PR modula2/115276 bugfix libgm2 wraptime.InitTM returns NIL

This patch fixes libgm2/libm2iso/wraptime.cc:InitTM so that
it does not always return NULL.  The incorrect autoconf macro
was used (inside InitTM) and the function short circuited
to return NULL.  The fix is to use HAVE_SYS_TIME_H and use
AC_HEADER_TIME in libgm2/configure.ac.

libgm2/ChangeLog:

	PR modula2/115276
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Use AC_HEADER_TIME.
	* libm2iso/wraptime.cc (InitTM): Check HAVE_SYS_TIME_H
	before using struct tm to obtain the size.

gcc/testsuite/ChangeLog:

	PR modula2/115276
	* gm2/isolib/run/pass/testinittm.mod: New test.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

4 files changed, 42 insertions, 3 deletions

diff --git a/libgm2/config.h.in b/libgm2/config.h.in
index 7426cb26cf8..321ef3b807f 100644
--- a/libgm2/config.h.in
+++ b/libgm2/config.h.in
@@ -335,6 +335,9 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
+/* Define to 1 if you can safely include both <sys/time.h> and <time.h>. */
+#undef TIME_WITH_SYS_TIME
+
 /* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE
diff --git a/libgm2/configure b/libgm2/configure
index 13861f0ff93..c36fd7d4cac 100755
--- a/libgm2/configure
+++ b/libgm2/configure
@@ -6837,6 +6837,41 @@ $as_echo "#define HAVE_SYS_WAIT_H 1" >>confdefs.h
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether time.h and sys/time.h may both be included" >&5
+$as_echo_n "checking whether time.h and sys/time.h may both be included... " >&6; }
+if ${ac_cv_header_time+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/types.h>
+#include <sys/time.h>
+#include <time.h>
+
+int
+main ()
+{
+if ((struct tm *) 0)
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_header_time=yes
+else
+  ac_cv_header_time=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_header_time" >&5
+$as_echo "$ac_cv_header_time" >&6; }
+if test $ac_cv_header_time = yes; then
+
+$as_echo "#define TIME_WITH_SYS_TIME 1" >>confdefs.h
+
+fi
+
 ac_fn_c_check_header_mongrel "$LINENO" "math.h" "ac_cv_header_math_h" "$ac_includes_default"
 if test "x$ac_cv_header_math_h" = xyes; then :
 
@@ -14544,7 +14579,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 14547 "configure"
+#line 14582 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -14650,7 +14685,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 14653 "configure"
+#line 14688 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/libgm2/configure.ac b/libgm2/configure.ac
index 9563831ddc5..1e6b82305ff 100644
--- a/libgm2/configure.ac
+++ b/libgm2/configure.ac
@@ -88,6 +88,7 @@ AC_ARG_WITH(cross-host,
 # Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
+AC_HEADER_TIME
 AC_CHECK_HEADER([math.h],
 	       [AC_DEFINE([HAVE_MATH_H], [1], [have math.h])])
 
diff --git a/libgm2/libm2iso/wraptime.cc b/libgm2/libm2iso/wraptime.cc
index 158086b75cc..4bbd5f9701d 100644
--- a/libgm2/libm2iso/wraptime.cc
+++ b/libgm2/libm2iso/wraptime.cc
@@ -113,7 +113,7 @@ EXPORT(KillTimezone) (struct timezone *tv)
 
 /* InitTM - returns a newly created opaque type.  */
 
-#if defined(HAVE_STRUCT_TM) && defined(HAVE_MALLOC_H)
+#if defined(HAVE_SYS_TIME_H) && defined(HAVE_MALLOC_H)
 extern "C" struct tm *
 EXPORT(InitTM) (void)
 {