share/libtool/libltdl/loaders/loadlibrary.c - toolchains/kvm - Git at Google

 /* loader-loadlibrary.c --  dynamic linking for Win32

    Copyright (C) 1998, 1999, 2000, 2004, 2005, 2006,
                  2007, 2008, 2010 Free Software Foundation, Inc.
    Written by Thomas Tanner, 1998

    NOTE: The canonical source of this file is maintained with the
    GNU Libtool package.  Report bugs to bug-libtool@gnu.org.

 GNU Libltdl 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 of the License, or (at your option) any later version.

 As a special exception to the GNU Lesser General Public License,
 if you distribute this file as part of a program or library that
 is built using GNU Libtool, you may include this file under the
 same distribution terms that you use for the rest of that program.

 GNU Libltdl 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 GNU Libltdl; see the file COPYING.LIB.  If not, a
 copy can be downloaded from  http://www.gnu.org/licenses/lgpl.html,
 or obtained by writing to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

 #include "lt__private.h"
 #include "lt_dlloader.h"

 #if defined(__CYGWIN__)
 # include <sys/cygwin.h>
 #endif

 /* Use the preprocessor to rename non-static symbols to avoid namespace
    collisions when the loader code is statically linked into libltdl.
    Use the "<module_name>_LTX_" prefix so that the symbol addresses can
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	loadlibrary_LTX_get_vtable

 LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
 LT_END_C_DECLS


 /* Boilerplate code to set up the vtable for hooking this loader into
    libltdl's loader list:  */
 static int	 vl_exit  (lt_user_data loader_data);
 static lt_module vm_open  (lt_user_data loader_data, const char *filename,
                            lt_dladvise advise);
 static int	 vm_close (lt_user_data loader_data, lt_module module);
 static void *	 vm_sym   (lt_user_data loader_data, lt_module module,
 			  const char *symbolname);

 static lt_dlinterface_id iface_id = 0;
 static lt_dlvtable *vtable = 0;

 /* Return the vtable for this loader, only the name and sym_prefix
    attributes (plus the virtual function implementations, obviously)
    change between loaders.  */
 lt_dlvtable *
 get_vtable (lt_user_data loader_data)
 {
   if (!vtable)
     {
       vtable = (lt_dlvtable *) lt__zalloc (sizeof *vtable);
       iface_id = lt_dlinterface_register ("ltdl loadlibrary", NULL);
     }

   if (vtable && !vtable->name)
     {
       vtable->name		= "lt_loadlibrary";
       vtable->module_open	= vm_open;
       vtable->module_close	= vm_close;
       vtable->find_sym		= vm_sym;
       vtable->dlloader_exit	= vl_exit;
       vtable->dlloader_data	= loader_data;
       vtable->priority		= LT_DLLOADER_APPEND;
     }

   if (vtable && (vtable->dlloader_data != loader_data))
     {
       LT__SETERROR (INIT_LOADER);
       return 0;
     }

   return vtable;
 }


 /* --- IMPLEMENTATION --- */


 #include <windows.h>

 #define LOCALFREE(mem)					     LT_STMT_START { \
 	if (mem) { LocalFree ((void *)mem); mem = NULL; }    } LT_STMT_END
 #define LOADLIB__SETERROR(errmsg) LT__SETERRORSTR (loadlibraryerror (errmsg))
 #define LOADLIB_SETERROR(errcode) LOADLIB__SETERROR (LT__STRERROR (errcode))

 static const char *loadlibraryerror (const char *default_errmsg);
 static DWORD WINAPI wrap_getthreaderrormode (void);
 static DWORD WINAPI fallback_getthreaderrormode (void);
 static BOOL WINAPI wrap_setthreaderrormode (DWORD mode, DWORD *oldmode);
 static BOOL WINAPI fallback_setthreaderrormode (DWORD mode, DWORD *oldmode);

 typedef DWORD (WINAPI getthreaderrormode_type) (void);
 typedef BOOL (WINAPI setthreaderrormode_type) (DWORD, DWORD *);

 static getthreaderrormode_type *getthreaderrormode = wrap_getthreaderrormode;
 static setthreaderrormode_type *setthreaderrormode = wrap_setthreaderrormode;
 static char *error_message = 0;


 /* A function called through the vtable when this loader is no
    longer needed by the application.  */
 static int
 vl_exit (lt_user_data LT__UNUSED loader_data)
 {
   vtable = NULL;
   LOCALFREE (error_message);
   return 0;
 }

 /* A function called through the vtable to open a module with this
    loader.  Returns an opaque representation of the newly opened
    module for processing with this loader's other vtable functions.  */
 static lt_module
 vm_open (lt_user_data LT__UNUSED loader_data, const char *filename,
          lt_dladvise LT__UNUSED advise)
 {
   lt_module	module	   = 0;
   char		*ext;
   char		wpath[MAX_PATH];
   size_t	len;

   if (!filename)
     {
       /* Get the name of main module */
       *wpath = 0;
       GetModuleFileName (NULL, wpath, sizeof (wpath));
       filename = wpath;
     }
   else
     {
       len = LT_STRLEN (filename);

       if (len >= MAX_PATH)
         {
 	  LT__SETERROR (CANNOT_OPEN);
 	  return 0;
 	}

 #if HAVE_DECL_CYGWIN_CONV_PATH
       if (cygwin_conv_path (CCP_POSIX_TO_WIN_A, filename, wpath, MAX_PATH))
 	{
 	  LT__SETERROR (CANNOT_OPEN);
 	  return 0;
 	}
       len = 0;
 #elif defined(__CYGWIN__)
       cygwin_conv_to_full_win32_path (filename, wpath);
       len = 0;
 #else
       strcpy(wpath, filename);
 #endif

       ext = strrchr (wpath, '.');
       if (!ext)
 	{
 	  /* Append a `.' to stop Windows from adding an
 	     implicit `.dll' extension. */
 	  if (!len)
 	    len = strlen (wpath);

 	  if (len + 1 >= MAX_PATH)
 	    {
 	      LT__SETERROR (CANNOT_OPEN);
 	      return 0;
 	    }

 	  wpath[len] = '.';
 	  wpath[len+1] = '\0';
 	}
     }

   {
     /* Silence dialog from LoadLibrary on some failures. */
     DWORD errormode = getthreaderrormode ();
     DWORD last_error;

     setthreaderrormode (errormode | SEM_FAILCRITICALERRORS, NULL);

     module = LoadLibrary (wpath);

     /* Restore the error mode. */
     last_error = GetLastError ();
     setthreaderrormode (errormode, NULL);
     SetLastError (last_error);
   }

   /* libltdl expects this function to fail if it is unable
      to physically load the library.  Sadly, LoadLibrary
      will search the loaded libraries for a match and return
      one of them if the path search load fails.

      We check whether LoadLibrary is returning a handle to
      an already loaded module, and simulate failure if we
      find one. */
   {
     lt_dlhandle cur = 0;

     while ((cur = lt_dlhandle_iterate (iface_id, cur)))
       {
         if (!cur->module)
           {
             cur = 0;
             break;
           }

         if (cur->module == module)
           {
             break;
           }
       }

     if (!module)
       LOADLIB_SETERROR (CANNOT_OPEN);
     else if (cur)
       {
         LT__SETERROR (CANNOT_OPEN);
         module = 0;
       }
   }

   return module;
 }


 /* A function called through the vtable when a particular module
    should be unloaded.  */
 static int
 vm_close (lt_user_data LT__UNUSED loader_data, lt_module module)
 {
   int errors = 0;

   if (FreeLibrary ((HMODULE) module) == 0)
     {
       LOADLIB_SETERROR (CANNOT_CLOSE);
       ++errors;
     }

   return errors;
 }


 /* A function called through the vtable to get the address of
    a symbol loaded from a particular module.  */
 static void *
 vm_sym (lt_user_data LT__UNUSED loader_data, lt_module module, const char *name)
 {
   void *address = (void *) GetProcAddress ((HMODULE) module, name);

   if (!address)
     {
       LOADLIB_SETERROR (SYMBOL_NOT_FOUND);
     }

   return address;
 }


 /* --- HELPER FUNCTIONS --- */


 /* Return the windows error message, or the passed in error message on
    failure. */
 static const char *
 loadlibraryerror (const char *default_errmsg)
 {
   size_t len;
   LOCALFREE (error_message);

   FormatMessageA (FORMAT_MESSAGE_ALLOCATE_BUFFER |
                   FORMAT_MESSAGE_FROM_SYSTEM |
                   FORMAT_MESSAGE_IGNORE_INSERTS,
                   NULL,
                   GetLastError (),
                   0,
                   (char *) &error_message,
                   0, NULL);

   /* Remove trailing CRNL */
   len = LT_STRLEN (error_message);
   if (len && error_message[len - 1] == '\n')
     error_message[--len] = LT_EOS_CHAR;
   if (len && error_message[len - 1] == '\r')
     error_message[--len] = LT_EOS_CHAR;

   return len ? error_message : default_errmsg;
 }

 /* A function called through the getthreaderrormode variable which checks
    if the system supports GetThreadErrorMode (or GetErrorMode) and arranges
    for it or a fallback implementation to be called directly in the future.
    The selected version is then called. */
 static DWORD WINAPI
 wrap_getthreaderrormode (void)
 {
   HMODULE kernel32 = GetModuleHandleA ("kernel32.dll");
   getthreaderrormode
     = (getthreaderrormode_type *) GetProcAddress (kernel32,
 						  "GetThreadErrorMode");
   if (!getthreaderrormode)
     getthreaderrormode
       = (getthreaderrormode_type *) GetProcAddress (kernel32,
 						    "GetErrorMode");
   if (!getthreaderrormode)
     getthreaderrormode = fallback_getthreaderrormode;
   return getthreaderrormode ();
 }

 /* A function called through the getthreaderrormode variable for cases
    where the system does not support GetThreadErrorMode or GetErrorMode */
 static DWORD WINAPI
 fallback_getthreaderrormode (void)
 {
   /* Prior to Windows Vista, the only way to get the current error
      mode was to set a new one. In our case, we are setting a new
      error mode right after "getting" it while ignoring the error
      mode in effect when setting the new error mode, so that's
      fairly ok. */
   return (DWORD) SetErrorMode (SEM_FAILCRITICALERRORS);
 }

 /* A function called through the setthreaderrormode variable which checks
    if the system supports SetThreadErrorMode and arranges for it or a
    fallback implementation to be called directly in the future.
    The selected version is then called. */
 static BOOL WINAPI
 wrap_setthreaderrormode (DWORD mode, DWORD *oldmode)
 {
   HMODULE kernel32 = GetModuleHandleA ("kernel32.dll");
   setthreaderrormode
     = (setthreaderrormode_type *) GetProcAddress (kernel32,
 						  "SetThreadErrorMode");
   if (!setthreaderrormode)
     setthreaderrormode = fallback_setthreaderrormode;
   return setthreaderrormode (mode, oldmode);
 }

 /* A function called through the setthreaderrormode variable for cases
    where the system does not support SetThreadErrorMode. */
 static BOOL WINAPI
 fallback_setthreaderrormode (DWORD mode, DWORD *oldmode)
 {
   /* Prior to Windows 7, there was no way to set the thread local error
      mode, so set the process global error mode instead. */
   DWORD old = (DWORD) SetErrorMode (mode);
   if (oldmode)
     *oldmode = old;
   return TRUE;
 }
	/* loader-loadlibrary.c -- dynamic linking for Win32

	Copyright (C) 1998, 1999, 2000, 2004, 2005, 2006,
	2007, 2008, 2010 Free Software Foundation, Inc.
	Written by Thomas Tanner, 1998

	NOTE: The canonical source of this file is maintained with the
	GNU Libtool package. Report bugs to bug-libtool@gnu.org.

	GNU Libltdl 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 of the License, or (at your option) any later version.

	As a special exception to the GNU Lesser General Public License,
	if you distribute this file as part of a program or library that
	is built using GNU Libtool, you may include this file under the
	same distribution terms that you use for the rest of that program.

	GNU Libltdl 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 GNU Libltdl; see the file COPYING.LIB. If not, a
	copy can be downloaded from http://www.gnu.org/licenses/lgpl.html,
	or obtained by writing to the Free Software Foundation, Inc.,
	51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	*/

	#include "lt__private.h"
	#include "lt_dlloader.h"

	#if defined(__CYGWIN__)
	# include <sys/cygwin.h>
	#endif

	/* Use the preprocessor to rename non-static symbols to avoid namespace
	collisions when the loader code is statically linked into libltdl.
	Use the "<module_name>_LTX_" prefix so that the symbol addresses can
	be fetched from the preloaded symbol list by lt_dlsym(): */
	#define get_vtable loadlibrary_LTX_get_vtable

	LT_BEGIN_C_DECLS
	LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
	LT_END_C_DECLS


	/* Boilerplate code to set up the vtable for hooking this loader into
	libltdl's loader list: */
	static int vl_exit (lt_user_data loader_data);
	static lt_module vm_open (lt_user_data loader_data, const char *filename,
	lt_dladvise advise);
	static int vm_close (lt_user_data loader_data, lt_module module);
	static void * vm_sym (lt_user_data loader_data, lt_module module,
	const char *symbolname);

	static lt_dlinterface_id iface_id = 0;
	static lt_dlvtable *vtable = 0;

	/* Return the vtable for this loader, only the name and sym_prefix
	attributes (plus the virtual function implementations, obviously)
	change between loaders. */
	lt_dlvtable *
	get_vtable (lt_user_data loader_data)
	{
	if (!vtable)
	{
	vtable = (lt_dlvtable ) lt__zalloc (sizeof vtable);
	iface_id = lt_dlinterface_register ("ltdl loadlibrary", NULL);
	}

	if (vtable && !vtable->name)
	{
	vtable->name = "lt_loadlibrary";
	vtable->module_open = vm_open;
	vtable->module_close = vm_close;
	vtable->find_sym = vm_sym;
	vtable->dlloader_exit = vl_exit;
	vtable->dlloader_data = loader_data;
	vtable->priority = LT_DLLOADER_APPEND;
	}

	if (vtable && (vtable->dlloader_data != loader_data))
	{
	LT__SETERROR (INIT_LOADER);
	return 0;
	}

	return vtable;
	}



	/* --- IMPLEMENTATION --- */


	#include <windows.h>

	#define LOCALFREE(mem) LT_STMT_START { \
	if (mem) { LocalFree ((void *)mem); mem = NULL; } } LT_STMT_END
	#define LOADLIB__SETERROR(errmsg) LT__SETERRORSTR (loadlibraryerror (errmsg))
	#define LOADLIB_SETERROR(errcode) LOADLIB__SETERROR (LT__STRERROR (errcode))

	static const char loadlibraryerror (const char default_errmsg);
	static DWORD WINAPI wrap_getthreaderrormode (void);
	static DWORD WINAPI fallback_getthreaderrormode (void);
	static BOOL WINAPI wrap_setthreaderrormode (DWORD mode, DWORD *oldmode);
	static BOOL WINAPI fallback_setthreaderrormode (DWORD mode, DWORD *oldmode);

	typedef DWORD (WINAPI getthreaderrormode_type) (void);
	typedef BOOL (WINAPI setthreaderrormode_type) (DWORD, DWORD *);

	static getthreaderrormode_type *getthreaderrormode = wrap_getthreaderrormode;
	static setthreaderrormode_type *setthreaderrormode = wrap_setthreaderrormode;
	static char *error_message = 0;


	/* A function called through the vtable when this loader is no
	longer needed by the application. */
	static int
	vl_exit (lt_user_data LT__UNUSED loader_data)
	{
	vtable = NULL;
	LOCALFREE (error_message);
	return 0;
	}

	/* A function called through the vtable to open a module with this
	loader. Returns an opaque representation of the newly opened
	module for processing with this loader's other vtable functions. */
	static lt_module
	vm_open (lt_user_data LT__UNUSED loader_data, const char *filename,
	lt_dladvise LT__UNUSED advise)
	{
	lt_module module = 0;
	char *ext;
	char wpath[MAX_PATH];
	size_t len;

	if (!filename)
	{
	/* Get the name of main module */
	*wpath = 0;
	GetModuleFileName (NULL, wpath, sizeof (wpath));
	filename = wpath;
	}
	else
	{
	len = LT_STRLEN (filename);

	if (len >= MAX_PATH)
	{
	LT__SETERROR (CANNOT_OPEN);
	return 0;
	}

	#if HAVE_DECL_CYGWIN_CONV_PATH
	if (cygwin_conv_path (CCP_POSIX_TO_WIN_A, filename, wpath, MAX_PATH))
	{
	LT__SETERROR (CANNOT_OPEN);
	return 0;
	}
	len = 0;
	#elif defined(__CYGWIN__)
	cygwin_conv_to_full_win32_path (filename, wpath);
	len = 0;
	#else
	strcpy(wpath, filename);
	#endif

	ext = strrchr (wpath, '.');
	if (!ext)
	{
	/* Append a `.' to stop Windows from adding an
	implicit `.dll' extension. */
	if (!len)
	len = strlen (wpath);

	if (len + 1 >= MAX_PATH)
	{
	LT__SETERROR (CANNOT_OPEN);
	return 0;
	}

	wpath[len] = '.';
	wpath[len+1] = '\0';
	}
	}

	{
	/* Silence dialog from LoadLibrary on some failures. */
	DWORD errormode = getthreaderrormode ();
	DWORD last_error;

	setthreaderrormode (errormode \| SEM_FAILCRITICALERRORS, NULL);

	module = LoadLibrary (wpath);

	/* Restore the error mode. */
	last_error = GetLastError ();
	setthreaderrormode (errormode, NULL);
	SetLastError (last_error);
	}

	/* libltdl expects this function to fail if it is unable
	to physically load the library. Sadly, LoadLibrary
	will search the loaded libraries for a match and return
	one of them if the path search load fails.

	We check whether LoadLibrary is returning a handle to
	an already loaded module, and simulate failure if we
	find one. */
	{
	lt_dlhandle cur = 0;

	while ((cur = lt_dlhandle_iterate (iface_id, cur)))
	{
	if (!cur->module)
	{
	cur = 0;
	break;
	}

	if (cur->module == module)
	{
	break;
	}
	}

	if (!module)
	LOADLIB_SETERROR (CANNOT_OPEN);
	else if (cur)
	{
	LT__SETERROR (CANNOT_OPEN);
	module = 0;
	}
	}

	return module;
	}


	/* A function called through the vtable when a particular module
	should be unloaded. */
	static int
	vm_close (lt_user_data LT__UNUSED loader_data, lt_module module)
	{
	int errors = 0;

	if (FreeLibrary ((HMODULE) module) == 0)
	{
	LOADLIB_SETERROR (CANNOT_CLOSE);
	++errors;
	}

	return errors;
	}


	/* A function called through the vtable to get the address of
	a symbol loaded from a particular module. */
	static void *
	vm_sym (lt_user_data LT__UNUSED loader_data, lt_module module, const char *name)
	{
	void address = (void ) GetProcAddress ((HMODULE) module, name);

	if (!address)
	{
	LOADLIB_SETERROR (SYMBOL_NOT_FOUND);
	}

	return address;
	}



	/* --- HELPER FUNCTIONS --- */


	/* Return the windows error message, or the passed in error message on
	failure. */
	static const char *
	loadlibraryerror (const char *default_errmsg)
	{
	size_t len;
	LOCALFREE (error_message);

	FormatMessageA (FORMAT_MESSAGE_ALLOCATE_BUFFER \|
	FORMAT_MESSAGE_FROM_SYSTEM \|
	FORMAT_MESSAGE_IGNORE_INSERTS,
	NULL,
	GetLastError (),
	0,
	(char *) &error_message,
	0, NULL);

	/* Remove trailing CRNL */
	len = LT_STRLEN (error_message);
	if (len && error_message[len - 1] == '\n')
	error_message[--len] = LT_EOS_CHAR;
	if (len && error_message[len - 1] == '\r')
	error_message[--len] = LT_EOS_CHAR;

	return len ? error_message : default_errmsg;
	}

	/* A function called through the getthreaderrormode variable which checks
	if the system supports GetThreadErrorMode (or GetErrorMode) and arranges
	for it or a fallback implementation to be called directly in the future.
	The selected version is then called. */
	static DWORD WINAPI
	wrap_getthreaderrormode (void)
	{
	HMODULE kernel32 = GetModuleHandleA ("kernel32.dll");
	getthreaderrormode
	= (getthreaderrormode_type *) GetProcAddress (kernel32,
	"GetThreadErrorMode");
	if (!getthreaderrormode)
	getthreaderrormode
	= (getthreaderrormode_type *) GetProcAddress (kernel32,
	"GetErrorMode");
	if (!getthreaderrormode)
	getthreaderrormode = fallback_getthreaderrormode;
	return getthreaderrormode ();
	}

	/* A function called through the getthreaderrormode variable for cases
	where the system does not support GetThreadErrorMode or GetErrorMode */
	static DWORD WINAPI
	fallback_getthreaderrormode (void)
	{
	/* Prior to Windows Vista, the only way to get the current error
	mode was to set a new one. In our case, we are setting a new
	error mode right after "getting" it while ignoring the error
	mode in effect when setting the new error mode, so that's
	fairly ok. */
	return (DWORD) SetErrorMode (SEM_FAILCRITICALERRORS);
	}

	/* A function called through the setthreaderrormode variable which checks
	if the system supports SetThreadErrorMode and arranges for it or a
	fallback implementation to be called directly in the future.
	The selected version is then called. */
	static BOOL WINAPI
	wrap_setthreaderrormode (DWORD mode, DWORD *oldmode)
	{
	HMODULE kernel32 = GetModuleHandleA ("kernel32.dll");
	setthreaderrormode
	= (setthreaderrormode_type *) GetProcAddress (kernel32,
	"SetThreadErrorMode");
	if (!setthreaderrormode)
	setthreaderrormode = fallback_setthreaderrormode;
	return setthreaderrormode (mode, oldmode);
	}

	/* A function called through the setthreaderrormode variable for cases
	where the system does not support SetThreadErrorMode. */
	static BOOL WINAPI
	fallback_setthreaderrormode (DWORD mode, DWORD *oldmode)
	{
	/* Prior to Windows 7, there was no way to set the thread local error
	mode, so set the process global error mode instead. */
	DWORD old = (DWORD) SetErrorMode (mode);
	if (oldmode)
	*oldmode = old;
	return TRUE;
	}