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// Copyright (C) 2016-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
// { dg-options "-std=gnu++17" }
// { dg-do run { target c++17 } }
// { dg-require-filesystem-ts "" }
// 15.25 Permissions [fs.op.last_write_time]
#include <filesystem>
#include <limits>
#include <testsuite_fs.h>
#include <testsuite_hooks.h>
#ifdef _GLIBCXX_HAVE_FCNTL_H
# include <fcntl.h>
#endif
#if _GLIBCXX_HAVE_UTIME_H
# include <utime.h>
#endif
#include <stdio.h>
using time_type = std::filesystem::file_time_type;
namespace chrono = std::chrono;
void
test01()
{
// read times
auto p = __gnu_test::nonexistent_path();
std::error_code ec;
time_type mtime = last_write_time(p, ec);
VERIFY( ec );
VERIFY( ec == std::make_error_code(std::errc::no_such_file_or_directory) );
#if __cpp_exceptions
bool caught = false;
try {
mtime = last_write_time(p);
} catch (std::system_error const& e) {
caught = true;
ec = e.code();
}
VERIFY( caught );
VERIFY( ec );
VERIFY( ec == std::make_error_code(std::errc::no_such_file_or_directory) );
#endif
__gnu_test::scoped_file file(p);
VERIFY( exists(p) );
mtime = last_write_time(p, ec);
VERIFY( !ec );
VERIFY( mtime <= time_type::clock::now() );
VERIFY( mtime == last_write_time(p) );
auto end_of_time = time_type::duration::max();
auto last_second
= chrono::duration_cast<chrono::seconds>(end_of_time).count();
if (last_second > std::numeric_limits<std::time_t>::max())
{
puts("Range of time_t is smaller than range of chrono::file_clock, "
"can't test for overflow on this target.");
return;
}
// Set mtime to a date past the maximum possible file_time_type:
#if _GLIBCXX_USE_UTIMENSAT
struct ::timespec ts[2];
ts[0].tv_sec = 0;
ts[0].tv_nsec = UTIME_NOW;
ts[1].tv_sec = std::numeric_limits<std::time_t>::max() - 1;
ts[1].tv_nsec = 0;
VERIFY( !::utimensat(AT_FDCWD, p.c_str(), ts, 0) );
#elif _GLIBCXX_HAVE_UTIME_H
::utimbuf times;
times.modtime = std::numeric_limits<std::time_t>::max() - 1;
times.actime = std::numeric_limits<std::time_t>::max() - 1;
VERIFY( !::utime(p.string().c_str(), ×) );
#else
puts("No utimensat or utime, giving up.");
return;
#endif
// Try to read back the impossibly-large mtime:
mtime = last_write_time(p, ec);
// Some filesystems (e.g. XFS) silently truncate distant times to
// the time_t epochalypse, Jan 19 2038, so we won't get an error when
// reading it back:
if (ec)
{
VERIFY( ec == std::make_error_code(std::errc::value_too_large) );
VERIFY( mtime == time_type::min() );
}
else
puts("No overflow error, filesystem may not support 64-bit time_t.");
#if __cpp_exceptions
// Once more, with exceptions:
try {
auto mtime2 = last_write_time(p);
// If it didn't throw, expect to have read back the same value:
VERIFY( mtime2 == mtime );
} catch (std::filesystem::filesystem_error const& e) {
// If it did throw, expect the error_code to be the same:
VERIFY( e.code() == ec );
VERIFY( e.path1() == p );
}
#endif
}
bool approx_equal(time_type file_time, time_type expected)
{
auto delta = expected - file_time;
if (delta < delta.zero())
delta = -delta;
return delta < chrono::seconds(1);
}
void
test02()
{
// write times
const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
__gnu_test::scoped_file f;
std::error_code ec;
time_type time;
ec = bad_ec;
time = last_write_time(f.path);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
ec = bad_ec;
time -= chrono::milliseconds(1000 * 60 * 10 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
ec = bad_ec;
time += chrono::milliseconds(1000 * 60 * 20 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
if (std::numeric_limits<std::time_t>::max()
< std::numeric_limits<std::int64_t>::max())
return; // file clock's epoch is out of range for 32-bit time_t
using sys_time_32b
= chrono::time_point<chrono::system_clock, chrono::duration<std::int32_t>>;
auto duration_until_2038 = sys_time_32b::max() - sys_time_32b::clock::now();
auto file_time_2038 = time_type::clock::now() + duration_until_2038;
ec = bad_ec;
time = file_time_2038 - chrono::seconds(1);
// Assume all filesystems can store times that fit in 32-bit time_t
// (i.e. up to Jan 19 2038)
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
// Check whether the filesystem supports times larger than 32-bit time_t:
time += chrono::seconds(60);
last_write_time(f.path, time, ec);
if (ec || !approx_equal(last_write_time(f.path), time))
{
puts("Filesystem seems to truncate times past Jan 19 2038, giving up.");
return; // Tests below will fail on this filesystem
}
ec = bad_ec;
// The file clock's epoch:
time = time_type();
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
ec = bad_ec;
// A time after the epoch
time += chrono::milliseconds(1000 * 60 * 10 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
ec = bad_ec;
// A time before than the epoch
time -= chrono::milliseconds(1000 * 60 * 20 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
}
int
main()
{
test01();
test02();
}
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