diff options
Diffstat (limited to 'absl/flags/flag.h')
| -rw-r--r-- | absl/flags/flag.h | 91 |
1 files changed, 42 insertions, 49 deletions
diff --git a/absl/flags/flag.h b/absl/flags/flag.h index ca7d581f..f84853ea 100644 --- a/absl/flags/flag.h +++ b/absl/flags/flag.h @@ -37,7 +37,6 @@ #include "absl/base/config.h" #include "absl/flags/config.h" #include "absl/flags/declare.h" -#include "absl/flags/internal/commandlineflag.h" #include "absl/flags/internal/flag.h" #include "absl/flags/internal/registry.h" #include "absl/flags/marshalling.h" @@ -265,27 +264,29 @@ ABSL_NAMESPACE_END // ----------------------------------------------------------------------------- // ABSL_FLAG_IMPL macro definition conditional on ABSL_FLAGS_STRIP_NAMES +#if !defined(_MSC_VER) || defined(__clang__) +#define ABSL_FLAG_IMPL_FLAG_PTR(flag) &flag +#define ABSL_FLAG_IMPL_HELP_ARG(name) \ + absl::flags_internal::HelpArg<AbslFlagHelpGenFor##name>( \ + FLAGS_help_storage_##name) +#define ABSL_FLAG_IMPL_DEFAULT_ARG(Type, name) \ + absl::flags_internal::DefaultArg<Type, AbslFlagDefaultGenFor##name>(0) +#else +#define ABSL_FLAG_IMPL_FLAG_PTR(flag) flag.GetImpl() +#define ABSL_FLAG_IMPL_HELP_ARG(name) &AbslFlagHelpGenFor##name::NonConst +#define ABSL_FLAG_IMPL_DEFAULT_ARG(Type, name) &AbslFlagDefaultGenFor##name::Gen +#endif #if ABSL_FLAGS_STRIP_NAMES #define ABSL_FLAG_IMPL_FLAGNAME(txt) "" #define ABSL_FLAG_IMPL_FILENAME() "" -#if !defined(_MSC_VER) || defined(__clang__) #define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \ - absl::flags_internal::FlagRegistrar<T, false>(&flag) -#else -#define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \ - absl::flags_internal::FlagRegistrar<T, false>(flag.GetImpl()) -#endif + absl::flags_internal::FlagRegistrar<T, false>(ABSL_FLAG_IMPL_FLAG_PTR(flag)) #else #define ABSL_FLAG_IMPL_FLAGNAME(txt) txt #define ABSL_FLAG_IMPL_FILENAME() __FILE__ -#if !defined(_MSC_VER) || defined(__clang__) -#define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \ - absl::flags_internal::FlagRegistrar<T, true>(&flag) -#else #define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \ - absl::flags_internal::FlagRegistrar<T, true>(flag.GetImpl()) -#endif + absl::flags_internal::FlagRegistrar<T, true>(ABSL_FLAG_IMPL_FLAG_PTR(flag)) #endif // ABSL_FLAG_IMPL macro definition conditional on ABSL_FLAGS_STRIP_HELP @@ -301,15 +302,24 @@ ABSL_NAMESPACE_END // between the two via the call to HelpArg in absl::Flag instantiation below. // If help message expression is constexpr evaluable compiler will optimize // away this whole struct. -#define ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, txt) \ - struct AbslFlagHelpGenFor##name { \ - template <typename T = void> \ - static constexpr const char* Const() { \ - return absl::flags_internal::HelpConstexprWrap( \ - ABSL_FLAG_IMPL_FLAGHELP(txt)); \ - } \ - static std::string NonConst() { return ABSL_FLAG_IMPL_FLAGHELP(txt); } \ - } +// TODO(rogeeff): place these generated structs into local namespace and apply +// ABSL_INTERNAL_UNIQUE_SHORT_NAME. +// TODO(rogeeff): Apply __attribute__((nodebug)) to FLAGS_help_storage_##name +#define ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, txt) \ + struct AbslFlagHelpGenFor##name { \ + /* The expression is run in the caller as part of the */ \ + /* default value argument. That keeps temporaries alive */ \ + /* long enough for NonConst to work correctly. */ \ + static constexpr absl::string_view Value( \ + absl::string_view v = ABSL_FLAG_IMPL_FLAGHELP(txt)) { \ + return v; \ + } \ + static std::string NonConst() { return std::string(Value()); } \ + }; \ + constexpr auto FLAGS_help_storage_##name ABSL_INTERNAL_UNIQUE_SMALL_NAME() \ + ABSL_ATTRIBUTE_SECTION_VARIABLE(flags_help_cold) = \ + absl::flags_internal::HelpStringAsArray<AbslFlagHelpGenFor##name>( \ + 0); #define ABSL_FLAG_IMPL_DECLARE_DEF_VAL_WRAPPER(name, Type, default_value) \ struct AbslFlagDefaultGenFor##name { \ @@ -317,40 +327,23 @@ ABSL_NAMESPACE_END static void Gen(void* p) { \ new (p) Type(AbslFlagDefaultGenFor##name{}.value); \ } \ - } + }; // ABSL_FLAG_IMPL // // Note: Name of registrar object is not arbitrary. It is used to "grab" // global name for FLAGS_no<flag_name> symbol, thus preventing the possibility // of defining two flags with names foo and nofoo. -#if !defined(_MSC_VER) || defined(__clang__) - -#define ABSL_FLAG_IMPL(Type, name, default_value, help) \ - namespace absl /* block flags in namespaces */ {} \ - ABSL_FLAG_IMPL_DECLARE_DEF_VAL_WRAPPER(name, Type, default_value); \ - ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, help); \ - ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name{ \ - ABSL_FLAG_IMPL_FLAGNAME(#name), ABSL_FLAG_IMPL_FILENAME(), \ - absl::flags_internal::HelpArg<AbslFlagHelpGenFor##name>(0), \ - absl::flags_internal::DefaultArg<Type, AbslFlagDefaultGenFor##name>(0)}; \ - extern absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name; \ - absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name = \ - ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name) -#else -// MSVC version uses aggregate initialization. We also do not try to -// optimize away help wrapper. -#define ABSL_FLAG_IMPL(Type, name, default_value, help) \ - namespace absl /* block flags in namespaces */ {} \ - ABSL_FLAG_IMPL_DECLARE_DEF_VAL_WRAPPER(name, Type, default_value); \ - ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, help); \ - ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name{ \ - ABSL_FLAG_IMPL_FLAGNAME(#name), ABSL_FLAG_IMPL_FILENAME(), \ - &AbslFlagHelpGenFor##name::NonConst, &AbslFlagDefaultGenFor##name::Gen}; \ - extern absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name; \ - absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name = \ +#define ABSL_FLAG_IMPL(Type, name, default_value, help) \ + namespace absl /* block flags in namespaces */ {} \ + ABSL_FLAG_IMPL_DECLARE_DEF_VAL_WRAPPER(name, Type, default_value) \ + ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, help) \ + ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name{ \ + ABSL_FLAG_IMPL_FLAGNAME(#name), ABSL_FLAG_IMPL_FILENAME(), \ + ABSL_FLAG_IMPL_HELP_ARG(name), ABSL_FLAG_IMPL_DEFAULT_ARG(Type, name)}; \ + extern absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name; \ + absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name = \ ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name) -#endif // ABSL_RETIRED_FLAG // |