[gcc r13-8262] libstdc++: Fix std::chrono::file_clock conversions for low-precision times
Jonathan Wakely
redi@gcc.gnu.org
Tue Jan 30 14:54:53 GMT 2024
https://gcc.gnu.org/g:4cdcfb4f84c9aa668731e3ee57dc686432097951
commit r13-8262-g4cdcfb4f84c9aa668731e3ee57dc686432097951
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Sun Jan 21 18:11:16 2024 +0000
libstdc++: Fix std::chrono::file_clock conversions for low-precision times
The std::chrono::file_clock conversions were not using common_type and
so failed to compile when converting anything that should have increased
precision after arithmetic with a std::chrono::seconds value.
libstdc++-v3/ChangeLog:
* include/bits/chrono.h (__file_clock::from_sys)
(__file_clock::to_sys, __file_clock::_S_from_sys)
(__file_clock::_S_to_sys): Use common_type for return type.
* testsuite/std/time/clock/file/members.cc: Check round trip
conversion for time with lower precision that seconds.
(cherry picked from commit fba15da8fa518bfb8d3e061795bc3ca2dea01d27)
Diff:
---
libstdc++-v3/include/bits/chrono.h | 14 ++++++++------
libstdc++-v3/testsuite/std/time/clock/file/members.cc | 9 +++++++++
2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/libstdc++-v3/include/bits/chrono.h b/libstdc++-v3/include/bits/chrono.h
index 0aeea0ae57eb..04078ff8f2df 100644
--- a/libstdc++-v3/include/bits/chrono.h
+++ b/libstdc++-v3/include/bits/chrono.h
@@ -1455,14 +1455,14 @@ _GLIBCXX_END_INLINE_ABI_NAMESPACE(_V2)
#if __cplusplus > 201703L
template<typename _Dur>
static
- chrono::file_time<_Dur>
+ chrono::file_time<common_type_t<_Dur, chrono::seconds>>
from_sys(const chrono::sys_time<_Dur>& __t) noexcept
{ return _S_from_sys(__t); }
// For internal use only
template<typename _Dur>
static
- chrono::sys_time<_Dur>
+ chrono::sys_time<common_type_t<_Dur, chrono::seconds>>
to_sys(const chrono::file_time<_Dur>& __t) noexcept
{ return _S_to_sys(__t); }
#endif // C++20
@@ -1479,20 +1479,22 @@ _GLIBCXX_END_INLINE_ABI_NAMESPACE(_V2)
// For internal use only
template<typename _Dur>
static
- chrono::time_point<__file_clock, _Dur>
+ chrono::time_point<__file_clock, common_type_t<_Dur, chrono::seconds>>
_S_from_sys(const chrono::time_point<__sys_clock, _Dur>& __t) noexcept
{
- using __file_time = chrono::time_point<__file_clock, _Dur>;
+ using _CDur = common_type_t<_Dur, chrono::seconds>;
+ using __file_time = chrono::time_point<__file_clock, _CDur>;
return __file_time{__t.time_since_epoch()} - _S_epoch_diff;
}
// For internal use only
template<typename _Dur>
static
- chrono::time_point<__sys_clock, _Dur>
+ chrono::time_point<__sys_clock, common_type_t<_Dur, chrono::seconds>>
_S_to_sys(const chrono::time_point<__file_clock, _Dur>& __t) noexcept
{
- using __sys_time = chrono::time_point<__sys_clock, _Dur>;
+ using _CDur = common_type_t<_Dur, chrono::seconds>;
+ using __sys_time = chrono::time_point<__sys_clock, _CDur>;
return __sys_time{__t.time_since_epoch()} + _S_epoch_diff;
}
};
diff --git a/libstdc++-v3/testsuite/std/time/clock/file/members.cc b/libstdc++-v3/testsuite/std/time/clock/file/members.cc
index b34df49c6500..2047b029e9bd 100644
--- a/libstdc++-v3/testsuite/std/time/clock/file/members.cc
+++ b/libstdc++-v3/testsuite/std/time/clock/file/members.cc
@@ -42,9 +42,18 @@ test02()
VERIFY( t - s < 1s );
}
+void
+test03()
+{
+ using namespace std::chrono;
+ auto st = sys_days(2024y/January/21);
+ VERIFY( file_clock::to_sys(file_clock::from_sys(st)) == st );
+}
+
int
main()
{
test01();
test02();
+ test03();
}
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