libstdc++: Fixed localized empty-spec formatting for months/weekdays [PR121154]

Previously for localized output, if _M_debug option was set, 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. 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++/121154

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.

diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h
index fe3c9126749732f7dbae4fa2862d21a1ade12a50..809d795cbf2b9cb4410f1ca0a072df948e124986 100644 (file)
--- 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 come directly from the
+      // 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 the input, 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 99ec07373059fbb1c74b686686f23f3095421465..edfa196b71ca675a3e53f4899cda29e985e74bb6 100644 (file)
--- 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 a56cdaef88ccd9bada5937563e22b698ba6f2c93..90a9bcbbb62f813653b4ab28caf7d1fa6d62877d 100644 (file)
--- 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";