Add macro for unused function attribute.

Suggested-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>

configure.ac

@@ -195,6 +195,7 @@ AX_GCC_FUNC_ATTRIBUTE([flatten])
 AX_GCC_FUNC_ATTRIBUTE([format])
 AX_GCC_FUNC_ATTRIBUTE([malloc])
 AX_GCC_FUNC_ATTRIBUTE([packed])
+AX_GCC_FUNC_ATTRIBUTE([unused])
 
 AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" = xyes)
 

scons/gallium.py

@@ -369,6 +369,7 @@ def generate(env):
             'HAVE___BUILTIN_FFS',
             'HAVE___BUILTIN_FFSLL',
             'HAVE_FUNC_ATTRIBUTE_FLATTEN',
+            'HAVE_FUNC_ATTRIBUTE_UNUSED',
             # GCC 3.0
             'HAVE_FUNC_ATTRIBUTE_FORMAT',
             'HAVE_FUNC_ATTRIBUTE_PACKED',

src/util/macros.h

@@ -176,5 +176,11 @@ do {                       \
 #  endif
 #endif
 
+#ifdef HAVE_FUNC_ATTRIBUTE_UNUSED
+#define UNUSED __attribute__((unused))
+#else
+#define UNUSED
+#endif
+
 
 #endif /* UTIL_MACROS_H */