Eliminate 'cast between incompatible func types' warnings for FARPROC vars

Direct conversion of GetProcAddress() result (of FARPROC type) to the
required functional type is performed by casting the result to word
type first.

* misc.c [MSGBOX_ON_ERROR && DONT_USE_USER32_DLL]
(GC_win32_MessageBoxA): Cast pfn to word type first.
* win32_threads.c [WOW64_THREAD_CONTEXT_WORKAROUND] (GC_thr_init):
Likewise.
* misc.c [GC_WIN32_THREADS && !GC_PTHREADS && !MSWINRT_FLAVOR
&& !MSWINCE] (GC_init): Change pfn type to FARPROC; cast pfn to word
type first and, then, to the required functional type.
* os_dep.c [!OS2 && GWW_VDB] (GetWriteWatch_func): Change type to
FARPROC.
* os_dep.c [!OS2 && GWW_VDB] (GC_GWW_AVAILABLE): Compare
GetWriteWatch_func to 0 instead of NULL.
* os_dep.c [GWW_VDB] (detect_GetWriteWatch, GC_gww_read_dirty): Cast
GetWriteWatch_func to word type first and, then, to the required
functional type.

1 files changed, 6 insertions, 6 deletions

diff --git a/misc.c b/misc.c
index d178790e..e60ea6c5 100644
--- a/misc.c
+++ b/misc.c
@@ -831,7 +831,7 @@ GC_API int GC_CALL GC_is_init_called(void)
       if (hU32) {
         FARPROC pfn = GetProcAddress(hU32, "MessageBoxA");
         if (pfn)
-          (void)(*(int (WINAPI *)(HWND, LPCSTR, LPCSTR, UINT))pfn)(
+          (void)(*(int (WINAPI *)(HWND, LPCSTR, LPCSTR, UINT))(word)pfn)(
                               NULL /* hWnd */, msg, caption, flags);
         (void)FreeLibrary(hU32);
       }
@@ -958,14 +958,14 @@ GC_API void GC_CALL GC_init(void)
 #     else
         {
 #         ifndef MSWINCE
-            BOOL (WINAPI *pfn)(LPCRITICAL_SECTION, DWORD) = 0;
+            FARPROC pfn = 0;
             HMODULE hK32 = GetModuleHandle(TEXT("kernel32.dll"));
             if (hK32)
-              pfn = (BOOL (WINAPI *)(LPCRITICAL_SECTION, DWORD))
-                      GetProcAddress(hK32,
-                                     "InitializeCriticalSectionAndSpinCount");
+              pfn = GetProcAddress(hK32,
+                                   "InitializeCriticalSectionAndSpinCount");
             if (pfn) {
-              pfn(&GC_allocate_ml, SPIN_COUNT);
+              (*(BOOL (WINAPI *)(LPCRITICAL_SECTION, DWORD))(word)pfn)(
+                                &GC_allocate_ml, SPIN_COUNT);
             } else
 #         endif /* !MSWINCE */
           /* else */ InitializeCriticalSection(&GC_allocate_ml);