diff options
Diffstat (limited to 'absl/base/attributes.h')
| -rw-r--r-- | absl/base/attributes.h | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/absl/base/attributes.h b/absl/base/attributes.h index 046fbea3..cf2cb550 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -18,8 +18,6 @@ // These macros are used within Abseil and allow the compiler to optimize, where // applicable, certain function calls. // -// This file is used for both C and C++! -// // Most macros here are exposing GCC or Clang features, and are stubbed out for // other compilers. // @@ -121,7 +119,7 @@ #if ABSL_HAVE_ATTRIBUTE(disable_tail_calls) #define ABSL_HAVE_ATTRIBUTE_NO_TAIL_CALL 1 #define ABSL_ATTRIBUTE_NO_TAIL_CALL __attribute__((disable_tail_calls)) -#elif defined(__GNUC__) && !defined(__clang__) +#elif defined(__GNUC__) && !defined(__clang__) && !defined(__e2k__) #define ABSL_HAVE_ATTRIBUTE_NO_TAIL_CALL 1 #define ABSL_ATTRIBUTE_NO_TAIL_CALL \ __attribute__((optimize("no-optimize-sibling-calls"))) @@ -607,6 +605,7 @@ // 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 @@ -645,7 +644,7 @@ // 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 +#if defined(__clang__) && defined(__cplusplus) && __cplusplus >= 201103L #define ABSL_DEPRECATED(message) __attribute__((deprecated(message))) #endif @@ -679,4 +678,25 @@ #define ABSL_CONST_INIT #endif // ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization) +// ABSL_ATTRIBUTE_PURE_FUNCTION +// +// ABSL_ATTRIBUTE_PURE_FUNCTION is used to annotate declarations of "pure" +// functions. A function is pure if its return value is only a function of its +// arguments. The pure attribute prohibits a function from modifying the state +// of the program that is observable by means other than inspecting the +// function's return value. Declaring such functions with the pure attribute +// allows the compiler to avoid emitting some calls in repeated invocations of +// the function with the same argument values. +// +// Example: +// +// ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Milliseconds(Duration d); +#if ABSL_HAVE_CPP_ATTRIBUTE(gnu::pure) +#define ABSL_ATTRIBUTE_PURE_FUNCTION [[gnu::pure]] +#elif ABSL_HAVE_ATTRIBUTE(pure) +#define ABSL_ATTRIBUTE_PURE_FUNCTION __attribute__((pure)) +#else +#define ABSL_ATTRIBUTE_PURE_FUNCTION +#endif + #endif // ABSL_BASE_ATTRIBUTES_H_ |