| /* 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; |
| } |