Skip to content

<chrono> formatting: fix UB, various cleanups #1848

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Stephan T. Lavavej (StephanTLavavej) merged 2 commits into from
Apr 17, 2021
Merged

<chrono> formatting: fix UB, various cleanups #1848

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
a7e771c
Fix UB, various cleanups.
StephanTLavavej Apr 16, 2021
7380489
Optimize with common_type_t<_Duration, days>.
StephanTLavavej Apr 17, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
85 changes: 44 additions & 41 deletions stl/inc/chrono
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5225,8 +5225,8 @@ concept _Chrono_parse_spec_callbacks = _Parse_align_callbacks<_Ty, _CharT>

// clang-format off
template <class _Ty>
concept _Has_ok = requires (_Ty _At) {
{_At.ok()} -> same_as<bool>;
concept _Has_ok = requires(_Ty _At) {
{ _At.ok() } -> same_as<bool>;
};
// clang-format on

Expand Down Expand Up @@ -5473,7 +5473,7 @@ namespace chrono {
_Month = static_cast<unsigned int>(_Val.month());
} else if constexpr (is_same_v<_Ty, month_day_last>) {
_Month = static_cast<unsigned int>(_Val.month());
_Day = static_cast<unsigned int>(_Last_day_table[_Month - 1]);
_Day = static_cast<unsigned int>(_Last_day_table[(_Month - 1) & 0xF]);
} else if constexpr (is_same_v<_Ty, year_month>) {
_Month = static_cast<unsigned int>(_Val.month());
_Year = static_cast<int>(_Val.year());
Expand Down Expand Up @@ -5621,7 +5621,7 @@ namespace chrono {

template <class _CharT, class _Traits, class _Duration>
// clang-format off
requires (!treat_as_floating_point_v<typename _Duration::rep> && (_Duration{1} < days{1}))
requires (!treat_as_floating_point_v<typename _Duration::rep> && _Duration{1} < days{1})
basic_ostream<_CharT, _Traits>& operator<<(basic_ostream<_CharT, _Traits>& _Os, const sys_time<_Duration>& _Val) {
// clang-format on
const auto _Dp = _CHRONO floor<days>(_Val);
Expand Down Expand Up @@ -5660,8 +5660,13 @@ namespace chrono {
}
} // namespace chrono

template <class _CharT, bool _Allow_precision>
template <class _CharT>
struct _Chrono_formatter {
_Chrono_formatter() = default;

explicit _Chrono_formatter(const basic_string_view<_CharT> _Time_zone_abbreviation_)
: _Time_zone_abbreviation{_Time_zone_abbreviation_} {}

template <class _Ty>
_NODISCARD auto _Parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
_Chrono_specs_setter<_CharT, basic_format_parse_context<_CharT>> _Callback{_Specs, _Parse_ctx};
Expand All @@ -5673,8 +5678,18 @@ struct _Chrono_formatter {
_THROW(format_error("Missing '}' in format string."));
}

if (!_Allow_precision && _Specs._Precision != -1) {
_THROW(format_error("Precision specification invalid for type."));
if constexpr (_Is_specialization_v<_Ty, _CHRONO duration>) {
if constexpr (!_CHRONO treat_as_floating_point_v<typename _Ty::rep>) {
if (_Specs._Precision != -1) {
_THROW(format_error("Precision specification invalid for chrono::duration type with "
"integral representation type, see N4885 [time.format]/1."));
}
}
} else {
if (_Specs._Precision != -1) {
_THROW(format_error("Precision specification invalid for non-chrono::duration type, "
"see N4885 [time.format]/1."));
}
}

const auto& _List = _Specs._Chrono_specs_list;
Expand Down Expand Up @@ -5843,9 +5858,11 @@ struct _Chrono_formatter {
_THROW(format_error("Cannot print the last day of February without a year"));
}
}

if (_Has_modifier) {
return false;
}

if (_Time.tm_mday < 10) {
_Os << (_Specs._Type == 'd' ? _CharT{'0'} : _CharT{' '});
}
Expand All @@ -5855,6 +5872,7 @@ struct _Chrono_formatter {
if (_Has_modifier) {
return false;
}

if (_Month < 10) {
_Os << _CharT{'0'};
}
Expand All @@ -5864,6 +5882,7 @@ struct _Chrono_formatter {
if (_Has_modifier) {
return false;
}

if (_Year < 0) {
_Os << _CharT{'-'};
}
Expand All @@ -5879,6 +5898,7 @@ struct _Chrono_formatter {
if (_Has_modifier) {
return false;
}

if (_Year < 0) {
_Os << _CharT{'-'};
}
Expand All @@ -5901,8 +5921,8 @@ struct _Chrono_formatter {
return true;
case 'H':
if constexpr (_Is_specialization_v<_Ty, _CHRONO hh_mm_ss>) {
if (-_CHRONO hours{24} >= _Val.hours() || _Val.hours() >= _CHRONO hours{24}) {
_THROW(format_error("Cannot localize hh_mm_ss longer than 24 hours."));
if (_Val.hours() <= -_CHRONO hours{24} || _CHRONO hours{24} <= _Val.hours()) {
Comment thread
StephanTLavavej marked this conversation as resolved.
_THROW(format_error("Cannot localize hh_mm_ss with an absolute value of 24 hours or more."));
}
}
return false;
Expand Down Expand Up @@ -5934,7 +5954,7 @@ struct _Chrono_formatter {

_Chrono_format_specs<_CharT> _Specs{};
bool _No_chrono_specs = false;
basic_string_view<_CharT> _Time_zone_abbreviation;
basic_string_view<_CharT> _Time_zone_abbreviation{};
};

template <class _Ty, class _CharT>
Expand All @@ -5949,7 +5969,7 @@ struct _Fill_tm_formatter {
}

private:
_Chrono_formatter<_CharT, false> _Impl;
_Chrono_formatter<_CharT> _Impl;
};

template <class _CharT>
Expand Down Expand Up @@ -6006,10 +6026,6 @@ struct formatter<_CHRONO hh_mm_ss<_CHRONO duration<_Rep, _Period>>, _CharT>

template <class _Duration, class _CharT>
struct formatter<_CHRONO sys_time<_Duration>, _CharT> {
formatter() {
_Impl._Time_zone_abbreviation = _STATICALLY_WIDEN(_CharT, "UTC");
}

auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
return _Impl.template _Parse<_CHRONO sys_time<_Duration>>(_Parse_ctx);
}
Expand All @@ -6020,15 +6036,11 @@ struct formatter<_CHRONO sys_time<_Duration>, _CharT> {
}

private:
_Chrono_formatter<_CharT, false> _Impl;
_Chrono_formatter<_CharT> _Impl{_STATICALLY_WIDEN(_CharT, "UTC")};
};

template <class _Duration, class _CharT>
struct formatter<_CHRONO utc_time<_Duration>, _CharT> {
formatter() {
_Impl._Time_zone_abbreviation = _STATICALLY_WIDEN(_CharT, "UTC");
}

auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
return _Impl.template _Parse<_CHRONO utc_time<_Duration>>(_Parse_ctx);
}
Expand All @@ -6040,58 +6052,49 @@ struct formatter<_CHRONO utc_time<_Duration>, _CharT> {
}
Comment thread
StephanTLavavej marked this conversation as resolved.

private:
_Chrono_formatter<_CharT, false> _Impl;
_Chrono_formatter<_CharT> _Impl{_STATICALLY_WIDEN(_CharT, "UTC")};
};

template <class _Duration, class _CharT>
struct formatter<_CHRONO tai_time<_Duration>, _CharT> {
formatter() {
_Impl._Time_zone_abbreviation = _STATICALLY_WIDEN(_CharT, "TAI");
}

auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
return _Impl.template _Parse<_CHRONO tai_time<_Duration>>(_Parse_ctx);
}

template <class _FormatContext>
auto format(const _CHRONO tai_time<_Duration>& _Val, _FormatContext& _FormatCtx) {
const auto _Sys = _CHRONO sys_time<_Duration>{_Val.time_since_epoch()}
- (_CHRONO sys_days{_CHRONO year{1970} / 1 / 1} - _CHRONO sys_days{_CHRONO year{1958} / 1 / 1});
using namespace chrono;
using _Common = common_type_t<_Duration, days>; // slightly optimize by performing conversion at compile time
constexpr _Common _Offset{sys_days{year{1970} / January / 1} - sys_days{year{1958} / January / 1}};
const auto _Sys = sys_time<_Duration>{_Val.time_since_epoch()} - _Offset;
return _Impl._Write(_FormatCtx, _Val, _Fill_tm(_Sys));
}

private:
_Chrono_formatter<_CharT, false> _Impl;
_Chrono_formatter<_CharT> _Impl{_STATICALLY_WIDEN(_CharT, "TAI")};
};

template <class _Duration, class _CharT>
struct formatter<_CHRONO gps_time<_Duration>, _CharT> {
formatter() {
_Impl._Time_zone_abbreviation = _STATICALLY_WIDEN(_CharT, "GPS");
}

auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
return _Impl.template _Parse<_CHRONO gps_time<_Duration>>(_Parse_ctx);
}

template <class _FormatContext>
auto format(const _CHRONO gps_time<_Duration>& _Val, _FormatContext& _FormatCtx) {
const auto _Sys = _CHRONO sys_time<_Duration>{_Val.time_since_epoch()}
+ (_CHRONO sys_days{_CHRONO year{1980} / 1 / _CHRONO Sunday[1]}
- _CHRONO sys_days{_CHRONO year{1970} / 1 / 1});
using namespace chrono;
using _Common = common_type_t<_Duration, days>; // slightly optimize by performing conversion at compile time
constexpr _Common _Offset{sys_days{year{1980} / January / Sunday[1]} - sys_days{year{1970} / January / 1}};
const auto _Sys = sys_time<_Duration>{_Val.time_since_epoch()} + _Offset;
return _Impl._Write(_FormatCtx, _Val, _Fill_tm(_Sys));
}

private:
_Chrono_formatter<_CharT, false> _Impl;
_Chrono_formatter<_CharT> _Impl{_STATICALLY_WIDEN(_CharT, "GPS")};
};

template <class _Duration, class _CharT>
struct formatter<_CHRONO file_time<_Duration>, _CharT> {
formatter() {
_Impl._Time_zone_abbreviation = _STATICALLY_WIDEN(_CharT, "UTC");
}

auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
return _Impl.template _Parse<_CHRONO file_time<_Duration>>(_Parse_ctx);
}
Expand All @@ -6103,7 +6106,7 @@ struct formatter<_CHRONO file_time<_Duration>, _CharT> {
}
Comment thread
StephanTLavavej marked this conversation as resolved.

private:
_Chrono_formatter<_CharT, false> _Impl;
_Chrono_formatter<_CharT> _Impl{_STATICALLY_WIDEN(_CharT, "UTC")};
};

template <class _Duration, class _CharT>
Expand Down