zone_info_source.cc (6850B)
1 // Copyright 2016 Google Inc. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #include "absl/time/internal/cctz/include/cctz/zone_info_source.h" 16 17 #include "absl/base/config.h" 18 19 namespace absl { 20 ABSL_NAMESPACE_BEGIN 21 namespace time_internal { 22 namespace cctz { 23 24 // Defined out-of-line to avoid emitting a weak vtable in all TUs. 25 ZoneInfoSource::~ZoneInfoSource() {} 26 std::string ZoneInfoSource::Version() const { return std::string(); } 27 28 } // namespace cctz 29 } // namespace time_internal 30 ABSL_NAMESPACE_END 31 } // namespace absl 32 33 namespace absl { 34 ABSL_NAMESPACE_BEGIN 35 namespace time_internal { 36 namespace cctz_extension { 37 38 namespace { 39 40 // A default for cctz_extension::zone_info_source_factory, which simply 41 // defers to the fallback factory. 42 std::unique_ptr<absl::time_internal::cctz::ZoneInfoSource> DefaultFactory( 43 const std::string& name, 44 const std::function< 45 std::unique_ptr<absl::time_internal::cctz::ZoneInfoSource>( 46 const std::string& name)>& fallback_factory) { 47 return fallback_factory(name); 48 } 49 50 } // namespace 51 52 // A "weak" definition for cctz_extension::zone_info_source_factory. 53 // The user may override this with their own "strong" definition (see 54 // zone_info_source.h). 55 #if !defined(__has_attribute) 56 #define __has_attribute(x) 0 57 #endif 58 // MinGW is GCC on Windows, so while it asserts __has_attribute(weak), the 59 // Windows linker cannot handle that. Nor does the MinGW compiler know how to 60 // pass "#pragma comment(linker, ...)" to the Windows linker. 61 #if (__has_attribute(weak) || defined(__GNUC__)) && !defined(__MINGW32__) && \ 62 !defined(__CYGWIN__) 63 ZoneInfoSourceFactory zone_info_source_factory __attribute__((weak)) = 64 DefaultFactory; 65 #elif defined(_MSC_VER) && !defined(__MINGW32__) && !defined(_LIBCPP_VERSION) 66 extern ZoneInfoSourceFactory zone_info_source_factory; 67 extern ZoneInfoSourceFactory default_factory; 68 ZoneInfoSourceFactory default_factory = DefaultFactory; 69 #if defined(_M_IX86) || defined(_M_ARM) 70 #pragma comment( \ 71 linker, \ 72 "/alternatename:?zone_info_source_factory@cctz_extension@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 73 "@@3P6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 74 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 75 "@@@std@@@std@@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 76 "@ABV?$function@$$A6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 77 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 78 "@@@std@@@std@@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@2@@Z@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 79 "@@ZA=?default_factory@cctz_extension@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 80 "@@3P6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 81 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 82 "@@@std@@@std@@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 83 "@ABV?$function@$$A6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 84 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 85 "@@@std@@@std@@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@2@@Z@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 86 "@@ZA") 87 #elif defined(_M_IA_64) || defined(_M_AMD64) || defined(_M_ARM64) 88 #pragma comment( \ 89 linker, \ 90 "/alternatename:?zone_info_source_factory@cctz_extension@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 91 "@@3P6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 92 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 93 "@@@std@@@std@@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 94 "@AEBV?$function@$$A6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 95 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 96 "@@@std@@@std@@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@2@@Z@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 97 "@@ZEA=?default_factory@cctz_extension@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 98 "@@3P6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 99 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 100 "@@@std@@@std@@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 101 "@AEBV?$function@$$A6A?AV?$unique_ptr@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 102 "@@U?$default_delete@VZoneInfoSource@cctz@time_internal@" ABSL_INTERNAL_MANGLED_NS \ 103 "@@@std@@@std@@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@2@@Z@" ABSL_INTERNAL_MANGLED_BACKREFERENCE \ 104 "@@ZEA") 105 #else 106 #error Unsupported MSVC platform 107 #endif // _M_<PLATFORM> 108 #else 109 // Make it a "strong" definition if we have no other choice. 110 ZoneInfoSourceFactory zone_info_source_factory = DefaultFactory; 111 #endif 112 113 } // namespace cctz_extension 114 } // namespace time_internal 115 ABSL_NAMESPACE_END 116 } // namespace absl