diff options
Diffstat (limited to 'absl/base/attributes.h')
| -rw-r--r-- | absl/base/attributes.h | 60 |
1 files changed, 37 insertions, 23 deletions
diff --git a/absl/base/attributes.h b/absl/base/attributes.h index e11a064a..3e5aafba 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -211,11 +211,20 @@ // out of bounds or does other scary things with memory. // NOTE: GCC supports AddressSanitizer(asan) since 4.8. // https://gcc.gnu.org/gcc-4.8/changes.html -#if ABSL_HAVE_ATTRIBUTE(no_sanitize_address) +#if defined(ABSL_HAVE_ADDRESS_SANITIZER) && \ + ABSL_HAVE_ATTRIBUTE(no_sanitize_address) #define ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address)) -#elif defined(_MSC_VER) && _MSC_VER >= 1928 +#elif defined(ABSL_HAVE_ADDRESS_SANITIZER) && defined(_MSC_VER) && \ + _MSC_VER >= 1928 // https://docs.microsoft.com/en-us/cpp/cpp/no-sanitize-address #define ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS __declspec(no_sanitize_address) +#elif defined(ABSL_HAVE_HWADDRESS_SANITIZER) && ABSL_HAVE_ATTRIBUTE(no_sanitize) +// HWAddressSanitizer is a sanitizer similar to AddressSanitizer, which uses CPU +// features to detect similar bugs with less CPU and memory overhead. +// NOTE: GCC supports HWAddressSanitizer(hwasan) since 11. +// https://gcc.gnu.org/gcc-11/changes.html +#define ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS \ + __attribute__((no_sanitize("hwaddress"))) #else #define ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS #endif @@ -322,8 +331,8 @@ // This functionality is supported by GNU linker. #ifndef ABSL_ATTRIBUTE_SECTION_VARIABLE #ifdef _AIX -// __attribute__((section(#name))) on AIX is achived by using the `.csect` psudo -// op which includes an additional integer as part of its syntax indcating +// __attribute__((section(#name))) on AIX is achieved by using the `.csect` +// psudo op which includes an additional integer as part of its syntax indcating // alignment. If data fall under different alignments then you might get a // compilation error indicating a `Section type conflict`. #define ABSL_ATTRIBUTE_SECTION_VARIABLE(name) @@ -716,26 +725,9 @@ #define ABSL_CONST_INIT #endif -// 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 +// These annotations are not available yet due to fear of breaking code. #define ABSL_ATTRIBUTE_PURE_FUNCTION -#endif +#define ABSL_ATTRIBUTE_CONST_FUNCTION // ABSL_ATTRIBUTE_LIFETIME_BOUND indicates that a resource owned by a function // parameter or implicit object parameter is retained by the return value of the @@ -796,4 +788,26 @@ #define ABSL_ATTRIBUTE_TRIVIAL_ABI #endif +// ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS +// +// Indicates a data member can be optimized to occupy no space (if it is empty) +// and/or its tail padding can be used for other members. +// +// For code that is assured to only build with C++20 or later, prefer using +// the standard attribute `[[no_unique_address]]` directly instead of this +// macro. +// +// https://devblogs.microsoft.com/cppblog/msvc-cpp20-and-the-std-cpp20-switch/#c20-no_unique_address +// Current versions of MSVC have disabled `[[no_unique_address]]` since it +// breaks ABI compatibility, but offers `[[msvc::no_unique_address]]` for +// situations when it can be assured that it is desired. Since Abseil does not +// claim ABI compatibility in mixed builds, we can offer it unconditionally. +#if defined(_MSC_VER) && _MSC_VER >= 1929 +#define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]] +#elif ABSL_HAVE_CPP_ATTRIBUTE(no_unique_address) +#define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS [[no_unique_address]] +#else +#define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS +#endif + #endif // ABSL_BASE_ATTRIBUTES_H_ |