src/dllinit.c

   1 /* dllinit.c -- Portable DLL initialization.
   2    Copyright (C) 1998, 1999 Free Software Foundation, Inc.
   3    Contributed by Mumit Khan (khan@xraylith.wisc.edu).
   4
   5    I've used DllMain as the DLL "main" since that's the most common
   6    usage. MSVC and Mingw32 both default to DllMain as the standard
   7    callback from the linker entry point. Cygwin, as of b20.1, also
   8    uses DllMain as the default callback from the entry point.
   9
  10    The real entry point is typically always defined by the runtime
  11    library, and usually never overridden by (casual) user. What you can
  12    override however is the callback routine that the entry point calls,
  13    and this file provides such a callback function, DllMain.
  14
  15    Mingw32: The default entry point for mingw32 is DllMainCRTStartup
  16    which is defined in libmingw32.a This in turn calls DllMain which is
  17    defined here. If not defined, there is a stub in libmingw32.a which
  18    does nothing.
  19
  20    Cygwin: The default entry point for Cygwin b20.1 or newer is
  21    __cygwin_dll_entry which is defined in libcygwin.a. This in turn
  22    calls the routine DllMain. If not defined, there is a stub in
  23    libcygwin.a which does nothing.
  24
  25    MSVC: MSVC runtime calls DllMain, just like Mingw32.
  26
  27    Summary: If you need to do anything special in DllMain, just add it
  28    here. Otherwise, the default setup should be just fine for 99%+ of
  29    the time. I strongly suggest that you *not* change the entry point,
  30    but rather change DllMain as appropriate.
  31
  32  */
  33
  34
  35 #define WIN32_LEAN_AND_MEAN
  36 #include <windows.h>
  37 #undef WIN32_LEAN_AND_MEAN
  38 #include <stdio.h>
  39
  40 BOOL APIENTRY DllMain (HINSTANCE hInst, DWORD reason,
  41                        LPVOID reserved /* Not used. */ );
  42
  43 /*
  44  *----------------------------------------------------------------------
  45  *
  46  * DllMain --
  47  *
  48  *      This routine is called by the Mingw32, Cygwin32 or VC++ C run
  49  *      time library init code, or the Borland DllEntryPoint routine. It
  50  *      is responsible for initializing various dynamically loaded
  51  *      libraries.
  52  *
  53  * Results:
  54  *      TRUE on sucess, FALSE on failure.
  55  *
  56  * Side effects:
  57  *
  58  *----------------------------------------------------------------------
  59  */
  60 BOOL APIENTRY
  61 DllMain (
  62          HINSTANCE hInst /* Library instance handle. */ ,
  63          DWORD reason /* Reason this function is being called. */ ,
  64          LPVOID reserved /* Not used. */ )
  65 {
  66   switch (reason)
  67     {
  68     case DLL_PROCESS_ATTACH:
  69       break;
  70
  71     case DLL_PROCESS_DETACH:
  72       break;
  73
  74     case DLL_THREAD_ATTACH:
  75       break;
  76
  77     case DLL_THREAD_DETACH:
  78       break;
  79     }
  80   return TRUE;
  81 }
  82