/* GMODULE - GLIB wrapper code for dynamic module loading

 * Copyright (C) 1998, 2000 Tim Janik

 *

 * Win32 GMODULE implementation

 * Copyright (C) 1998 Tor Lillqvist

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

/*

 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS

 * file for a list of people on the GLib Team.  See the ChangeLog

 * files for a list of changes.  These files are distributed with

 * GLib at ftp://ftp.gtk.org/pub/gtk/. 

 */

/* 

 * MT safe

 */

#include "config.h"

#include <stdio.h>

#include <windows.h>

#include <tlhelp32.h>

#ifdef G_WITH_CYGWIN

#include <sys/cygwin.h>

#endif

static void

set_error (const gchar *format,

	   ...)

{

  gchar *error;

  gchar *detail;

  gchar *message;

  va_list args;

  error = g_win32_error_message (GetLastError ());

  va_start (args, format);

  detail = g_strdup_vprintf (format, args);

  va_end (args);

  message = g_strconcat (detail, error, NULL);

  g_module_set_error (message);

  g_free (message);

  g_free (detail);

  g_free (error);

}

/* --- functions --- */

static gpointer

_g_module_open (const gchar *file_name,

		gboolean     bind_lazy,

		gboolean     bind_local)

{

  HINSTANCE handle;

  wchar_t *wfilename;

  DWORD old_mode;

  BOOL success;

#ifdef G_WITH_CYGWIN

  gchar tmp[MAX_PATH];

  cygwin_conv_to_win32_path(file_name, tmp);

  file_name = tmp;

#endif

  wfilename = g_utf8_to_utf16 (file_name, -1, NULL, NULL, NULL);

  /* suppress error dialog */

  success = SetThreadErrorMode (SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS, &old_mode);

  if (!success)

    set_error ("");

  handle = LoadLibraryW (wfilename);

  if (success)

    SetThreadErrorMode (old_mode, NULL);

  g_free (wfilename);

  if (!handle)

    set_error ("'%s': ", file_name);

  return handle;

}

static gint dummy;

static gpointer null_module_handle = &dummy;

static gpointer

_g_module_self (void)

{

  return null_module_handle;

}

static void

_g_module_close (gpointer handle,

		 gboolean is_unref)

{

  if (handle != null_module_handle)

    if (!FreeLibrary (handle))

      set_error ("");

}

static gpointer

find_in_any_module_using_toolhelp (const gchar *symbol_name)

{

  HANDLE snapshot; 

  MODULEENTRY32 me32;

  gpointer p;

  if ((snapshot = CreateToolhelp32Snapshot (TH32CS_SNAPMODULE, 0)) == (HANDLE) -1)

    return NULL;

  me32.dwSize = sizeof (me32);

  p = NULL;

  if (Module32First (snapshot, &me32))

    {

      do {

	if ((p = GetProcAddress (me32.hModule, symbol_name)) != NULL)

	  break;

      } while (Module32Next (snapshot, &me32));

    }

  CloseHandle (snapshot);

  return p;

}

static gpointer

find_in_any_module (const gchar *symbol_name)

{

  gpointer result;

  if ((result = find_in_any_module_using_toolhelp (symbol_name)) == NULL)

    return NULL;

  else

    return result;

}

static gpointer

_g_module_symbol (gpointer     handle,

		  const gchar *symbol_name)

{

  gpointer p;

  if (handle == null_module_handle)

    {

      if ((p = GetProcAddress (GetModuleHandle (NULL), symbol_name)) == NULL)

	p = find_in_any_module (symbol_name);

    }

  else

    p = GetProcAddress (handle, symbol_name);

  if (!p)

    set_error ("");

  return p;

}

static gchar*

_g_module_build_path (const gchar *directory,

		      const gchar *module_name)

{

  gint k;

  k = strlen (module_name);

  if (directory && *directory)

    if (k > 4 && g_ascii_strcasecmp (module_name + k - 4, ".dll") == 0)

      return g_strconcat (directory, G_DIR_SEPARATOR_S, module_name, NULL);

#ifdef G_WITH_CYGWIN

    else if (strncmp (module_name, "lib", 3) == 0 || strncmp (module_name, "cyg", 3) == 0)

      return g_strconcat (directory, G_DIR_SEPARATOR_S, module_name, ".dll", NULL);

    else

      return g_strconcat (directory, G_DIR_SEPARATOR_S, "cyg", module_name, ".dll", NULL);

#else

    else if (strncmp (module_name, "lib", 3) == 0)

      return g_strconcat (directory, G_DIR_SEPARATOR_S, module_name, ".dll", NULL);

    else

      return g_strconcat (directory, G_DIR_SEPARATOR_S, "lib", module_name, ".dll", NULL);

#endif

  else if (k > 4 && g_ascii_strcasecmp (module_name + k - 4, ".dll") == 0)

    return g_strdup (module_name);

#ifdef G_WITH_CYGWIN

  else if (strncmp (module_name, "lib", 3) == 0 || strncmp (module_name, "cyg", 3) == 0)

    return g_strconcat (module_name, ".dll", NULL);

  else

    return g_strconcat ("cyg", module_name, ".dll", NULL);

#else

  else if (strncmp (module_name, "lib", 3) == 0)

    return g_strconcat (module_name, ".dll", NULL);

  else

    return g_strconcat ("lib", module_name, ".dll", NULL);

#endif

}