[compiler-rt] a44a873 - sanitizer_common: add FALLTHROUGH macro

[Dmitry Vyukov via llvm-commits]

Author: Dmitry Vyukov
Date: 2021-08-10T20:04:37+02:00
New Revision: a44a873e11de99a6e31609f8f6075e0c46eb7006

URL: https://github.com/llvm/llvm-project/commit/a44a873e11de99a6e31609f8f6075e0c46eb7006
DIFF: https://github.com/llvm/llvm-project/commit/a44a873e11de99a6e31609f8f6075e0c46eb7006.diff

LOG: sanitizer_common: add FALLTHROUGH macro

Add FALLTHROUGH portably defined to [[clang::fallthrough]].
We have -Wimplicit-fallthrough already enabled, and currently
it's not possible to fix the warning.

Depends on D107735.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D107736

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h b/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
index e8de3932a619..f7fdc160eeb1 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
@@ -125,6 +125,10 @@
 # define __has_attribute(x) 0
 #endif
 
+#if !defined(__has_cpp_attribute)
+#  define __has_cpp_attribute(x) 0
+#endif
+
 // For portability reasons we do not include stddef.h, stdint.h or any other
 // system header, but we do need some basic types that are not defined
 // in a portable way by the language itself.
@@ -250,6 +254,12 @@ typedef u64 tid_t;
 # define NOEXCEPT throw()
 #endif
 
+#if __has_cpp_attribute(clang::fallthrough)
+#  define FALLTHROUGH [[clang::fallthrough]]
+#else
+#  define FALLTHROUGH
+#endif
+
 // Unaligned versions of basic types.
 typedef ALIGNED(1) u16 uu16;
 typedef ALIGNED(1) u32 uu32;