.Number_Of_Mains > 1 then
         Osint.Fail ("cannot specify an executable name for several mains");
      end if;

      --  Check how we are going to do the link

      if not Data.Other_Sources_Present then

         --  Only Ada sources in the main project, and even maybe not

         if Data.Extends = No_Project and then
           not Data.Langs (Ada_Language_Index)
         then
            --  Fail if the main project has no source of any language

            Osint.Fail
              ("project """,
               Get_Name_String (Data.Name),
               """ has no sources, so no main can be linked");

         else
            --  Only Ada sources in the main project, call gnatmake directly

            Last_Argument := 0;

            --  Choose correct linker if there is C++ code in other projects

            if C_Plus_Plus_Is_Used then
               Choose_C_Plus_Plus_Link_Process;
               Add_Argument (Dash_largs, Verbose_Mode);
               Add_C_Plus_Plus_Link_For_Gnatmake;
               Add_Argument (Dash_margs, Verbose_Mode);
            end if;

            Compile_Link_With_Gnatmake (Mains_Specified);
         end if;

      else
         --  There are other language sources. First check if there are also
         --  sources in Ada.

         if Data.Langs (Ada_Language_Index) then

            --  There is a mix of Ada and other language sources in the main
            --  project. Any main that is not a source of the other languages
            --  will be deemed to be an Ada main.

            --  Find the mains of the other languages and the Ada mains

            Mains.Reset;
            Ada_Mains.Set_Last (0);
            Other_Mains.Set_Last (0);

            --  For each main

            loop
               declare
                  Main    : constant String := Mains.Next_Main;
                  Main_Id : File_Name_Type;

               begin
                  exit when Main'Length = 0;

                  --  Get the main file name

                  Name_Len := 0;
                  Add_Str_To_Name_Buffer (Main);
                  Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
                  Main_Id := Name_Find;

                  --  Check if it is a source of a language other than Ada

                  Source_Id := Data.First_Other_Source;
                  while Source_Id /= No_Other_Source loop
                     Source :=
                       Project_Tree.Other_Sources.Table (Source_Id);
                     exit when Source.File_Name = Main_Id;
                     Source_Id := Source.Next;
                  end loop;

                  --  If it is not, put it in the list of Ada mains

                  if Source_Id = No_Other_Source then
                     Ada_Mains.Increment_Last;
                     Ada_Mains.Table (Ada_Mains.Last) := new String'(Main);

                  --  Otherwise, put it in the list of other mains

                  else
                     Other_Mains.Increment_Last;
                     Other_Mains.Table (Other_Mains.Last) := Source;
                  end if;
               end;
            end loop;

            --  If C++ is one of the other language, create the shell script
            --  to do the link.

            if C_Plus_Plus_Is_Used then
               Choose_C_Plus_Plus_Link_Process;
            end if;

            --  Call gnatmake with the necessary switches for each non-Ada
            --  main, if there are some.

            for Main in 1 .. Other_Mains.Last loop
               declare
                  Source : constant Other_Source := Other_Mains.Table (Main);

               begin
                  Last_Argument := 0;

                  --  Add -o if -o was specified

                  if Output_File_Name = null then
                     Add_Argument (Dash_o, True);
                     Add_Argument
                       (Get_Name_String
                          (Executable_Of
                             (Project  => Main_Project,
                              In_Tree  => Project_Tree,
                              Main     => Other_Mains.Table (Main).File_Name,
                              Index    => 0,
                              Ada_Main => False)),
                        True);
                  end if;

                  --  Call gnatmake with the -B switch

                  Add_Argument (Dash_B, True);

                  --  Add to the linking options the object file of the source

                  Add_Argument (Dash_largs, Verbose_Mode);
                  Add_Argument
                    (Get_Name_String (Source.Object_Name), Verbose_Mode);

                  --  If C++ is one of the language, add the --LINK switch
                  --  to the linking switches.

                  if C_Plus_Plus_Is_Used then
                     Add_C_Plus_Plus_Link_For_Gnatmake;
                  end if;

                  --  Add -margs so that the following switches are for
                  --  gnatmake

                  Add_Argument (Dash_margs, Verbose_Mode);

                  --  And link with gnatmake

                  Compile_Link_With_Gnatmake (Mains_Specified => False);
               end;
            end loop;

            --  If there are also Ada mains, call gnatmake for all these mains

            if Ada_Mains.Last /= 0 then
               Last_Argument := 0;

               --  Put all the Ada mains as the first arguments

               for Main in 1 .. Ada_Mains.Last loop
                  Add_Argument (Ada_Mains.Table (Main).all, True);
               end loop;

               --  If C++ is one of the languages, add the --LINK switch to
               --  the linking switches.

               if Data.Langs (C_Plus_Plus_Language_Index) then
                  Add_Argument (Dash_largs, Verbose_Mode);
                  Add_C_Plus_Plus_Link_For_Gnatmake;
                  Add_Argument (Dash_margs, Verbose_Mode);
               end if;

               --  And link with gnatmake

               Compile_Link_With_Gnatmake (Mains_Specified => False);
            end if;

         else
            --  No Ada source in main project

            --  First, get the linker to invoke

            if Data.Langs (C_Plus_Plus_Language_Index) then
               Get_Compiler (C_Plus_Plus_Language_Index);
               Linker_Name := Compiler_Names (C_Plus_Plus_Language_Index);
               Linker_Path := Compiler_Paths (C_Plus_Plus_Language_Index);

            else
               Get_Compiler (C_Language_Index);
               Linker_Name := Compiler_Names (C_Language_Index);
               Linker_Path := Compiler_Paths (C_Language_Index);
            end if;

            Link_Done := False;

            Mains.Reset;

            --  Get each main, check if it is a source of the main project,
            --  and if it is, invoke the linker.

            loop
               declare
                  Main    : constant String := Mains.Next_Main;
                  Main_Id : File_Name_Type;

               begin
                  exit when Main'Length = 0;

                  --  Get the file name of the main

                  Name_Len := 0;
                  Add_Str_To_Name_Buffer (Main);
                  Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
                  Main_Id := Name_Find;

                  --  Check if it is a source of the main project file

                  Source_Id := Data.First_Other_Source;
                  while Source_Id /= No_Other_Source loop
                     Source :=
                       Project_Tree.Other_Sources.Table (Source_Id);
                     exit when Source.File_Name = Main_Id;
                     Source_Id := Source.Next;
                  end loop;

                  --  Report an error if it is not

                  if Source_Id = No_Other_Source then
                     Report_Error
                       (Main, "is not a source of project ",
                        Get_Name_String (Data.Name));

                  else
                     Link_Foreign (Main, Main_Id, Source);
                  end if;
               end;
            end loop;

            --  If no linking was done, report it, except in Quiet Output

            if (Verbose_Mode or (not Quiet_Output)) and (not Link_Done) then
               Osint.Write_Program_Name;

               if Mains.Number_Of_Mains = 1 then

                  --  If there is only one executable, report its name too

                  Write_Str (": """);
                  Mains.Reset;

                  declare
                     Main    : constant String := Mains.Next_Main;
                     Main_Id : File_Name_Type;
                  begin
                     Name_Len := 0;
                     Add_Str_To_Name_Buffer (Main);
                     Main_Id := Name_Find;
                     Write_Str
                       (Get_Name_String
                          (Executable_Of
                             (Project  => Main_Project,
                              In_Tree  => Project_Tree,
                              Main     => Main_Id,
                              Index    => 0,
                              Ada_Main => False)));
                     Write_Line (""" up to date");
                  end;

               else
                  Write_Line (": all executables up to date");
               end if;
            end if;
         end if;
      end if;
   end Link_Executables;

   ------------------
   -- Report_Error --
   ------------------

   procedure Report_Error
     (S1 : String;
      S2 : String := "";
      S3 : String := "")
   is
   begin
      --  If Keep_Going is True, output error message preceded by error header

      if Keep_Going then
         Total_Number_Of_Errors := Total_Number_Of_Errors + 1;
         Write_Str (Error_Header);
         Write_Str (S1);
         Write_Str (S2);
         Write_Str (S3);
         Write_Eol;

      --  Otherwise just fail

      else
         Osint.Fail (S1, S2, S3);
      end if;
   end Report_Error;

   -------------------------
   -- Report_Total_Errors --
   -------------------------

   procedure Report_Total_Errors (Kind : String) is
   begin
      if Total_Number_Of_Errors /= 0 then
         if Total_Number_Of_Errors = 1 then
            Osint.Fail
              ("One ", Kind, " error");

         else
            Osint.Fail
              ("Total of" & Total_Number_Of_Errors'Img,
               ' ' & Kind & " errors");
         end if;
      end if;
   end Report_Total_Errors;

   --------------
   -- Scan_Arg --
   --------------

   procedure Scan_Arg (Arg : String) is
   begin
      pragma Assert (Arg'First = 1);

      if Arg'Length = 0 then
         return;
      end if;

      --  If preceding switch was -P, a project file name need to be
      --  specified, not a switch.

      if Project_File_Name_Expected then
         if Arg (1) = '-' then
            Osint.Fail ("project file name missing after -P");
         else
            Project_File_Name_Expected := False;
            Project_File_Name := new String'(Arg);
         end if;

      --  If preceding switch was -o, an executable name need to be
      --  specified, not a switch.

      elsif Output_File_Name_Expected then
         if Arg (1) = '-' then
            Osint.Fail ("output file name missing after -o");
         else
            Output_File_Name_Expected := False;
            Output_File_Name := new String'(Arg);
         end if;

      --  Set the processor/language for the following switches

      --  -cargs: Ada compiler arguments

      elsif Arg = "-cargs" then
         Current_Language  := Ada_Language_Index;
         Current_Processor := Compiler;

      elsif Arg'Length > 7 and then Arg (1 .. 7) = "-cargs:" then
         Name_Len := 0;
         Add_Str_To_Name_Buffer (Arg (8 .. Arg'Last));
         To_Lower (Name_Buffer (1 .. Name_Len));

         declare
            Lang : constant Name_Id := Name_Find;
         begin
            Current_Language := Language_Indexes.Get (Lang);

            if Current_Language = No_Language_Index then
               Add_Language_Name (Lang);
               Current_Language := Last_Language_Index;
            end if;

            Current_Processor := Compiler;
         end;

      elsif Arg = "-largs" then
         Current_Processor := Linker;

      --  -gargs: gprmake

      elsif Arg = "-gargs" then
         Current_Processor := None;

      --  A special test is needed for the -o switch within a -largs since
      --  that is another way to specify the name of the final executable.

      elsif Current_Processor = Linker and then Arg = "-o" then
         Osint.Fail
           ("switch -o not allowed within a -largs. Use -o directly.");

      --  If current processor is not gprmake directly, store the option in
      --  the appropriate table.

      elsif Current_Processor /= None then
         Add_Option (Arg);

      --  Switches start with '-'

      elsif Arg (1) = '-' then
         if Arg'Length > 3 and then Arg (1 .. 3) = "-aP" then
            Add_Search_Project_Directory (Arg (4 .. Arg'Last));

            --  Record the switch, so that it is passed to gnatmake, if
            --  gnatmake is called.

            Saved_Switches.Append (new String'(Arg));

         elsif Arg = "-c" then
            Compile_Only := True;

            --  Make sure that when a main is specified and switch -c is used,
            --  only the main(s) is/are compiled.

            if Mains.Number_Of_Mains > 0 then
               Unique_Compile := True;
            end if;

         elsif Arg = "-d" then
            Display_Compilation_Progress := True;

         elsif Arg = "-eL" then
            Follow_Links_For_Files := True;

         elsif Arg = "-f" then
            Force_Compilations := True;

         elsif Arg = "-h" then
            Usage;

         elsif Arg = "-k" then
            Keep_Going := True;

         elsif Arg = "-o" then
            if Output_File_Name /= null then
               Osint.Fail ("cannot specify several -o switches");

            else
               Output_File_Name_Expected := True;
            end if;

         elsif Arg'Length >= 2 and then Arg (2) = 'P' then
            if Project_File_Name /= null then
               Osint.Fail ("cannot have several project files specified");

            elsif Arg'Length = 2 then
               Project_File_Name_Expected := True;

            else
               Project_File_Name := new String'(Arg (3 .. Arg'Last));
            end if;

         elsif Arg = "-p" or else Arg = "--create-missing-dirs" then
            Setup_Projects := True;

         elsif Arg = "-q" then
            Quiet_Output := True;

         elsif Arg = "-u" then
            Unique_Compile := True;
            Compile_Only   := True;

         elsif Arg = "-v" then
            Verbose_Mode := True;
            Copyright;

         elsif Arg'Length = 4 and then Arg (1 .. 3) = "-vP"
           and then Arg (4) in '0' .. '2'
         then
            case Arg (4) is
               when '0' =>
                  Current_Verbosity := Prj.Default;
               when '1' =>
                  Current_Verbosity := Prj.Medium;
               when '2' =>
                  Current_Verbosity := Prj.High;
               when others =>
                  null;
            end case;

         elsif Arg'Length >= 3 and then Arg (2) = 'X'
           and then Is_External_Assignment (Arg)
         then
            --  Is_External_Assignment has side effects when it returns True

            --  Record the -X switch, so that it will be passed to gnatmake,
            --  if gnatmake is called.

            Saved_Switches.Append (new String'(Arg));

         else
            Osint.Fail ("illegal option """, Arg, """");
         end if;

      else
         --  Not a switch: must be a main

         Mains.Add_Main (Arg);

         --  Make sure that when a main is specified and switch -c is used,
         --  only the main(s) is/are compiled.

         if Compile_Only then
            Unique_Compile := True;
         end if;
      end if;
   end Scan_Arg;

   -----------------
   -- Strip_CR_LF --
   -----------------

   function Strip_CR_LF (Text : String) return String is
      To       : String (1 .. Text'Length);
      Index_To : Natural := 0;

   begin
      for Index in Text'Range loop
         if (Text (Index) /= ASCII.CR) and then (Text (Index) /= ASCII.LF) then
            Index_To := Index_To + 1;
            To (Index_To) := Text (Index);
         end if;
      end loop;

      return To (1 .. Index_To);
   end Strip_CR_LF;

   -----------
   -- Usage --
   -----------

   procedure Usage is
   begin
      if not Usage_Output then
         Usage_Output := True;
         Copyright;

         Write_Str ("Usage: ");
         Osint.Write_Program_Name;
         Write_Str (" -P<project file> [opts]  [name] {");
         Write_Str ("[-cargs:lang opts] ");
         Write_Str ("[-largs opts] [-gargs opts]}");
         Write_Eol;
         Write_Eol;
         Write_Str ("  name is zero or more file names");
         Write_Eol;
         Write_Eol;

         --  GPRMAKE switches

         Write_Str ("gprmake switches:");
         Write_Eol;

         --  Line for -aP

         Write_Str ("  -aPdir   Add directory dir to project search path");
         Write_Eol;

         --  Line for -c

         Write_Str ("  -c       Compile only");
         Write_Eol;

         --  Line for -eL

         Write_Str ("  -eL      Follow symbolic links when processing " &
                    "project files");
         Write_Eol;

         --  Line for -f

         Write_Str ("  -f       Force recompilations");
         Write_Eol;

         --  Line for -k

         Write_Str ("  -k       Keep going after compilation errors");
         Write_Eol;

         --  Line for -o

         Write_Str ("  -o name  Choose an alternate executable name");
         Write_Eol;

         --  Line for -p

         Write_Str ("  -p       Create missing obj, lib and exec dirs");
         Write_Eol;

         --  Line for -P

         Write_Str ("  -Pproj   Use GNAT Project File proj");
         Write_Eol;

         --  Line for -q

         Write_Str ("  -q       Be quiet/terse");
         Write_Eol;

         --  Line for -u

         Write_Str
           ("  -u       Unique compilation. Only compile the given files");
         Write_Eol;

         --  Line for -v

         Write_Str ("  -v       Verbose output");
         Write_Eol;

         --  Line for -vPx

         Write_Str ("  -vPx     Specify verbosity when parsing Project Files");
         Write_Eol;

         --  Line for -X

         Write_Str ("  -Xnm=val Specify an external reference for " &
                    "Project Files");
         Write_Eol;
         Write_Eol;

         --  Line for -cargs

         Write_Line ("  -cargs opts     opts are passed to the Ada compiler");

         --  Line for -cargs:lang

         Write_Line ("  -cargs:<lang> opts");
         Write_Line ("     opts are passed to the compiler " &
                     "for language < lang > ");

         --  Line for -largs

         Write_Str ("  -largs opts    opts are passed to the linker");
         Write_Eol;

         --  Line for -gargs

         Write_Str ("  -gargs opts    opts directly interpreted by gprmake");
         Write_Eol;
         Write_Eol;

      end if;
   end Usage;

begin
   Makeutl.Do_Fail := Report_Error'Access;
end Makegpr;