From 9fed693b161b2b1a799ffd22535d7e7c9fe8c3cf Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Wed, 19 Jul 2023 14:42:51 +0100 Subject: libstdc++: Fix formatting of negative chrono::hh_mm_ss When formatting with an empty chrono spec ("{}") two minus signs were being added to hh_mm_ss values. This is because the __is_neg flag was checked to add one explicitly, and then the ostream operator added another one. We should only check the __is_neg flag for durations, because those are the only types which are modified to be non-negative before calling _M_format. We don't change hh_mm_ss values to be negative, because that would require performing arithmetic on the hh_mm_ss members to sum them, and then again to construct a new hh_mm_ss object with the positive value. Instead, we can just be careful about using the __is_neg flag correctly. To fix the bug, _M_format_to_ostream no longer checks the __is_neg flag for non-durations, and _M_format doesn't set it for hh_mm_ss until after the call to _M_format_to_ostream. We can also avoid setting it for types that it doesn't apply to, by making the __print_sign lambda only inspect it for duration and hh_mm_ss types. libstdc++-v3/ChangeLog: * include/bits/chrono_io.h (__formatter_chrono::_M_format): Do not set __is_neg for hh_mm_ss before calling _M_format_to_ostream. Change __print_sign lambda to only check __is_neg for durations and hh_mm_ss types. (__formatter_chrono::_M_format_to_ostream): Only check __is_neg for duration types. * testsuite/std/time/hh_mm_ss/io.cc: Check negative values. (cherry picked from commit 344f41322023cdbf4532b5278443a22a4f391627) --- libstdc++-v3/include/bits/chrono_io.h | 27 ++++++++++++++------------ libstdc++-v3/testsuite/std/time/hh_mm_ss/io.cc | 4 ++++ 2 files changed, 19 insertions(+), 12 deletions(-) (limited to 'libstdc++-v3') diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h index 0c5f9f5058b..c95301361d8 100644 --- a/libstdc++-v3/include/bits/chrono_io.h +++ b/libstdc++-v3/include/bits/chrono_io.h @@ -486,11 +486,6 @@ namespace __format _M_format(const _Tp& __t, _FormatContext& __fc, bool __is_neg = false) const { - if constexpr (__is_specialization_of<_Tp, chrono::hh_mm_ss>) - __is_neg = __t.is_negative(); - else if constexpr (!chrono::__is_duration_v<_Tp>) - __is_neg = false; - auto __first = _M_spec._M_chrono_specs.begin(); const auto __last = _M_spec._M_chrono_specs.end(); if (__first == __last) @@ -513,12 +508,19 @@ namespace __format else __out = __sink.out(); + // formatter passes the correct value of __is_neg + // for durations but for hh_mm_ss we decide it here. + if constexpr (__is_specialization_of<_Tp, chrono::hh_mm_ss>) + __is_neg = __t.is_negative(); + auto __print_sign = [&__is_neg, &__out] { - if (__is_neg) - { - *__out++ = _S_plus_minus[1]; - __is_neg = false; - } + if constexpr (chrono::__is_duration_v<_Tp> + || __is_specialization_of<_Tp, chrono::hh_mm_ss>) + if (__is_neg) + { + *__out++ = _S_plus_minus[1]; + __is_neg = false; + } return std::move(__out); }; @@ -708,8 +710,9 @@ namespace __format __os << __t._M_date << ' ' << __t._M_time; else { - if (__is_neg) [[unlikely]] - __os << _S_plus_minus[1]; + if constexpr (chrono::__is_duration_v<_Tp>) + if (__is_neg) [[unlikely]] + __os << _S_plus_minus[1]; __os << __t; } diff --git a/libstdc++-v3/testsuite/std/time/hh_mm_ss/io.cc b/libstdc++-v3/testsuite/std/time/hh_mm_ss/io.cc index 072234328c7..ddb1ad77d1e 100644 --- a/libstdc++-v3/testsuite/std/time/hh_mm_ss/io.cc +++ b/libstdc++-v3/testsuite/std/time/hh_mm_ss/io.cc @@ -47,9 +47,13 @@ test_format() auto s = std::format("{}", hh_mm_ss{1h + 23min + 45s}); VERIFY( s == "01:23:45" ); + s = std::format("{}", hh_mm_ss{-42min}); + VERIFY( s == "-00:42:00" ); auto ws = std::format(L"{}", hh_mm_ss{1h + 23min + 45s}); VERIFY( ws == L"01:23:45" ); + ws = std::format(L"{}", hh_mm_ss{-42min}); + VERIFY( ws == L"-00:42:00" ); // Locale-specific formats: auto loc = std::locale::classic(); -- cgit v1.2.3