Patch from Sylvain to fix clang warnings

src/video/SDL_RLEaccel.c

@@ -90,9 +90,11 @@
 #include "SDL_blit.h"
 #include "SDL_RLEaccel_c.h"
 
+/*
 #ifndef MAX
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif
+*/
 #ifndef MIN
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 #endif

src/video/SDL_blit_1.c

@@ -70,12 +70,14 @@ Blit1to1(SDL_BlitInfo * info)
 }
 
 /* This is now endian dependent */
-#if ( SDL_BYTEORDER == SDL_LIL_ENDIAN )
-#define HI	1
-#define LO	0
-#else /* ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) */
-#define HI	0
-#define LO	1
+#ifndef USE_DUFFS_LOOP
+# if ( SDL_BYTEORDER == SDL_LIL_ENDIAN )
+#  define HI	1
+#  define LO	0
+# else /* ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) */
+#  define HI	0
+#  define LO	1
+# endif
 #endif
 static void
 Blit1to2(SDL_BlitInfo * info)

src/video/SDL_bmp.c

@@ -43,8 +43,8 @@
 /* Compression encodings for BMP files */
 #ifndef BI_RGB
 #define BI_RGB      0
-#define BI_RLE8     1
-#define BI_RLE4     2
+/* #define BI_RLE8     1 */
+/* #define BI_RLE4     2 */
 #define BI_BITFIELDS    3
 #endif
 

src/video/SDL_video.c

@@ -46,9 +46,11 @@
 #include "SDL_opengles2.h"
 #endif /* SDL_VIDEO_OPENGL_ES2 && !SDL_VIDEO_OPENGL */
 
+#if !SDL_VIDEO_OPENGL
 #ifndef GL_CONTEXT_RELEASE_BEHAVIOR_KHR
 #define GL_CONTEXT_RELEASE_BEHAVIOR_KHR 0x82FB
 #endif
+#endif
 
 /* On Windows, windows.h defines CreateWindow */
 #ifdef CreateWindow
@@ -3617,8 +3619,9 @@ SDL_IsScreenKeyboardShown(SDL_Window *window)
 #include "x11/SDL_x11messagebox.h"
 #endif
 
-// This function will be unused if none of the above video drivers are present.
-SDL_UNUSED static SDL_bool SDL_MessageboxValidForDriver(const SDL_MessageBoxData *messageboxdata, SDL_SYSWM_TYPE drivertype)
+
+#if SDL_VIDEO_DRIVER_WINDOWS || SDL_VIDEO_DRIVER_WINRT || SDL_VIDEO_DRIVER_COCOA || SDL_VIDEO_DRIVER_UIKIT || SDL_VIDEO_DRIVER_X11
+static SDL_bool SDL_MessageboxValidForDriver(const SDL_MessageBoxData *messageboxdata, SDL_SYSWM_TYPE drivertype)
 {
     SDL_SysWMinfo info;
     SDL_Window *window = messageboxdata->window;
@@ -3634,6 +3637,7 @@ SDL_UNUSED static SDL_bool SDL_MessageboxValidForDriver(const SDL_MessageBoxData
         return (info.subsystem == drivertype);
     }
 }
+#endif
 
 int
 SDL_ShowMessageBox(const SDL_MessageBoxData *messageboxdata, int *buttonid)

src/video/x11/SDL_x11events.c

@@ -201,7 +201,7 @@ X11_IsWheelEvent(Display * display,XEvent * event,int * xticks,int * yticks)
 
    On error, -1 is returned.
  */
-int X11_URIDecode(char *buf, int len) {
+static int X11_URIDecode(char *buf, int len) {
     int ri, wi, di;
     char decode = '\0';
     if (buf == NULL || len < 0) {

src/video/x11/SDL_x11messagebox.c

@@ -27,6 +27,7 @@
 #include "SDL_x11video.h"
 #include "SDL_x11dyn.h"
 #include "SDL_assert.h"
+#include "SDL_x11messagebox.h"
 
 #include <X11/keysym.h>
 #include <locale.h>

src/video/x11/SDL_x11modes.c

@@ -134,14 +134,14 @@ X11_GetPixelFormatFromVisualInfo(Display * display, XVisualInfo * vinfo)
             } else {
                 return SDL_PIXELFORMAT_INDEX4MSB;
             }
-            break;
+            /* break; -Wunreachable-code-break */
         case 1:
             if (BitmapBitOrder(display) == LSBFirst) {
                 return SDL_PIXELFORMAT_INDEX1LSB;
             } else {
                 return SDL_PIXELFORMAT_INDEX1MSB;
             }
-            break;
+            /* break; -Wunreachable-code-break */
         }
     }
 
@@ -149,7 +149,7 @@ X11_GetPixelFormatFromVisualInfo(Display * display, XVisualInfo * vinfo)
 }
 
 /* Global for the error handler */
-int vm_event, vm_error = -1;
+static int vm_event, vm_error = -1;
 
 #if SDL_VIDEO_DRIVER_X11_XINERAMA
 static SDL_bool
@@ -349,7 +349,7 @@ SetXRandRDisplayName(Display *dpy, Atom EDID, char *name, const size_t namelen,
 }
 
 
-int
+static int
 X11_InitModes_XRandR(_THIS)
 {
     SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
@@ -569,7 +569,7 @@ CalculateXVidModeRefreshRate(const XF86VidModeModeInfo * info)
                                                          info->vtotal)) : 0;
 }
 
-SDL_bool
+static SDL_bool
 SetXVidModeModeInfo(const XF86VidModeModeInfo *info, SDL_DisplayMode *mode)
 {
     mode->w = info->hdisplay;
@@ -584,7 +584,7 @@ int
 X11_InitModes(_THIS)
 {
     SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
-    int snum, screen, screencount;
+    int snum, screen, screencount = 0;
 #if SDL_VIDEO_DRIVER_X11_XINERAMA
     int xinerama_major, xinerama_minor;
     int use_xinerama = 0;

src/video/x11/SDL_x11opengl.c

@@ -519,6 +519,7 @@ X11_GL_GetVisual(_THIS, Display * display, int screen)
     return vinfo;
 }
 
+#if 0
 #ifndef GLXBadContext
 #define GLXBadContext 0
 #endif
@@ -528,6 +529,8 @@ X11_GL_GetVisual(_THIS, Display * display, int screen)
 #ifndef GLXBadProfileARB
 #define GLXBadProfileARB 13
 #endif
+#endif
+
 static int (*handler) (Display *, XErrorEvent *) = NULL;
 static const char *errorHandlerOperation = NULL;
 static int errorBase = 0;

src/video/x11/SDL_x11window.c

@@ -44,7 +44,7 @@
 
 #define _NET_WM_STATE_REMOVE    0l
 #define _NET_WM_STATE_ADD       1l
-#define _NET_WM_STATE_TOGGLE    2l
+/* #define _NET_WM_STATE_TOGGLE    2l */
 
 static Bool isMapNotify(Display *dpy, XEvent *ev, XPointer win)
 {