Work-around for -Wcast-function-type warning from GetProcAddress()

Apparently,  the way to silence this warning is to cast the value returned
by GetProcAddress() to a void function pointer,  _then_ cast it to the type
we actually want.  Hat tipped to GPUOpen-Tools/volk@8219a21189 .

Author: Bill-Gray

wincon/pdcscrn.c

@@ -89,8 +89,8 @@ typedef struct _CONSOLE_SCREEN_BUFFER_INFOEX {
 typedef CONSOLE_SCREEN_BUFFER_INFOEX    *PCONSOLE_SCREEN_BUFFER_INFOEX;
 #endif
 
-typedef BOOL (WINAPI *SetConsoleScreenBufferInfoExFn) (HANDLE, CONSOLE_SCREEN_BUFFER_INFOEX *);
-typedef BOOL (WINAPI *GetConsoleScreenBufferInfoExFn) (HANDLE, CONSOLE_SCREEN_BUFFER_INFOEX *);
+typedef BOOL (WINAPI *SetConsoleScreenBufferInfoExFn) (_In_ HANDLE, _Out_ CONSOLE_SCREEN_BUFFER_INFOEX *);
+typedef BOOL (WINAPI *GetConsoleScreenBufferInfoExFn) (_In_ HANDLE, _Out_ CONSOLE_SCREEN_BUFFER_INFOEX *);
 
 static SetConsoleScreenBufferInfoExFn pSetConsoleScreenBufferInfoEx = NULL;
 static GetConsoleScreenBufferInfoExFn pGetConsoleScreenBufferInfoEx = NULL;
@@ -376,6 +376,11 @@ void PDC_scr_free(void)
     SetConsoleCtrlHandler(_ctrl_break, FALSE);
 }
 
+/* In casting function pointers,  we first cast them through a void function pointer.
+This suppresses cast-function-type warnings on gcc and MinGW.   */
+
+#define VOID_FN_PTR (void(*)(void))
+
 /* open the physical screen -- miscellaneous initialization, may save
    the existing screen for later restoration */
 
@@ -479,10 +484,10 @@ int PDC_scr_open(void)
 
     h_kernel = GetModuleHandleA("kernel32.dll");
     pGetConsoleScreenBufferInfoEx =
-        (GetConsoleScreenBufferInfoExFn)GetProcAddress(h_kernel,
+        (GetConsoleScreenBufferInfoExFn) VOID_FN_PTR GetProcAddress(h_kernel,
         "GetConsoleScreenBufferInfoEx");
     pSetConsoleScreenBufferInfoEx =
-        (SetConsoleScreenBufferInfoExFn)GetProcAddress(h_kernel,
+        (SetConsoleScreenBufferInfoExFn) VOID_FN_PTR GetProcAddress(h_kernel,
         "SetConsoleScreenBufferInfoEx");
 
     return OK;

wingui/pdcscrn.c

@@ -2080,6 +2080,11 @@ INLINE int set_up_window( void)
     return( 0);
 }
 
+/* In casting function pointers,  we first cast them through a void function pointer.
+This suppresses cast-function-type warnings on gcc and MinGW.   */
+
+#define VOID_FN_PTR (void(*)(void))
+
 /* open the physical screen -- allocate SP, miscellaneous intialization,
    and may save the existing screen for later restoration.
 
@@ -2093,6 +2098,8 @@ INLINE int set_up_window( void)
 #define MAX_LINES   50000
 #define MAX_COLUMNS 50000
 
+typedef HRESULT (*dpi_aware_func_t)(int);
+
 int PDC_scr_open(void)
 {
     const HMODULE hntdll = GetModuleHandle( _T("ntdll.dll"));
@@ -2105,8 +2112,8 @@ int PDC_scr_open(void)
 
     if ( shcoredll) {
         static int ADJUST_DPI_PER_MONITOR = 2;
-        FARPROC set_process_dpi_awareness_func =
-                     GetProcAddress(shcoredll, "SetProcessDpiAwareness");
+        dpi_aware_func_t set_process_dpi_awareness_func = (dpi_aware_func_t)
+                VOID_FN_PTR GetProcAddress(shcoredll, "SetProcessDpiAwareness");
 
         if ( set_process_dpi_awareness_func) {
             set_process_dpi_awareness_func(ADJUST_DPI_PER_MONITOR);