1 files changed, 59 insertions, 0 deletions
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 7875828..56d0bcb 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -54425,6 +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.