2016-10-26 François Dumont <fdumont@gcc.gnu.org>

[official-gcc.git] / gcc / ada / makeutl.adb

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                              M A K E U T L                               --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 2004-2015, 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 ALI;      use ALI;
with Atree;    use Atree;
with Debug;
with Err_Vars; use Err_Vars;
with Errutil;
with Fname;
with Osint;    use Osint;
with Output;   use Output;
with Opt;      use Opt;
with Prj.Com;
with Prj.Err;
with Prj.Ext;
with Prj.Util; use Prj.Util;
with Sinput.P;
with Tempdir;

with Ada.Command_Line;           use Ada.Command_Line;
with Ada.Unchecked_Deallocation;

with GNAT.Case_Util;             use GNAT.Case_Util;
with GNAT.Directory_Operations;  use GNAT.Directory_Operations;
with GNAT.HTable;
with GNAT.Regexp;                use GNAT.Regexp;

package body Makeutl is

   type Linker_Options_Data is record
      Project : Project_Id;
      Options : String_List_Id;
   end record;

   Linker_Option_Initial_Count : constant := 20;

   Linker_Options_Buffer : String_List_Access :=
     new String_List (1 .. Linker_Option_Initial_Count);

   Last_Linker_Option : Natural := 0;

   package Linker_Opts is new Table.Table (
     Table_Component_Type => Linker_Options_Data,
     Table_Index_Type     => Integer,
     Table_Low_Bound      => 1,
     Table_Initial        => 10,
     Table_Increment      => 100,
     Table_Name           => "Make.Linker_Opts");

   procedure Add_Linker_Option (Option : String);

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

   procedure Add
     (Option : String_Access;
      To     : in out String_List_Access;
      Last   : in out Natural)
   is
   begin
      if Last = To'Last then
         declare
            New_Options : constant String_List_Access :=
                            new String_List (1 .. To'Last * 2);

         begin
            New_Options (To'Range) := To.all;

            --  Set all elements of the original options to null to avoid
            --  deallocation of copies.

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

            Free (To);
            To := New_Options;
         end;
      end if;

      Last := Last + 1;
      To (Last) := Option;
   end Add;

   procedure Add
     (Option : String;
      To     : in out String_List_Access;
      Last   : in out Natural)
   is
   begin
      Add (Option => new String'(Option), To => To, Last => Last);
   end Add;

   -----------------------
   -- Add_Linker_Option --
   -----------------------

   procedure Add_Linker_Option (Option : String) is
   begin
      if Option'Length > 0 then
         if Last_Linker_Option = Linker_Options_Buffer'Last then
            declare
               New_Buffer : constant String_List_Access :=
                              new String_List
                                (1 .. Linker_Options_Buffer'Last +
                                        Linker_Option_Initial_Count);
            begin
               New_Buffer (Linker_Options_Buffer'Range) :=
                 Linker_Options_Buffer.all;
               Linker_Options_Buffer.all := (others => null);
               Free (Linker_Options_Buffer);
               Linker_Options_Buffer := New_Buffer;
            end;
         end if;

         Last_Linker_Option := Last_Linker_Option + 1;
         Linker_Options_Buffer (Last_Linker_Option) := new String'(Option);
      end if;
   end Add_Linker_Option;

   -------------------
   -- Absolute_Path --
   -------------------

   function Absolute_Path
     (Path    : Path_Name_Type;
      Project : Project_Id) return String
   is
   begin
      Get_Name_String (Path);

      declare
         Path_Name : constant String := Name_Buffer (1 .. Name_Len);

      begin
         if Is_Absolute_Path (Path_Name) then
            return Path_Name;

         else
            declare
               Parent_Directory : constant String :=
                 Get_Name_String
                   (Project.Directory.Display_Name);

            begin
               return Parent_Directory & Path_Name;
            end;
         end if;
      end;
   end Absolute_Path;

   ----------------------------
   -- Aggregate_Libraries_In --
   ----------------------------

   function Aggregate_Libraries_In (Tree : Project_Tree_Ref) return Boolean is
      List : Project_List;

   begin
      List := Tree.Projects;
      while List /= null loop
         if List.Project.Qualifier = Aggregate_Library then
            return True;
         end if;

         List := List.Next;
      end loop;

      return False;
   end Aggregate_Libraries_In;

   -------------------------
   -- Base_Name_Index_For --
   -------------------------

   function Base_Name_Index_For
     (Main            : String;
      Main_Index      : Int;
      Index_Separator : Character) return File_Name_Type
   is
      Result : File_Name_Type;

   begin
      Name_Len := 0;
      Add_Str_To_Name_Buffer (Base_Name (Main));

      --  Remove the extension, if any, that is the last part of the base name
      --  starting with a dot and following some characters.

      for J in reverse 2 .. Name_Len loop
         if Name_Buffer (J) = '.' then
            Name_Len := J - 1;
            exit;
         end if;
      end loop;

      --  Add the index info, if index is different from 0

      if Main_Index > 0 then
         Add_Char_To_Name_Buffer (Index_Separator);

         declare
            Img : constant String := Main_Index'Img;
         begin
            Add_Str_To_Name_Buffer (Img (2 .. Img'Last));
         end;
      end if;

      Result := Name_Find;
      return Result;
   end Base_Name_Index_For;

   ------------------------------
   -- Check_Source_Info_In_ALI --
   ------------------------------

   function Check_Source_Info_In_ALI
     (The_ALI : ALI_Id;
      Tree    : Project_Tree_Ref) return Name_Id
   is
      Result    : Name_Id := No_Name;
      Unit_Name : Name_Id;

   begin
      --  Loop through units

      for U in ALIs.Table (The_ALI).First_Unit ..
               ALIs.Table (The_ALI).Last_Unit
      loop
         --  Check if the file name is one of the source of the unit

         Get_Name_String (Units.Table (U).Uname);
         Name_Len  := Name_Len - 2;
         Unit_Name := Name_Find;

         if File_Not_A_Source_Of (Tree, Unit_Name, Units.Table (U).Sfile) then
            return No_Name;
         end if;

         if Result = No_Name then
            Result := Unit_Name;
         end if;

         --  Loop to do same check for each of the withed units

         for W in Units.Table (U).First_With .. Units.Table (U).Last_With loop
            declare
               WR : ALI.With_Record renames Withs.Table (W);

            begin
               if WR.Sfile /= No_File then
                  Get_Name_String (WR.Uname);
                  Name_Len  := Name_Len - 2;
                  Unit_Name := Name_Find;

                  if File_Not_A_Source_Of (Tree, Unit_Name, WR.Sfile) then
                     return No_Name;
                  end if;
               end if;
            end;
         end loop;
      end loop;

      --  Loop to check subunits and replaced sources

      for D in ALIs.Table (The_ALI).First_Sdep ..
               ALIs.Table (The_ALI).Last_Sdep
      loop
         declare
            SD : Sdep_Record renames Sdep.Table (D);

         begin
            Unit_Name := SD.Subunit_Name;

            if Unit_Name = No_Name then

               --  Check if this source file has been replaced by a source with
               --  a different file name.

               if Tree /= null and then Tree.Replaced_Source_Number > 0 then
                  declare
                     Replacement : constant File_Name_Type :=
                       Replaced_Source_HTable.Get
                         (Tree.Replaced_Sources, SD.Sfile);

                  begin
                     if Replacement /= No_File then
                        if Verbose_Mode then
                           Write_Line
                             ("source file"
                              & Get_Name_String (SD.Sfile)
                              & " has been replaced by "
                              & Get_Name_String (Replacement));
                        end if;

                        return No_Name;
                     end if;
                  end;
               end if;

               --  Check that a dependent source for a unit that is from a
               --  project is indeed a source of this unit.

               Unit_Name := SD.Unit_Name;

               if Unit_Name /= No_Name
                 and then not Fname.Is_Internal_File_Name (SD.Sfile)
                 and then File_Not_A_Source_Of (Tree, Unit_Name, SD.Sfile)
               then
                  return No_Name;
               end if;

            else
               --  For separates, the file is no longer associated with the
               --  unit ("proc-sep.adb" is not associated with unit "proc.sep")
               --  so we need to check whether the source file still exists in
               --  the source tree: it will if it matches the naming scheme
               --  (and then will be for the same unit).

               if Find_Source
                    (In_Tree   => Tree,
                     Project   => No_Project,
                     Base_Name => SD.Sfile) = No_Source
               then
                  --  If this is not a runtime file or if, when gnatmake switch
                  --  -a is used, we are not able to find this subunit in the
                  --  source directories, then recompilation is needed.

                  if not Fname.Is_Internal_File_Name (SD.Sfile)
                    or else
                      (Check_Readonly_Files
                        and then Full_Source_Name (SD.Sfile) = No_File)
                  then
                     if Verbose_Mode then
                        Write_Line
                          ("While parsing ALI file, file "
                           & Get_Name_String (SD.Sfile)
                           & " is indicated as containing subunit "
                           & Get_Name_String (Unit_Name)
                           & " but this does not match what was found while"
                           & " parsing the project. Will recompile");
                     end if;

                     return No_Name;
                  end if;
               end if;
            end if;
         end;
      end loop;

      return Result;
   end Check_Source_Info_In_ALI;

   --------------------------------
   -- Create_Binder_Mapping_File --
   --------------------------------

   function Create_Binder_Mapping_File
     (Project_Tree : Project_Tree_Ref) return Path_Name_Type
   is
      Mapping_Path : Path_Name_Type := No_Path;

      Mapping_FD : File_Descriptor := Invalid_FD;
      --  A File Descriptor for an eventual mapping file

      ALI_Unit : Unit_Name_Type := No_Unit_Name;
      --  The unit name of an ALI file

      ALI_Name : File_Name_Type := No_File;
      --  The file name of the ALI file

      ALI_Project : Project_Id := No_Project;
      --  The project of the ALI file

      Bytes : Integer;
      OK    : Boolean := False;
      Unit  : Unit_Index;

      Status : Boolean;
      --  For call to Close

      Iter : Source_Iterator := For_Each_Source
                                  (In_Tree           => Project_Tree,
                                   Language          => Name_Ada,
                                   Encapsulated_Libs => False,
                                   Locally_Removed   => False);

      Source : Prj.Source_Id;

   begin
      Tempdir.Create_Temp_File (Mapping_FD, Mapping_Path);
      Record_Temp_File (Project_Tree.Shared, Mapping_Path);

      if Mapping_FD /= Invalid_FD then
         OK := True;

         loop
            Source := Element (Iter);
            exit when Source = No_Source;

            Unit := Source.Unit;

            if Source.Replaced_By /= No_Source
              or else Unit = No_Unit_Index
              or else Unit.Name = No_Name
            then
               ALI_Name := No_File;

            --  If this is a body, put it in the mapping

            elsif Source.Kind = Impl
              and then Unit.File_Names (Impl) /= No_Source
              and then Unit.File_Names (Impl).Project /= No_Project
            then
               Get_Name_String (Unit.Name);
               Add_Str_To_Name_Buffer ("%b");
               ALI_Unit := Name_Find;
               ALI_Name :=
                 Lib_File_Name (Unit.File_Names (Impl).Display_File);
               ALI_Project := Unit.File_Names (Impl).Project;

            --  Otherwise, if this is a spec and there is no body, put it in
            --  the mapping.

            elsif Source.Kind = Spec
              and then Unit.File_Names (Impl) = No_Source
              and then Unit.File_Names (Spec) /= No_Source
              and then Unit.File_Names (Spec).Project /= No_Project
            then
               Get_Name_String (Unit.Name);
               Add_Str_To_Name_Buffer ("%s");
               ALI_Unit := Name_Find;
               ALI_Name :=
                 Lib_File_Name (Unit.File_Names (Spec).Display_File);
               ALI_Project := Unit.File_Names (Spec).Project;

            else
               ALI_Name := No_File;
            end if;

            --  If we have something to put in the mapping then do it now. If
            --  the project is extended, look for the ALI file in the project,
            --  then in the extending projects in order, and use the last one
            --  found.

            if ALI_Name /= No_File then

               --  Look in the project and the projects that are extending it
               --  to find the real ALI file.

               declare
                  ALI      : constant String := Get_Name_String (ALI_Name);
                  ALI_Path : Name_Id         := No_Name;

               begin
                  loop
                     --  For library projects, use the library ALI directory,
                     --  for other projects, use the object directory.

                     if ALI_Project.Library then
                        Get_Name_String
                          (ALI_Project.Library_ALI_Dir.Display_Name);
                     else
                        Get_Name_String
                          (ALI_Project.Object_Directory.Display_Name);
                     end if;

                     Add_Str_To_Name_Buffer (ALI);

                     if Is_Regular_File (Name_Buffer (1 .. Name_Len)) then
                        ALI_Path := Name_Find;
                     end if;

                     ALI_Project := ALI_Project.Extended_By;
                     exit when ALI_Project = No_Project;
                  end loop;

                  if ALI_Path /= No_Name then

                     --  First line is the unit name

                     Get_Name_String (ALI_Unit);
                     Add_Char_To_Name_Buffer (ASCII.LF);
                     Bytes :=
                       Write
                         (Mapping_FD,
                          Name_Buffer (1)'Address,
                          Name_Len);
                     OK := Bytes = Name_Len;

                     exit when not OK;

                     --  Second line is the ALI file name

                     Get_Name_String (ALI_Name);
                     Add_Char_To_Name_Buffer (ASCII.LF);
                     Bytes :=
                       Write
                         (Mapping_FD,
                          Name_Buffer (1)'Address,
                          Name_Len);
                     OK := (Bytes = Name_Len);

                     exit when not OK;

                     --  Third line is the ALI path name

                     Get_Name_String (ALI_Path);
                     Add_Char_To_Name_Buffer (ASCII.LF);
                     Bytes :=
                       Write
                         (Mapping_FD,
                          Name_Buffer (1)'Address,
                          Name_Len);
                     OK := (Bytes = Name_Len);

                     --  If OK is False, it means we were unable to write a
                     --  line. No point in continuing with the other units.

                     exit when not OK;
                  end if;
               end;
            end if;

            Next (Iter);
         end loop;

         Close (Mapping_FD, Status);

         OK := OK and Status;
      end if;

      --  If the creation of the mapping file was successful, we add the switch
      --  to the arguments of gnatbind.

      if OK then
         return Mapping_Path;

      else
         return No_Path;
      end if;
   end Create_Binder_Mapping_File;

   -----------------
   -- Create_Name --
   -----------------

   function Create_Name (Name : String) return File_Name_Type is
   begin
      Name_Len := 0;
      Add_Str_To_Name_Buffer (Name);
      return Name_Find;
   end Create_Name;

   function Create_Name (Name : String) return Name_Id is
   begin
      Name_Len := 0;
      Add_Str_To_Name_Buffer (Name);
      return Name_Find;
   end Create_Name;

   function Create_Name (Name : String) return Path_Name_Type is
   begin
      Name_Len := 0;
      Add_Str_To_Name_Buffer (Name);
      return Name_Find;
   end Create_Name;

   ---------------------------
   -- Ensure_Absolute_Path --
   ---------------------------

   procedure Ensure_Absolute_Path
     (Switch               : in out String_Access;
      Parent               : String;
      Do_Fail              : Fail_Proc;
      For_Gnatbind         : Boolean := False;
      Including_Non_Switch : Boolean := True;
      Including_RTS        : Boolean := False)
   is
   begin
      if Switch /= null then
         declare
            Sw    : String (1 .. Switch'Length);
            Start : Positive;

         begin
            Sw := Switch.all;

            if Sw (1) = '-' then
               if Sw'Length >= 3
                 and then (Sw (2) = 'I'
                            or else (not For_Gnatbind
                                      and then (Sw (2) = 'L'
                                                 or else
                                                Sw (2) = 'A')))
               then
                  Start := 3;

                  if Sw = "-I-" then
                     return;
                  end if;

               elsif Sw'Length >= 4
                 and then
                   (Sw (2 .. 3) = "aL" or else
                    Sw (2 .. 3) = "aO" or else
                    Sw (2 .. 3) = "aI"
                      or else (For_Gnatbind and then Sw (2 .. 3) = "A="))
               then
                  Start := 4;

               elsif Including_RTS
                 and then Sw'Length >= 7
                 and then Sw (2 .. 6) = "-RTS="
               then
                  Start := 7;

               else
                  return;
               end if;

               --  Because relative path arguments to --RTS= may be relative to
               --  the search directory prefix, those relative path arguments
               --  are converted only when they include directory information.

               if not Is_Absolute_Path (Sw (Start .. Sw'Last)) then
                  if Parent'Length = 0 then
                     Do_Fail
                       ("relative search path switches ("""
                        & Sw
                        & """) are not allowed");

                  elsif Including_RTS then
                     for J in Start .. Sw'Last loop
                        if Sw (J) = Directory_Separator then
                           Switch :=
                             new String'
                               (Sw (1 .. Start - 1)
                                & Parent
                                & Directory_Separator
                                & Sw (Start .. Sw'Last));
                           return;
                        end if;
                     end loop;

                  else
                     Switch :=
                       new String'
                         (Sw (1 .. Start - 1)
                          & Parent
                          & Directory_Separator
                          & Sw (Start .. Sw'Last));
                  end if;
               end if;

            elsif Including_Non_Switch then
               if not Is_Absolute_Path (Sw) then
                  if Parent'Length = 0 then
                     Do_Fail
                       ("relative paths (""" & Sw & """) are not allowed");
                  else
                     Switch := new String'(Parent & Directory_Separator & Sw);
                  end if;
               end if;
            end if;
         end;
      end if;
   end Ensure_Absolute_Path;

   ----------------------------
   -- Executable_Prefix_Path --
   ----------------------------

   function Executable_Prefix_Path return String is
      Exec_Name : constant String := Command_Name;

      function Get_Install_Dir (S : String) return String;
      --  S is the executable name preceded by the absolute or relative path,
      --  e.g. "c:\usr\bin\gcc.exe". Returns the absolute directory where "bin"
      --  lies (in the example "C:\usr"). If the executable is not in a "bin"
      --  directory, return "".

      ---------------------
      -- Get_Install_Dir --
      ---------------------

      function Get_Install_Dir (S : String) return String is
         Exec      : String  := S;
         Path_Last : Integer := 0;

      begin
         for J in reverse Exec'Range loop
            if Exec (J) = Directory_Separator then
               Path_Last := J - 1;
               exit;
            end if;
         end loop;

         if Path_Last >= Exec'First + 2 then
            To_Lower (Exec (Path_Last - 2 .. Path_Last));
         end if;

         if Path_Last < Exec'First + 2
           or else Exec (Path_Last - 2 .. Path_Last) /= "bin"
           or else (Path_Last - 3 >= Exec'First
                     and then Exec (Path_Last - 3) /= Directory_Separator)
         then
            return "";
         end if;

         return Normalize_Pathname
                  (Exec (Exec'First .. Path_Last - 4),
                   Resolve_Links => Opt.Follow_Links_For_Dirs)
           & Directory_Separator;
      end Get_Install_Dir;

   --  Beginning of Executable_Prefix_Path

   begin
      --  First determine if a path prefix was placed in front of the
      --  executable name.

      for J in reverse Exec_Name'Range loop
         if Exec_Name (J) = Directory_Separator then
            return Get_Install_Dir (Exec_Name);
         end if;
      end loop;

      --  If we get here, the user has typed the executable name with no
      --  directory prefix.

      declare
         Path : String_Access := Locate_Exec_On_Path (Exec_Name);
      begin
         if Path = null then
            return "";
         else
            declare
               Dir : constant String := Get_Install_Dir (Path.all);
            begin
               Free (Path);
               return Dir;
            end;
         end if;
      end;
   end Executable_Prefix_Path;

   ------------------
   -- Fail_Program --
   ------------------

   procedure Fail_Program
     (Project_Tree   : Project_Tree_Ref;
      S              : String;
      Flush_Messages : Boolean := True)
   is
   begin
      if Flush_Messages and not No_Exit_Message then
         if Total_Errors_Detected /= 0 or else Warnings_Detected /= 0 then
            Errutil.Finalize;
         end if;
      end if;

      Finish_Program (Project_Tree, E_Fatal, S => S);
   end Fail_Program;

   --------------------
   -- Finish_Program --
   --------------------

   procedure Finish_Program
     (Project_Tree : Project_Tree_Ref;
      Exit_Code    : Osint.Exit_Code_Type := Osint.E_Success;
      S            : String := "")
   is
   begin
      if not Debug.Debug_Flag_N then
         Delete_Temp_Config_Files (Project_Tree);

         if Project_Tree /= null then
            Delete_All_Temp_Files (Project_Tree.Shared);
         end if;
      end if;

      if S'Length > 0 then
         if Exit_Code /= E_Success then
            if No_Exit_Message then
               Osint.Exit_Program (E_Fatal);
            else
               Osint.Fail (S);
            end if;

         elsif not No_Exit_Message then
            Write_Str (S);
         end if;
      end if;

      --  Output Namet statistics

      Namet.Finalize;

      Exit_Program (Exit_Code);
   end Finish_Program;

   --------------------------
   -- File_Not_A_Source_Of --
   --------------------------

   function File_Not_A_Source_Of
     (Project_Tree : Project_Tree_Ref;
      Uname        : Name_Id;
      Sfile        : File_Name_Type) return Boolean
   is
      Unit : constant Unit_Index :=
               Units_Htable.Get (Project_Tree.Units_HT, Uname);

      At_Least_One_File : Boolean := False;

   begin
      if Unit /= No_Unit_Index then
         for F in Unit.File_Names'Range loop
            if Unit.File_Names (F) /= null then
               At_Least_One_File := True;
               if Unit.File_Names (F).File = Sfile then
                  return False;
               end if;
            end if;
         end loop;

         if not At_Least_One_File then

            --  The unit was probably created initially for a separate unit
            --  (which are initially created as IMPL when both suffixes are the
            --  same). Later on, Override_Kind changed the type of the file,
            --  and the unit is no longer valid in fact.

            return False;
         end if;

         Verbose_Msg (Uname, "sources do not include ", Name_Id (Sfile));
         return True;
      end if;

      return False;
   end File_Not_A_Source_Of;

   ---------------------
   -- Get_Directories --
   ---------------------

   procedure Get_Directories
     (Project_Tree : Project_Tree_Ref;
      For_Project  : Project_Id;
      Activity     : Activity_Type;
      Languages    : Name_Ids)
   is

      procedure Recursive_Add
        (Project  : Project_Id;
         Tree     : Project_Tree_Ref;
         Extended : in out Boolean);
      --  Add all the source directories of a project to the path only if
      --  this project has not been visited. Calls itself recursively for
      --  projects being extended, and imported projects.

      procedure Add_Dir (Value : Path_Name_Type);
      --  Add directory Value in table Directories, if it is defined and not
      --  already there.

      -------------
      -- Add_Dir --
      -------------

      procedure Add_Dir (Value : Path_Name_Type) is
         Add_It : Boolean := True;

      begin
         if Value /= No_Path
           and then Is_Directory (Get_Name_String (Value))
         then
            for Index in 1 .. Directories.Last loop
               if Directories.Table (Index) = Value then
                  Add_It := False;
                  exit;
               end if;
            end loop;

            if Add_It then
               Directories.Increment_Last;
               Directories.Table (Directories.Last) := Value;
            end if;
         end if;
      end Add_Dir;

      -------------------
      -- Recursive_Add --
      -------------------

      procedure Recursive_Add
        (Project  : Project_Id;
         Tree     : Project_Tree_Ref;
         Extended : in out Boolean)
      is
         Current   : String_List_Id;
         Dir       : String_Element;
         OK        : Boolean := False;
         Lang_Proc : Language_Ptr := Project.Languages;

      begin
         --  Add to path all directories of this project

         if Activity = Compilation then
            Lang_Loop :
            while Lang_Proc /= No_Language_Index loop
               for J in Languages'Range loop
                  OK := Lang_Proc.Name = Languages (J);
                  exit Lang_Loop when OK;
               end loop;

               Lang_Proc := Lang_Proc.Next;
            end loop Lang_Loop;

            if OK then
               Current := Project.Source_Dirs;

               while Current /= Nil_String loop
                  Dir := Tree.Shared.String_Elements.Table (Current);
                  Add_Dir (Path_Name_Type (Dir.Value));
                  Current := Dir.Next;
               end loop;
            end if;

         elsif Project.Library then
            if Activity = SAL_Binding and then Extended then
               Add_Dir (Project.Object_Directory.Display_Name);

            else
               Add_Dir (Project.Library_ALI_Dir.Display_Name);
            end if;

         else
            Add_Dir (Project.Object_Directory.Display_Name);
         end if;

         if Project.Extends = No_Project then
            Extended := False;
         end if;
      end Recursive_Add;

      procedure For_All_Projects is
        new For_Every_Project_Imported (Boolean, Recursive_Add);

      Extended : Boolean := True;

      --  Start of processing for Get_Directories

   begin
      Directories.Init;
      For_All_Projects (For_Project, Project_Tree, Extended);
   end Get_Directories;

   ------------------
   -- Get_Switches --
   ------------------

   procedure Get_Switches
     (Source       : Prj.Source_Id;
      Pkg_Name     : Name_Id;
      Project_Tree : Project_Tree_Ref;
      Value        : out Variable_Value;
      Is_Default   : out Boolean)
   is
   begin
      Get_Switches
        (Source_File  => Source.File,
         Source_Lang  => Source.Language.Name,
         Source_Prj   => Source.Project,
         Pkg_Name     => Pkg_Name,
         Project_Tree => Project_Tree,
         Value        => Value,
         Is_Default   => Is_Default);
   end Get_Switches;

   ------------------
   -- Get_Switches --
   ------------------

   procedure Get_Switches
     (Source_File         : File_Name_Type;
      Source_Lang         : Name_Id;
      Source_Prj          : Project_Id;
      Pkg_Name            : Name_Id;
      Project_Tree        : Project_Tree_Ref;
      Value               : out Variable_Value;
      Is_Default          : out Boolean;
      Test_Without_Suffix : Boolean := False;
      Check_ALI_Suffix    : Boolean := False)
   is
      Project : constant Project_Id :=
                  Ultimate_Extending_Project_Of (Source_Prj);
      Pkg     : constant Package_Id :=
                  Prj.Util.Value_Of
                    (Name        => Pkg_Name,
                     In_Packages => Project.Decl.Packages,
                     Shared      => Project_Tree.Shared);
      Lang : Language_Ptr;

   begin
      Is_Default := False;

      if Source_File /= No_File then
         Value := Prj.Util.Value_Of
           (Name                    => Name_Id (Source_File),
            Attribute_Or_Array_Name => Name_Switches,
            In_Package              => Pkg,
            Shared                  => Project_Tree.Shared,
            Allow_Wildcards         => True);
      end if;

      if Value = Nil_Variable_Value and then Test_Without_Suffix then
         Lang :=
           Get_Language_From_Name (Project, Get_Name_String (Source_Lang));

         if Lang /= null then
            declare
               Naming      : Lang_Naming_Data renames Lang.Config.Naming_Data;
               SF_Name     : constant String := Get_Name_String (Source_File);
               Last        : Positive := SF_Name'Length;
               Name        : String (1 .. Last + 3);
               Spec_Suffix : String   := Get_Name_String (Naming.Spec_Suffix);
               Body_Suffix : String   := Get_Name_String (Naming.Body_Suffix);
               Truncated   : Boolean  := False;

            begin
               Canonical_Case_File_Name (Spec_Suffix);
               Canonical_Case_File_Name (Body_Suffix);
               Name (1 .. Last) := SF_Name;

               if Last > Body_Suffix'Length
                 and then
                   Name (Last - Body_Suffix'Length + 1 .. Last) = Body_Suffix
               then
                  Truncated := True;
                  Last := Last - Body_Suffix'Length;
               end if;

               if not Truncated
                 and then Last > Spec_Suffix'Length
                 and then
                   Name (Last - Spec_Suffix'Length + 1 .. Last) = Spec_Suffix
               then
                  Truncated := True;
                  Last := Last - Spec_Suffix'Length;
               end if;

               if Truncated then
                  Name_Len := 0;
                  Add_Str_To_Name_Buffer (Name (1 .. Last));

                  Value := Prj.Util.Value_Of
                    (Name                    => Name_Find,
                     Attribute_Or_Array_Name => Name_Switches,
                     In_Package              => Pkg,
                     Shared                  => Project_Tree.Shared,
                     Allow_Wildcards         => True);
               end if;

               if Value = Nil_Variable_Value and then Check_ALI_Suffix then
                  Last := SF_Name'Length;
                  while Name (Last) /= '.' loop
                     Last := Last - 1;
                  end loop;

                  Name_Len := 0;
                  Add_Str_To_Name_Buffer (Name (1 .. Last));
                  Add_Str_To_Name_Buffer ("ali");

                  Value := Prj.Util.Value_Of
                    (Name                    => Name_Find,
                     Attribute_Or_Array_Name => Name_Switches,
                     In_Package              => Pkg,
                     Shared                  => Project_Tree.Shared,
                     Allow_Wildcards         => True);
               end if;
            end;
         end if;
      end if;

      if Value = Nil_Variable_Value then
         Is_Default := True;
         Value :=
           Prj.Util.Value_Of
             (Name                    => Source_Lang,
              Attribute_Or_Array_Name => Name_Switches,
              In_Package              => Pkg,
              Shared                  => Project_Tree.Shared,
              Force_Lower_Case_Index  => True);
      end if;

      if Value = Nil_Variable_Value then
         Value :=
           Prj.Util.Value_Of
             (Name                    => All_Other_Names,
              Attribute_Or_Array_Name => Name_Switches,
              In_Package              => Pkg,
              Shared                  => Project_Tree.Shared,
              Force_Lower_Case_Index  => True);
      end if;

      if Value = Nil_Variable_Value then
         Value :=
           Prj.Util.Value_Of
             (Name                    => Source_Lang,
              Attribute_Or_Array_Name => Name_Default_Switches,
              In_Package              => Pkg,
              Shared                  => Project_Tree.Shared);
      end if;
   end Get_Switches;

   ------------
   -- Inform --
   ------------

   procedure Inform (N : File_Name_Type; Msg : String) is
   begin
      Inform (Name_Id (N), Msg);
   end Inform;

   procedure Inform (N : Name_Id := No_Name; Msg : String) is
   begin
      Osint.Write_Program_Name;

      Write_Str (": ");

      if N /= No_Name then
         Write_Str ("""");

         declare
            Name : constant String := Get_Name_String (N);
         begin
            if Debug.Debug_Flag_F and then Is_Absolute_Path (Name) then
               Write_Str (File_Name (Name));
            else
               Write_Str (Name);
            end if;
         end;

         Write_Str (""" ");
      end if;

      Write_Str (Msg);
      Write_Eol;
   end Inform;

   ------------------------------
   -- Initialize_Source_Record --
   ------------------------------

   procedure Initialize_Source_Record (Source : Prj.Source_Id) is

      procedure Set_Object_Project
        (Obj_Dir  : String;
         Obj_Proj : Project_Id;
         Obj_Path : Path_Name_Type;
         Stamp    : Time_Stamp_Type);
      --  Update information about object file, switches file,...

      ------------------------
      -- Set_Object_Project --
      ------------------------

      procedure Set_Object_Project
        (Obj_Dir  : String;
         Obj_Proj : Project_Id;
         Obj_Path : Path_Name_Type;
         Stamp    : Time_Stamp_Type) is
      begin
         Source.Object_Project := Obj_Proj;
         Source.Object_Path    := Obj_Path;
         Source.Object_TS      := Stamp;

         if Source.Language.Config.Dependency_Kind /= None then
            declare
               Dep_Path : constant String :=
                            Normalize_Pathname
                              (Name          =>
                                 Get_Name_String (Source.Dep_Name),
                               Resolve_Links => Opt.Follow_Links_For_Files,
                               Directory     => Obj_Dir);
            begin
               Source.Dep_Path := Create_Name (Dep_Path);
               Source.Dep_TS   := Osint.Unknown_Attributes;
            end;
         end if;

         --  Get the path of the switches file, even if Opt.Check_Switches is
         --  not set, as switch -s may be in the Builder switches that have not
         --  been scanned yet.

         declare
            Switches_Path : constant String :=
                              Normalize_Pathname
                                (Name          =>
                                   Get_Name_String (Source.Switches),
                                 Resolve_Links => Opt.Follow_Links_For_Files,
                                 Directory     => Obj_Dir);
         begin
            Source.Switches_Path := Create_Name (Switches_Path);

            if Stamp /= Empty_Time_Stamp then
               Source.Switches_TS := File_Stamp (Source.Switches_Path);
            end if;
         end;
      end Set_Object_Project;

      Obj_Proj : Project_Id;

   begin
      --  Nothing to do if source record has already been fully initialized

      if Source.Initialized then
         return;
      end if;

      --  Systematically recompute the time stamp

      Source.Source_TS := File_Stamp (Source.Path.Display_Name);

      --  Parse the source file to check whether we have a subunit

      if Source.Language.Config.Kind = Unit_Based
        and then Source.Kind = Impl
        and then Is_Subunit (Source)
      then
         Source.Kind := Sep;
      end if;

      if Source.Language.Config.Object_Generated
        and then Is_Compilable (Source)
      then
         --  First, get the correct object file name and dependency file name
         --  if the source is in a multi-unit file.

         if Source.Index /= 0 then
            Source.Object :=
              Object_Name
                (Source_File_Name   => Source.File,
                 Source_Index       => Source.Index,
                 Index_Separator    =>
                   Source.Language.Config.Multi_Unit_Object_Separator,
                 Object_File_Suffix =>
                   Source.Language.Config.Object_File_Suffix);

            Source.Dep_Name :=
              Dependency_Name
                (Source.Object, Source.Language.Config.Dependency_Kind);
         end if;

         --  Find the object file for that source. It could be either in the
         --  current project or in an extended project (it might actually not
         --  exist yet in the ultimate extending project, but if not found
         --  elsewhere that's where we'll expect to find it).

         Obj_Proj := Source.Project;

         while Obj_Proj /= No_Project loop
            if Obj_Proj.Object_Directory /= No_Path_Information then
               declare
                  Dir : constant String :=
                    Get_Name_String (Obj_Proj.Object_Directory.Display_Name);

                  Object_Path : constant String :=
                    Normalize_Pathname
                      (Name          => Get_Name_String (Source.Object),
                       Resolve_Links => Opt.Follow_Links_For_Files,
                       Directory     => Dir);

                  Obj_Path : constant Path_Name_Type :=
                    Create_Name (Object_Path);

                  Stamp : Time_Stamp_Type := Empty_Time_Stamp;

               begin
                  --  For specs, we do not check object files if there is a
                  --  body. This saves a system call. On the other hand, we do
                  --  need to know the object_path, in case the user has passed
                  --  the .ads on the command line to compile the spec only.

                  if Source.Kind /= Spec
                    or else Source.Unit = No_Unit_Index
                    or else Source.Unit.File_Names (Impl) = No_Source
                  then
                     Stamp := File_Stamp (Obj_Path);
                  end if;

                  if Stamp /= Empty_Time_Stamp
                    or else (Obj_Proj.Extended_By = No_Project
                              and then Source.Object_Project = No_Project)
                  then
                     Set_Object_Project (Dir, Obj_Proj, Obj_Path, Stamp);
                  end if;
               end;
            end if;

            Obj_Proj := Obj_Proj.Extended_By;
         end loop;

      elsif Source.Language.Config.Dependency_Kind = Makefile then
         declare
            Object_Dir : constant String :=
              Get_Name_String (Source.Project.Object_Directory.Display_Name);
            Dep_Path   : constant String :=
              Normalize_Pathname
                (Name          => Get_Name_String (Source.Dep_Name),
                 Resolve_Links => Opt.Follow_Links_For_Files,
                 Directory     => Object_Dir);
         begin
            Source.Dep_Path := Create_Name (Dep_Path);
            Source.Dep_TS   := Osint.Unknown_Attributes;
         end;
      end if;

      Source.Initialized := True;
   end Initialize_Source_Record;

   ----------------------------
   -- Is_External_Assignment --
   ----------------------------

   function Is_External_Assignment
     (Env  : Prj.Tree.Environment;
      Argv : String) return Boolean
   is
      Start  : Positive := 3;
      Finish : Natural := Argv'Last;

      pragma Assert (Argv'First = 1);
      pragma Assert (Argv (1 .. 2) = "-X");

   begin
      if Argv'Last < 5 then
         return False;

      elsif Argv (3) = '"' then
         if Argv (Argv'Last) /= '"' or else Argv'Last < 7 then
            return False;
         else
            Start := 4;
            Finish := Argv'Last - 1;
         end if;
      end if;

      return Prj.Ext.Check
        (Self        => Env.External,
         Declaration => Argv (Start .. Finish));
   end Is_External_Assignment;

   ----------------
   -- Is_Subunit --
   ----------------

   function Is_Subunit (Source : Prj.Source_Id) return Boolean is
      Src_Ind : Source_File_Index;

   begin
      if Source.Kind = Sep then
         return True;

      --  A Spec, a file based language source or a body with a spec cannot be
      --  a subunit.

      elsif Source.Kind = Spec
        or else Source.Unit = No_Unit_Index
        or else Other_Part (Source) /= No_Source
      then
         return False;
      end if;

      --  Here, we are assuming that the language is Ada, as it is the only
      --  unit based language that we know.

      Src_Ind :=
        Sinput.P.Load_Project_File
          (Get_Name_String (Source.Path.Display_Name));

      return Sinput.P.Source_File_Is_Subunit (Src_Ind);
   end Is_Subunit;

   -----------------------------
   -- Linker_Options_Switches --
   -----------------------------

   function Linker_Options_Switches
     (Project  : Project_Id;
      Do_Fail  : Fail_Proc;
      In_Tree  : Project_Tree_Ref) return String_List
   is
      procedure Recursive_Add
        (Proj    : Project_Id;
         In_Tree : Project_Tree_Ref;
         Dummy   : in out Boolean);
      --  The recursive routine used to add linker options

      -------------------
      -- Recursive_Add --
      -------------------

      procedure Recursive_Add
        (Proj    : Project_Id;
         In_Tree : Project_Tree_Ref;
         Dummy   : in out Boolean)
      is
         Linker_Package : Package_Id;
         Options        : Variable_Value;

      begin
         Linker_Package :=
           Prj.Util.Value_Of
             (Name        => Name_Linker,
              In_Packages => Proj.Decl.Packages,
              Shared      => In_Tree.Shared);

         Options :=
           Prj.Util.Value_Of
             (Name                    => Name_Ada,
              Index                   => 0,
              Attribute_Or_Array_Name => Name_Linker_Options,
              In_Package              => Linker_Package,
              Shared                  => In_Tree.Shared);

         --  If attribute is present, add the project with the attribute to
         --  table Linker_Opts.

         if Options /= Nil_Variable_Value then
            Linker_Opts.Increment_Last;
            Linker_Opts.Table (Linker_Opts.Last) :=
              (Project => Proj, Options => Options.Values);
         end if;
      end Recursive_Add;

      procedure For_All_Projects is
        new For_Every_Project_Imported (Boolean, Recursive_Add);

      Dummy : Boolean := False;

   --  Start of processing for Linker_Options_Switches

   begin
      Linker_Opts.Init;

      For_All_Projects (Project, In_Tree, Dummy, Imported_First => True);

      Last_Linker_Option := 0;

      for Index in reverse 1 .. Linker_Opts.Last loop
         declare
            Options  : String_List_Id;
            Proj     : constant Project_Id :=
                         Linker_Opts.Table (Index).Project;
            Option   : Name_Id;
            Dir_Path : constant String :=
                         Get_Name_String (Proj.Directory.Name);

         begin
            Options := Linker_Opts.Table (Index).Options;
            while Options /= Nil_String loop
               Option := In_Tree.Shared.String_Elements.Table (Options).Value;
               Get_Name_String (Option);

               --  Do not consider empty linker options

               if Name_Len /= 0 then
                  Add_Linker_Option (Name_Buffer (1 .. Name_Len));

                  --  Object files and -L switches specified with relative
                  --  paths must be converted to absolute paths.

                  Ensure_Absolute_Path
                    (Switch       =>
                       Linker_Options_Buffer (Last_Linker_Option),
                     Parent       => Dir_Path,
                     Do_Fail      => Do_Fail,
                     For_Gnatbind => False);
               end if;

               Options := In_Tree.Shared.String_Elements.Table (Options).Next;
            end loop;
         end;
      end loop;

      return Linker_Options_Buffer (1 .. Last_Linker_Option);
   end Linker_Options_Switches;

   -----------
   -- Mains --
   -----------

   package body Mains is

      package Names is new Table.Table
        (Table_Component_Type => Main_Info,
         Table_Index_Type     => Integer,
         Table_Low_Bound      => 1,
         Table_Initial        => 10,
         Table_Increment      => 100,
         Table_Name           => "Makeutl.Mains.Names");
      --  The table that stores the mains

      Current : Natural := 0;
      --  The index of the last main retrieved from the table

      Count_Of_Mains_With_No_Tree : Natural := 0;
      --  Number of main units for which we do not know the project tree

      --------------
      -- Add_Main --
      --------------

      procedure Add_Main
        (Name     : String;
         Index    : Int := 0;
         Location : Source_Ptr := No_Location;
         Project  : Project_Id := No_Project;
         Tree     : Project_Tree_Ref := null)
      is
      begin
         if Current_Verbosity = High then
            Debug_Output ("Add_Main """ & Name & """ " & Index'Img
                          & " with_tree? "
                          & Boolean'Image (Tree /= null));
         end if;

         Name_Len := 0;
         Add_Str_To_Name_Buffer (Name);
         Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));

         Names.Increment_Last;
         Names.Table (Names.Last) :=
           (Name_Find, Index, Location, No_Source, Project, Tree);

         if Tree /= null then
            Builder_Data (Tree).Number_Of_Mains :=
              Builder_Data (Tree).Number_Of_Mains + 1;

         else
            Mains.Count_Of_Mains_With_No_Tree :=
              Mains.Count_Of_Mains_With_No_Tree + 1;
         end if;
      end Add_Main;

      --------------------
      -- Complete_Mains --
      --------------------

      procedure Complete_Mains
        (Flags        : Processing_Flags;
         Root_Project : Project_Id;
         Project_Tree : Project_Tree_Ref)
      is
         procedure Do_Complete (Project : Project_Id; Tree : Project_Tree_Ref);
         --  Check the mains for this specific project

         procedure Complete_All is new For_Project_And_Aggregated
           (Do_Complete);

         procedure Add_Multi_Unit_Sources
           (Tree   : Project_Tree_Ref;
            Source : Prj.Source_Id);
         --  Add all units from the same file as the multi-unit Source

         function Find_File_Add_Extension
           (Tree      : Project_Tree_Ref;
            Base_Main : String) return Prj.Source_Id;
         --  Search for Main in the project, adding body or spec extensions

         ----------------------------
         -- Add_Multi_Unit_Sources --
         ----------------------------

         procedure Add_Multi_Unit_Sources
           (Tree   : Project_Tree_Ref;
            Source : Prj.Source_Id)
         is
            Iter : Source_Iterator;
            Src  : Prj.Source_Id;

         begin
            Debug_Output
              ("found multi-unit source file in project", Source.Project.Name);

            Iter := For_Each_Source
              (In_Tree => Tree, Project => Source.Project);

            while Element (Iter) /= No_Source loop
               Src := Element (Iter);

               if Src.File = Source.File
                 and then Src.Index /= Source.Index
               then
                  if Src.File = Source.File then
                     Debug_Output
                       ("add main in project, index=" & Src.Index'Img);
                  end if;

                  Names.Increment_Last;
                  Names.Table (Names.Last) :=
                    (File     => Src.File,
                     Index    => Src.Index,
                     Location => No_Location,
                     Source   => Src,
                     Project  => Src.Project,
                     Tree     => Tree);

                  Builder_Data (Tree).Number_Of_Mains :=
                    Builder_Data (Tree).Number_Of_Mains + 1;
               end if;

               Next (Iter);
            end loop;
         end Add_Multi_Unit_Sources;

         -----------------------------
         -- Find_File_Add_Extension --
         -----------------------------

         function Find_File_Add_Extension
           (Tree      : Project_Tree_Ref;
            Base_Main : String) return Prj.Source_Id
         is
            Spec_Source : Prj.Source_Id := No_Source;
            Source      : Prj.Source_Id;
            Iter        : Source_Iterator;
            Suffix      : File_Name_Type;

         begin
            Source := No_Source;
            Iter := For_Each_Source (Tree);  --  In all projects
            loop
               Source := Prj.Element (Iter);
               exit when Source = No_Source;

               if Source.Kind = Impl then
                  Get_Name_String (Source.File);

                  if Name_Len > Base_Main'Length
                    and then Name_Buffer (1 .. Base_Main'Length) = Base_Main
                  then
                     Suffix :=
                       Source.Language.Config.Naming_Data.Body_Suffix;

                     if Suffix /= No_File then
                        declare
                           Suffix_Str : String := Get_Name_String (Suffix);
                        begin
                           Canonical_Case_File_Name (Suffix_Str);
                           exit when
                             Name_Buffer (Base_Main'Length + 1 .. Name_Len) =
                             Suffix_Str;
                        end;
                     end if;
                  end if;

               elsif Source.Kind = Spec
                 and then Source.Language.Config.Kind = Unit_Based
               then
                  --  An Ada spec needs to be taken into account unless there
                  --  is also a body. So we delay the decision for them.

                  Get_Name_String (Source.File);

                  if Name_Len > Base_Main'Length
                    and then Name_Buffer (1 .. Base_Main'Length) = Base_Main
                  then
                     Suffix := Source.Language.Config.Naming_Data.Spec_Suffix;

                     if Suffix /= No_File then
                        declare
                           Suffix_Str : String := Get_Name_String (Suffix);

                        begin
                           Canonical_Case_File_Name (Suffix_Str);

                           if Name_Buffer (Base_Main'Length + 1 .. Name_Len) =
                             Suffix_Str
                           then
                              Spec_Source := Source;
                           end if;
                        end;
                     end if;
                  end if;
               end if;

               Next (Iter);
            end loop;

            if Source = No_Source then
               Source := Spec_Source;
            end if;

            return Source;
         end Find_File_Add_Extension;

         -----------------
         -- Do_Complete --
         -----------------

         procedure Do_Complete
           (Project : Project_Id; Tree : Project_Tree_Ref)
         is
            J : Integer;

         begin
            if Mains.Number_Of_Mains (Tree) > 0
              or else Mains.Count_Of_Mains_With_No_Tree > 0
            then
               --  Traverse in reverse order, since in the case of multi-unit
               --  files we will be adding extra files at the end, and there's
               --  no need to process them in turn.

               J := Names.Last;
               Main_Loop : loop
                  declare
                     File        : Main_Info       := Names.Table (J);
                     Main_Id     : File_Name_Type  := File.File;
                     Main        : constant String :=
                                     Get_Name_String (Main_Id);
                     Base        : constant String := Base_Name (Main);
                     Source      : Prj.Source_Id   := No_Source;
                     Is_Absolute : Boolean         := False;

                  begin
                     if Base /= Main then
                        Is_Absolute := True;

                        if Is_Absolute_Path (Main) then
                           Main_Id := Create_Name (Base);

                        --  Not an absolute path

                        else
                           --  Always resolve links here, so that users can be
                           --  specify any name on the command line. If the
                           --  project itself uses links, the user will be
                           --  using -eL anyway, and thus files are also stored
                           --  with resolved names.

                           declare
                              Absolute : constant String :=
                                           Normalize_Pathname
                                             (Name           => Main,
                                              Directory      => "",
                                              Resolve_Links  => True,
                                              Case_Sensitive => False);
                           begin
                              File.File := Create_Name (Absolute);
                              Main_Id := Create_Name (Base);
                           end;
                        end if;
                     end if;

                     --  If no project or tree was specified for the main, it
                     --  came from the command line.
                     --  Note that the assignments below will not modify inside
                     --  the table itself.

                     if File.Project = null then
                        File.Project := Project;
                     end if;

                     if File.Tree = null then
                        File.Tree := Tree;
                     end if;

                     if File.Source = null then
                        if Current_Verbosity = High then
                           Debug_Output
                             ("search for main """ & Main
                              & '"' & File.Index'Img & " in "
                              & Get_Name_String (Debug_Name (File.Tree))
                              & ", project", Project.Name);
                        end if;

                        --  First, look for the main as specified. We need to
                        --  search for the base name though, and if needed
                        --  check later that we found the correct file.

                        declare
                           Sources : constant Source_Ids :=
                                       Find_All_Sources
                                         (In_Tree          => File.Tree,
                                          Project          => File.Project,
                                          Base_Name        => Main_Id,
                                          Index            => File.Index,
                                          In_Imported_Only => True);

                        begin
                           if Is_Absolute then
                              for J in Sources'Range loop
                                 if File_Name_Type (Sources (J).Path.Name) =
                                                                    File.File
                                 then
                                    Source := Sources (J);
                                    exit;
                                 end if;
                              end loop;

                           elsif Sources'Length > 1 then

                              --  This is only allowed if the units are from
                              --  the same multi-unit source file.

                              Source := Sources (1);

                              for J in 2 .. Sources'Last loop
                                 if Sources (J).Path /= Source.Path
                                   or else Sources (J).Index = Source.Index
                                 then
                                    Error_Msg_File_1 := Main_Id;
                                    Prj.Err.Error_Msg
                                      (Flags, "several main sources {",
                                       No_Location, File.Project);
                                    exit Main_Loop;
                                 end if;
                              end loop;

                           elsif Sources'Length = 1 then
                              Source := Sources (Sources'First);
                           end if;
                        end;

                        if Source = No_Source then
                           Source := Find_File_Add_Extension
                                       (File.Tree, Get_Name_String (Main_Id));
                        end if;

                        if Is_Absolute
                          and then Source /= No_Source
                          and then
                            File_Name_Type (Source.Path.Name) /= File.File
                        then
                           Debug_Output
                             ("Found a non-matching file",
                              Name_Id (Source.Path.Display_Name));
                           Source := No_Source;
                        end if;

                        if Source /= No_Source then
                           if not Is_Allowed_Language
                                    (Source.Language.Name)
                           then
                              --  Remove any main that is not in the list of
                              --  restricted languages.

                              Names.Table (J .. Names.Last - 1) :=
                                Names.Table (J + 1 .. Names.Last);
                              Names.Set_Last (Names.Last - 1);

                           else
                              --  If we have found a multi-unit source file but
                              --  did not specify an index initially, we'll
                              --  need to compile all the units from the same
                              --  source file.

                              if Source.Index /= 0 and then File.Index = 0 then
                                 Add_Multi_Unit_Sources (File.Tree, Source);
                              end if;

                              --  Now update the original Main, otherwise it
                              --  will be reported as not found.

                              Debug_Output
                                ("found main in project", Source.Project.Name);
                              Names.Table (J).File    := Source.File;
                              Names.Table (J).Project := Source.Project;

                              if Names.Table (J).Tree = null then
                                 Names.Table (J).Tree := File.Tree;

                                 Builder_Data (File.Tree).Number_Of_Mains :=
                                   Builder_Data (File.Tree).Number_Of_Mains
                                                                         + 1;
                                 Mains.Count_Of_Mains_With_No_Tree :=
                                   Mains.Count_Of_Mains_With_No_Tree - 1;
                              end if;

                              Names.Table (J).Source  := Source;
                              Names.Table (J).Index   := Source.Index;
                           end if;

                        elsif File.Location /= No_Location then

                           --  If the main is declared in package Builder of
                           --  the main project, report an error. If the main
                           --  is on the command line, it may be a main from
                           --  another project, so do nothing: if the main does
                           --  not exist in another project, an error will be
                           --  reported later.

                           Error_Msg_File_1 := Main_Id;
                           Error_Msg_Name_1 := File.Project.Name;
                           Prj.Err.Error_Msg
                             (Flags, "{ is not a source of project %%",
                              File.Location, File.Project);
                        end if;
                     end if;
                  end;

                  J := J - 1;
                  exit Main_Loop when J < Names.First;
               end loop Main_Loop;
            end if;

            if Total_Errors_Detected > 0 then
               Fail_Program (Tree, "problems with main sources");
            end if;
         end Do_Complete;

      --  Start of processing for Complete_Mains

      begin
         Complete_All (Root_Project, Project_Tree);

         if Mains.Count_Of_Mains_With_No_Tree > 0 then
            for J in Names.First .. Names.Last loop
               if Names.Table (J).Source = No_Source then
                  Fail_Program
                    (Project_Tree, '"' & Get_Name_String (Names.Table (J).File)
                     & """ is not a source of any project");
               end if;
            end loop;
         end if;
      end Complete_Mains;

      ------------
      -- Delete --
      ------------

      procedure Delete is
      begin
         Names.Set_Last (0);
         Mains.Reset;
      end Delete;

      -----------------------
      -- Fill_From_Project --
      -----------------------

      procedure Fill_From_Project
        (Root_Project : Project_Id;
         Project_Tree : Project_Tree_Ref)
      is
         procedure Add_Mains_From_Project
           (Project : Project_Id;
            Tree    : Project_Tree_Ref);
         --  Add the main units from this project into Mains.
         --  This takes into account the aggregated projects

         ----------------------------
         -- Add_Mains_From_Project --
         ----------------------------

         procedure Add_Mains_From_Project
           (Project : Project_Id;
            Tree    : Project_Tree_Ref)
         is
            List    : String_List_Id;
            Element : String_Element;

         begin
            if Number_Of_Mains (Tree) = 0
              and then Mains.Count_Of_Mains_With_No_Tree = 0
            then
               Debug_Output ("Add_Mains_From_Project", Project.Name);
               List := Project.Mains;

               if List /= Prj.Nil_String then

                  --  The attribute Main is not an empty list. Get the mains in
                  --  the list.

                  while List /= Prj.Nil_String loop
                     Element := Tree.Shared.String_Elements.Table (List);
                     Debug_Output ("Add_Main", Element.Value);

                     if Project.Library then
                        Fail_Program
                          (Tree,
                           "cannot specify a main program "
                           & "for a library project file");
                     end if;

                     Add_Main (Name     => Get_Name_String (Element.Value),
                               Index    => Element.Index,
                               Location => Element.Location,
                               Project  => Project,
                               Tree     => Tree);
                     List := Element.Next;
                  end loop;
               end if;
            end if;

            if Total_Errors_Detected > 0 then
               Fail_Program (Tree, "problems with main sources");
            end if;
         end Add_Mains_From_Project;

         procedure Fill_All is new For_Project_And_Aggregated
           (Add_Mains_From_Project);

      --  Start of processing for Fill_From_Project

      begin
         Fill_All (Root_Project, Project_Tree);
      end Fill_From_Project;

      ---------------
      -- Next_Main --
      ---------------

      function Next_Main return String is
         Info : constant Main_Info := Next_Main;
      begin
         if Info = No_Main_Info then
            return "";
         else
            return Get_Name_String (Info.File);
         end if;
      end Next_Main;

      function Next_Main return Main_Info is
      begin
         if Current >= Names.Last then
            return No_Main_Info;
         else
            Current := Current + 1;

            --  If not using projects, and in the gnatmake case, the main file
            --  may have not have the extension. Try ".adb" first then ".ads"

            if Names.Table (Current).Project = No_Project then
               declare
                  Orig_Main : constant File_Name_Type :=
                    Names.Table (Current).File;
                  Current_Main : File_Name_Type;

               begin
                  if Strip_Suffix (Orig_Main) = Orig_Main then
                     Get_Name_String (Orig_Main);
                     Add_Str_To_Name_Buffer (".adb");
                     Current_Main := Name_Find;

                     if Full_Source_Name (Current_Main) = No_File then
                        Get_Name_String (Orig_Main);
                        Add_Str_To_Name_Buffer (".ads");
                        Current_Main := Name_Find;

                        if Full_Source_Name (Current_Main) /= No_File then
                           Names.Table (Current).File := Current_Main;
                        end if;

                     else
                        Names.Table (Current).File := Current_Main;
                     end if;
                  end if;
               end;
            end if;

            return Names.Table (Current);
         end if;
      end Next_Main;

      ---------------------
      -- Number_Of_Mains --
      ---------------------

      function Number_Of_Mains (Tree : Project_Tree_Ref) return Natural is
      begin
         if Tree = null then
            return Names.Last;
         else
            return Builder_Data (Tree).Number_Of_Mains;
         end if;
      end Number_Of_Mains;

      -----------
      -- Reset --
      -----------

      procedure Reset is
      begin
         Current := 0;
      end Reset;

      --------------------------
      -- Set_Multi_Unit_Index --
      --------------------------

      procedure Set_Multi_Unit_Index
        (Project_Tree : Project_Tree_Ref := null;
         Index        : Int := 0)
      is
      begin
         if Index /= 0 then
            if Names.Last = 0 then
               Fail_Program
                 (Project_Tree,
                  "cannot specify a multi-unit index but no main "
                  & "on the command line");

            elsif Names.Last > 1 then
               Fail_Program
                 (Project_Tree,
                  "cannot specify several mains with a multi-unit index");

            else
               Names.Table (Names.Last).Index := Index;
            end if;
         end if;
      end Set_Multi_Unit_Index;

   end Mains;

   -----------------------
   -- Path_Or_File_Name --
   -----------------------

   function Path_Or_File_Name (Path : Path_Name_Type) return String is
      Path_Name : constant String := Get_Name_String (Path);
   begin
      if Debug.Debug_Flag_F then
         return File_Name (Path_Name);
      else
         return Path_Name;
      end if;
   end Path_Or_File_Name;

   -------------------
   -- Unit_Index_Of --
   -------------------

   function Unit_Index_Of (ALI_File : File_Name_Type) return Int is
      Start  : Natural;
      Finish : Natural;
      Result : Int := 0;

   begin
      Get_Name_String (ALI_File);

      --  First, find the last dot

      Finish := Name_Len;

      while Finish >= 1 and then Name_Buffer (Finish) /= '.' loop
         Finish := Finish - 1;
      end loop;

      if Finish = 1 then
         return 0;
      end if;

      --  Now check that the dot is preceded by digits

      Start := Finish;
      Finish := Finish - 1;
      while Start >= 1 and then Name_Buffer (Start - 1) in '0' .. '9' loop
         Start := Start - 1;
      end loop;

      --  If there are no digits, or if the digits are not preceded by the
      --  character that precedes a unit index, this is not the ALI file of
      --  a unit in a multi-unit source.

      if Start > Finish
        or else Start = 1
        or else Name_Buffer (Start - 1) /= Multi_Unit_Index_Character
      then
         return 0;
      end if;

      --  Build the index from the digit(s)

      while Start <= Finish loop
         Result := Result * 10 +
                     Character'Pos (Name_Buffer (Start)) - Character'Pos ('0');
         Start := Start + 1;
      end loop;

      return Result;
   end Unit_Index_Of;

   -----------------
   -- Verbose_Msg --
   -----------------

   procedure Verbose_Msg
     (N1                : Name_Id;
      S1                : String;
      N2                : Name_Id := No_Name;
      S2                : String  := "";
      Prefix            : String := "  -> ";
      Minimum_Verbosity : Opt.Verbosity_Level_Type := Opt.Low)
   is
   begin
      if not Opt.Verbose_Mode
        or else Minimum_Verbosity > Opt.Verbosity_Level
      then
         return;
      end if;

      Write_Str (Prefix);
      Write_Str ("""");
      Write_Name (N1);
      Write_Str (""" ");
      Write_Str (S1);

      if N2 /= No_Name then
         Write_Str (" """);
         Write_Name (N2);
         Write_Str (""" ");
      end if;

      Write_Str (S2);
      Write_Eol;
   end Verbose_Msg;

   procedure Verbose_Msg
     (N1                : File_Name_Type;
      S1                : String;
      N2                : File_Name_Type := No_File;
      S2                : String  := "";
      Prefix            : String := "  -> ";
      Minimum_Verbosity : Opt.Verbosity_Level_Type := Opt.Low)
   is
   begin
      Verbose_Msg
        (Name_Id (N1), S1, Name_Id (N2), S2, Prefix, Minimum_Verbosity);
   end Verbose_Msg;

   -----------
   -- Queue --
   -----------

   package body Queue is

      type Q_Record is record
         Info      : Source_Info;
         Processed : Boolean;
      end record;

      package Q is new Table.Table
        (Table_Component_Type => Q_Record,
         Table_Index_Type     => Natural,
         Table_Low_Bound      => 1,
         Table_Initial        => 1000,
         Table_Increment      => 100,
         Table_Name           => "Makeutl.Queue.Q");
      --  This is the actual Queue

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

      type Mark_Key is record
         File  : File_Name_Type;
         Index : Int;
      end record;
      --  Identify either a mono-unit source (when Index = 0) or a specific
      --  unit (index = 1's origin index of unit) in a multi-unit source.

      Max_Mask_Num : constant := 2048;
      subtype Mark_Num is Union_Id range 0 .. Max_Mask_Num - 1;

      function Hash (Key : Mark_Key) return Mark_Num;

      package Marks is new GNAT.HTable.Simple_HTable
        (Header_Num => Mark_Num,
         Element    => Boolean,
         No_Element => False,
         Key        => Mark_Key,
         Hash       => Hash,
         Equal      => "=");
      --  A hash table to keep tracks of the marked units.
      --  These are the units that have already been processed, when using the
      --  gnatmake format. When using the gprbuild format, we can directly
      --  store in the source_id whether the file has already been processed.

      procedure Mark (Source_File : File_Name_Type; Index : Int := 0);
      --  Mark a unit, identified by its source file and, when Index is not 0,
      --  the index of the unit in the source file. Marking is used to signal
      --  that the unit has already been inserted in the Q.

      function Is_Marked
        (Source_File : File_Name_Type;
         Index       : Int := 0) return Boolean;
      --  Returns True if the unit was previously marked

      Q_Processed   : Natural := 0;
      Q_Initialized : Boolean := False;

      Q_First : Natural := 1;
      --  Points to the first valid element in the queue

      One_Queue_Per_Obj_Dir : Boolean := False;
      --  See parameter to Initialize

      function Available_Obj_Dir (S : Source_Info) return Boolean;
      --  Whether the object directory for S is available for a build

      procedure Debug_Display (S : Source_Info);
      --  A debug display for S

      function Was_Processed (S : Source_Info) return Boolean;
      --  Whether S has already been processed. This marks the source as
      --  processed, if it hasn't already been processed.

      function Insert_No_Roots (Source  : Source_Info) return Boolean;
      --  Insert Source, but do not look for its roots (see doc for Insert)

      -------------------
      -- Was_Processed --
      -------------------

      function Was_Processed (S : Source_Info) return Boolean is
      begin
         case S.Format is
            when Format_Gprbuild =>
               if S.Id.In_The_Queue then
                  return True;
               end if;

               S.Id.In_The_Queue := True;

            when Format_Gnatmake =>
               if Is_Marked (S.File, S.Index) then
                  return True;
               end if;

               Mark (S.File, Index => S.Index);
         end case;

         return False;
      end Was_Processed;

      -----------------------
      -- Available_Obj_Dir --
      -----------------------

      function Available_Obj_Dir (S : Source_Info) return Boolean is
      begin
         case S.Format is
            when Format_Gprbuild =>
               return not Busy_Obj_Dirs.Get
                 (S.Id.Project.Object_Directory.Name);

            when Format_Gnatmake =>
               return S.Project = No_Project
                 or else
                   not Busy_Obj_Dirs.Get (S.Project.Object_Directory.Name);
         end case;
      end Available_Obj_Dir;

      -------------------
      -- Debug_Display --
      -------------------

      procedure Debug_Display (S : Source_Info) is
      begin
         case S.Format is
            when Format_Gprbuild =>
               Write_Name (S.Id.File);

               if S.Id.Index /= 0 then
                  Write_Str (", ");
                  Write_Int (S.Id.Index);
               end if;

            when Format_Gnatmake =>
               Write_Name (S.File);

               if S.Index /= 0 then
                  Write_Str (", ");
                  Write_Int (S.Index);
               end if;
         end case;
      end Debug_Display;

      ----------
      -- Hash --
      ----------

      function Hash (Key : Mark_Key) return Mark_Num is
      begin
         return Union_Id (Key.File) mod Max_Mask_Num;
      end Hash;

      ---------------
      -- Is_Marked --
      ---------------

      function Is_Marked
        (Source_File : File_Name_Type;
         Index       : Int := 0) return Boolean
      is
      begin
         return Marks.Get (K => (File => Source_File, Index => Index));
      end Is_Marked;

      ----------
      -- Mark --
      ----------

      procedure Mark (Source_File : File_Name_Type; Index : Int := 0) is
      begin
         Marks.Set (K => (File => Source_File, Index => Index), E => True);
      end Mark;

      -------------
      -- Extract --
      -------------

      procedure Extract
        (Found  : out Boolean;
         Source : out Source_Info)
      is
      begin
         Found := False;

         if One_Queue_Per_Obj_Dir then
            for J in Q_First .. Q.Last loop
               if not Q.Table (J).Processed
                 and then Available_Obj_Dir (Q.Table (J).Info)
               then
                  Found := True;
                  Source := Q.Table (J).Info;
                  Q.Table (J).Processed := True;

                  if J = Q_First then
                     while Q_First <= Q.Last
                       and then Q.Table (Q_First).Processed
                     loop
                        Q_First := Q_First + 1;
                     end loop;
                  end if;

                  exit;
               end if;
            end loop;

         elsif Q_First <= Q.Last then
            Source := Q.Table (Q_First).Info;
            Q.Table (Q_First).Processed := True;
            Q_First := Q_First + 1;
            Found := True;
         end if;

         if Found then
            Q_Processed := Q_Processed + 1;
         end if;

         if Found and then Debug.Debug_Flag_Q then
            Write_Str ("   Q := Q - [ ");
            Debug_Display (Source);
            Write_Str (" ]");
            Write_Eol;

            Write_Str ("   Q_First =");
            Write_Int (Int (Q_First));
            Write_Eol;

            Write_Str ("   Q.Last =");
            Write_Int (Int (Q.Last));
            Write_Eol;
         end if;
      end Extract;

      ---------------
      -- Processed --
      ---------------

      function Processed return Natural is
      begin
         return Q_Processed;
      end Processed;

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

      procedure Initialize
        (Queue_Per_Obj_Dir : Boolean;
         Force             : Boolean := False)
      is
      begin
         if Force or else not Q_Initialized then
            Q_Initialized := True;

            for J in 1 .. Q.Last loop
               case Q.Table (J).Info.Format is
               when Format_Gprbuild =>
                  Q.Table (J).Info.Id.In_The_Queue := False;
               when Format_Gnatmake =>
                  null;
               end case;
            end loop;

            Q.Init;
            Q_Processed := 0;
            Q_First     := 1;
            One_Queue_Per_Obj_Dir := Queue_Per_Obj_Dir;
         end if;
      end Initialize;

      ---------------------
      -- Insert_No_Roots --
      ---------------------

      function Insert_No_Roots (Source  : Source_Info) return Boolean is
      begin
         pragma Assert
           (Source.Format = Format_Gnatmake or else Source.Id /= No_Source);

         --  Only insert in the Q if it is not already done, to avoid
         --  simultaneous compilations if -jnnn is used.

         if Was_Processed (Source) then
            return False;
         end if;

         --  For gprbuild, check if a source has already been inserted in the
         --  queue from the same project in a different project tree.

         if Source.Format = Format_Gprbuild then
            for J in 1 .. Q.Last loop
               if Source.Id.Path.Name = Q.Table (J).Info.Id.Path.Name
                 and then Source.Id.Index = Q.Table (J).Info.Id.Index
                 and then
                   Ultimate_Extending_Project_Of (Source.Id.Project).Path.Name
                     =
                   Ultimate_Extending_Project_Of (Q.Table (J).Info.Id.Project).
                                                                     Path.Name
               then
                  --  No need to insert this source in the queue, but still
                  --  return True as we may need to insert its roots.

                  return True;
               end if;
            end loop;
         end if;

         if Current_Verbosity = High then
            Write_Str ("Adding """);
            Debug_Display (Source);
            Write_Line (""" to the queue");
         end if;

         Q.Append (New_Val => (Info => Source, Processed => False));

         if Debug.Debug_Flag_Q then
            Write_Str ("   Q := Q + [ ");
            Debug_Display (Source);
            Write_Str (" ] ");
            Write_Eol;

            Write_Str ("   Q_First =");
            Write_Int (Int (Q_First));
            Write_Eol;

            Write_Str ("   Q.Last =");
            Write_Int (Int (Q.Last));
            Write_Eol;
         end if;

         return True;
      end Insert_No_Roots;

      ------------
      -- Insert --
      ------------

      function Insert
        (Source     : Source_Info;
         With_Roots : Boolean := False) return Boolean
      is
         Root_Arr     : Array_Element_Id;
         Roots        : Variable_Value;
         List         : String_List_Id;
         Elem         : String_Element;
         Unit_Name    : Name_Id;
         Pat_Root     : Boolean;
         Root_Pattern : Regexp;
         Root_Found   : Boolean;
         Roots_Found  : Boolean;
         Root_Source  : Prj.Source_Id;
         Iter         : Source_Iterator;

         Dummy : Boolean;

      begin
         if not Insert_No_Roots (Source) then

            --  Was already in the queue

            return False;
         end if;

         if With_Roots and then Source.Format = Format_Gprbuild then
            Debug_Output ("looking for roots of", Name_Id (Source.Id.File));

            Root_Arr :=
              Prj.Util.Value_Of
                (Name      => Name_Roots,
                 In_Arrays => Source.Id.Project.Decl.Arrays,
                 Shared    => Source.Tree.Shared);

            Roots :=
              Prj.Util.Value_Of
                (Index     => Name_Id (Source.Id.File),
                 Src_Index => 0,
                 In_Array  => Root_Arr,
                 Shared    => Source.Tree.Shared);

            --  If there is no roots for the specific main, try the language

            if Roots = Nil_Variable_Value then
               Roots :=
                 Prj.Util.Value_Of
                   (Index                  => Source.Id.Language.Name,
                    Src_Index              => 0,
                    In_Array               => Root_Arr,
                    Shared                 => Source.Tree.Shared,
                    Force_Lower_Case_Index => True);
            end if;

            --  Then try "*"

            if Roots = Nil_Variable_Value then
               Name_Len := 1;
               Name_Buffer (1) := '*';

               Roots :=
                 Prj.Util.Value_Of
                   (Index                  => Name_Find,
                    Src_Index              => 0,
                    In_Array               => Root_Arr,
                    Shared                 => Source.Tree.Shared,
                    Force_Lower_Case_Index => True);
            end if;

            if Roots = Nil_Variable_Value then
               Debug_Output ("   -> no roots declared");

            else
               List := Roots.Values;

               Pattern_Loop :
               while List /= Nil_String loop
                  Elem := Source.Tree.Shared.String_Elements.Table (List);
                  Get_Name_String (Elem.Value);
                  To_Lower (Name_Buffer (1 .. Name_Len));
                  Unit_Name := Name_Find;

                  --  Check if it is a unit name or a pattern

                  Pat_Root := False;

                  for J in 1 .. Name_Len loop
                     if Name_Buffer (J) not in 'a' .. 'z' and then
                        Name_Buffer (J) not in '0' .. '9' and then
                        Name_Buffer (J) /= '_'            and then
                        Name_Buffer (J) /= '.'
                     then
                        Pat_Root := True;
                        exit;
                     end if;
                  end loop;

                  if Pat_Root then
                     begin
                        Root_Pattern :=
                          Compile
                            (Pattern => Name_Buffer (1 .. Name_Len),
                             Glob    => True);

                     exception
                        when Error_In_Regexp =>
                           Err_Vars.Error_Msg_Name_1 := Unit_Name;
                           Errutil.Error_Msg
                             ("invalid pattern %", Roots.Location);
                           exit Pattern_Loop;
                     end;
                  end if;

                  Roots_Found := False;
                  Iter        := For_Each_Source (Source.Tree);

                  Source_Loop :
                  loop
                     Root_Source := Prj.Element (Iter);
                     exit Source_Loop when Root_Source = No_Source;

                     Root_Found := False;
                     if Pat_Root then
                        Root_Found := Root_Source.Unit /= No_Unit_Index
                          and then Match
                            (Get_Name_String (Root_Source.Unit.Name),
                             Root_Pattern);

                     else
                        Root_Found :=
                          Root_Source.Unit /= No_Unit_Index
                            and then Root_Source.Unit.Name = Unit_Name;
                     end if;

                     if Root_Found then
                        case Root_Source.Kind is
                        when Impl =>
                           null;

                        when Spec =>
                           Root_Found := Other_Part (Root_Source) = No_Source;

                        when Sep =>
                           Root_Found := False;
                        end case;
                     end if;

                     if Root_Found then
                        Roots_Found := True;
                        Debug_Output
                          ("   -> ", Name_Id (Root_Source.Display_File));
                        Dummy := Queue.Insert_No_Roots
                          (Source => (Format  => Format_Gprbuild,
                                      Tree    => Source.Tree,
                                      Id      => Root_Source,
                                      Closure => False));

                        Initialize_Source_Record (Root_Source);

                        if Other_Part (Root_Source) /= No_Source then
                           Initialize_Source_Record (Other_Part (Root_Source));
                        end if;

                        --  Save the root for the binder

                        Source.Id.Roots := new Source_Roots'
                          (Root => Root_Source,
                           Next => Source.Id.Roots);

                        exit Source_Loop when not Pat_Root;
                     end if;

                     Next (Iter);
                  end loop Source_Loop;

                  if not Roots_Found then
                     if Pat_Root then
                        if not Quiet_Output then
                           Error_Msg_Name_1 := Unit_Name;
                           Errutil.Error_Msg
                             ("?no unit matches pattern %", Roots.Location);
                        end if;

                     else
                        Errutil.Error_Msg
                          ("Unit " & Get_Name_String (Unit_Name)
                           & " does not exist", Roots.Location);
                     end if;
                  end if;

                  List := Elem.Next;
               end loop Pattern_Loop;
            end if;
         end if;

         return True;
      end Insert;

      ------------
      -- Insert --
      ------------

      procedure Insert
        (Source     : Source_Info;
         With_Roots : Boolean := False)
      is
         Discard : Boolean;
      begin
         Discard := Insert (Source, With_Roots);
      end Insert;

      --------------
      -- Is_Empty --
      --------------

      function Is_Empty return Boolean is
      begin
         return Q_Processed >= Q.Last;
      end Is_Empty;

      ------------------------
      -- Is_Virtually_Empty --
      ------------------------

      function Is_Virtually_Empty return Boolean is
      begin
         if One_Queue_Per_Obj_Dir then
            for J in Q_First .. Q.Last loop
               if not Q.Table (J).Processed
                 and then Available_Obj_Dir (Q.Table (J).Info)
               then
                  return False;
               end if;
            end loop;

            return True;

         else
            return Is_Empty;
         end if;
      end Is_Virtually_Empty;

      ----------------------
      -- Set_Obj_Dir_Busy --
      ----------------------

      procedure Set_Obj_Dir_Busy (Obj_Dir : Path_Name_Type) is
      begin
         if One_Queue_Per_Obj_Dir then
            Busy_Obj_Dirs.Set (Obj_Dir, True);
         end if;
      end Set_Obj_Dir_Busy;

      ----------------------
      -- Set_Obj_Dir_Free --
      ----------------------

      procedure Set_Obj_Dir_Free (Obj_Dir : Path_Name_Type) is
      begin
         if One_Queue_Per_Obj_Dir then
            Busy_Obj_Dirs.Set (Obj_Dir, False);
         end if;
      end Set_Obj_Dir_Free;

      ----------
      -- Size --
      ----------

      function Size return Natural is
      begin
         return Q.Last;
      end Size;

      -------------
      -- Element --
      -------------

      function Element (Rank : Positive) return File_Name_Type is
      begin
         if Rank <= Q.Last then
            case Q.Table (Rank).Info.Format is
               when Format_Gprbuild =>
                  return Q.Table (Rank).Info.Id.File;
               when Format_Gnatmake =>
                  return Q.Table (Rank).Info.File;
            end case;
         else
            return No_File;
         end if;
      end Element;

      ------------------
      -- Remove_Marks --
      ------------------

      procedure Remove_Marks is
      begin
         Marks.Reset;
      end Remove_Marks;

      ----------------------------
      -- Insert_Project_Sources --
      ----------------------------

      procedure Insert_Project_Sources
        (Project        : Project_Id;
         Project_Tree   : Project_Tree_Ref;
         All_Projects   : Boolean;
         Unique_Compile : Boolean)
      is

         procedure Do_Insert
           (Project : Project_Id;
            Tree    : Project_Tree_Ref;
            Context : Project_Context);
         --  Local procedures must be commented ???

         ---------------
         -- Do_Insert --
         ---------------

         procedure Do_Insert
           (Project : Project_Id;
            Tree    : Project_Tree_Ref;
            Context : Project_Context)
         is
            Unit_Based : constant Boolean :=
                           Unique_Compile
                             or else not Builder_Data (Tree).Closure_Needed;
            --  When Unit_Based is True, we enqueue all compilable sources
            --  including the unit based (Ada) one. When Unit_Based is False,
            --  put the Ada sources only when they are in a library project.

            Iter    : Source_Iterator;
            Source  : Prj.Source_Id;
            OK      : Boolean;
            Closure : Boolean;

         begin
            --  Nothing to do when "-u" was specified and some files were
            --  specified on the command line

            if Unique_Compile and then Mains.Number_Of_Mains (Tree) > 0 then
               return;
            end if;

            Iter := For_Each_Source (Tree);
            loop
               Source := Prj.Element (Iter);
               exit when Source = No_Source;

               if Is_Allowed_Language (Source.Language.Name)
                 and then Is_Compilable (Source)
                 and then (All_Projects
                            or else Is_Extending (Project, Source.Project))
                 and then not Source.Locally_Removed
                 and then Source.Replaced_By = No_Source
                 and then (not Source.Project.Externally_Built
                            or else (Is_Extending (Project, Source.Project)
                                      and then not Project.Externally_Built))
                 and then Source.Kind /= Sep
                 and then Source.Path /= No_Path_Information
               then
                  if Source.Kind = Impl
                    or else (Source.Unit /= No_Unit_Index
                              and then Source.Kind = Spec
                              and then (Other_Part (Source) = No_Source
                                          or else
                                        Other_Part (Source).Locally_Removed))
                  then
                     if (Unit_Based
                          or else Source.Unit = No_Unit_Index
                          or else Source.Project.Library
                          or else Context.In_Aggregate_Lib
                          or else Project.Qualifier = Aggregate_Library)
                       and then not Is_Subunit (Source)
                     then
                        OK := True;
                        Closure := False;

                        if Source.Unit /= No_Unit_Index
                          and then
                            (Source.Project.Library
                              or else Project.Qualifier = Aggregate_Library
                              or else Context.In_Aggregate_Lib)
                          and then Source.Project.Standalone_Library /= No
                        then
                           --  Check if the unit is in the interface

                           OK := False;

                           declare
                              List    : String_List_Id;
                              Element : String_Element;

                           begin
                              List := Source.Project.Lib_Interface_ALIs;
                              while List /= Nil_String loop
                                 Element :=
                                   Project_Tree.Shared.String_Elements.Table
                                     (List);

                                 if Element.Value = Name_Id (Source.Dep_Name)
                                 then
                                    OK := True;
                                    Closure := True;
                                    exit;
                                 end if;

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

                        if OK then
                           Queue.Insert
                             (Source => (Format  => Format_Gprbuild,
                                         Tree    => Tree,
                                         Id      => Source,
                                         Closure => Closure));
                        end if;
                     end if;
                  end if;
               end if;

               Next (Iter);
            end loop;
         end Do_Insert;

         procedure Insert_All is
           new For_Project_And_Aggregated_Context (Do_Insert);

      begin
         Insert_All (Project, Project_Tree);
      end Insert_Project_Sources;

      -------------------------------
      -- Insert_Withed_Sources_For --
      -------------------------------

      procedure Insert_Withed_Sources_For
        (The_ALI               : ALI.ALI_Id;
         Project_Tree          : Project_Tree_Ref;
         Excluding_Shared_SALs : Boolean := False)
      is
         Sfile  : File_Name_Type;
         Afile  : File_Name_Type;
         Src_Id : Prj.Source_Id;

      begin
         --  Insert in the queue the unmarked source files (i.e. those which
         --  have never been inserted in the queue and hence never considered).

         for J in ALI.ALIs.Table (The_ALI).First_Unit ..
           ALI.ALIs.Table (The_ALI).Last_Unit
         loop
            for K in ALI.Units.Table (J).First_With ..
              ALI.Units.Table (J).Last_With
            loop
               Sfile := ALI.Withs.Table (K).Sfile;

               --  Skip generics

               if Sfile /= No_File then
                  Afile := ALI.Withs.Table (K).Afile;

                  Src_Id := Source_Files_Htable.Get
                              (Project_Tree.Source_Files_HT, Sfile);
                  while Src_Id /= No_Source loop
                     Initialize_Source_Record (Src_Id);

                     if Is_Compilable (Src_Id)
                       and then Src_Id.Dep_Name = Afile
                     then
                        case Src_Id.Kind is
                           when Spec =>
                              declare
                                 Bdy : constant Prj.Source_Id :=
                                         Other_Part (Src_Id);
                              begin
                                 if Bdy /= No_Source
                                   and then not Bdy.Locally_Removed
                                 then
                                    Src_Id := Other_Part (Src_Id);
                                 end if;
                              end;

                           when Impl =>
                              if Is_Subunit (Src_Id) then
                                 Src_Id := No_Source;
                              end if;

                           when Sep =>
                              Src_Id := No_Source;
                        end case;

                        exit;
                     end if;

                     Src_Id := Src_Id.Next_With_File_Name;
                  end loop;

                  --  If Excluding_Shared_SALs is True, do not insert in the
                  --  queue the sources of a shared Stand-Alone Library.

                  if Src_Id /= No_Source
                    and then (not Excluding_Shared_SALs
                               or else Src_Id.Project.Standalone_Library = No
                               or else Src_Id.Project.Library_Kind = Static)
                  then
                     Queue.Insert
                       (Source => (Format  => Format_Gprbuild,
                                   Tree    => Project_Tree,
                                   Id      => Src_Id,
                                   Closure => True));
                  end if;
               end if;
            end loop;
         end loop;
      end Insert_Withed_Sources_For;

   end Queue;

   ----------
   -- Free --
   ----------

   procedure Free (Data : in out Builder_Project_Tree_Data) is
      procedure Unchecked_Free is new Ada.Unchecked_Deallocation
        (Binding_Data_Record, Binding_Data);

      TmpB, Binding : Binding_Data := Data.Binding;

   begin
      while Binding /= null loop
         TmpB := Binding.Next;
         Unchecked_Free (Binding);
         Binding := TmpB;
      end loop;
   end Free;

   ------------------
   -- Builder_Data --
   ------------------

   function Builder_Data
     (Tree : Project_Tree_Ref) return Builder_Data_Access
   is
   begin
      if Tree.Appdata = null then
         Tree.Appdata := new Builder_Project_Tree_Data;
      end if;

      return Builder_Data_Access (Tree.Appdata);
   end Builder_Data;

   --------------------------------
   -- Compute_Compilation_Phases --
   --------------------------------

   procedure Compute_Compilation_Phases
     (Tree                  : Project_Tree_Ref;
      Root_Project          : Project_Id;
      Option_Unique_Compile : Boolean := False;   --  Was "-u" specified ?
      Option_Compile_Only   : Boolean := False;   --  Was "-c" specified ?
      Option_Bind_Only      : Boolean := False;
      Option_Link_Only      : Boolean := False)
   is
      procedure Do_Compute (Project : Project_Id; Tree : Project_Tree_Ref);

      ----------------
      -- Do_Compute --
      ----------------

      procedure Do_Compute (Project : Project_Id; Tree : Project_Tree_Ref) is
         Data       : constant Builder_Data_Access := Builder_Data (Tree);
         All_Phases : constant Boolean :=
                        not Option_Compile_Only
                        and then not Option_Bind_Only
                        and then not Option_Link_Only;
         --  Whether the command line asked for all three phases. Depending on
         --  the project settings, we might still disable some of the phases.

         Has_Mains : constant Boolean := Data.Number_Of_Mains > 0;
         --  Whether there are some main units defined for this project tree
         --  (either from one of the projects, or from the command line)

      begin
         if Option_Unique_Compile then

            --  If -u or -U is specified on the command line, disregard any -c,
            --  -b or -l switch: only perform compilation.

            Data.Closure_Needed   := False;
            Data.Need_Compilation := True;
            Data.Need_Binding     := False;
            Data.Need_Linking     := False;

         else
            Data.Closure_Needed   :=
              Has_Mains
                or else (Root_Project.Library
                          and then Root_Project.Standalone_Library /= No);
            Data.Need_Compilation := All_Phases or Option_Compile_Only;
            Data.Need_Binding     := All_Phases or Option_Bind_Only;
            Data.Need_Linking     := (All_Phases or Option_Link_Only)
                                       and Has_Mains;
         end if;

         if Current_Verbosity = High then
            Debug_Output ("compilation phases: "
                          & " compile=" & Data.Need_Compilation'Img
                          & " bind="    & Data.Need_Binding'Img
                          & " link="    & Data.Need_Linking'Img
                          & " closure=" & Data.Closure_Needed'Img
                          & " mains="   & Data.Number_Of_Mains'Img,
                          Project.Name);
         end if;
      end Do_Compute;

      procedure Compute_All is new For_Project_And_Aggregated (Do_Compute);

   begin
      Compute_All (Root_Project, Tree);
   end Compute_Compilation_Phases;

   ------------------------------
   -- Compute_Builder_Switches --
   ------------------------------

   procedure Compute_Builder_Switches
     (Project_Tree        : Project_Tree_Ref;
      Env                 : in out Prj.Tree.Environment;
      Main_Project        : Project_Id;
      Only_For_Lang       : Name_Id := No_Name)
   is
      Builder_Package  : constant Package_Id :=
                           Value_Of (Name_Builder, Main_Project.Decl.Packages,
                                     Project_Tree.Shared);

      Global_Compilation_Array    : Array_Element_Id;
      Global_Compilation_Elem     : Array_Element;
      Global_Compilation_Switches : Variable_Value;

      Default_Switches_Array : Array_Id;

      Builder_Switches_Lang : Name_Id := No_Name;

      List             : String_List_Id;
      Element          : String_Element;

      Index            : Name_Id;
      Source           : Prj.Source_Id;

      Lang              : Name_Id := No_Name;  --  language index for Switches
      Switches_For_Lang : Variable_Value := Nil_Variable_Value;
      --  Value of Builder'Default_Switches(lang)

      Name              : Name_Id := No_Name;  --  main file index for Switches
      Switches_For_Main : Variable_Value := Nil_Variable_Value;
      --  Switches for a specific main. When there are several mains, Name is
      --  set to No_Name, and Switches_For_Main might be left with an actual
      --  value (so that we can display a warning that it was ignored).

      Other_Switches : Variable_Value := Nil_Variable_Value;
      --  Value of Builder'Switches(others)

      Defaults : Variable_Value := Nil_Variable_Value;

      Switches : Variable_Value := Nil_Variable_Value;
      --  The computed builder switches

      Success          : Boolean := False;
   begin
      if Builder_Package /= No_Package then
         Mains.Reset;

         --  If there is no main, and there is only one compilable language,
         --  use this language as the switches index.

         if Mains.Number_Of_Mains (Project_Tree) = 0 then
            if Only_For_Lang = No_Name then
               declare
                  Language : Language_Ptr := Main_Project.Languages;

               begin
                  while Language /= No_Language_Index loop
                     if Language.Config.Compiler_Driver /= No_File
                       and then Language.Config.Compiler_Driver /= Empty_File
                     then
                        if Lang /= No_Name then
                           Lang := No_Name;
                           exit;
                        else
                           Lang := Language.Name;
                        end if;
                     end if;
                     Language := Language.Next;
                  end loop;
               end;
            else
               Lang := Only_For_Lang;
            end if;

         else
            for Index in 1 .. Mains.Number_Of_Mains (Project_Tree) loop
               Source := Mains.Next_Main.Source;

               if Source /= No_Source then
                  if Switches_For_Main = Nil_Variable_Value then
                     Switches_For_Main := Value_Of
                       (Name                    => Name_Id (Source.File),
                        Attribute_Or_Array_Name => Name_Switches,
                        In_Package              => Builder_Package,
                        Shared                  => Project_Tree.Shared,
                        Force_Lower_Case_Index  => False,
                        Allow_Wildcards         => True);

                     --  If not found, try without extension.
                     --  That's because gnatmake accepts truncated file names
                     --  in Builder'Switches

                     if Switches_For_Main = Nil_Variable_Value
                       and then Source.Unit /= null
                     then
                        Switches_For_Main := Value_Of
                          (Name                    => Source.Unit.Name,
                           Attribute_Or_Array_Name => Name_Switches,
                           In_Package              => Builder_Package,
                           Shared                  => Project_Tree.Shared,
                           Force_Lower_Case_Index  => False,
                           Allow_Wildcards         => True);
                     end if;
                  end if;

                  if Index = 1 then
                     Lang := Source.Language.Name;
                     Name := Name_Id (Source.File);
                  else
                     Name := No_Name;  --  Can't use main specific switches

                     if Lang /= Source.Language.Name then
                        Lang := No_Name;
                     end if;
                  end if;
               end if;
            end loop;
         end if;

         Global_Compilation_Array := Value_Of
           (Name      => Name_Global_Compilation_Switches,
            In_Arrays => Project_Tree.Shared.Packages.Table
              (Builder_Package).Decl.Arrays,
            Shared    => Project_Tree.Shared);

         Default_Switches_Array :=
           Project_Tree.Shared.Packages.Table (Builder_Package).Decl.Arrays;

         while Default_Switches_Array /= No_Array
           and then
             Project_Tree.Shared.Arrays.Table (Default_Switches_Array).Name /=
               Name_Default_Switches
         loop
            Default_Switches_Array :=
              Project_Tree.Shared.Arrays.Table (Default_Switches_Array).Next;
         end loop;

         if Global_Compilation_Array /= No_Array_Element
           and then Default_Switches_Array /= No_Array
         then
            Prj.Err.Error_Msg
              (Env.Flags,
               "Default_Switches forbidden in presence of "
               & "Global_Compilation_Switches. Use Switches instead.",
               Project_Tree.Shared.Arrays.Table
                 (Default_Switches_Array).Location);
            Fail_Program
              (Project_Tree, "*** illegal combination of Builder attributes");
         end if;

         if Lang /= No_Name then
            Switches_For_Lang := Prj.Util.Value_Of
              (Name                    => Lang,
               Index                   => 0,
               Attribute_Or_Array_Name => Name_Switches,
               In_Package              => Builder_Package,
               Shared                  => Project_Tree.Shared,
               Force_Lower_Case_Index  => True);

            Defaults := Prj.Util.Value_Of
              (Name                    => Lang,
               Index                   => 0,
               Attribute_Or_Array_Name => Name_Default_Switches,
               In_Package              => Builder_Package,
               Shared                  => Project_Tree.Shared,
               Force_Lower_Case_Index  => True);
         end if;

         Other_Switches := Prj.Util.Value_Of
           (Name                    => All_Other_Names,
            Index                   => 0,
            Attribute_Or_Array_Name => Name_Switches,
            In_Package              => Builder_Package,
            Shared                  => Project_Tree.Shared);

         if not Quiet_Output
           and then Mains.Number_Of_Mains (Project_Tree) > 1
           and then Switches_For_Main /= Nil_Variable_Value
         then
            --  More than one main, but we had main-specific switches that
            --  are ignored.

            if Switches_For_Lang /= Nil_Variable_Value then
               Write_Line
                 ("Warning: using Builder'Switches("""
                  & Get_Name_String (Lang)
                  & """), as there are several mains");

            elsif Other_Switches /= Nil_Variable_Value then
               Write_Line
                 ("Warning: using Builder'Switches(others), "
                  & "as there are several mains");

            elsif Defaults /= Nil_Variable_Value then
               Write_Line
                 ("Warning: using Builder'Default_Switches("""
                  & Get_Name_String (Lang)
                  & """), as there are several mains");
            else
               Write_Line
                 ("Warning: using no switches from package "
                  & "Builder, as there are several mains");
            end if;
         end if;

         Builder_Switches_Lang := Lang;

         if Name /= No_Name then
            --  Get the switches for the single main
            Switches := Switches_For_Main;
         end if;

         if Switches = Nil_Variable_Value or else Switches.Default then
            --  Get the switches for the common language of the mains
            Switches := Switches_For_Lang;
         end if;

         if Switches = Nil_Variable_Value or else Switches.Default then
            Switches := Other_Switches;
         end if;

         --  For backward compatibility with gnatmake, if no Switches
         --  are declared, check for Default_Switches (<language>).

         if Switches = Nil_Variable_Value or else Switches.Default then
            Switches := Defaults;
         end if;

         --  If switches have been found, scan them

         if Switches /= Nil_Variable_Value and then not Switches.Default then
            List := Switches.Values;

            while List /= Nil_String loop
               Element := Project_Tree.Shared.String_Elements.Table (List);
               Get_Name_String (Element.Value);

               if Name_Len /= 0 then
                  declare
                     --  Add_Switch might itself be using the name_buffer, so
                     --  we make a temporary here.
                     Switch : constant String := Name_Buffer (1 .. Name_Len);
                  begin
                     Success := Add_Switch
                       (Switch      => Switch,
                        For_Lang    => Builder_Switches_Lang,
                        For_Builder => True,
                        Has_Global_Compilation_Switches =>
                          Global_Compilation_Array /= No_Array_Element);
                  end;

                  if not Success then
                     for J in reverse 1 .. Name_Len loop
                        Name_Buffer (J + J) := Name_Buffer (J);
                        Name_Buffer (J + J - 1) := ''';
                     end loop;

                     Name_Len := Name_Len + Name_Len;

                     Prj.Err.Error_Msg
                       (Env.Flags,
                        '"' & Name_Buffer (1 .. Name_Len)
                        & """ is not a builder switch. Consider moving "
                        & "it to Global_Compilation_Switches.",
                        Element.Location);
                     Fail_Program
                       (Project_Tree,
                        "*** illegal switch """
                        & Get_Name_String (Element.Value) & '"');
                  end if;
               end if;

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

         --  Reset the Builder Switches language

         Builder_Switches_Lang := No_Name;

         --  Take into account attributes Global_Compilation_Switches

         while Global_Compilation_Array /= No_Array_Element loop
            Global_Compilation_Elem :=
              Project_Tree.Shared.Array_Elements.Table
                (Global_Compilation_Array);

            Get_Name_String (Global_Compilation_Elem.Index);
            To_Lower (Name_Buffer (1 .. Name_Len));
            Index := Name_Find;

            if Only_For_Lang = No_Name or else Index = Only_For_Lang then
               Global_Compilation_Switches := Global_Compilation_Elem.Value;

               if Global_Compilation_Switches /= Nil_Variable_Value
                 and then not Global_Compilation_Switches.Default
               then
                  --  We have found an attribute
                  --  Global_Compilation_Switches for a language: put the
                  --  switches in the appropriate table.

                  List := Global_Compilation_Switches.Values;
                  while List /= Nil_String loop
                     Element :=
                       Project_Tree.Shared.String_Elements.Table (List);

                     if Element.Value /= No_Name then
                        Success := Add_Switch
                          (Switch      => Get_Name_String (Element.Value),
                           For_Lang    => Index,
                           For_Builder => False,
                           Has_Global_Compilation_Switches =>
                             Global_Compilation_Array /= No_Array_Element);
                     end if;

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

            Global_Compilation_Array := Global_Compilation_Elem.Next;
         end loop;
      end if;
   end Compute_Builder_Switches;

   ---------------------
   -- Write_Path_File --
   ---------------------

   procedure Write_Path_File (FD : File_Descriptor) is
      Last   : Natural;
      Status : Boolean;

   begin
      Name_Len := 0;

      for Index in Directories.First .. Directories.Last loop
         Add_Str_To_Name_Buffer (Get_Name_String (Directories.Table (Index)));
         Add_Char_To_Name_Buffer (ASCII.LF);
      end loop;

      Last := Write (FD, Name_Buffer (1)'Address, Name_Len);

      if Last = Name_Len then
         Close (FD, Status);
      else
         Status := False;
      end if;

      if not Status then
         Prj.Com.Fail ("could not write temporary file");
      end if;
   end Write_Path_File;

end Makeutl;