/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * Dynamic link libraries management functions
 *
 * Copyright 2001 Antonio Linares <alinares@fivetech.com>
 * www - http://www.harbour-project.org
 *
 * This program 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 of the License, or
 * (at your option) any later version, with one exception:
 *
 * This program 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.
 *
 * This program 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 this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA (or visit the web site http://www.gnu.org/).
 *
 * As a special exception, the Harbour Project gives permission for
 * additional uses of the text contained in its release of Harbour.
 *
 * The exception is that, if you link the Harbour libraries with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the Harbour library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the Harbour
 * Project under the name Harbour.  If you copy code from other
 * Harbour Project or Free Software Foundation releases into a copy of
 * Harbour, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for Harbour, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 *
 */

#define HB_OS_WIN_USED
#define INCL_DOSMODULEMGR

#include "hbvmopt.h"
#include "hbapi.h"
#include "hbapiitm.h"
#include "hbstack.h"
#include "hbvm.h"

#if defined(HB_OS_LINUX) && !defined(__WATCOMC__)
#  include <dlfcn.h>
#endif

static HB_GARBAGE_FUNC( hb_libRelease )
{
   /* do nothing */
   HB_SYMBOL_UNUSED( Cargo );
}

HB_FUNC( HB_LIBLOAD )
{
   void * hDynLib = NULL;

   if( hb_parclen( 1 ) > 0 )
   {
      int argc = hb_pcount() - 1, i;
      char **argv = NULL;

      if( argc > 0 )
      {
         argv = ( char** ) hb_xgrab( sizeof( char* ) * argc );
         for( i = 0; i < argc; ++i )
            argv[i] = hb_parcx( i + 2 );
      }

      if( hb_vmLockModuleSymbols() )
      {
         /* use stack address as first level marker */
         hb_vmBeginSymbolGroup( ( void * ) hb_stackId(), TRUE );
#if defined( HB_OS_WIN )
         hDynLib = ( void * ) LoadLibraryA( hb_parc( 1 ) );
#elif defined( HB_OS_OS2 )
         {
            UCHAR LoadError[ 256 ] = "";  /* Area for load failure information */
            HMODULE hDynModule;
            if( DosLoadModule( ( PSZ ) LoadError, sizeof( LoadError ),
                               ( PCSZ ) hb_parc( 1 ), &hDynModule ) == NO_ERROR )
               hDynLib = ( void * ) hDynModule;
         }
#elif defined( HB_OS_LINUX ) && !defined( __WATCOMC__ )
         hDynLib = ( void * ) dlopen( hb_parc( 1 ), RTLD_LAZY | RTLD_GLOBAL );
#endif
         /* set real marker */
         hb_vmInitSymbolGroup( hDynLib, argc, argv );

         hb_vmUnlockModuleSymbols();
      }

      if( argv )
         hb_xfree( argv );
   }

   if( hDynLib )
   {
      void ** pLibPtr = ( void ** ) hb_gcAlloc( sizeof( void * ), hb_libRelease );
      * pLibPtr = hDynLib;
      hb_retptrGC( pLibPtr );
   }
   else
      hb_ret();
}

HB_FUNC( HB_LIBFREE )
{
   BOOL fResult = FALSE;
   void ** pDynLibPtr = ( void ** ) hb_parptrGC( hb_libRelease, 1 );

   if( pDynLibPtr && *pDynLibPtr &&
       hb_vmLockModuleSymbols() )
   {
      void * hDynLib = *pDynLibPtr;
      if( hDynLib )
      {
         *pDynLibPtr = NULL;
         hb_vmExitSymbolGroup( hDynLib );
#if defined( HB_OS_WIN )
         fResult = FreeLibrary( ( HMODULE ) hDynLib );
#elif defined( HB_OS_OS2 )
         fResult = DosFreeModule( ( HMODULE ) hDynLib ) == NO_ERROR;
#elif defined( HB_OS_LINUX ) && !defined (__WATCOMC__ )
         fResult = dlclose( hDynLib ) == 0;
#endif
      }
      hb_vmUnlockModuleSymbols();
   }
   hb_retl( fResult );
}

HB_FUNC( HB_LIBERROR )
{
#if defined(HB_OS_LINUX) && !defined(__WATCOMC__)
   hb_retc( dlerror() );
#else
   hb_retc( NULL );
#endif
}

/* Executes a Harbour pcode dynamically loaded DLL function or procedure
 * Syntax: HB_libDo( <cFuncName> [,<params...>] ) --> [<uResult>]
 */

HB_FUNC( HB_LIBDO )
{
   if( hb_parclen( 1 ) > 0 )
   {
      PHB_DYNS pDynSym = hb_dynsymFindName( hb_parc( 1 ) );

      if( pDynSym )
      {
         USHORT uiPCount = hb_pcount();
         USHORT uiParam;

         hb_vmPushSymbol( pDynSym->pSymbol );
         hb_vmPushNil();

         /* same logic here as from HB_FUNC( EVAL ) */
         for( uiParam = 2; uiParam <= uiPCount; uiParam++ )
         {
            hb_vmPush( hb_stackItemFromBase( uiParam ) );
         }

         hb_vmDo( ( USHORT ) ( uiPCount - 1 ) );
      }
   }
}