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Diffstat (limited to 'third_party/abseil_cpp/absl/base/attributes.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/base/attributes.h | 623 |
1 files changed, 0 insertions, 623 deletions
diff --git a/third_party/abseil_cpp/absl/base/attributes.h b/third_party/abseil_cpp/absl/base/attributes.h deleted file mode 100644 index c4fd81b002..0000000000 --- a/third_party/abseil_cpp/absl/base/attributes.h +++ /dev/null @@ -1,623 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. -// -// This header file defines macros for declaring attributes for functions, -// types, and variables. -// -// 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. -// -// GCC attributes documentation: -// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html -// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Variable-Attributes.html -// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Type-Attributes.html -// -// Most attributes in this file are already supported by GCC 4.7. However, some -// of them are not supported in older version of Clang. Thus, we check -// `__has_attribute()` first. If the check fails, we check if we are on GCC and -// assume the attribute exists on GCC (which is verified on GCC 4.7). -// -// ----------------------------------------------------------------------------- -// Sanitizer Attributes -// ----------------------------------------------------------------------------- -// -// Sanitizer-related attributes are not "defined" in this file (and indeed -// are not defined as such in any file). To utilize the following -// sanitizer-related attributes within your builds, define the following macros -// within your build using a `-D` flag, along with the given value for -// `-fsanitize`: -// -// * `ADDRESS_SANITIZER` + `-fsanitize=address` (Clang, GCC 4.8) -// * `MEMORY_SANITIZER` + `-fsanitize=memory` (Clang-only) -// * `THREAD_SANITIZER` + `-fsanitize=thread` (Clang, GCC 4.8+) -// * `UNDEFINED_BEHAVIOR_SANITIZER` + `-fsanitize=undefined` (Clang, GCC 4.9+) -// * `CONTROL_FLOW_INTEGRITY` + `-fsanitize=cfi` (Clang-only) -// -// Example: -// -// // Enable branches in the Abseil code that are tagged for ASan: -// $ bazel build --copt=-DADDRESS_SANITIZER --copt=-fsanitize=address -// --linkopt=-fsanitize=address *target* -// -// Since these macro names are only supported by GCC and Clang, we only check -// for `__GNUC__` (GCC or Clang) and the above macros. -#ifndef ABSL_BASE_ATTRIBUTES_H_ -#define ABSL_BASE_ATTRIBUTES_H_ - -// ABSL_HAVE_ATTRIBUTE -// -// A function-like feature checking macro that is a wrapper around -// `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a -// nonzero constant integer if the attribute is supported or 0 if not. -// -// It evaluates to zero if `__has_attribute` is not defined by the compiler. -// -// GCC: https://gcc.gnu.org/gcc-5/changes.html -// Clang: https://clang.llvm.org/docs/LanguageExtensions.html -#ifdef __has_attribute -#define ABSL_HAVE_ATTRIBUTE(x) __has_attribute(x) -#else -#define ABSL_HAVE_ATTRIBUTE(x) 0 -#endif - -// ABSL_HAVE_CPP_ATTRIBUTE -// -// A function-like feature checking macro that accepts C++11 style attributes. -// It's a wrapper around `__has_cpp_attribute`, defined by ISO C++ SD-6 -// (https://en.cppreference.com/w/cpp/experimental/feature_test). If we don't -// find `__has_cpp_attribute`, will evaluate to 0. -#if defined(__cplusplus) && defined(__has_cpp_attribute) -// NOTE: requiring __cplusplus above should not be necessary, but -// works around https://bugs.llvm.org/show_bug.cgi?id=23435. -#define ABSL_HAVE_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) -#else -#define ABSL_HAVE_CPP_ATTRIBUTE(x) 0 -#endif - -// ----------------------------------------------------------------------------- -// Function Attributes -// ----------------------------------------------------------------------------- -// -// GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html -// Clang: https://clang.llvm.org/docs/AttributeReference.html - -// ABSL_PRINTF_ATTRIBUTE -// ABSL_SCANF_ATTRIBUTE -// -// Tells the compiler to perform `printf` format string checking if the -// compiler supports it; see the 'format' attribute in -// <https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html>. -// -// Note: As the GCC manual states, "[s]ince non-static C++ methods -// have an implicit 'this' argument, the arguments of such methods -// should be counted from two, not one." -#if ABSL_HAVE_ATTRIBUTE(format) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_PRINTF_ATTRIBUTE(string_index, first_to_check) \ - __attribute__((__format__(__printf__, string_index, first_to_check))) -#define ABSL_SCANF_ATTRIBUTE(string_index, first_to_check) \ - __attribute__((__format__(__scanf__, string_index, first_to_check))) -#else -#define ABSL_PRINTF_ATTRIBUTE(string_index, first_to_check) -#define ABSL_SCANF_ATTRIBUTE(string_index, first_to_check) -#endif - -// ABSL_ATTRIBUTE_ALWAYS_INLINE -// ABSL_ATTRIBUTE_NOINLINE -// -// Forces functions to either inline or not inline. Introduced in gcc 3.1. -#if ABSL_HAVE_ATTRIBUTE(always_inline) || \ - (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline)) -#define ABSL_HAVE_ATTRIBUTE_ALWAYS_INLINE 1 -#else -#define ABSL_ATTRIBUTE_ALWAYS_INLINE -#endif - -#if ABSL_HAVE_ATTRIBUTE(noinline) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_NOINLINE __attribute__((noinline)) -#define ABSL_HAVE_ATTRIBUTE_NOINLINE 1 -#else -#define ABSL_ATTRIBUTE_NOINLINE -#endif - -// ABSL_ATTRIBUTE_NO_TAIL_CALL -// -// Prevents the compiler from optimizing away stack frames for functions which -// end in a call to another function. -#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__) -#define ABSL_HAVE_ATTRIBUTE_NO_TAIL_CALL 1 -#define ABSL_ATTRIBUTE_NO_TAIL_CALL \ - __attribute__((optimize("no-optimize-sibling-calls"))) -#else -#define ABSL_ATTRIBUTE_NO_TAIL_CALL -#define ABSL_HAVE_ATTRIBUTE_NO_TAIL_CALL 0 -#endif - -// ABSL_ATTRIBUTE_WEAK -// -// Tags a function as weak for the purposes of compilation and linking. -// Weak attributes currently do not work properly in LLVM's Windows backend, -// so disable them there. See https://bugs.llvm.org/show_bug.cgi?id=37598 -// for further information. -// The MinGW compiler doesn't complain about the weak attribute until the link -// step, presumably because Windows doesn't use ELF binaries. -#if (ABSL_HAVE_ATTRIBUTE(weak) || \ - (defined(__GNUC__) && !defined(__clang__))) && \ - !(defined(__llvm__) && defined(_WIN32)) && !defined(__MINGW32__) -#undef ABSL_ATTRIBUTE_WEAK -#define ABSL_ATTRIBUTE_WEAK __attribute__((weak)) -#define ABSL_HAVE_ATTRIBUTE_WEAK 1 -#else -#define ABSL_ATTRIBUTE_WEAK -#define ABSL_HAVE_ATTRIBUTE_WEAK 0 -#endif - -// ABSL_ATTRIBUTE_NONNULL -// -// Tells the compiler either (a) that a particular function parameter -// should be a non-null pointer, or (b) that all pointer arguments should -// be non-null. -// -// Note: As the GCC manual states, "[s]ince non-static C++ methods -// have an implicit 'this' argument, the arguments of such methods -// should be counted from two, not one." -// -// Args are indexed starting at 1. -// -// For non-static class member functions, the implicit `this` argument -// is arg 1, and the first explicit argument is arg 2. For static class member -// functions, there is no implicit `this`, and the first explicit argument is -// arg 1. -// -// Example: -// -// /* arg_a cannot be null, but arg_b can */ -// void Function(void* arg_a, void* arg_b) ABSL_ATTRIBUTE_NONNULL(1); -// -// class C { -// /* arg_a cannot be null, but arg_b can */ -// void Method(void* arg_a, void* arg_b) ABSL_ATTRIBUTE_NONNULL(2); -// -// /* arg_a cannot be null, but arg_b can */ -// static void StaticMethod(void* arg_a, void* arg_b) -// ABSL_ATTRIBUTE_NONNULL(1); -// }; -// -// If no arguments are provided, then all pointer arguments should be non-null. -// -// /* No pointer arguments may be null. */ -// void Function(void* arg_a, void* arg_b, int arg_c) ABSL_ATTRIBUTE_NONNULL(); -// -// NOTE: The GCC nonnull attribute actually accepts a list of arguments, but -// ABSL_ATTRIBUTE_NONNULL does not. -#if ABSL_HAVE_ATTRIBUTE(nonnull) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_NONNULL(arg_index) __attribute__((nonnull(arg_index))) -#else -#define ABSL_ATTRIBUTE_NONNULL(...) -#endif - -// ABSL_ATTRIBUTE_NORETURN -// -// Tells the compiler that a given function never returns. -#if ABSL_HAVE_ATTRIBUTE(noreturn) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_NORETURN __attribute__((noreturn)) -#elif defined(_MSC_VER) -#define ABSL_ATTRIBUTE_NORETURN __declspec(noreturn) -#else -#define ABSL_ATTRIBUTE_NORETURN -#endif - -// ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS -// -// Tells the AddressSanitizer (or other memory testing tools) to ignore a given -// function. Useful for cases when a function reads random locations on stack, -// calls _exit from a cloned subprocess, deliberately accesses buffer -// 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 defined(__GNUC__) -#define ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address)) -#else -#define ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS -#endif - -// ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY -// -// Tells the MemorySanitizer to relax the handling of a given function. All -// "Use of uninitialized value" warnings from such functions will be suppressed, -// and all values loaded from memory will be considered fully initialized. -// This attribute is similar to the ADDRESS_SANITIZER attribute above, but deals -// with initialized-ness rather than addressability issues. -// NOTE: MemorySanitizer(msan) is supported by Clang but not GCC. -#if defined(__clang__) -#define ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory)) -#else -#define ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY -#endif - -// ABSL_ATTRIBUTE_NO_SANITIZE_THREAD -// -// Tells the ThreadSanitizer to not instrument a given function. -// NOTE: GCC supports ThreadSanitizer(tsan) since 4.8. -// https://gcc.gnu.org/gcc-4.8/changes.html -#if defined(__GNUC__) -#define ABSL_ATTRIBUTE_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread)) -#else -#define ABSL_ATTRIBUTE_NO_SANITIZE_THREAD -#endif - -// ABSL_ATTRIBUTE_NO_SANITIZE_UNDEFINED -// -// Tells the UndefinedSanitizer to ignore a given function. Useful for cases -// where certain behavior (eg. division by zero) is being used intentionally. -// NOTE: GCC supports UndefinedBehaviorSanitizer(ubsan) since 4.9. -// https://gcc.gnu.org/gcc-4.9/changes.html -#if defined(__GNUC__) && \ - (defined(UNDEFINED_BEHAVIOR_SANITIZER) || defined(ADDRESS_SANITIZER)) -#define ABSL_ATTRIBUTE_NO_SANITIZE_UNDEFINED \ - __attribute__((no_sanitize("undefined"))) -#else -#define ABSL_ATTRIBUTE_NO_SANITIZE_UNDEFINED -#endif - -// ABSL_ATTRIBUTE_NO_SANITIZE_CFI -// -// Tells the ControlFlowIntegrity sanitizer to not instrument a given function. -// See https://clang.llvm.org/docs/ControlFlowIntegrity.html for details. -#if defined(__GNUC__) && defined(CONTROL_FLOW_INTEGRITY) -#define ABSL_ATTRIBUTE_NO_SANITIZE_CFI __attribute__((no_sanitize("cfi"))) -#else -#define ABSL_ATTRIBUTE_NO_SANITIZE_CFI -#endif - -// ABSL_ATTRIBUTE_NO_SANITIZE_SAFESTACK -// -// Tells the SafeStack to not instrument a given function. -// See https://clang.llvm.org/docs/SafeStack.html for details. -#if defined(__GNUC__) && defined(SAFESTACK_SANITIZER) -#define ABSL_ATTRIBUTE_NO_SANITIZE_SAFESTACK \ - __attribute__((no_sanitize("safe-stack"))) -#else -#define ABSL_ATTRIBUTE_NO_SANITIZE_SAFESTACK -#endif - -// ABSL_ATTRIBUTE_RETURNS_NONNULL -// -// Tells the compiler that a particular function never returns a null pointer. -#if ABSL_HAVE_ATTRIBUTE(returns_nonnull) || \ - (defined(__GNUC__) && \ - (__GNUC__ > 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)) && \ - !defined(__clang__)) -#define ABSL_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull)) -#else -#define ABSL_ATTRIBUTE_RETURNS_NONNULL -#endif - -// ABSL_HAVE_ATTRIBUTE_SECTION -// -// Indicates whether labeled sections are supported. Weak symbol support is -// a prerequisite. Labeled sections are not supported on Darwin/iOS. -#ifdef ABSL_HAVE_ATTRIBUTE_SECTION -#error ABSL_HAVE_ATTRIBUTE_SECTION cannot be directly set -#elif (ABSL_HAVE_ATTRIBUTE(section) || \ - (defined(__GNUC__) && !defined(__clang__))) && \ - !defined(__APPLE__) && ABSL_HAVE_ATTRIBUTE_WEAK -#define ABSL_HAVE_ATTRIBUTE_SECTION 1 - -// ABSL_ATTRIBUTE_SECTION -// -// Tells the compiler/linker to put a given function into a section and define -// `__start_ ## name` and `__stop_ ## name` symbols to bracket the section. -// This functionality is supported by GNU linker. Any function annotated with -// `ABSL_ATTRIBUTE_SECTION` must not be inlined, or it will be placed into -// whatever section its caller is placed into. -// -#ifndef ABSL_ATTRIBUTE_SECTION -#define ABSL_ATTRIBUTE_SECTION(name) \ - __attribute__((section(#name))) __attribute__((noinline)) -#endif - - -// ABSL_ATTRIBUTE_SECTION_VARIABLE -// -// Tells the compiler/linker to put a given variable into a section and define -// `__start_ ## name` and `__stop_ ## name` symbols to bracket the section. -// This functionality is supported by GNU linker. -#ifndef ABSL_ATTRIBUTE_SECTION_VARIABLE -#define ABSL_ATTRIBUTE_SECTION_VARIABLE(name) __attribute__((section(#name))) -#endif - -// ABSL_DECLARE_ATTRIBUTE_SECTION_VARS -// -// A weak section declaration to be used as a global declaration -// for ABSL_ATTRIBUTE_SECTION_START|STOP(name) to compile and link -// even without functions with ABSL_ATTRIBUTE_SECTION(name). -// ABSL_DEFINE_ATTRIBUTE_SECTION should be in the exactly one file; it's -// a no-op on ELF but not on Mach-O. -// -#ifndef ABSL_DECLARE_ATTRIBUTE_SECTION_VARS -#define ABSL_DECLARE_ATTRIBUTE_SECTION_VARS(name) \ - extern char __start_##name[] ABSL_ATTRIBUTE_WEAK; \ - extern char __stop_##name[] ABSL_ATTRIBUTE_WEAK -#endif -#ifndef ABSL_DEFINE_ATTRIBUTE_SECTION_VARS -#define ABSL_INIT_ATTRIBUTE_SECTION_VARS(name) -#define ABSL_DEFINE_ATTRIBUTE_SECTION_VARS(name) -#endif - -// ABSL_ATTRIBUTE_SECTION_START -// -// Returns `void*` pointers to start/end of a section of code with -// functions having ABSL_ATTRIBUTE_SECTION(name). -// Returns 0 if no such functions exist. -// One must ABSL_DECLARE_ATTRIBUTE_SECTION_VARS(name) for this to compile and -// link. -// -#define ABSL_ATTRIBUTE_SECTION_START(name) \ - (reinterpret_cast<void *>(__start_##name)) -#define ABSL_ATTRIBUTE_SECTION_STOP(name) \ - (reinterpret_cast<void *>(__stop_##name)) - -#else // !ABSL_HAVE_ATTRIBUTE_SECTION - -#define ABSL_HAVE_ATTRIBUTE_SECTION 0 - -// provide dummy definitions -#define ABSL_ATTRIBUTE_SECTION(name) -#define ABSL_ATTRIBUTE_SECTION_VARIABLE(name) -#define ABSL_INIT_ATTRIBUTE_SECTION_VARS(name) -#define ABSL_DEFINE_ATTRIBUTE_SECTION_VARS(name) -#define ABSL_DECLARE_ATTRIBUTE_SECTION_VARS(name) -#define ABSL_ATTRIBUTE_SECTION_START(name) (reinterpret_cast<void *>(0)) -#define ABSL_ATTRIBUTE_SECTION_STOP(name) (reinterpret_cast<void *>(0)) - -#endif // ABSL_ATTRIBUTE_SECTION - -// ABSL_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC -// -// Support for aligning the stack on 32-bit x86. -#if ABSL_HAVE_ATTRIBUTE(force_align_arg_pointer) || \ - (defined(__GNUC__) && !defined(__clang__)) -#if defined(__i386__) -#define ABSL_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC \ - __attribute__((force_align_arg_pointer)) -#define ABSL_REQUIRE_STACK_ALIGN_TRAMPOLINE (0) -#elif defined(__x86_64__) -#define ABSL_REQUIRE_STACK_ALIGN_TRAMPOLINE (1) -#define ABSL_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC -#else // !__i386__ && !__x86_64 -#define ABSL_REQUIRE_STACK_ALIGN_TRAMPOLINE (0) -#define ABSL_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC -#endif // __i386__ -#else -#define ABSL_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC -#define ABSL_REQUIRE_STACK_ALIGN_TRAMPOLINE (0) -#endif - -// ABSL_MUST_USE_RESULT -// -// Tells the compiler to warn about unused results. -// -// When annotating a function, it must appear as the first part of the -// declaration or definition. The compiler will warn if the return value from -// such a function is unused: -// -// ABSL_MUST_USE_RESULT Sprocket* AllocateSprocket(); -// AllocateSprocket(); // Triggers a warning. -// -// When annotating a class, it is equivalent to annotating every function which -// returns an instance. -// -// class ABSL_MUST_USE_RESULT Sprocket {}; -// Sprocket(); // Triggers a warning. -// -// Sprocket MakeSprocket(); -// MakeSprocket(); // Triggers a warning. -// -// Note that references and pointers are not instances: -// -// Sprocket* SprocketPointer(); -// SprocketPointer(); // Does *not* trigger a warning. -// -// ABSL_MUST_USE_RESULT allows using cast-to-void to suppress the unused result -// warning. For that, warn_unused_result is used only for clang but not for gcc. -// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425 -// -// Note: past advice was to place the macro after the argument list. -#if ABSL_HAVE_ATTRIBUTE(nodiscard) -#define ABSL_MUST_USE_RESULT [[nodiscard]] -#elif defined(__clang__) && ABSL_HAVE_ATTRIBUTE(warn_unused_result) -#define ABSL_MUST_USE_RESULT __attribute__((warn_unused_result)) -#else -#define ABSL_MUST_USE_RESULT -#endif - -// ABSL_ATTRIBUTE_HOT, ABSL_ATTRIBUTE_COLD -// -// Tells GCC that a function is hot or cold. GCC can use this information to -// improve static analysis, i.e. a conditional branch to a cold function -// is likely to be not-taken. -// This annotation is used for function declarations. -// -// Example: -// -// int foo() ABSL_ATTRIBUTE_HOT; -#if ABSL_HAVE_ATTRIBUTE(hot) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_HOT __attribute__((hot)) -#else -#define ABSL_ATTRIBUTE_HOT -#endif - -#if ABSL_HAVE_ATTRIBUTE(cold) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_COLD __attribute__((cold)) -#else -#define ABSL_ATTRIBUTE_COLD -#endif - -// ABSL_XRAY_ALWAYS_INSTRUMENT, ABSL_XRAY_NEVER_INSTRUMENT, ABSL_XRAY_LOG_ARGS -// -// We define the ABSL_XRAY_ALWAYS_INSTRUMENT and ABSL_XRAY_NEVER_INSTRUMENT -// macro used as an attribute to mark functions that must always or never be -// instrumented by XRay. Currently, this is only supported in Clang/LLVM. -// -// For reference on the LLVM XRay instrumentation, see -// http://llvm.org/docs/XRay.html. -// -// A function with the XRAY_ALWAYS_INSTRUMENT macro attribute in its declaration -// will always get the XRay instrumentation sleds. These sleds may introduce -// some binary size and runtime overhead and must be used sparingly. -// -// These attributes only take effect when the following conditions are met: -// -// * The file/target is built in at least C++11 mode, with a Clang compiler -// that supports XRay attributes. -// * The file/target is built with the -fxray-instrument flag set for the -// Clang/LLVM compiler. -// * The function is defined in the translation unit (the compiler honors the -// attribute in either the definition or the declaration, and must match). -// -// There are cases when, even when building with XRay instrumentation, users -// might want to control specifically which functions are instrumented for a -// particular build using special-case lists provided to the compiler. These -// special case lists are provided to Clang via the -// -fxray-always-instrument=... and -fxray-never-instrument=... flags. The -// attributes in source take precedence over these special-case lists. -// -// To disable the XRay attributes at build-time, users may define -// ABSL_NO_XRAY_ATTRIBUTES. Do NOT define ABSL_NO_XRAY_ATTRIBUTES on specific -// packages/targets, as this may lead to conflicting definitions of functions at -// link-time. -// -// XRay isn't currently supported on Android: -// https://github.com/android/ndk/issues/368 -#if ABSL_HAVE_CPP_ATTRIBUTE(clang::xray_always_instrument) && \ - !defined(ABSL_NO_XRAY_ATTRIBUTES) && !defined(__ANDROID__) -#define ABSL_XRAY_ALWAYS_INSTRUMENT [[clang::xray_always_instrument]] -#define ABSL_XRAY_NEVER_INSTRUMENT [[clang::xray_never_instrument]] -#if ABSL_HAVE_CPP_ATTRIBUTE(clang::xray_log_args) -#define ABSL_XRAY_LOG_ARGS(N) \ - [[clang::xray_always_instrument, clang::xray_log_args(N)]] -#else -#define ABSL_XRAY_LOG_ARGS(N) [[clang::xray_always_instrument]] -#endif -#else -#define ABSL_XRAY_ALWAYS_INSTRUMENT -#define ABSL_XRAY_NEVER_INSTRUMENT -#define ABSL_XRAY_LOG_ARGS(N) -#endif - -// ABSL_ATTRIBUTE_REINITIALIZES -// -// Indicates that a member function reinitializes the entire object to a known -// state, independent of the previous state of the object. -// -// The clang-tidy check bugprone-use-after-move allows member functions marked -// with this attribute to be called on objects that have been moved from; -// without the attribute, this would result in a use-after-move warning. -#if ABSL_HAVE_CPP_ATTRIBUTE(clang::reinitializes) -#define ABSL_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]] -#else -#define ABSL_ATTRIBUTE_REINITIALIZES -#endif - -// ----------------------------------------------------------------------------- -// Variable Attributes -// ----------------------------------------------------------------------------- - -// ABSL_ATTRIBUTE_UNUSED -// -// Prevents the compiler from complaining about variables that appear unused. -#if ABSL_HAVE_ATTRIBUTE(unused) || (defined(__GNUC__) && !defined(__clang__)) -#undef ABSL_ATTRIBUTE_UNUSED -#define ABSL_ATTRIBUTE_UNUSED __attribute__((__unused__)) -#else -#define ABSL_ATTRIBUTE_UNUSED -#endif - -// ABSL_ATTRIBUTE_INITIAL_EXEC -// -// Tells the compiler to use "initial-exec" mode for a thread-local variable. -// See http://people.redhat.com/drepper/tls.pdf for the gory details. -#if ABSL_HAVE_ATTRIBUTE(tls_model) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_INITIAL_EXEC __attribute__((tls_model("initial-exec"))) -#else -#define ABSL_ATTRIBUTE_INITIAL_EXEC -#endif - -// ABSL_ATTRIBUTE_PACKED -// -// Instructs the compiler not to use natural alignment for a tagged data -// structure, but instead to reduce its alignment to 1. This attribute can -// either be applied to members of a structure or to a structure in its -// entirety. Applying this attribute (judiciously) to a structure in its -// entirety to optimize the memory footprint of very commonly-used structs is -// fine. Do not apply this attribute to a structure in its entirety if the -// purpose is to control the offsets of the members in the structure. Instead, -// apply this attribute only to structure members that need it. -// -// When applying ABSL_ATTRIBUTE_PACKED only to specific structure members the -// natural alignment of structure members not annotated is preserved. Aligned -// member accesses are faster than non-aligned member accesses even if the -// targeted microprocessor supports non-aligned accesses. -#if ABSL_HAVE_ATTRIBUTE(packed) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_PACKED __attribute__((__packed__)) -#else -#define ABSL_ATTRIBUTE_PACKED -#endif - -// ABSL_ATTRIBUTE_FUNC_ALIGN -// -// Tells the compiler to align the function start at least to certain -// alignment boundary -#if ABSL_HAVE_ATTRIBUTE(aligned) || (defined(__GNUC__) && !defined(__clang__)) -#define ABSL_ATTRIBUTE_FUNC_ALIGN(bytes) __attribute__((aligned(bytes))) -#else -#define ABSL_ATTRIBUTE_FUNC_ALIGN(bytes) -#endif - -// ABSL_CONST_INIT -// -// A variable declaration annotated with the `ABSL_CONST_INIT` attribute will -// not compile (on supported platforms) unless the variable has a constant -// initializer. This is useful for variables with static and thread storage -// duration, because it guarantees that they will not suffer from the so-called -// "static init order fiasco". Prefer to put this attribute on the most visible -// declaration of the variable, if there's more than one, because code that -// accesses the variable can then use the attribute for optimization. -// -// Example: -// -// class MyClass { -// public: -// ABSL_CONST_INIT static MyType my_var; -// }; -// -// MyType MyClass::my_var = MakeMyType(...); -// -// Note that this attribute is redundant if the variable is declared constexpr. -#if ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization) -#define ABSL_CONST_INIT [[clang::require_constant_initialization]] -#else -#define ABSL_CONST_INIT -#endif // ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization) - -#endif // ABSL_BASE_ATTRIBUTES_H_ |