Check for some header defines before redefining functions. Silences warnings.

include/GL/internal/dri_interface.h

@@ -149,6 +149,8 @@ typedef GLboolean (* PFNGLXGETDRAWABLEINFOPROC) ( __DRInativeDisplay *dpy, int s
     int * backX, int * backY,
     int * numBackClipRects, drm_clip_rect_t ** pBackClipRects );
 
+/* Test for the xf86dri.h header file */
+#ifndef _XF86DRI_H_
 extern GLboolean XF86DRIDestroyContext( __DRInativeDisplay *dpy, int screen,
     __DRIid context_id );
 
@@ -157,6 +159,7 @@ extern GLboolean XF86DRICreateDrawable( __DRInativeDisplay *dpy, int screen,
 
 extern GLboolean XF86DRIDestroyDrawable( __DRInativeDisplay *dpy, int screen, 
     __DRIid drawable);
+#endif
 /*@}*/
 
 

src/mesa/drivers/dri/common/dri_util.h

@@ -558,8 +558,11 @@ extern float
 driCalculateSwapUsage( __DRIdrawablePrivate *dPriv,
 		       int64_t last_swap_ust, int64_t current_ust );
 
+/* Test for the GLX header glx.h */
+#ifndef GLX
 extern void 
 (*glXGetProcAddress(const GLubyte *procname))( void );
+#endif
 
 #endif /* GLX_DIRECT_RENDERING */