[jgardou] 57171: [MINGWEX] - mark DllMain as a weak symbol for GCC. - supply a stubbed DllMain for MSVC. - DllMain is optional, and some DLLs don't implement it. That doesn't mean that they have no...

Author: jgardou
Date: Sun Aug 26 23:31:49 2012
New Revision: 57171

URL: http://svn.reactos.org/svn/reactos?rev=57171&view=rev
Log:
[MINGWEX]
- mark DllMain as a weak symbol for GCC.
- supply a stubbed DllMain for MSVC.
- DllMain is optional, and some DLLs don't implement it. That doesn't mean that
they have no entry point, it means "I have nothing more to initialize than the
CRT".

Added:
    trunk/reactos/lib/sdk/crt/startup/mscdllmain.c   (with props)
Modified:
    trunk/reactos/lib/sdk/crt/msvcrtex.cmake
    trunk/reactos/lib/sdk/crt/startup/crtdll.c

Modified: trunk/reactos/lib/sdk/crt/msvcrtex.cmake
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/msvcrtex.cmake…
==============================================================================
--- trunk/reactos/lib/sdk/crt/msvcrtex.cmake [iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/msvcrtex.cmake [iso-8859-1] Sun Aug 26 23:31:49 2012
@@ -66,7 +66,9 @@
 endif()
 
 if(MSVC)
-    list(APPEND MSVCRTEX_SOURCE startup/mscmain.c)
+    list(APPEND MSVCRTEX_SOURCE 
+        startup/mscmain.c
+        startup/mscdllmain.c)
 else()
     list(APPEND MSVCRTEX_SOURCE startup/gccmain.c)
 endif()

Modified: trunk/reactos/lib/sdk/crt/startup/crtdll.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/startup/crtdll…
==============================================================================
--- trunk/reactos/lib/sdk/crt/startup/crtdll.c [iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/startup/crtdll.c [iso-8859-1] Sun Aug 26 23:31:49 2012
@@ -50,7 +50,19 @@
 
 extern int mingw_app_type;
 
+/* 
+ * It is possible that a DLL provides no DllMain entry point.
+ * Mark it as a weak symbol for GCC.
+ * Tests show that at link time, MSVC looks for a function first in the object files
provided, and then
+ * in the libraries. This means that we must provide a basic implementation in msvcrtex,
which will be used 
+ * if none is found in the object files provided to link.exe.
+ * This also means that we can't rely on a DllMain function implemented in a static
library when linking a DLL.
+ */
+#ifdef __GNUC__
+extern WINBOOL WINAPI DllMain (HANDLE hDllHandle, DWORD dwReason, LPVOID lpreserved)
__attribute__((weak));
+#else
 extern WINBOOL WINAPI DllMain (HANDLE hDllHandle, DWORD dwReason, LPVOID lpreserved);
+#endif
 
 extern WINBOOL WINAPI DllEntryPoint (HANDLE, DWORD, LPVOID);
 
@@ -198,10 +210,12 @@
     }
   if (dwReason == DLL_PROCESS_ATTACH)
     __main ();
-  retcode = DllMain(hDllHandle,dwReason,lpreserved);
+  if(DllMain)
+    retcode = DllMain(hDllHandle,dwReason,lpreserved);
   if (dwReason == DLL_PROCESS_ATTACH && ! retcode)
     {
-	DllMain (hDllHandle, DLL_PROCESS_DETACH, lpreserved);
+    if(DllMain)
+	  DllMain (hDllHandle, DLL_PROCESS_DETACH, lpreserved);
 	DllEntryPoint (hDllHandle, DLL_PROCESS_DETACH, lpreserved);
 	_CRT_INIT (hDllHandle, DLL_PROCESS_DETACH, lpreserved);
     }

Added: trunk/reactos/lib/sdk/crt/startup/mscdllmain.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/startup/mscdll…
==============================================================================
--- trunk/reactos/lib/sdk/crt/startup/mscdllmain.c (added)
+++ trunk/reactos/lib/sdk/crt/startup/mscdllmain.c [iso-8859-1] Sun Aug 26 23:31:49 2012
@@ -1,0 +1,11 @@
+#include <oscalls.h>
+#define _DECL_DLLMAIN
+#include <process.h>
+
+WINBOOL WINAPI DllMain (HANDLE hDllHandle, DWORD dwReason, LPVOID lpreserved)
+{
+    /* If the DLL provides no DllMain, then chances are that it doesn't bother with
thread initialization */
+    if(dwReason == DLL_PROCESS_ATTACH)
+        DisableThreadLibraryCalls(hDllHandle);
+    return TRUE;
+}

Propchange: trunk/reactos/lib/sdk/crt/startup/mscdllmain.c
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