https://github.com/python/cpython/commit/7d9b2671c6fcdb09cf49a235e3ef3bd5230b4156 commit: 7d9b2671c6fcdb09cf49a235e3ef3bd5230b4156 branch: 3.14 author: Miss Islington (bot) <[email protected]> committer: encukou <[email protected]> date: 2025-10-07T19:59:06+02:00 summary:
[3.14] gh-123681: Check NORMALIZE_CENTURY behavior at runtime; require C99 (GH-136022) (GH-137947) A runtime check is needed to support cross-compiling. Remove the _Py_NORMALIZE_CENTURY macro. Remove _pydatetime.py's _can_support_c99. (cherry picked from commit 719e5c3f7111bcda5eee72fe648786c427c4d4c2) Co-authored-by: Petr Viktorin <[email protected]> Co-authored-by: Serhiy Storchaka <[email protected]> files: A Misc/NEWS.d/next/Build/2025-01-03-13-02-06.gh-issue-123681.gQ67nK.rst M Lib/_pydatetime.py M Lib/test/datetimetester.py M Modules/_datetimemodule.c M Tools/c-analyzer/cpython/ignored.tsv M configure M configure.ac M pyconfig.h.in diff --git a/Lib/_pydatetime.py b/Lib/_pydatetime.py index cfcd35827a275a..70251dbb6535d2 100644 --- a/Lib/_pydatetime.py +++ b/Lib/_pydatetime.py @@ -213,17 +213,6 @@ def _need_normalize_century(): _normalize_century = True return _normalize_century -_supports_c99 = None -def _can_support_c99(): - global _supports_c99 - if _supports_c99 is None: - try: - _supports_c99 = ( - _time.strftime("%F", (1900, 1, 1, 0, 0, 0, 0, 1, 0)) == "1900-01-01") - except ValueError: - _supports_c99 = False - return _supports_c99 - # Correctly substitute for %z and %Z escapes in strftime formats. def _wrap_strftime(object, format, timetuple): # Don't call utcoffset() or tzname() unless actually needed. @@ -283,7 +272,7 @@ def _wrap_strftime(object, format, timetuple): newformat.append(Zreplace) # Note that datetime(1000, 1, 1).strftime('%G') == '1000' so # year 1000 for %G can go on the fast path. - elif ((ch in 'YG' or ch in 'FC' and _can_support_c99()) and + elif ((ch in 'YG' or ch in 'FC') and object.year < 1000 and _need_normalize_century()): if ch == 'G': year = int(_time.strftime("%G", timetuple)) diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py index 1c1cbd03d02ccc..aca5fbc04b18cb 100644 --- a/Lib/test/datetimetester.py +++ b/Lib/test/datetimetester.py @@ -1807,7 +1807,7 @@ def test_bool(self): self.assertTrue(self.theclass.min) self.assertTrue(self.theclass.max) - def test_strftime_y2k(self): + def check_strftime_y2k(self, specifier): # Test that years less than 1000 are 0-padded; note that the beginning # of an ISO 8601 year may fall in an ISO week of the year before, and # therefore needs an offset of -1 when formatting with '%G'. @@ -1821,22 +1821,28 @@ def test_strftime_y2k(self): (1000, 0), (1970, 0), ) - specifiers = 'YG' - if _time.strftime('%F', (1900, 1, 1, 0, 0, 0, 0, 1, 0)) == '1900-01-01': - specifiers += 'FC' for year, g_offset in dataset: - for specifier in specifiers: - with self.subTest(year=year, specifier=specifier): - d = self.theclass(year, 1, 1) - if specifier == 'G': - year += g_offset - if specifier == 'C': - expected = f"{year // 100:02d}" - else: - expected = f"{year:04d}" - if specifier == 'F': - expected += f"-01-01" - self.assertEqual(d.strftime(f"%{specifier}"), expected) + with self.subTest(year=year, specifier=specifier): + d = self.theclass(year, 1, 1) + if specifier == 'G': + year += g_offset + if specifier == 'C': + expected = f"{year // 100:02d}" + else: + expected = f"{year:04d}" + if specifier == 'F': + expected += f"-01-01" + self.assertEqual(d.strftime(f"%{specifier}"), expected) + + def test_strftime_y2k(self): + self.check_strftime_y2k('Y') + self.check_strftime_y2k('G') + + def test_strftime_y2k_c99(self): + # CPython requires C11; specifiers new in C99 must work. + # (Other implementations may want to disable this test.) + self.check_strftime_y2k('F') + self.check_strftime_y2k('C') def test_replace(self): cls = self.theclass diff --git a/Misc/NEWS.d/next/Build/2025-01-03-13-02-06.gh-issue-123681.gQ67nK.rst b/Misc/NEWS.d/next/Build/2025-01-03-13-02-06.gh-issue-123681.gQ67nK.rst new file mode 100644 index 00000000000000..a60b4607456096 --- /dev/null +++ b/Misc/NEWS.d/next/Build/2025-01-03-13-02-06.gh-issue-123681.gQ67nK.rst @@ -0,0 +1,3 @@ +Check the ``strftime()`` behavior at runtime instead of at the compile time +to support cross-compiling. +Remove the internal macro ``_Py_NORMALIZE_CENTURY``. diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c index c4bb44f1234990..ddb9e9fd2e57c0 100644 --- a/Modules/_datetimemodule.c +++ b/Modules/_datetimemodule.c @@ -1753,6 +1753,24 @@ format_utcoffset(char *buf, size_t buflen, const char *sep, return 0; } +/* Check whether year with century should be normalized for strftime. */ +inline static int +normalize_century(void) +{ + static int cache = -1; + if (cache < 0) { + char year[5]; + struct tm date = { + .tm_year = -1801, + .tm_mon = 0, + .tm_mday = 1 + }; + cache = (strftime(year, sizeof(year), "%Y", &date) && + strcmp(year, "0099") != 0); + } + return cache; +} + static PyObject * make_somezreplacement(PyObject *object, char *sep, PyObject *tzinfoarg) { @@ -1924,10 +1942,9 @@ wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple, } replacement = freplacement; } -#ifdef _Py_NORMALIZE_CENTURY - else if (ch == 'Y' || ch == 'G' - || ch == 'F' || ch == 'C' - ) { + else if (normalize_century() + && (ch == 'Y' || ch == 'G' || ch == 'F' || ch == 'C')) + { /* 0-pad year with century as necessary */ PyObject *item = PySequence_GetItem(timetuple, 0); if (item == NULL) { @@ -1978,7 +1995,6 @@ wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple, } continue; } -#endif else { /* percent followed by something else */ continue; diff --git a/Tools/c-analyzer/cpython/ignored.tsv b/Tools/c-analyzer/cpython/ignored.tsv index d5d806be42f39d..687871068e8bae 100644 --- a/Tools/c-analyzer/cpython/ignored.tsv +++ b/Tools/c-analyzer/cpython/ignored.tsv @@ -226,6 +226,7 @@ Modules/_datetimemodule.c datetime_isoformat specs - Modules/_datetimemodule.c parse_hh_mm_ss_ff correction - Modules/_datetimemodule.c time_isoformat specs - Modules/_datetimemodule.c - capi_types - +Modules/_datetimemodule.c normalize_century cache - Modules/_decimal/_decimal.c - cond_map_template - Modules/_decimal/_decimal.c - dec_signal_string - Modules/_decimal/_decimal.c - dflt_ctx - diff --git a/configure b/configure index d31c24dffa2e9d..dc66ea068ebc1f 100755 --- a/configure +++ b/configure @@ -28186,110 +28186,6 @@ printf "%s\n" "#define HAVE_STAT_TV_NSEC2 1" >>confdefs.h fi -{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether year with century should be normalized for strftime" >&5 -printf %s "checking whether year with century should be normalized for strftime... " >&6; } -if test ${ac_cv_normalize_century+y} -then : - printf %s "(cached) " >&6 -else case e in #( - e) -if test "$cross_compiling" = yes -then : - ac_cv_normalize_century=yes -else case e in #( - e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ - -#include <time.h> -#include <string.h> - -int main(void) -{ - char year[5]; - struct tm date = { - .tm_year = -1801, - .tm_mon = 0, - .tm_mday = 1 - }; - if (strftime(year, sizeof(year), "%Y", &date) && !strcmp(year, "0099")) { - return 1; - } - return 0; -} - -_ACEOF -if ac_fn_c_try_run "$LINENO" -then : - ac_cv_normalize_century=yes -else case e in #( - e) ac_cv_normalize_century=no ;; -esac -fi -rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \ - conftest.$ac_objext conftest.beam conftest.$ac_ext ;; -esac -fi - ;; -esac -fi -{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_normalize_century" >&5 -printf "%s\n" "$ac_cv_normalize_century" >&6; } -if test "$ac_cv_normalize_century" = yes -then - -printf "%s\n" "#define _Py_NORMALIZE_CENTURY 1" >>confdefs.h - -fi - -{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether C99-compatible strftime specifiers are supported" >&5 -printf %s "checking whether C99-compatible strftime specifiers are supported... " >&6; } -if test ${ac_cv_strftime_c99_support+y} -then : - printf %s "(cached) " >&6 -else case e in #( - e) -if test "$cross_compiling" = yes -then : - ac_cv_strftime_c99_support= -else case e in #( - e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ - -#include <time.h> -#include <string.h> - -int main(void) -{ - char full_date[11]; - struct tm date = { - .tm_year = 0, - .tm_mon = 0, - .tm_mday = 1 - }; - if (strftime(full_date, sizeof(full_date), "%F", &date) && !strcmp(full_date, "1900-01-01")) { - return 0; - } - return 1; -} - -_ACEOF -if ac_fn_c_try_run "$LINENO" -then : - ac_cv_strftime_c99_support=yes -else case e in #( - e) as_fn_error $? "Python requires C99-compatible strftime specifiers" "$LINENO" 5 ;; -esac -fi -rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \ - conftest.$ac_objext conftest.beam conftest.$ac_ext ;; -esac -fi - ;; -esac -fi -{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_strftime_c99_support" >&5 -printf "%s\n" "$ac_cv_strftime_c99_support" >&6; } - have_curses=no have_panel=no diff --git a/configure.ac b/configure.ac index af7a9623d7bd79..8340319c7e63f2 100644 --- a/configure.ac +++ b/configure.ac @@ -6792,57 +6792,6 @@ then [Define if you have struct stat.st_mtimensec]) fi -AC_CACHE_CHECK([whether year with century should be normalized for strftime], [ac_cv_normalize_century], [ -AC_RUN_IFELSE([AC_LANG_SOURCE([[ -#include <time.h> -#include <string.h> - -int main(void) -{ - char year[5]; - struct tm date = { - .tm_year = -1801, - .tm_mon = 0, - .tm_mday = 1 - }; - if (strftime(year, sizeof(year), "%Y", &date) && !strcmp(year, "0099")) { - return 1; - } - return 0; -} -]])], -[ac_cv_normalize_century=yes], -[ac_cv_normalize_century=no], -[ac_cv_normalize_century=yes])]) -if test "$ac_cv_normalize_century" = yes -then - AC_DEFINE([_Py_NORMALIZE_CENTURY], [1], - [Define if year with century should be normalized for strftime.]) -fi - -AC_CACHE_CHECK([whether C99-compatible strftime specifiers are supported], [ac_cv_strftime_c99_support], [ -AC_RUN_IFELSE([AC_LANG_SOURCE([[ -#include <time.h> -#include <string.h> - -int main(void) -{ - char full_date[11]; - struct tm date = { - .tm_year = 0, - .tm_mon = 0, - .tm_mday = 1 - }; - if (strftime(full_date, sizeof(full_date), "%F", &date) && !strcmp(full_date, "1900-01-01")) { - return 0; - } - return 1; -} -]])], -[ac_cv_strftime_c99_support=yes], -[AC_MSG_ERROR([Python requires C99-compatible strftime specifiers])], -[ac_cv_strftime_c99_support=])]) - dnl check for ncursesw/ncurses and panelw/panel dnl NOTE: old curses is not detected. dnl have_curses=[no, yes] diff --git a/pyconfig.h.in b/pyconfig.h.in index 1c533b2bfb7fb4..0d6ad4465c0e93 100644 --- a/pyconfig.h.in +++ b/pyconfig.h.in @@ -2023,9 +2023,6 @@ /* HACL* library can compile SIMD256 implementations */ #undef _Py_HACL_CAN_COMPILE_VEC256 -/* Define if year with century should be normalized for strftime. */ -#undef _Py_NORMALIZE_CENTURY - /* Define to force use of thread-safe errno, h_errno, and other functions */ #undef _REENTRANT _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
