Re: [PATCH] libgcobol: Check for struct tm tm_zone

[Rainer Orth]

Rainer Orth <r...@cebitec.uni-bielefeld.de> writes:

> Hi Andreas,
>
>> On Apr 11 2025, Rainer Orth wrote:
>>
>>> This patch uses Autoconf's AC_STRUCT_TIMEZONE to determine its presence
>>> and guard the use accordingly.
>>
>> You cannot use AC_STRUCT_TIMEZONE because it requires a link test (which
>> is forbidden in a target module, see PR119550).
>
> drats.  Must have taken this from libstdc++ shortly before it was
> replaced.
>
> I suspect a simple
>
> AC_CHECK_MEMBER([struct tm.tm_zone],,[#include <time.h>])
>
> does the trick.
>
> Thanks for the hint.

That's what I actually tested on amd64-pc-solaris2.11,
sparcv9-sun-solaris2.11, and x86_64-pc-linux-gnu.

Ok for trunk and gcc-15 branch?

        Rainer

-- 
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University


2025-04-08  Rainer Orth  <r...@cebitec.uni-bielefeld.de>

        libgcobol:
        * configure.ac: Check for struct tm.tm_zone.
        * configure, config.h.in: Regenerate.
        * intrinsic.cc (__gg__formatted_current_date): Guard tm.tm_zone
        use with HAVE_STRUCT_TM_TM_ZONE.


# HG changeset patch
# Parent  2e0b7a6cac052729ce96489827f3f1e03e96d9b1
libgcobol: Check for struct tm tm_zone

diff --git a/libgcobol/configure b/libgcobol/configure
--- a/libgcobol/configure
+++ b/libgcobol/configure
@@ -2449,6 +2449,63 @@ eval ac_res=\$$3
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
 
 } # ac_fn_cxx_check_func
+
+# ac_fn_cxx_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_cxx_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.$3)
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$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.$3)
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$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; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_cxx_check_member
 cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
@@ -11693,7 +11750,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11696 "configure"
+#line 11753 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11799,7 +11856,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11802 "configure"
+#line 11859 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -17426,6 +17483,14 @@ fi
 
 
 
+# struct tm tm_zone is a POSIX.1-2024 addition.
+ac_fn_cxx_check_member "$LINENO" "struct tm" "tm_zone" "ac_cv_member_struct_tm_tm_zone" "#include <time.h>
+"
+if test "x$ac_cv_member_struct_tm_tm_zone" = xyes; then :
+
+fi
+
+
 if test "${multilib}" = "yes"; then
   multilib_arg="--enable-multilib"
 else
diff --git a/libgcobol/configure.ac b/libgcobol/configure.ac
--- a/libgcobol/configure.ac
+++ b/libgcobol/configure.ac
@@ -231,6 +231,9 @@ elif test "${ENABLE_LIBQUADMATH_SUPPORT}
 fi
 LIBGCOBOL_CHECK_FLOAT128
 
+# struct tm tm_zone is a POSIX.1-2024 addition.
+AC_CHECK_MEMBER([struct tm.tm_zone],,,[#include <time.h>])
+
 if test "${multilib}" = "yes"; then
   multilib_arg="--enable-multilib"
 else
diff --git a/libgcobol/intrinsic.cc b/libgcobol/intrinsic.cc
--- a/libgcobol/intrinsic.cc
+++ b/libgcobol/intrinsic.cc
@@ -1490,7 +1490,9 @@ void
   __gg__clock_gettime(CLOCK_REALTIME, &ts);
 
   struct tm tm = {};
+#ifdef HAVE_STRUCT_TM_TM_ZONE
   tm.tm_zone = "GMT";
+#endif
   if( is_zulu )
     {
     gmtime_r(&ts.tv_sec, &tm);