diff options
Diffstat (limited to 'absl/base/config.h')
| -rw-r--r-- | absl/base/config.h | 211 |
1 files changed, 205 insertions, 6 deletions
diff --git a/absl/base/config.h b/absl/base/config.h index 1c3cb08e..ee99f946 100644 --- a/absl/base/config.h +++ b/absl/base/config.h @@ -63,8 +63,72 @@ #include <TargetConditionals.h> #endif +#include "absl/base/options.h" #include "absl/base/policy_checks.h" +// Helper macro to convert a CPP variable to a string literal. +#define ABSL_INTERNAL_DO_TOKEN_STR(x) #x +#define ABSL_INTERNAL_TOKEN_STR(x) ABSL_INTERNAL_DO_TOKEN_STR(x) + +// ----------------------------------------------------------------------------- +// Abseil namespace annotations +// ----------------------------------------------------------------------------- + +// ABSL_NAMESPACE_BEGIN/ABSL_NAMESPACE_END +// +// An annotation placed at the beginning/end of each `namespace absl` scope. +// This is used to inject an inline namespace. +// +// The proper way to write Abseil code in the `absl` namespace is: +// +// namespace absl { +// ABSL_NAMESPACE_BEGIN +// +// void Foo(); // absl::Foo(). +// +// ABSL_NAMESPACE_END +// } // namespace absl +// +// Users of Abseil should not use these macros, because users of Abseil should +// not write `namespace absl {` in their own code for any reason. (Abseil does +// not support forward declarations of its own types, nor does it support +// user-provided specialization of Abseil templates. Code that violates these +// rules may be broken without warning.) +#if !defined(ABSL_OPTION_USE_INLINE_NAMESPACE) || \ + !defined(ABSL_OPTION_INLINE_NAMESPACE_NAME) +#error options.h is misconfigured. +#endif + +// Check that ABSL_OPTION_INLINE_NAMESPACE_NAME is neither "head" nor "" +#if defined(__cplusplus) && ABSL_OPTION_USE_INLINE_NAMESPACE == 1 + +#define ABSL_INTERNAL_INLINE_NAMESPACE_STR \ + ABSL_INTERNAL_TOKEN_STR(ABSL_OPTION_INLINE_NAMESPACE_NAME) + +static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != '\0', + "options.h misconfigured: ABSL_OPTION_INLINE_NAMESPACE_NAME must " + "not be empty."); +static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[1] != 'e' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[2] != 'a' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[3] != 'd' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[4] != '\0', + "options.h misconfigured: ABSL_OPTION_INLINE_NAMESPACE_NAME must " + "be changed to a new, unique identifier name."); + +#endif + +#if ABSL_OPTION_USE_INLINE_NAMESPACE == 0 +#define ABSL_NAMESPACE_BEGIN +#define ABSL_NAMESPACE_END +#elif ABSL_OPTION_USE_INLINE_NAMESPACE == 1 +#define ABSL_NAMESPACE_BEGIN \ + inline namespace ABSL_OPTION_INLINE_NAMESPACE_NAME { +#define ABSL_NAMESPACE_END } +#else +#error options.h is misconfigured. +#endif + // ----------------------------------------------------------------------------- // Compiler Feature Checks // ----------------------------------------------------------------------------- @@ -84,6 +148,12 @@ #define ABSL_HAVE_BUILTIN(x) 0 #endif +#if defined(__is_identifier) +#define ABSL_INTERNAL_HAS_KEYWORD(x) !(__is_identifier(x)) +#else +#define ABSL_INTERNAL_HAS_KEYWORD(x) 0 +#endif + // ABSL_HAVE_TLS is defined to 1 when __thread should be supported. // We assume __thread is supported on Linux when compiled with Clang or compiled // against libstdc++ with _GLIBCXX_HAVE_TLS defined. @@ -125,13 +195,24 @@ #error ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE cannot directly set #elif (defined(__clang__) && defined(_LIBCPP_VERSION)) || \ (!defined(__clang__) && defined(__GNUC__) && \ - (__GNUC__ > 5 || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)) && \ + (__GNUC__ > 7 || (__GNUC__ == 7 && __GNUC_MINOR__ >= 4)) && \ (defined(_LIBCPP_VERSION) || defined(__GLIBCXX__))) || \ (defined(_MSC_VER) && !defined(__NVCC__)) #define ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE 1 #define ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE 1 #endif +// ABSL_HAVE_SOURCE_LOCATION_CURRENT +// +// Indicates whether `absl::SourceLocation::current()` will return useful +// information in some contexts. +#ifndef ABSL_HAVE_SOURCE_LOCATION_CURRENT +#if ABSL_INTERNAL_HAS_KEYWORD(__builtin_LINE) && \ + ABSL_INTERNAL_HAS_KEYWORD(__builtin_FILE) +#define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1 +#endif +#endif + // ABSL_HAVE_THREAD_LOCAL // // Checks whether C++11's `thread_local` storage duration specifier is @@ -235,13 +316,19 @@ #error ABSL_HAVE_EXCEPTIONS cannot be directly set. #elif defined(__clang__) -// TODO(calabrese) -// Switch to using __cpp_exceptions when we no longer support versions < 3.6. -// For details on this check, see: -// http://releases.llvm.org/3.6.0/tools/clang/docs/ReleaseNotes.html#the-exceptions-macro + +#if __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 6) +// Clang >= 3.6 +#if __has_feature(cxx_exceptions) +#define ABSL_HAVE_EXCEPTIONS 1 +#endif // __has_feature(cxx_exceptions) +#else +// Clang < 3.6 +// http://releases.llvm.org/3.6.0/tools/clang/docs/ReleaseNotes.html#the-exceptions-macro #if defined(__EXCEPTIONS) && __has_feature(cxx_exceptions) #define ABSL_HAVE_EXCEPTIONS 1 #endif // defined(__EXCEPTIONS) && __has_feature(cxx_exceptions) +#endif // __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 6) // Handle remaining special cases and default to exceptions being supported. #elif !(defined(__GNUC__) && (__GNUC__ < 5) && !defined(__EXCEPTIONS)) && \ @@ -307,7 +394,7 @@ // ABSL_HAVE_SEMAPHORE_H // -// Checks whether the platform supports the <semaphore.h> header and sem_open(3) +// Checks whether the platform supports the <semaphore.h> header and sem_init(3) // family of functions as standardized in POSIX.1-2001. // // Note: While Apple provides <semaphore.h> for both iOS and macOS, it is @@ -334,8 +421,15 @@ #define ABSL_HAVE_ALARM 1 #elif defined(_MSC_VER) // feature tests for Microsoft's library +#elif defined(__MINGW32__) +// mingw32 doesn't provide alarm(2): +// https://osdn.net/projects/mingw/scm/git/mingw-org-wsl/blobs/5.2-trunk/mingwrt/include/unistd.h +// mingw-w64 provides a no-op implementation: +// https://sourceforge.net/p/mingw-w64/mingw-w64/ci/master/tree/mingw-w64-crt/misc/alarm.c #elif defined(__EMSCRIPTEN__) // emscripten doesn't support signals +#elif defined(__Fuchsia__) +// Signals don't exist on fuchsia. #elif defined(__native_client__) #else // other standard libraries @@ -461,6 +555,68 @@ #define ABSL_HAVE_STD_STRING_VIEW 1 #endif +// ABSL_USES_STD_ANY +// +// Indicates whether absl::any is an alias for std::any. +#if !defined(ABSL_OPTION_USE_STD_ANY) +#error options.h is misconfigured. +#elif ABSL_OPTION_USE_STD_ANY == 0 || \ + (ABSL_OPTION_USE_STD_ANY == 2 && !defined(ABSL_HAVE_STD_ANY)) +#undef ABSL_USES_STD_ANY +#elif ABSL_OPTION_USE_STD_ANY == 1 || \ + (ABSL_OPTION_USE_STD_ANY == 2 && defined(ABSL_HAVE_STD_ANY)) +#define ABSL_USES_STD_ANY 1 +#else +#error options.h is misconfigured. +#endif + +// ABSL_USES_STD_OPTIONAL +// +// Indicates whether absl::optional is an alias for std::optional. +#if !defined(ABSL_OPTION_USE_STD_OPTIONAL) +#error options.h is misconfigured. +#elif ABSL_OPTION_USE_STD_OPTIONAL == 0 || \ + (ABSL_OPTION_USE_STD_OPTIONAL == 2 && !defined(ABSL_HAVE_STD_OPTIONAL)) +#undef ABSL_USES_STD_OPTIONAL +#elif ABSL_OPTION_USE_STD_OPTIONAL == 1 || \ + (ABSL_OPTION_USE_STD_OPTIONAL == 2 && defined(ABSL_HAVE_STD_OPTIONAL)) +#define ABSL_USES_STD_OPTIONAL 1 +#else +#error options.h is misconfigured. +#endif + +// ABSL_USES_STD_VARIANT +// +// Indicates whether absl::variant is an alias for std::variant. +#if !defined(ABSL_OPTION_USE_STD_VARIANT) +#error options.h is misconfigured. +#elif ABSL_OPTION_USE_STD_VARIANT == 0 || \ + (ABSL_OPTION_USE_STD_VARIANT == 2 && !defined(ABSL_HAVE_STD_VARIANT)) +#undef ABSL_USES_STD_VARIANT +#elif ABSL_OPTION_USE_STD_VARIANT == 1 || \ + (ABSL_OPTION_USE_STD_VARIANT == 2 && defined(ABSL_HAVE_STD_VARIANT)) +#define ABSL_USES_STD_VARIANT 1 +#else +#error options.h is misconfigured. +#endif + +// ABSL_USES_STD_STRING_VIEW +// +// Indicates whether absl::string_view is an alias for std::string_view. +#if !defined(ABSL_OPTION_USE_STD_STRING_VIEW) +#error options.h is misconfigured. +#elif ABSL_OPTION_USE_STD_STRING_VIEW == 0 || \ + (ABSL_OPTION_USE_STD_STRING_VIEW == 2 && \ + !defined(ABSL_HAVE_STD_STRING_VIEW)) +#undef ABSL_USES_STD_STRING_VIEW +#elif ABSL_OPTION_USE_STD_STRING_VIEW == 1 || \ + (ABSL_OPTION_USE_STD_STRING_VIEW == 2 && \ + defined(ABSL_HAVE_STD_STRING_VIEW)) +#define ABSL_USES_STD_STRING_VIEW 1 +#else +#error options.h is misconfigured. +#endif + // In debug mode, MSVC 2017's std::variant throws a EXCEPTION_ACCESS_VIOLATION // SEH exception from emplace for variant<SomeStruct> when constructing the // struct can throw. This defeats some of variant_test and @@ -469,4 +625,47 @@ #define ABSL_INTERNAL_MSVC_2017_DBG_MODE #endif +// ABSL_INTERNAL_MANGLED_NS +// ABSL_INTERNAL_MANGLED_BACKREFERENCE +// +// Internal macros for building up mangled names in our internal fork of CCTZ. +// This implementation detail is only needed and provided for the MSVC build. +// +// These macros both expand to string literals. ABSL_INTERNAL_MANGLED_NS is +// the mangled spelling of the `absl` namespace, and +// ABSL_INTERNAL_MANGLED_BACKREFERENCE is a back-reference integer representing +// the proper count to skip past the CCTZ fork namespace names. (This number +// is one larger when there is an inline namespace name to skip.) +#if defined(_MSC_VER) +#if ABSL_OPTION_USE_INLINE_NAMESPACE == 0 +#define ABSL_INTERNAL_MANGLED_NS "absl" +#define ABSL_INTERNAL_MANGLED_BACKREFERENCE "5" +#else +#define ABSL_INTERNAL_MANGLED_NS \ + ABSL_INTERNAL_TOKEN_STR(ABSL_OPTION_INLINE_NAMESPACE_NAME) "@absl" +#define ABSL_INTERNAL_MANGLED_BACKREFERENCE "6" +#endif +#endif + +#undef ABSL_INTERNAL_HAS_KEYWORD + +// ABSL_DLL +// +// When building Abseil as a DLL, this macro expands to `__declspec(dllexport)` +// so we can annotate symbols appropriately as being exported. When used in +// headers consuming a DLL, this macro expands to `__declspec(dllimport)` so +// that consumers know the symbol is defined inside the DLL. In all other cases, +// the macro expands to nothing. +#if defined(_MSC_VER) +#if defined(ABSL_BUILD_DLL) +#define ABSL_DLL __declspec(dllexport) +#elif defined(ABSL_CONSUME_DLL) +#define ABSL_DLL __declspec(dllimport) +#else +#define ABSL_DLL +#endif +#else +#define ABSL_DLL +#endif // defined(_MSC_VER) + #endif // ABSL_BASE_CONFIG_H_ |