------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                              G N A T S Y M                               --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 2003-2010, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  This utility application creates symbol files in a format that is
--  platform-dependent.

--  A symbol file is a text file that lists the symbols to be exported from
--  a shared library. The format of a symbol file depends on the platform;
--  it may be a simple enumeration of the symbol (one per line) or a more
--  elaborate format (on VMS, for example). A symbol file may be used as an
--  input to the platform linker when building a shared library.

--  This utility is not available on all platforms. It is currently supported
--  only on OpenVMS.

--  gnatsym takes as parameters:
--    - the name of the symbol file to create
--    - (optional) the policy to create the symbol file
--    - (optional) the name of the reference symbol file
--    - the names of one or more object files where the symbols are found

with Gnatvsn; use Gnatvsn;
with Osint;   use Osint;
with Output;  use Output;
with Symbols; use Symbols;
with Table;

with Ada.Exceptions; use Ada.Exceptions;
with Ada.Text_IO;    use Ada.Text_IO;

with GNAT.Command_Line;         use GNAT.Command_Line;
with GNAT.Directory_Operations; use GNAT.Directory_Operations;
with GNAT.OS_Lib;               use GNAT.OS_Lib;

procedure Gnatsym is

   Empty_String : aliased String := "";
   Empty        : constant String_Access := Empty_String'Unchecked_Access;
   --  To initialize variables Reference and Version_String

   Copyright_Displayed : Boolean := False;
   --  A flag to prevent multiple display of the Copyright notice

   Success : Boolean := True;

   Symbol_Policy : Policy := Autonomous;

   Verbose : Boolean := False;
   --  True when -v switch is used

   Quiet : Boolean := False;
   --  True when -q switch is used

   Symbol_File_Name : String_Access := null;
   --  The name of the symbol file

   Reference_Symbol_File_Name : String_Access := Empty;
   --  The name of the reference symbol file

   Version_String : String_Access := Empty;
   --  The version of the library (used on VMS)

   type Object_File_Data is record
      Path : String_Access;
      Name : String_Access;
   end record;

   package Object_Files is new Table.Table
     (Table_Component_Type => Object_File_Data,
      Table_Index_Type     => Natural,
      Table_Low_Bound      => 0,
      Table_Initial        => 10,
      Table_Increment      => 100,
      Table_Name           => "Gnatsymb.Object_Files");
   --  A table to store the object file names

   Object_File : Natural := 0;
   --  An index to traverse the Object_Files table

   procedure Display_Copyright;
   --  Display Copyright notice

   procedure Parse_Cmd_Line;
   --  Parse the command line switches and file names

   procedure Usage;
   --  Display the usage

   -----------------------
   -- Display_Copyright --
   -----------------------

   procedure Display_Copyright is
   begin
      if not Copyright_Displayed then
         Write_Eol;
         Write_Str ("GNATSYMB ");
         Write_Str (Gnat_Version_String);
         Write_Eol;
         Write_Str ("Copyright 2003-2004 Free Software Foundation, Inc");
         Write_Eol;
         Copyright_Displayed := True;
      end if;
   end Display_Copyright;

   --------------------
   -- Parse_Cmd_Line --
   --------------------

   procedure Parse_Cmd_Line is
   begin
      loop
         case GNAT.Command_Line.Getopt ("c C D q r: R s: v V:") is
            when ASCII.NUL =>
               exit;

            when 'c' =>
               Symbol_Policy := Compliant;

            when 'C' =>
               Symbol_Policy := Controlled;

            when 'D' =>
               Symbol_Policy := Direct;

            when 'q' =>
               Quiet := True;

            when 'r' =>
               Reference_Symbol_File_Name :=
                 new String'(GNAT.Command_Line.Parameter);

            when 'R' =>
               Symbol_Policy := Restricted;

            when 's' =>
               Symbol_File_Name := new String'(GNAT.Command_Line.Parameter);

            when 'v' =>
               Verbose := True;

            when 'V' =>
               Version_String := new String'(GNAT.Command_Line.Parameter);

            when others =>
               Fail ("invalid switch: " & Full_Switch);
         end case;
      end loop;

      --  Get the object file names and put them in the table in alphabetical
      --  order of base names.

      loop
         declare
            S : constant String_Access :=
                           new String'(GNAT.Command_Line.Get_Argument);

         begin
            exit when S'Length = 0;

            Object_Files.Increment_Last;

            declare
               Base : constant String := Base_Name (S.all);
               Last : constant Positive := Object_Files.Last;
               J    : Positive;

            begin
               J := 1;
               while J < Last loop
                  if Object_Files.Table (J).Name.all > Base then
                     Object_Files.Table (J + 1 .. Last) :=
                       Object_Files.Table (J .. Last - 1);
                     exit;
                  end if;

                  J := J + 1;
               end loop;

               Object_Files.Table (J) := (S, new String'(Base));
            end;
         end;
      end loop;
   exception
      when Invalid_Switch =>
         Usage;
         Fail ("invalid switch : " & Full_Switch);
   end Parse_Cmd_Line;

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

   procedure Usage is
   begin
      Write_Line ("gnatsym [options] object_file {object_file}");
      Write_Eol;
      Write_Line ("   -c       Compliant symbol policy");
      Write_Line ("   -C       Controlled symbol policy");
      Write_Line ("   -q       Quiet mode");
      Write_Line ("   -r<ref>  Reference symbol file name");
      Write_Line ("   -R       Restricted symbol policy");
      Write_Line ("   -s<sym>  Symbol file name");
      Write_Line ("   -v       Verbose mode");
      Write_Line ("   -V<ver>  Version");
      Write_Eol;
      Write_Line ("Specifying a symbol file with -s<sym> is compulsory");
      Write_Eol;
   end Usage;

--  Start of processing of Gnatsym

begin
   --  Initialize Object_Files table

   Object_Files.Set_Last (0);

   --  Parse the command line

   Parse_Cmd_Line;

   if Verbose then
      Display_Copyright;
   end if;

   --  If there is no symbol file or no object files on the command line,
   --  display the usage and exit with an error status.

   if Symbol_File_Name = null or else Object_Files.Last = 0 then
      Usage;
      OS_Exit (1);

   --  When symbol policy is direct, simply copy the reference symbol file to
   --  the symbol file.

   elsif Symbol_Policy = Direct then
      declare
         File_In  : Ada.Text_IO.File_Type;
         File_Out : Ada.Text_IO.File_Type;
         Line     : String (1 .. 1_000);
         Last     : Natural;

      begin
         begin
            Open (File_In, In_File, Reference_Symbol_File_Name.all);

         exception
            when X : others =>
               if not Quiet then
                  Put_Line
                    ("could not open """ &
                     Reference_Symbol_File_Name.all
                     & """");
                  Put_Line (Exception_Message (X));
               end if;

               OS_Exit (1);
         end;

         begin
            Create (File_Out, Out_File, Symbol_File_Name.all);

         exception
            when X : others =>
               if not Quiet then
                  Put_Line
                    ("could not create """ & Symbol_File_Name.all & """");
                  Put_Line (Exception_Message (X));
               end if;

               OS_Exit (1);
         end;

         while not End_Of_File (File_In) loop
            Get_Line (File_In, Line, Last);
            Put_Line (File_Out, Line (1 .. Last));
         end loop;

         Close (File_In);
         Close (File_Out);
      end;

   else
      if Verbose then
         Write_Str ("Initializing symbol file """);
         Write_Str (Symbol_File_Name.all);
         Write_Line ("""");
      end if;

      --  Initialize symbol file and, if specified, read reference file

      Symbols.Initialize
        (Symbol_File   => Symbol_File_Name.all,
         Reference     => Reference_Symbol_File_Name.all,
         Symbol_Policy => Symbol_Policy,
         Quiet         => Quiet,
         Version       => Version_String.all,
         Success       => Success);

      --  Process the object files in order. Stop as soon as there is
      --  something wrong.

      Object_File := 0;

      while Success and then Object_File < Object_Files.Last loop
         Object_File := Object_File + 1;

         if Verbose then
            Write_Str ("Processing object file """);
            Write_Str (Object_Files.Table (Object_File).Path.all);
            Write_Line ("""");
         end if;

         Processing.Process
           (Object_Files.Table (Object_File).Path.all,
            Success);
      end loop;

      --  Finalize the symbol file

      if Success then
         if Verbose then
            Write_Str ("Finalizing """);
            Write_Str (Symbol_File_Name.all);
            Write_Line ("""");
         end if;

         Finalize (Quiet, Success);
      end if;

      --  Fail if there was anything wrong

      if not Success then
         Fail ("unable to build symbol file");
      end if;
   end if;
end Gnatsym;