a8d3c98746
glibc strptime passes around some state, what fields in struct tm have been set and what needs to be finalized through possibly recursive calls, and at the end performs various finalizations, like applying %p so that it works for both %I %p and %p %I orders, or applying century so that both %C %y and %y %C works, or computation of missing fields from others (e.g. from %Y and %j one can compute tm_mon, tm_mday and tm_wday, from %Y %U %w, %Y %W %w, %Y %U %a, or %Y %W %w one can compute tm_mon, tm_mday, tm_yday or e.g. from %Y %m %d one can compute tm_wday and tm_yday. As the finalization is quite large and doesn't need to be a template (doesn't depend on any iterators or char types), I've put it into libstdc++, and left some padding in the state struct, so that perhaps in the future we can track some more state without changing ABI. Unfortunately, there is an ugly problem that the standard mandates that get method calls the do_get virtual method and I don't see how we can cary on any state in between those calls (even if we did an ABI change for the facets, the methods are const, so that I think multiple threads could use the same time_get objects and we couldn't store state in there). There is a hack for that for GCC (seems to work with ICC too, doesn't work with clang++) if the do_get method isn't overriden we can pass the state around. For both do_get_year and per IRC discussions also for %y, the behavior is if 1-2 digits are parsed, the year is treated according to POSIX 2008 %y rules (0-68 is 2000-2068, 69-99 is 1969-1999), if 3-4 digits are parsed, it is treated as %Y. 2022-01-10 Jakub Jelinek <jakub@redhat.com> PR libstdc++/77760 * include/bits/locale_facets_nonio.h (__time_get_state): New struct. (time_get::_M_extract_via_format): Declare new method with __time_get_state& as an extra argument. * include/bits/locale_facets_nonio.tcc (_M_extract_via_format): Add __state argument, set various fields in it while parsing. Handle %j, %U, %w and %W, fix up handling of %y, %Y and %C, don't adjust tm_hour for %p immediately. Add a wrapper around the method without the __state argument for backwards compatibility. (_M_extract_num): Remove all __len == 4 special cases. (time_get::do_get_time, time_get::do_get_date, time_get::do_get): Zero initialize __state, pass it to _M_extract_via_format and finalize it at the end. (do_get_year): For 1-2 digit parsed years, map 0-68 to 2000-2068, 69-99 to 1969-1999. For 3-4 digit parsed years use that as year. (get): If do_get isn't overloaded from the locale_facets_nonio.tcc version, don't call do_get but call _M_extract_via_format instead to pass around state. * config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Export _M_extract_via_format with extra __time_get_state and __time_get_state::_M_finalize_state. * src/c++98/locale_facets.cc (is_leap, day_of_the_week, day_of_the_year): New functions in anon namespace. (mon_yday): New var in anon namespace. (__time_get_state::_M_finalize_state): Define. * testsuite/22_locale/time_get/get/char/4.cc: New test. * testsuite/22_locale/time_get/get/wchar_t/4.cc: New test. * testsuite/22_locale/time_get/get_year/char/1.cc (test01): Parse 197 as year 197AD instead of error. * testsuite/22_locale/time_get/get_year/char/5.cc (test01): Parse 1 as year 2001 instead of error. * testsuite/22_locale/time_get/get_year/char/6.cc: New test. * testsuite/22_locale/time_get/get_year/wchar_t/1.cc (test01): Parse 197 as year 197AD instead of error. * testsuite/22_locale/time_get/get_year/wchar_t/5.cc (test01): Parse 1 as year 2001 instead of error. * testsuite/22_locale/time_get/get_year/wchar_t/6.cc: New test. |
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