Guard __has_attribute for compilers that don't support it (AcademyS…

…oftwareFoundation#1129) * Guard `__has_attribute` for compilers that don't support it Signed-off-by: Larry Gritz <lg@larrygritz.com> * Revision Signed-off-by: Larry Gritz <lg@larrygritz.com>
cary-ilm · Sep 2, 2021 · 855415f · 855415f
1 parent 0e32af6
commit 855415f
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/cmake/OpenEXRConfig.h.in b/cmake/OpenEXRConfig.h.in
@@ -56,6 +56,14 @@
                              (uint32_t(OPENEXR_VERSION_MINOR) << 16) | \
                              (uint32_t(OPENEXR_VERSION_PATCH) <<  8))
 
+
+// On modern versions of gcc & clang, __has_attribute can test support for
+// __attribute__((attr)).  Make sure it's safe for other compilers.
+#ifndef __has_attribute
+#    define __has_attribute(x) 0
+#endif
+
+
 // Whether the user configured the library to have symbol visibility
 // tagged
 #cmakedefine OPENEXR_ENABLE_API_VISIBILITY