dlls/winecrt0/delay_load.c

   1 /*
   2  * Support for delayed imports
   3  *
   4  * Copyright 2005 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include <stdarg.h>
  22 #include "windef.h"
  23 #include "winbase.h"
  24 #include "delayloadhandler.h"
  25
  26 WINBASEAPI void *WINAPI DelayLoadFailureHook( LPCSTR name, LPCSTR function );
  27
  28 #ifdef _WIN32
  29
  30 extern IMAGE_DOS_HEADER __ImageBase;
  31
  32 WINBASEAPI void *WINAPI ResolveDelayLoadedAPI( void* base, const IMAGE_DELAYLOAD_DESCRIPTOR* desc,
  33                                                PDELAYLOAD_FAILURE_DLL_CALLBACK dllhook,
  34                                                PDELAYLOAD_FAILURE_SYSTEM_ROUTINE syshook,
  35                                                IMAGE_THUNK_DATA* addr, ULONG flags );
  36
  37 FARPROC WINAPI __delayLoadHelper2( const IMAGE_DELAYLOAD_DESCRIPTOR *descr, IMAGE_THUNK_DATA *addr )
  38 {
  39     return ResolveDelayLoadedAPI( &__ImageBase, descr, NULL, DelayLoadFailureHook, addr, 0 );
  40 }
  41
  42 #else /* _WIN32 */
  43
  44 struct ImgDelayDescr
  45 {
  46     DWORD_PTR               grAttrs;
  47     LPCSTR                  szName;
  48     HMODULE                *phmod;
  49     IMAGE_THUNK_DATA       *pIAT;
  50     const IMAGE_THUNK_DATA *pINT;
  51     const IMAGE_THUNK_DATA *pBoundIAT;
  52     const IMAGE_THUNK_DATA *pUnloadIAT;
  53     DWORD_PTR               dwTimeStamp;
  54 };
  55
  56 extern struct ImgDelayDescr __wine_spec_delay_imports[];
  57
  58 FARPROC WINAPI DECLSPEC_HIDDEN __wine_spec_delay_load( unsigned int id )
  59 {
  60     struct ImgDelayDescr *descr = __wine_spec_delay_imports + HIWORD(id);
  61     WORD func = LOWORD(id);
  62     FARPROC proc;
  63
  64     if (!*descr->phmod) *descr->phmod = LoadLibraryA( descr->szName );
  65     if (!*descr->phmod ||
  66         !(proc = GetProcAddress( *descr->phmod, (LPCSTR)descr->pINT[func].u1.Function )))
  67         proc = DelayLoadFailureHook( descr->szName, (LPCSTR)descr->pINT[func].u1.Function );
  68     descr->pIAT[func].u1.Function = (ULONG_PTR)proc;
  69     return proc;
  70 }
  71
  72 #if defined(__GNUC__) && !defined(__APPLE__)  /* we can't support destructors properly on Mac OS */
  73 static void free_delay_imports(void) __attribute__((destructor));
  74 static void free_delay_imports(void)
  75 {
  76     struct ImgDelayDescr *descr;
  77     for (descr = __wine_spec_delay_imports; descr->szName; descr++)
  78         if (*descr->phmod) FreeLibrary( *descr->phmod );
  79 }
  80 #endif
  81
  82 #endif /* _WIN32 */