[committed] libstdc++: Implement std::chrono::current_zone() for AIX [PR108409]
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Commit Message
Tested x86_64-linux and powerpc-aix. Pushed to trunk.
-- >8 --
libstdc++-v3/ChangeLog:
PR libstdc++/108409
* src/c++20/tzdb.cc (current_zone()) [_AIX]: Use TZ environment
variable.
---
libstdc++-v3/src/c++20/tzdb.cc | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
@@ -34,6 +34,10 @@
#include <mutex> // mutex
#include <filesystem> // filesystem::read_symlink
+#ifndef _AIX
+# include <cstdlib> // getenv
+#endif
+
#ifndef __GTHREADS
# define USE_ATOMIC_SHARED_PTR 0
#elif _WIN32
@@ -1625,6 +1629,7 @@ namespace std::chrono
{
// TODO cache this function's result?
+#ifndef _AIX
error_code ec;
// This should be a symlink to e.g. /usr/share/zoneinfo/Europe/London
auto path = filesystem::read_symlink("/etc/localtime", ec);
@@ -1655,11 +1660,25 @@ namespace std::chrono
if (auto tz = do_locate_zone(this->zones, this->links, name))
return tz;
}
-
- // TODO AIX stores current zone in $TZ in /etc/environment but the value
+#else
+ // AIX stores current zone in $TZ in /etc/environment but the value
// is typically a POSIX time zone name, not IANA zone.
// https://developer.ibm.com/articles/au-aix-posix/
// https://www.ibm.com/support/pages/managing-time-zone-variable-posix
+ if (const char* env = std::getenv("TZ"))
+ {
+ string_view s(env);
+ if (s == "GMT0")
+ s = "Etc/GMT";
+ else if (s.size() == 4 && s[3] == '0')
+ s = "Etc/UTC";
+
+ // This will fail unless TZ contains an IANA time zone name,
+ // or one of the special cases above.
+ if (auto tz = do_locate_zone(this->zones, this->links, s))
+ return tz;
+ }
+#endif
__throw_runtime_error("tzdb: cannot determine current zone");
}