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| author | trav90 <travawine@openmailbox.org> | 2018-03-04 15:17:01 -0600 |
|---|---|---|
| committer | trav90 <travawine@openmailbox.org> | 2018-03-04 15:17:01 -0600 |
| commit | a973e506c148589593226c1f0ccfbed59fff8790 (patch) | |
| tree | 1ac4cd95dd64558b7d5d68d69b33beb564c212ba /mfbt/Attributes.h | |
| parent | 45378506119d9d2f851856d46ca86652d229b68e (diff) | |
| download | uxp-a973e506c148589593226c1f0ccfbed59fff8790.tar.gz | |
Add MOZ_FALLTHROUGH macro definition for gcc 7 to suppress -Wimplicit-fallthrough warnings
The generic fallback MOZ_FALLTHROUGH definition is insufficient for GCC 7 and above, resulting in build warning spam and --enable-warnings-as-errors builds failing. The check for clang support is changed to use the __has_cpp_attribute macro, which is more robust than checking the __cplusplus version. Also, MOZ_FALLTHROUGH is now only defined in C++ code, since GCC errors out if it encounters a scoped attribute being used with __has_cpp_attribute in C code. No C code uses MOZ_FALLTHROUGH or derivatives at the moment.
Diffstat (limited to 'mfbt/Attributes.h')
| -rw-r--r-- | mfbt/Attributes.h | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/mfbt/Attributes.h b/mfbt/Attributes.h index c875e3a8cd..a382579692 100644 --- a/mfbt/Attributes.h +++ b/mfbt/Attributes.h @@ -256,6 +256,8 @@ # define MOZ_MUST_USE #endif +#ifdef __cplusplus + /** * MOZ_FALLTHROUGH is an annotation to suppress compiler warnings about switch * cases that fall through without a break or return statement. MOZ_FALLTHROUGH @@ -282,9 +284,14 @@ * return 5; * } */ -#if defined(__clang__) && __cplusplus >= 201103L - /* clang's fallthrough annotations are only available starting in C++11. */ +#ifndef __has_cpp_attribute +# define __has_cpp_attribute(x) 0 +#endif + +#if __has_cpp_attribute(clang::fallthrough) # define MOZ_FALLTHROUGH [[clang::fallthrough]] +#elif __has_cpp_attribute(gnu::fallthrough) +# define MOZ_FALLTHROUGH [[gnu::fallthrough]] #elif defined(_MSC_VER) /* * MSVC's __fallthrough annotations are checked by /analyze (Code Analysis): @@ -296,8 +303,6 @@ # define MOZ_FALLTHROUGH /* FALLTHROUGH */ #endif -#ifdef __cplusplus - /* * The following macros are attributes that support the static analysis plugin * included with Mozilla, and will be implemented (when such support is enabled) |