In r15-8491-g778c28c70f8573 I added a use of the Autoconf macro
AC_STRUCT_TIMEZONE, but that requires a link-test for the global tzname
object if tm.tm_zone isn't supported. That link-test isn't allowed for
cross-compilation, so bootstrap fails if tm.tm_zone isn't supported.
Since libstdc++ only cares about tm.tm_zone and won't use tzname anyway,
we don't need the link-test. Replace AC_STRUCT_TIMEZONE with a custom
macro that only checks for tm.tm_zone. We can improve on the Autoconf
macro by checking it's a suitable type, which isn't actually checked by
AC_STRUCT_TIMEZONE.
libstdc++-v3/ChangeLog:
PR libstdc++/119550
* acinclude.m4 (GLIBCXX_STRUCT_TM_TM_ZONE): New macro.
* config.h.in: Regenerate.
* configure: Regenerate.
* configure.ac: Use GLIBCXX_STRUCT_TM_TM_ZONE.
* include/bits/chrono_io.h (__formatter_chrono::_M_c): Check
_GLIBCXX_USE_STRUCT_TM_TM_ZONE instead of
_GLIBCXX_HAVE_STRUCT_TM_TM_ZONE.
---
Testing x86_64-linux and sparc-solaris2.11, looks fine so far.
libstdc++-v3/acinclude.m4 | 35 ++++
libstdc++-v3/config.h.in | 21 +--
libstdc++-v3/configure | 238 ++++++++------------------
libstdc++-v3/configure.ac | 5 +-
libstdc++-v3/include/bits/chrono_io.h | 2 +-
5 files changed, 109 insertions(+), 192 deletions(-)
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index e668d2dba27..02fd349e11d 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -5744,6 +5744,41 @@ AC_DEFUN([GLIBCXX_ZONEINFO_DIR], [
fi
])
+dnl
+dnl Check for a tm_zone member in struct tm.
+dnl
+dnl This member is defined as const char* in Glibc, newlib, POSIX.1-2024,
+dnl and as char* in BSD (including macOS).
+dnl
+dnl Defines:
+dnl _GLIBCXX_USE_STRUCT_TM_TM_ZONE if struct tm has a tm_zone member.
+dnl
+AC_DEFUN([GLIBCXX_STRUCT_TM_TM_ZONE], [
+
+ AC_LANG_SAVE
+ AC_LANG_CPLUSPLUS
+ ac_save_CXXFLAGS="$CXXFLAGS"
+ CXXFLAGS="$CXXFLAGS -std=c++20"
+
+ AC_CACHE_CHECK([for tm_zone member of struct tm], glibcxx_cv_tm_zone, [
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <time.h>
+ ],
+ [struct tm t{}; t.tm_zone = (char*)0;]
+ )],
+ [glibcxx_cv_tm_zone=yes],
+ [glibcxx_cv_tm_zone=no]
+ )
+ ])
+
+ if test $glibcxx_cv_tm_zone = yes; then
+ AC_DEFINE(_GLIBCXX_USE_STRUCT_TM_TM_ZONE, 1,
+ [Define if struct tm has a tm_zone member.])
+ fi
+
+ CXXFLAGS="$ac_save_CXXFLAGS"
+ AC_LANG_RESTORE
+])
+
dnl
dnl Check whether lock tables can be aligned to avoid false sharing.
dnl
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index be151f43dd6..77bbaf1beaa 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -74,10 +74,6 @@
don't. */
#undef HAVE_DECL_STRNLEN
-/* Define to 1 if you have the declaration of `tzname', and to 0 if you don't.
- */
-#undef HAVE_DECL_TZNAME
-
/* Define to 1 if you have the <dirent.h> header file. */
#undef HAVE_DIRENT_H
@@ -412,9 +408,6 @@
/* Define to 1 if `d_type' is a member of `struct dirent'. */
#undef HAVE_STRUCT_DIRENT_D_TYPE
-/* Define to 1 if `tm_zone' is a member of `struct tm'. */
-#undef HAVE_STRUCT_TM_TM_ZONE
-
/* Define if strxfrm_l is available in <string.h>. */
#undef HAVE_STRXFRM_L
@@ -506,17 +499,9 @@
/* Define to 1 if the target supports thread-local storage. */
#undef HAVE_TLS
-/* Define to 1 if your `struct tm' has `tm_zone'. Deprecated, use
- `HAVE_STRUCT_TM_TM_ZONE' instead. */
-#undef HAVE_TM_ZONE
-
/* Define if truncate is available in <unistd.h>. */
#undef HAVE_TRUNCATE
-/* Define to 1 if you don't have `tm_zone' but do have the external array
- `tzname'. */
-#undef HAVE_TZNAME
-
/* Define to 1 if you have the <uchar.h> header file. */
#undef HAVE_UCHAR_H
@@ -605,9 +590,6 @@
/* Define to 1 if you have the ANSI C header files. */
#undef STDC_HEADERS
-/* Define to 1 if your <sys/time.h> declares `struct tm'. */
-#undef TM_IN_SYS_TIME
-
/* Version number of package */
#undef VERSION
@@ -906,6 +888,9 @@
/* Define to restrict std::__basic_file<> to stdio APIs. */
#undef _GLIBCXX_USE_STDIO_PURE
+/* Define if struct tm has a tm_zone member. */
+#undef _GLIBCXX_USE_STRUCT_TM_TM_ZONE
+
/* Define if struct stat has timespec members. */
#undef _GLIBCXX_USE_ST_MTIM
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 67d2b8c7b72..56d0bcb297e 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -2731,63 +2731,6 @@ $as_echo "$ac_res" >&6; }
eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
} # ac_fn_c_check_decl
-
-# ac_fn_c_check_member LINENO AGGR MEMBER VAR INCLUDES
-# ----------------------------------------------------
-# Tries to find if the field MEMBER exists in type AGGR, after including
-# INCLUDES, setting cache variable VAR accordingly.
-ac_fn_c_check_member ()
-{
- as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2.$3" >&5
-$as_echo_n "checking for $2.$3... " >&6; }
-if eval \${$4+:} false; then :
- $as_echo_n "(cached) " >&6
-else
- cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h. */
-$5
-int
-main ()
-{
-static $2 ac_aggr;
-if (ac_aggr.$3)
-return 0;
- ;
- return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
- eval "$4=yes"
-else
- cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h. */
-$5
-int
-main ()
-{
-static $2 ac_aggr;
-if (sizeof ac_aggr.$3)
-return 0;
- ;
- return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
- eval "$4=yes"
-else
- eval "$4=no"
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-eval ac_res=\$$4
- { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
- eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
-
-} # ac_fn_c_check_member
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.
@@ -12337,7 +12280,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 12340 "configure"
+#line 12283 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -12443,7 +12386,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 12446 "configure"
+#line 12389 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -16239,7 +16182,7 @@ $as_echo "$glibcxx_cv_atomic_long_long" >&6; }
# Fake what AC_TRY_COMPILE does.
cat > conftest.$ac_ext << EOF
-#line 16242 "configure"
+#line 16185 "configure"
int main()
{
typedef bool atomic_type;
@@ -16274,7 +16217,7 @@ $as_echo "$glibcxx_cv_atomic_bool" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 16277 "configure"
+#line 16220 "configure"
int main()
{
typedef short atomic_type;
@@ -16309,7 +16252,7 @@ $as_echo "$glibcxx_cv_atomic_short" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 16312 "configure"
+#line 16255 "configure"
int main()
{
// NB: _Atomic_word not necessarily int.
@@ -16345,7 +16288,7 @@ $as_echo "$glibcxx_cv_atomic_int" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 16348 "configure"
+#line 16291 "configure"
int main()
{
typedef long long atomic_type;
@@ -16501,7 +16444,7 @@ $as_echo "mutex" >&6; }
# unnecessary for this test.
cat > conftest.$ac_ext << EOF
-#line 16504 "configure"
+#line 16447 "configure"
int main()
{
_Decimal32 d1;
@@ -16543,7 +16486,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
# unnecessary for this test.
cat > conftest.$ac_ext << EOF
-#line 16546 "configure"
+#line 16489 "configure"
template<typename T1, typename T2>
struct same
{ typedef T2 type; };
@@ -54482,6 +54425,65 @@ _ACEOF
fi
+# For std::chrono formatters to use tm::tm_zone
+
+
+
+ ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS
conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+ ac_save_CXXFLAGS="$CXXFLAGS"
+ CXXFLAGS="$CXXFLAGS -std=c++20"
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for tm_zone member of
struct tm" >&5
+$as_echo_n "checking for tm_zone member of struct tm... " >&6; }
+if ${glibcxx_cv_tm_zone+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#include <time.h>
+
+int
+main ()
+{
+struct tm t{}; t.tm_zone = (char*)0;
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ glibcxx_cv_tm_zone=yes
+else
+ glibcxx_cv_tm_zone=no
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_tm_zone" >&5
+$as_echo "$glibcxx_cv_tm_zone" >&6; }
+
+ if test $glibcxx_cv_tm_zone = yes; then
+
+$as_echo "#define _GLIBCXX_USE_STRUCT_TM_TM_ZONE 1" >>confdefs.h
+
+ fi
+
+ CXXFLAGS="$ac_save_CXXFLAGS"
+ ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext
$LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
# For src/c++11/shared_ptr.cc alignment.
@@ -54697,112 +54699,6 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether struct tm is in
sys/time.h or time.h" >&5
-$as_echo_n "checking whether struct tm is in sys/time.h or time.h... " >&6; }
-if ${ac_cv_struct_tm+:} false; then :
- $as_echo_n "(cached) " >&6
-else
- cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h. */
-#include <sys/types.h>
-#include <time.h>
-
-int
-main ()
-{
-struct tm tm;
- int *p = &tm.tm_sec;
- return !p;
- ;
- return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
- ac_cv_struct_tm=time.h
-else
- ac_cv_struct_tm=sys/time.h
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_struct_tm" >&5
-$as_echo "$ac_cv_struct_tm" >&6; }
-if test $ac_cv_struct_tm = sys/time.h; then
-
-$as_echo "#define TM_IN_SYS_TIME 1" >>confdefs.h
-
-fi
-
-ac_fn_c_check_member "$LINENO" "struct tm" "tm_zone"
"ac_cv_member_struct_tm_tm_zone" "#include <sys/types.h>
-#include <$ac_cv_struct_tm>
-
-"
-if test "x$ac_cv_member_struct_tm_tm_zone" = xyes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_STRUCT_TM_TM_ZONE 1
-_ACEOF
-
-
-fi
-
-if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
-
-$as_echo "#define HAVE_TM_ZONE 1" >>confdefs.h
-
-else
- ac_fn_c_check_decl "$LINENO" "tzname" "ac_cv_have_decl_tzname" "#include
<time.h>
-"
-if test "x$ac_cv_have_decl_tzname" = xyes; then :
- ac_have_decl=1
-else
- ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_TZNAME $ac_have_decl
-_ACEOF
-
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for tzname" >&5
-$as_echo_n "checking for tzname... " >&6; }
-if ${ac_cv_var_tzname+:} false; then :
- $as_echo_n "(cached) " >&6
-else
- if test x$gcc_no_link = xyes; then
- as_fn_error $? "Link tests are not allowed after GCC_NO_EXECUTABLES."
"$LINENO" 5
-fi
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h. */
-#include <time.h>
-#if !HAVE_DECL_TZNAME
-extern char *tzname[];
-#endif
-
-int
-main ()
-{
-return tzname[0][0];
- ;
- return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
- ac_cv_var_tzname=yes
-else
- ac_cv_var_tzname=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
- conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_var_tzname" >&5
-$as_echo "$ac_cv_var_tzname" >&6; }
- if test $ac_cv_var_tzname = yes; then
-
-$as_echo "#define HAVE_TZNAME 1" >>confdefs.h
-
- fi
-fi
-
-
# Define documentation rules conditionally.
# See if makeinfo has been installed and is modern enough
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index fe0cdde1f7a..a6c01b29e94 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -572,6 +572,9 @@ GLIBCXX_EMERGENCY_EH_ALLOC
# For src/c++20/tzdb.cc defaults.
GLIBCXX_ZONEINFO_DIR
+# For std::chrono formatters to use tm::tm_zone
+GLIBCXX_STRUCT_TM_TM_ZONE
+
# For src/c++11/shared_ptr.cc alignment.
GLIBCXX_CHECK_ALIGNAS_CACHELINE
@@ -584,8 +587,6 @@ GLIBCXX_CHECK_FILEBUF_NATIVE_HANDLES
# For std::text_encoding
GLIBCXX_CHECK_TEXT_ENCODING
-AC_STRUCT_TIMEZONE
-
# Define documentation rules conditionally.
# See if makeinfo has been installed and is modern enough
diff --git a/libstdc++-v3/include/bits/chrono_io.h
b/libstdc++-v3/include/bits/chrono_io.h
index 3a5bc5695fb..d8721093706 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -905,7 +905,7 @@ namespace __format
// time zone info available for the time in __tm.
__tm.tm_isdst = -1;
-#ifdef _GLIBCXX_HAVE_STRUCT_TM_TM_ZONE
+#ifdef _GLIBCXX_USE_STRUCT_TM_TM_ZONE
// POSIX.1-2024 adds tm.tm_zone which will be used for %Z.
// BSD has had tm_zone since 1987 but as char* so cast away const.
if constexpr (__is_time_point_v<_Tp>)
--
2.49.0
