[PATCH v3] libstdc++: Fixed localized empty-spec formatting for months/weekdays [PR121154]
Tomasz Kamiński
tkaminsk@redhat.com
Fri Jul 18 12:01:00 GMT 2025
Previously for localized output, if _M_debug option was send, the _M_check_ok
completed succesfully and _M_locale_fmt was called for months/weekdays that
are !ok().
This patch lifts debug checks from each conversion function into _M_check_ok,
that in case of !ok() values return a string_view containing the kind of
calendar data, to be included after "is not a valid" string. The localized
output (_M_locale_fmt) is not used if string is non-empty.
The emitting of this message is now handled in _M_format_to, further reducing
each specifier function.
To handle weekday (%a,%A) and month (%b,%B), _M_check_ok now accepts a
mutable reference to conversion specifier, and updates it to corresponding
numeric value (%w, %m). Extra care needs to be taken to handle a month(0)
that needs to be printed as single digit in debug format.
Finally, the _M_time_point is replaced with _M_needs_ok_check member, that
indicates if input contains any user-suplied values that are checked for
being ok() and these values are referenced in chrono-specs.
PR libstdc++/PR121154
libstdc++-v3/ChangeLog:
* include/bits/chrono_io.h _ChronoSpec::_M_time_point: Remove.
(_ChronoSpec::_M_needs_ok_check): Define
(__formatter_chrono::_M_parse): Set _M_needs_ok_check.
(__formatter_chrono::_M_check_ok): Check values also for debug mode,
and return __string_view.
(__formatter_chrono::_M_format_to): Handle results of _M_check_ok.
(__formatter_chrono::_M_wi, __formatter_chrono::_M_a_A)
(__formatter_chrono::_M_b_B, __formatter_chrono::_M_C_y_Y)
(__formatter_chrono::_M_d_e, __formatter_chrono::_M_F):
Removed handling of _M_debug.
(__formatter_chrono::__M_m): Print zero unpadded in _M_debug mode.
(__formatter_duration::_S_spec_for): Remove _M_time_point refernce.
(__formatter_duration::_M_parse): Override _M_needs_ok_check.
* testsuite/std/time/month/io.cc: Test for localized !ok() values.
* testsuite/std/time/weekday/io.cc: Test for localized !ok() values.
---
v3 just fixes some typos in comments and commit message.
libstdc++-v3/include/bits/chrono_io.h | 139 +++++++++++-------
libstdc++-v3/testsuite/std/time/month/io.cc | 7 +
libstdc++-v3/testsuite/std/time/weekday/io.cc | 2 +
3 files changed, 96 insertions(+), 52 deletions(-)
diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h
index fe3c9126749..95e0d489cf4 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -280,8 +280,9 @@ namespace __format
// in the format-spec, e.g. "{:L%a}" is localized and locale-specific,
// but "{:L}" is only localized and "{:%a}" is only locale-specific.
unsigned _M_locale_specific : 1;
- // Indicates that we are handling time_point.
- unsigned _M_time_point : 1;
+ // Indicates if parts that are checked for ok are comming directly from input,
+ // instead of being computed.
+ unsigned _M_needs_ok_check : 1;
// Indicates that duration should be treated as floating point.
unsigned _M_floating_point_rep : 1;
// Indicate that duration uses user-defined representation.
@@ -570,7 +571,15 @@ namespace __format
_ChronoSpec<_CharT> __spec = __def;
- auto __finalize = [this, &__spec] {
+ auto __finalize = [this, &__spec, &__def] {
+ using enum _ChronoParts;
+ _ChronoParts __checked
+ = __spec._M_debug ? _YearMonthDay|_IndexedWeekday
+ : _Month|_Weekday;
+ // n.b. for calendar types __def._M_needed contains only parts
+ // copied from source, remaining ones are computed, and thus ok
+ __spec._M_needs_ok_check
+ = __spec._M_needs(__def._M_needed & __checked);
_M_spec = __spec;
};
@@ -821,10 +830,10 @@ namespace __format
__throw_format_error("chrono format error: unescaped '%' in "
"chrono-specs");
- _M_spec = __spec;
- _M_spec._M_chrono_specs
- = __string_view(__chrono_specs, __first - __chrono_specs);
+ __spec._M_chrono_specs
+ = __string_view(__chrono_specs, __first - __chrono_specs);
+ __finalize();
return __first;
}
@@ -972,30 +981,71 @@ namespace __format
return __out;
}
- void
- _M_check_ok(const _ChronoData<_CharT>& __t, _CharT __conv) const
+ __string_view
+ _M_check_ok(const _ChronoData<_CharT>& __t, _CharT& __conv) const
{
- // n.b. for time point all date parts are computed, so
- // they are always ok.
- if (_M_spec._M_time_point || _M_spec._M_debug)
- return;
+ if (!_M_spec._M_debug)
+ {
+ switch (__conv)
+ {
+ case 'a':
+ case 'A':
+ if (!__t._M_weekday.ok()) [[unlikely]]
+ __throw_format_error("format error: invalid weekday");
+ break;
+ case 'b':
+ case 'h':
+ case 'B':
+ if (!__t._M_month.ok()) [[unlikely]]
+ __throw_format_error("format error: invalid month");
+ break;
+ default:
+ break;
+ }
+ return __string_view();
+ }
switch (__conv)
{
+ // %\0 is extension for handling weekday index
+ case '\0':
+ if (__t._M_weekday_index < 1 || __t._M_weekday_index > 5) [[unlikely]]
+ return _GLIBCXX_WIDEN("index");
+ break;
case 'a':
case 'A':
if (!__t._M_weekday.ok()) [[unlikely]]
- __throw_format_error("format error: invalid weekday");
- return;
+ {
+ __conv = 'w'; // print as decimal number
+ return _GLIBCXX_WIDEN("weekday");
+ }
+ break;
case 'b':
case 'h':
case 'B':
if (!__t._M_month.ok()) [[unlikely]]
- __throw_format_error("format error: invalid month");
- return;
+ {
+ __conv = 'm'; // print as decimal number
+ return _GLIBCXX_WIDEN("month");
+ }
+ break;
+ case 'd':
+ case 'e':
+ if (!__t._M_day.ok()) [[unlikely]]
+ return _GLIBCXX_WIDEN("day");
+ break;
+ case 'F':
+ if (!(__t._M_year/__t._M_month/__t._M_day).ok()) [[unlikely]]
+ return _GLIBCXX_WIDEN("date");
+ break;
+ case 'Y':
+ if (!__t._M_year.ok()) [[unlikely]]
+ return _GLIBCXX_WIDEN("year");
+ break;
default:
- return;
+ break;
}
+ return __string_view();
}
template<typename _OutIter, typename _FormatContext>
@@ -1054,9 +1104,12 @@ namespace __format
do
{
_CharT __c = *__first++;
- _M_check_ok(__t, __c);
+ __string_view __invalid;
+ if (_M_spec._M_needs_ok_check)
+ __invalid = _M_check_ok(__t, __c);
- if (__use_locale_fmt && _S_localized_spec(__c, __mod)) [[unlikely]]
+ if (__invalid.empty() &&__use_locale_fmt
+ && _S_localized_spec(__c, __mod)) [[unlikely]]
__out = _M_locale_fmt(std::move(__out), __fc.locale(),
__tm, __c, __mod);
else switch (__c)
@@ -1164,6 +1217,14 @@ namespace __format
__first = __last;
break;
}
+
+ if (!__invalid.empty())
+ {
+ constexpr __string_view __pref = _GLIBCXX_WIDEN(" is not a valid ");
+ __out = __format::__write(std::move(__out), __pref);
+ __out = __format::__write(std::move(__out), __invalid);
+ }
+
__mod = _CharT();
// Scan for next '%' and write out everything before it.
__string_view __str(__first, __last - __first);
@@ -1193,9 +1254,6 @@ namespace __format
// %\0 Extension to format weekday index, used only by empty format spec
_CharT __buf[3];
__out = __format::__write(std::move(__out), _S_str_d1(__buf, __wi));
- if (_M_spec._M_debug && (__wi < 1 || __wi > 5))
- __out = __format::__write(std::move(__out),
- __string_view(_GLIBCXX_WIDEN(" is not a valid index")));
return std::move(__out);
}
@@ -1205,15 +1263,6 @@ namespace __format
{
// %a Locale's abbreviated weekday name.
// %A Locale's full weekday name.
- if (_M_spec._M_debug && !__wd.ok())
- {
- _CharT __buf[3];
- __out = __format::__write(std::move(__out),
- _S_str_d1(__buf, __wd.c_encoding()));
- return __format::__write(std::move(__out),
- __string_view(_GLIBCXX_WIDEN(" is not a valid weekday")));
- }
-
__string_view __str = _S_weekdays[__wd.c_encoding()];
if (!__full)
__str = __str.substr(0, 3);
@@ -1226,15 +1275,6 @@ namespace __format
{
// %b Locale's abbreviated month name.
// %B Locale's full month name.
- if (_M_spec._M_debug && !__m.ok())
- {
- _CharT __buf[3];
- __out = __format::__write(std::move(__out),
- _S_str_d1(__buf, (unsigned)__m));
- return __format::__write(std::move(__out),
- __string_view(_GLIBCXX_WIDEN(" is not a valid month")));
- }
-
__string_view __str = _S_months[(unsigned)__m - 1];
if (!__full)
__str = __str.substr(0, 3);
@@ -1303,10 +1343,6 @@ namespace __format
}
__out = __format::__write(std::move(__out), __sv);
}
-
- if (_M_spec._M_debug && __conv == 'Y' && !__y.ok()) [[unlikely]]
- __out = __format::__write(std::move(__out),
- __string_view(_GLIBCXX_WIDEN(" is not a valid year")));
return __out;
}
@@ -1365,9 +1401,6 @@ namespace __format
}
__out = __format::__write(std::move(__out), __sv);
- if (_M_spec._M_debug && !__d.ok()) [[unlikely]]
- __out = __format::__write(std::move(__out),
- __string_view(_GLIBCXX_WIDEN(" is not a valid day")));
return std::move(__out);
}
@@ -1404,9 +1437,6 @@ namespace __format
__out = __format::__write(std::move(__out), __sv);
}
- if (_M_spec._M_debug && !(__t._M_year/__t._M_month/__t._M_day).ok())
- __out = __format::__write(std::move(__out),
- __string_view(_GLIBCXX_WIDEN(" is not a valid date")));
return std::move(__out);
}
@@ -1474,8 +1504,10 @@ namespace __format
{
// %m month as a decimal number.
// %Om Locale's alternative representation.
-
auto __i = (unsigned)__m;
+ if (__i == 0 && _M_spec._M_debug) [[unlikely]]
+ // 0 should not be padded to two digits
+ return __format::__write(std::move(__out), _S_digit(0));
_CharT __buf[3];
return __format::__write(std::move(__out), _S_str_d2(__buf, __i));
@@ -1852,7 +1884,6 @@ namespace __format
using enum _ChronoParts;
_ChronoSpec<_CharT> __res{};
- __res._M_time_point = (__parts & _DateTime) == _DateTime;
__res._M_floating_point_rep = chrono::treat_as_floating_point_v<_Rep>;
__res._M_custom_rep = !is_arithmetic_v<_Rep>;
__res._M_prec = chrono::hh_mm_ss<_Duration>::fractional_width;
@@ -1901,6 +1932,10 @@ namespace __format
auto __res
= __formatter_chrono<_CharT>::_M_parse(__pc, __parts, __def);
+ // n.b. durations do not contain date parts, and for time point all
+ // date parts are computed, and they are always ok.
+ _M_spec._M_needs_ok_check = false;
+
// check for custom floating point durations, if digits of output
// will contain subseconds, then formatters must support specifying
// precision.
diff --git a/libstdc++-v3/testsuite/std/time/month/io.cc b/libstdc++-v3/testsuite/std/time/month/io.cc
index 99ec0737305..edfa196b71c 100644
--- a/libstdc++-v3/testsuite/std/time/month/io.cc
+++ b/libstdc++-v3/testsuite/std/time/month/io.cc
@@ -24,6 +24,9 @@ test_ostream()
ss.imbue(std::locale(ISO_8859(15,fr_FR)));
ss << month(1);
VERIFY( ss.str() == "janv." );
+ ss.str("");
+ ss << month(0) << '|' << month(13);
+ VERIFY( ss.str() == "0 is not a valid month|13 is not a valid month" );
}
void
@@ -66,6 +69,10 @@ test_format()
VERIFY( s == "Jan" );
s = std::format(loc_fr, "{:L%b}", month(1));
VERIFY( s == "janv." );
+ s = std::format(loc_fr, "{:L}", month(0));
+ VERIFY( s == "0 is not a valid month" );
+ s = std::format(loc_fr, "{:L}", month(13));
+ VERIFY( s == "13 is not a valid month" );
std::string_view specs = "aAbBcCdDeFgGhHIjmMpqQrRSTuUVwWxXyYzZ";
std::string_view my_specs = "bBhm";
diff --git a/libstdc++-v3/testsuite/std/time/weekday/io.cc b/libstdc++-v3/testsuite/std/time/weekday/io.cc
index a56cdaef88c..90a9bcbbb62 100644
--- a/libstdc++-v3/testsuite/std/time/weekday/io.cc
+++ b/libstdc++-v3/testsuite/std/time/weekday/io.cc
@@ -69,6 +69,8 @@ test_format()
VERIFY( s == "Mon" );
s = std::format(loc_fr, "{:L%a}", weekday(1));
VERIFY( s == "lun." );
+ s = std::format(loc_fr, "{:L}", weekday(25));
+ VERIFY( s == "25 is not a valid weekday" );
std::string_view specs = "aAbBcCdDeFgGhHIjmMpqQrRSTuUVwWxXyYzZ";
std::string_view my_specs = "aAuw";
--
2.49.0
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