user32: Add assembly wrapper for calling hook procedures.

dlls/user32/hook.c

@@ -202,6 +202,48 @@ static HHOOK set_windows_hook( INT id, HOOKPROC proc, HINSTANCE inst, DWORD tid,
     return handle;
 }
 
+#ifdef __i386__
+/* Some apps pass a non-stdcall proc to SetWindowsHookExA,
+ * so we need a small assembly wrapper to call the proc.
+ */
+extern LRESULT HOOKPROC_wrapper( HOOKPROC proc,
+                                 INT code, WPARAM wParam, LPARAM lParam );
+__ASM_GLOBAL_FUNC( HOOKPROC_wrapper,
+                   "pushl %ebp\n\t"
+                   __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
+                   __ASM_CFI(".cfi_rel_offset %ebp,0\n\t")
+                   "movl %esp,%ebp\n\t"
+                   __ASM_CFI(".cfi_def_cfa_register %ebp\n\t")
+                   "pushl %edi\n\t"
+                   __ASM_CFI(".cfi_rel_offset %edi,-4\n\t")
+                   "pushl %esi\n\t"
+                   __ASM_CFI(".cfi_rel_offset %esi,-8\n\t")
+                   "pushl %ebx\n\t"
+                   __ASM_CFI(".cfi_rel_offset %ebx,-12\n\t")
+                   "pushl 20(%ebp)\n\t"
+                   "pushl 16(%ebp)\n\t"
+                   "pushl 12(%ebp)\n\t"
+                   "movl 8(%ebp),%eax\n\t"
+                   "call *%eax\n\t"
+                   "leal -12(%ebp),%esp\n\t"
+                   "popl %ebx\n\t"
+                   __ASM_CFI(".cfi_same_value %ebx\n\t")
+                   "popl %esi\n\t"
+                   __ASM_CFI(".cfi_same_value %esi\n\t")
+                   "popl %edi\n\t"
+                   __ASM_CFI(".cfi_same_value %edi\n\t")
+                   "leave\n\t"
+                   __ASM_CFI(".cfi_def_cfa %esp,4\n\t")
+                   __ASM_CFI(".cfi_same_value %ebp\n\t")
+                   "ret" )
+#else
+static inline LRESULT HOOKPROC_wrapper( HOOKPROC proc,
+                                 INT code, WPARAM wParam, LPARAM lParam )
+{
+    return proc( code, wParam, lParam );
+}
+#endif  /* __i386__ */
+
 
 /***********************************************************************
  *		call_hook_AtoW
@@ -210,7 +252,8 @@ static LRESULT call_hook_AtoW( HOOKPROC proc, INT id, INT code, WPARAM wparam, L
 {
     LRESULT ret;
     UNICODE_STRING usBuffer;
-    if (id != WH_CBT || code != HCBT_CREATEWND) ret = proc( code, wparam, lparam );
+    if (id != WH_CBT || code != HCBT_CREATEWND)
+        ret = HOOKPROC_wrapper( proc, code, wparam, lparam );
     else
     {
         CBT_CREATEWNDA *cbtcwA = (CBT_CREATEWNDA *)lparam;
@@ -233,7 +276,7 @@ static LRESULT call_hook_AtoW( HOOKPROC proc, INT id, INT code, WPARAM wparam, L
             RtlCreateUnicodeStringFromAsciiz(&usBuffer,cbtcwA->lpcs->lpszClass);
             csW.lpszClass = classW = usBuffer.Buffer;
         }
-        ret = proc( code, wparam, (LPARAM)&cbtcwW );
+        ret = HOOKPROC_wrapper( proc, code, wparam, (LPARAM)&cbtcwW );
         cbtcwA->hwndInsertAfter = cbtcwW.hwndInsertAfter;
         HeapFree( GetProcessHeap(), 0, nameW );
         HeapFree( GetProcessHeap(), 0, classW );
@@ -249,7 +292,8 @@ static LRESULT call_hook_WtoA( HOOKPROC proc, INT id, INT code, WPARAM wparam, L
 {
     LRESULT ret;
 
-    if (id != WH_CBT || code != HCBT_CREATEWND) ret = proc( code, wparam, lparam );
+    if (id != WH_CBT || code != HCBT_CREATEWND)
+        ret = HOOKPROC_wrapper( proc, code, wparam, lparam );
     else
     {
         CBT_CREATEWNDW *cbtcwW = (CBT_CREATEWNDW *)lparam;
@@ -277,7 +321,7 @@ static LRESULT call_hook_WtoA( HOOKPROC proc, INT id, INT code, WPARAM wparam, L
             csA.lpszClass = classA;
         }
 
-        ret = proc( code, wparam, (LPARAM)&cbtcwA );
+        ret = HOOKPROC_wrapper( proc, code, wparam, (LPARAM)&cbtcwA );
         cbtcwW->hwndInsertAfter = cbtcwA.hwndInsertAfter;
         HeapFree( GetProcessHeap(), 0, nameA );
         HeapFree( GetProcessHeap(), 0, classA );