diff options
Diffstat (limited to 'absl/base/macros.h')
| -rw-r--r-- | absl/base/macros.h | 145 |
1 files changed, 36 insertions, 109 deletions
diff --git a/absl/base/macros.h b/absl/base/macros.h index 547f93ba..02dd9ff4 100644 --- a/absl/base/macros.h +++ b/absl/base/macros.h @@ -32,6 +32,7 @@ #include <cstddef> #include "absl/base/attributes.h" +#include "absl/base/config.h" #include "absl/base/optimization.h" #include "absl/base/port.h" @@ -54,115 +55,6 @@ auto ArraySizeHelper(const T (&array)[N]) -> char (&)[N]; ABSL_NAMESPACE_END } // namespace absl -// kLinkerInitialized -// -// An enum used only as a constructor argument to indicate that a variable has -// static storage duration, and that the constructor should do nothing to its -// state. Use of this macro indicates to the reader that it is legal to -// declare a static instance of the class, provided the constructor is given -// the absl::base_internal::kLinkerInitialized argument. -// -// Normally, it is unsafe to declare a static variable that has a constructor or -// a destructor because invocation order is undefined. However, if the type can -// be zero-initialized (which the loader does for static variables) into a valid -// state and the type's destructor does not affect storage, then a constructor -// for static initialization can be declared. -// -// Example: -// // Declaration -// explicit MyClass(absl::base_internal:LinkerInitialized x) {} -// -// // Invocation -// static MyClass my_global(absl::base_internal::kLinkerInitialized); -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace base_internal { -enum LinkerInitialized { - kLinkerInitialized = 0, -}; -} // namespace base_internal -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 @@ -207,6 +99,41 @@ ABSL_NAMESPACE_END : [] { assert(false && #expr); }()) // NOLINT #endif +// `ABSL_INTERNAL_HARDENING_ABORT()` controls how `ABSL_HARDENING_ASSERT()` +// aborts the program in release mode (when NDEBUG is defined). The +// implementation should abort the program as quickly as possible and ideally it +// should not be possible to ignore the abort request. +#if (ABSL_HAVE_BUILTIN(__builtin_trap) && \ + ABSL_HAVE_BUILTIN(__builtin_unreachable)) || \ + (defined(__GNUC__) && !defined(__clang__)) +#define ABSL_INTERNAL_HARDENING_ABORT() \ + do { \ + __builtin_trap(); \ + __builtin_unreachable(); \ + } while (false) +#else +#define ABSL_INTERNAL_HARDENING_ABORT() abort() +#endif + +// ABSL_HARDENING_ASSERT() +// +// `ABSL_HARDENING_ASSERT()` is like `ABSL_ASSERT()`, but used to implement +// runtime assertions that should be enabled in hardened builds even when +// `NDEBUG` is defined. +// +// When `NDEBUG` is not defined, `ABSL_HARDENING_ASSERT()` is identical to +// `ABSL_ASSERT()`. +// +// See `ABSL_OPTION_HARDENED` in `absl/base/options.h` for more information on +// hardened mode. +#if ABSL_OPTION_HARDENED == 1 && defined(NDEBUG) +#define ABSL_HARDENING_ASSERT(expr) \ + (ABSL_PREDICT_TRUE((expr)) ? static_cast<void>(0) \ + : [] { ABSL_INTERNAL_HARDENING_ABORT(); }()) +#else +#define ABSL_HARDENING_ASSERT(expr) ABSL_ASSERT(expr) +#endif + #ifdef ABSL_HAVE_EXCEPTIONS #define ABSL_INTERNAL_TRY try #define ABSL_INTERNAL_CATCH_ANY catch (...) |