diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/base/macros.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/base/macros.h | 90 |
1 files changed, 11 insertions, 79 deletions
diff --git a/third_party/abseil_cpp/absl/base/macros.h b/third_party/abseil_cpp/absl/base/macros.h index ea1da65ba272..3e085a916bbe 100644 --- a/third_party/abseil_cpp/absl/base/macros.h +++ b/third_party/abseil_cpp/absl/base/macros.h @@ -55,85 +55,6 @@ auto ArraySizeHelper(const T (&array)[N]) -> char (&)[N]; ABSL_NAMESPACE_END } // namespace absl -// ABSL_FALLTHROUGH_INTENDED -// -// Annotates implicit fall-through between switch labels, allowing a case to -// indicate intentional fallthrough and turn off warnings about any lack of a -// `break` statement. The ABSL_FALLTHROUGH_INTENDED macro should be followed by -// a semicolon and can be used in most places where `break` can, provided that -// no statements exist between it and the next switch label. -// -// Example: -// -// switch (x) { -// case 40: -// case 41: -// if (truth_is_out_there) { -// ++x; -// ABSL_FALLTHROUGH_INTENDED; // Use instead of/along with annotations -// // in comments -// } else { -// return x; -// } -// case 42: -// ... -// -// Notes: when compiled with clang in C++11 mode, the ABSL_FALLTHROUGH_INTENDED -// macro is expanded to the [[clang::fallthrough]] attribute, which is analysed -// when performing switch labels fall-through diagnostic -// (`-Wimplicit-fallthrough`). See clang documentation on language extensions -// for details: -// https://clang.llvm.org/docs/AttributeReference.html#fallthrough-clang-fallthrough -// -// When used with unsupported compilers, the ABSL_FALLTHROUGH_INTENDED macro -// has no effect on diagnostics. In any case this macro has no effect on runtime -// behavior and performance of code. -#ifdef ABSL_FALLTHROUGH_INTENDED -#error "ABSL_FALLTHROUGH_INTENDED should not be defined." -#endif - -// TODO(zhangxy): Use c++17 standard [[fallthrough]] macro, when supported. -#if defined(__clang__) && defined(__has_warning) -#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough") -#define ABSL_FALLTHROUGH_INTENDED [[clang::fallthrough]] -#endif -#elif defined(__GNUC__) && __GNUC__ >= 7 -#define ABSL_FALLTHROUGH_INTENDED [[gnu::fallthrough]] -#endif - -#ifndef ABSL_FALLTHROUGH_INTENDED -#define ABSL_FALLTHROUGH_INTENDED \ - do { \ - } while (0) -#endif - -// ABSL_DEPRECATED() -// -// Marks a deprecated class, struct, enum, function, method and variable -// declarations. The macro argument is used as a custom diagnostic message (e.g. -// suggestion of a better alternative). -// -// Examples: -// -// class ABSL_DEPRECATED("Use Bar instead") Foo {...}; -// -// ABSL_DEPRECATED("Use Baz() instead") void Bar() {...} -// -// template <typename T> -// ABSL_DEPRECATED("Use DoThat() instead") -// void DoThis(); -// -// Every usage of a deprecated entity will trigger a warning when compiled with -// clang's `-Wdeprecated-declarations` option. This option is turned off by -// default, but the warnings will be reported by clang-tidy. -#if defined(__clang__) && __cplusplus >= 201103L -#define ABSL_DEPRECATED(message) __attribute__((deprecated(message))) -#endif - -#ifndef ABSL_DEPRECATED -#define ABSL_DEPRECATED(message) -#endif - // ABSL_BAD_CALL_IF() // // Used on a function overload to trap bad calls: any call that matches the @@ -223,4 +144,15 @@ ABSL_NAMESPACE_END #define ABSL_INTERNAL_RETHROW do {} while (false) #endif // ABSL_HAVE_EXCEPTIONS +// `ABSL_INTERNAL_UNREACHABLE` is an unreachable statement. A program which +// reaches one has undefined behavior, and the compiler may optimize +// accordingly. +#if defined(__GNUC__) || ABSL_HAVE_BUILTIN(__builtin_unreachable) +#define ABSL_INTERNAL_UNREACHABLE __builtin_unreachable() +#elif defined(_MSC_VER) +#define ABSL_INTERNAL_UNREACHABLE __assume(0) +#else +#define ABSL_INTERNAL_UNREACHABLE +#endif + #endif // ABSL_BASE_MACROS_H_ |