--  Find installation path (using executable).
--  Copyright (C) 2002 - 2016 Tristan Gingold
--
--  GHDL is free software; you can redistribute it and/or modify it under
--  the terms of the GNU General Public License as published by the Free
--  Software Foundation; either version 2, or (at your option) any later
--  version.
--
--  GHDL is distributed in the hope that it will be useful, but WITHOUT 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
--  along with GCC; see the file COPYING.  If not, write to the Free
--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
--  02111-1307, USA.
--
--  As a special exception, if other files instantiate generics from this
--  unit, or you link this unit with other files to produce an executable,
--  this unit does not by itself cause the resulting executable to be
--  covered by the GNU General Public License. This exception does not
--  however invalidate any other reasons why the executable file might be
--  covered by the GNU Public License.

with Interfaces.C; use Interfaces.C;
with System; use System;

package body Windows_Default_Path is

   subtype DWORD is Interfaces.C.Unsigned_Long;
   subtype HINSTANCE is Address;
   function GetModuleFileName (Inst : HINSTANCE; Buf : Address; Size : DWORD)
                              return DWORD;
   pragma Import (Stdcall, GetModuleFileName, "GetModuleFileNameA");

   function Get_Windows_Exec_Path return String
   is
      File : String (1 .. 256);
      Size : DWORD;
      P : Natural;
   begin
      --  Get exe file path.
      Size := GetModuleFileName (Null_Address, File'Address, File'Length);
      if Size = 0 or Size = File'Length then
         return "{cannot find install path}\lib";
      end if;

      --  Remove Program file.
      P := Natural (Size);
      while P > 0 loop
         exit when File (P) = '\';
         exit when File (P) = ':' and P = 2;
         P := P - 1;
      end loop;
      if File (P) = '\' and P > 1 then
         --  Remove directory
         P := P - 1;
         while P > 0 loop
            exit when File (P) = '\';
            exit when File (P) = ':' and P = 2;
            P := P - 1;
         end loop;
      end if;

      return File (1 .. P);
   end Get_Windows_Exec_Path;
end Windows_Default_Path;