diff options
Diffstat (limited to 'absl/base/attributes.h')
| -rw-r--r-- | absl/base/attributes.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/absl/base/attributes.h b/absl/base/attributes.h index d4f67a12..5ea5ee3e 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -195,6 +195,9 @@ // ABSL_ATTRIBUTE_NORETURN // // Tells the compiler that a given function never returns. +// +// Deprecated: Prefer the `[[noreturn]]` attribute standardized by C++11 over +// this macro. #if ABSL_HAVE_ATTRIBUTE(noreturn) || (defined(__GNUC__) && !defined(__clang__)) #define ABSL_ATTRIBUTE_NORETURN __attribute__((noreturn)) #elif defined(_MSC_VER) @@ -702,6 +705,11 @@ _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"") #define ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING \ _Pragma("GCC diagnostic pop") +#elif defined(_MSC_VER) +#define ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING \ + _Pragma("warning(push)") _Pragma("warning(disable: 4996)") +#define ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING \ + _Pragma("warning(pop)") #else #define ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING #define ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING @@ -808,14 +816,43 @@ // // See also the upstream documentation: // https://clang.llvm.org/docs/AttributeReference.html#lifetimebound +// https://learn.microsoft.com/en-us/cpp/code-quality/c26816?view=msvc-170 #if ABSL_HAVE_CPP_ATTRIBUTE(clang::lifetimebound) #define ABSL_ATTRIBUTE_LIFETIME_BOUND [[clang::lifetimebound]] +#elif ABSL_HAVE_CPP_ATTRIBUTE(msvc::lifetimebound) +#define ABSL_ATTRIBUTE_LIFETIME_BOUND [[msvc::lifetimebound]] #elif ABSL_HAVE_ATTRIBUTE(lifetimebound) #define ABSL_ATTRIBUTE_LIFETIME_BOUND __attribute__((lifetimebound)) #else #define ABSL_ATTRIBUTE_LIFETIME_BOUND #endif +// ABSL_INTERNAL_ATTRIBUTE_VIEW indicates that a type acts like a view i.e. a +// raw (non-owning) pointer. This enables diagnoses similar to those enabled by +// ABSL_ATTRIBUTE_LIFETIME_BOUND. +// +// See the following links for details: +// https://reviews.llvm.org/D64448 +// https://lists.llvm.org/pipermail/cfe-dev/2018-November/060355.html +#if ABSL_HAVE_CPP_ATTRIBUTE(gsl::Pointer) +#define ABSL_INTERNAL_ATTRIBUTE_VIEW [[gsl::Pointer]] +#else +#define ABSL_INTERNAL_ATTRIBUTE_VIEW +#endif + +// ABSL_INTERNAL_ATTRIBUTE_OWNER indicates that a type acts like a smart +// (owning) pointer. This enables diagnoses similar to those enabled by +// ABSL_ATTRIBUTE_LIFETIME_BOUND. +// +// See the following links for details: +// https://reviews.llvm.org/D64448 +// https://lists.llvm.org/pipermail/cfe-dev/2018-November/060355.html +#if ABSL_HAVE_CPP_ATTRIBUTE(gsl::Owner) +#define ABSL_INTERNAL_ATTRIBUTE_OWNER [[gsl::Owner]] +#else +#define ABSL_INTERNAL_ATTRIBUTE_OWNER +#endif + // ABSL_ATTRIBUTE_TRIVIAL_ABI // Indicates that a type is "trivially relocatable" -- meaning it can be // relocated without invoking the constructor/destructor, using a form of move @@ -871,4 +908,51 @@ #define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS #endif +// ABSL_ATTRIBUTE_UNINITIALIZED +// +// GCC and Clang support a flag `-ftrivial-auto-var-init=<option>` (<option> +// can be "zero" or "pattern") that can be used to initialize automatic stack +// variables. Variables with this attribute will be left uninitialized, +// overriding the compiler flag. +// +// See https://clang.llvm.org/docs/AttributeReference.html#uninitialized +// and https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-uninitialized-variable-attribute +#if ABSL_HAVE_CPP_ATTRIBUTE(clang::uninitialized) +#define ABSL_ATTRIBUTE_UNINITIALIZED [[clang::uninitialized]] +#elif ABSL_HAVE_CPP_ATTRIBUTE(gnu::uninitialized) +#define ABSL_ATTRIBUTE_UNINITIALIZED [[gnu::uninitialized]] +#elif ABSL_HAVE_ATTRIBUTE(uninitialized) +#define ABSL_ATTRIBUTE_UNINITIALIZED __attribute__((uninitialized)) +#else +#define ABSL_ATTRIBUTE_UNINITIALIZED +#endif + +// ABSL_ATTRIBUTE_WARN_UNUSED +// +// Compilers routinely warn about trivial variables that are unused. For +// non-trivial types, this warning is suppressed since the +// constructor/destructor may be intentional and load-bearing, for example, with +// a RAII scoped lock. +// +// For example: +// +// class ABSL_ATTRIBUTE_WARN_UNUSED MyType { +// public: +// MyType(); +// ~MyType(); +// }; +// +// void foo() { +// // Warns with ABSL_ATTRIBUTE_WARN_UNUSED attribute present. +// MyType unused; +// } +// +// See https://clang.llvm.org/docs/AttributeReference.html#warn-unused and +// https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Attributes.html#index-warn_005funused-type-attribute +#if ABSL_HAVE_CPP_ATTRIBUTE(gnu::warn_unused) +#define ABSL_ATTRIBUTE_WARN_UNUSED [[gnu::warn_unused]] +#else +#define ABSL_ATTRIBUTE_WARN_UNUSED +#endif + #endif // ABSL_BASE_ATTRIBUTES_H_ |