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-rw-r--r--absl/time/internal/cctz/src/time_zone_lookup.cc142
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diff --git a/absl/time/internal/cctz/src/time_zone_lookup.cc b/absl/time/internal/cctz/src/time_zone_lookup.cc
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+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// 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
+//
+// http://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.
+
+#include "absl/time/internal/cctz/include/cctz/time_zone.h"
+
+#if defined(__ANDROID__)
+#include <sys/system_properties.h>
+#if __ANDROID_API__ >= 21
+#include <dlfcn.h>
+#endif
+#endif
+#include <cstdlib>
+#include <cstring>
+#include <string>
+
+#include "time_zone_fixed.h"
+#include "time_zone_impl.h"
+
+namespace absl {
+namespace time_internal {
+namespace cctz {
+
+#if defined(__ANDROID__) && __ANDROID_API__ >= 21
+namespace {
+// Android 'L' removes __system_property_get() from the NDK, however
+// it is still a hidden symbol in libc so we use dlsym() to access it.
+// See Chromium's base/sys_info_android.cc for a similar example.
+
+using property_get_func = int (*)(const char*, char*);
+
+property_get_func LoadSystemPropertyGet() {
+ int flag = RTLD_LAZY | RTLD_GLOBAL;
+#if defined(RTLD_NOLOAD)
+ flag |= RTLD_NOLOAD; // libc.so should already be resident
+#endif
+ if (void* handle = dlopen("libc.so", flag)) {
+ void* sym = dlsym(handle, "__system_property_get");
+ dlclose(handle);
+ return reinterpret_cast<property_get_func>(sym);
+ }
+ return nullptr;
+}
+
+int __system_property_get(const char* name, char* value) {
+ static property_get_func system_property_get = LoadSystemPropertyGet();
+ return system_property_get ? system_property_get(name, value) : -1;
+}
+
+} // namespace
+#endif
+
+std::string time_zone::name() const {
+ return time_zone::Impl::get(*this).name();
+}
+
+time_zone::absolute_lookup time_zone::lookup(
+ const time_point<sys_seconds>& tp) const {
+ return time_zone::Impl::get(*this).BreakTime(tp);
+}
+
+time_zone::civil_lookup time_zone::lookup(const civil_second& cs) const {
+ return time_zone::Impl::get(*this).MakeTime(cs);
+}
+
+bool operator==(time_zone lhs, time_zone rhs) {
+ return &time_zone::Impl::get(lhs) == &time_zone::Impl::get(rhs);
+}
+
+bool load_time_zone(const std::string& name, time_zone* tz) {
+ return time_zone::Impl::LoadTimeZone(name, tz);
+}
+
+time_zone utc_time_zone() {
+ return time_zone::Impl::UTC(); // avoid name lookup
+}
+
+time_zone fixed_time_zone(const sys_seconds& offset) {
+ time_zone tz;
+ load_time_zone(FixedOffsetToName(offset), &tz);
+ return tz;
+}
+
+time_zone local_time_zone() {
+ const char* zone = ":localtime";
+
+ // Allow ${TZ} to override to default zone.
+ char* tz_env = nullptr;
+#if defined(_MSC_VER)
+ _dupenv_s(&tz_env, nullptr, "TZ");
+#else
+ tz_env = std::getenv("TZ");
+#endif
+#if defined(__ANDROID__)
+ char sysprop[PROP_VALUE_MAX];
+ if (tz_env == nullptr)
+ if (__system_property_get("persist.sys.timezone", sysprop) > 0)
+ tz_env = sysprop;
+#endif
+ if (tz_env) zone = tz_env;
+
+ // We only support the "[:]<zone-name>" form.
+ if (*zone == ':') ++zone;
+
+ // Map "localtime" to a system-specific name, but
+ // allow ${LOCALTIME} to override the default name.
+ char* localtime_env = nullptr;
+ if (strcmp(zone, "localtime") == 0) {
+#if defined(_MSC_VER)
+ // System-specific default is just "localtime".
+ _dupenv_s(&localtime_env, nullptr, "LOCALTIME");
+#else
+ zone = "/etc/localtime"; // System-specific default.
+ localtime_env = std::getenv("LOCALTIME");
+#endif
+ if (localtime_env) zone = localtime_env;
+ }
+
+ const std::string name = zone;
+#if defined(_MSC_VER)
+ free(localtime_env);
+ free(tz_env);
+#endif
+
+ time_zone tz;
+ load_time_zone(name, &tz); // Falls back to UTC.
+ return tz;
+}
+
+} // namespace cctz
+} // namespace time_internal
+} // namespace absl