public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r12-3019] libstdc++: Improve overflow check for file timestamps
@ 2021-08-19 12:02 Jonathan Wakely
0 siblings, 0 replies; only message in thread
From: Jonathan Wakely @ 2021-08-19 12:02 UTC (permalink / raw)
To: gcc-cvs, libstdc++-cvs
https://gcc.gnu.org/g:65441d8fc3c132a58c8bef6faefa2bc25e82a913
commit r12-3019-g65441d8fc3c132a58c8bef6faefa2bc25e82a913
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Aug 19 11:03:01 2021 +0100
libstdc++: Improve overflow check for file timestamps
The current code assumes that system_clock::duration is nanoseconds, and
also performs a value-changing conversion from nanoseconds::max() to
double (which doesn't matter after dividing by 1e9, but triggers a
warning with Clang nonetheless).
A better solution is to use system_clock::duration::max() and perform
the comparison entirely using the std::chrono types, rather than with
dimensionless arithmetic types.
This doesn't address the FIXME in the function, so the overflow check
still rejects some values that could be represented by the file_clock.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* src/filesystem/ops-common.h (filesystem::file_time): Improve
overflow check by using system_clock::duration::max().
Diff:
---
libstdc++-v3/src/filesystem/ops-common.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index 304e5b263fb..bf26c06b7b5 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -229,7 +229,7 @@ namespace __gnu_posix
// (This only applies to the C++17 Filesystem library, because for the
// Filesystem TS we don't have a distinct __file_clock, we just use the
// system clock for file timestamps).
- if (s >= (nanoseconds::max().count() / 1e9))
+ if (seconds{s} >= floor<seconds>(system_clock::duration::max()))
{
ec = std::make_error_code(std::errc::value_too_large); // EOVERFLOW
return system_clock::time_point::min();
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2021-08-19 12:02 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-19 12:02 [gcc r12-3019] libstdc++: Improve overflow check for file timestamps Jonathan Wakely
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).