Make division by zero signal SIGFPE on all platforms.

9 files changed, 122 insertions, 14 deletions

diff --git a/intl/ChangeLog b/intl/ChangeLog
index 35ff7f8..2e18e90 100644
--- a/intl/ChangeLog
+++ b/intl/ChangeLog
@@ -1,3 +1,10 @@
+2002-06-07  Bruno Haible  <bruno@clisp.org>
+
+	* dcigettext.c (INTDIV0_RAISES_SIGFPE): Define a fallback.
+	Include <signal.h>.
+	* eval-plural.h (plural_eval): Let division by zero cause SIGFPE on
+	all platforms.
+
 2002-05-30  Bruno Haible  <bruno@clisp.org>
 
 	* libgnuintl.h (_INTL_REDIRECT_ASM, _INTL_REDIRECT_INLINE,
diff --git a/intl/dcigettext.c b/intl/dcigettext.c
index 329dc09..b5bf3fb 100644
--- a/intl/dcigettext.c
+++ b/intl/dcigettext.c
@@ -64,6 +64,20 @@ extern int errno;
 
 #include <locale.h>
 
+#ifdef _LIBC
+  /* Guess whether integer division by zero raises signal SIGFPE.
+     Set to 1 only if you know for sure.  In case of doubt, set to 0.  */
+# if defined __alpha__ || defined __arm__ || defined __i386__ \
+     || defined __m68k__ || defined __s390__
+#  define INTDIV0_RAISES_SIGFPE 1
+# else
+#  define INTDIV0_RAISES_SIGFPE 0
+# endif
+#endif
+#if !INTDIV0_RAISES_SIGFPE
+# include <signal.h>
+#endif
+
 #if defined HAVE_SYS_PARAM_H || defined _LIBC
 # include <sys/param.h>
 #endif
diff --git a/intl/eval-plural.h b/intl/eval-plural.h
index 44f4934..19c7ca6 100644
--- a/intl/eval-plural.h
+++ b/intl/eval-plural.h
@@ -68,8 +68,16 @@ plural_eval (pexp, n)
 	      case mult:
 		return leftarg * rightarg;
 	      case divide:
+#if !INTDIV0_RAISES_SIGFPE
+		if (rightarg == 0)
+		  raise (SIGFPE);
+#endif
 		return leftarg / rightarg;
 	      case module:
+#if !INTDIV0_RAISES_SIGFPE
+		if (rightarg == 0)
+		  raise (SIGFPE);
+#endif
 		return leftarg % rightarg;
 	      case plus:
 		return leftarg + rightarg;
diff --git a/m4/ChangeLog b/m4/ChangeLog
index 8fec47a..9a40fd5 100644
--- a/m4/ChangeLog
+++ b/m4/ChangeLog
@@ -1,3 +1,10 @@
+2002-06-07  Bruno Haible  <bruno@clisp.org>
+
+	* intdiv0.m4: New file.
+	* gettext.m4 (AM_INTL_SUBDIR): Require gt_INTDIV0.
+	* Makefile.am (aclocal_DATA): Add intdiv0.m4.
+	(EXTRA_DIST): Add intdiv0.m4.
+
 2002-05-18  Bruno Haible  <bruno@clisp.org>
 
 	Make it possible to invoke AM_ICONV after AM_GNU_GETTEXT.
diff --git a/m4/Makefile.am b/m4/Makefile.am
index 58d06f4..7ebe8b8 100644
--- a/m4/Makefile.am
+++ b/m4/Makefile.am
@@ -1,15 +1,16 @@
 ## Process this file with automake to produce Makefile.in -*-Makefile-*-
 
 aclocaldir = @aclocaldir@
-aclocal_DATA = codeset.m4 gettext.m4 glibc21.m4 iconv.m4 isc-posix.m4 lib-ld.m4 lib-link.m4 lib-prefix.m4 lcmessage.m4 progtest.m4
+aclocal_DATA = codeset.m4 gettext.m4 glibc21.m4 iconv.m4 intdiv0.m4 isc-posix.m4 lib-ld.m4 lib-link.m4 lib-prefix.m4 lcmessage.m4 progtest.m4
 
 # Generate this list with
 # find . -type f -name '*.m4' -printf '%f\n'|sort |fmt |tr '\012' @ \
 #   |sed 's/@$/%/;s/@/ \\@/g' |tr @% '\012\012'
 EXTRA_DIST = README \
 backupfile.m4 c-bs-a.m4 codeset.m4 error.m4 flex.m4 fnmatch.m4 getline.m4 \
-gettext.m4 glibc21.m4 hostname.m4 iconv.m4 inttypes_h.m4 isc-posix.m4 \
-javacomp.m4 javaexec.m4 lcmessage.m4 lib-ld.m4 lib-link.m4 lib-prefix.m4 \
-libtool.m4 mbrtowc.m4 mbstate_t.m4 mbswidth.m4 mkdtemp.m4 progtest.m4 \
-setenv.m4 setlocale.m4 siginfo.m4 signalblocking.m4 signed.m4 ssize_t.m4 \
-stdbool.m4 stdint_h.m4 tmpdir.m4 uintmax_t.m4 ulonglong.m4 unionwait.m4
+gettext.m4 glibc21.m4 hostname.m4 iconv.m4 intdiv0.m4 inttypes_h.m4 \
+isc-posix.m4 javacomp.m4 javaexec.m4 lcmessage.m4 lib-ld.m4 lib-link.m4 \
+lib-prefix.m4 libtool.m4 mbrtowc.m4 mbstate_t.m4 mbswidth.m4 mkdtemp.m4 \
+progtest.m4 setenv.m4 setlocale.m4 siginfo.m4 signalblocking.m4 signed.m4 \
+ssize_t.m4 stdbool.m4 stdint_h.m4 tmpdir.m4 uintmax_t.m4 ulonglong.m4 \
+unionwait.m4
diff --git a/m4/gettext.m4 b/m4/gettext.m4
index a65b03d..146cef2 100644
--- a/m4/gettext.m4
+++ b/m4/gettext.m4
@@ -494,6 +494,7 @@ AC_DEFUN([AM_INTL_SUBDIR],
   AC_REQUIRE([AC_FUNC_ALLOCA])dnl
   AC_REQUIRE([AC_FUNC_MMAP])dnl
   AC_REQUIRE([jm_GLIBC21])dnl
+  AC_REQUIRE([gt_INTDIV0])dnl
 
   AC_CHECK_HEADERS([argz.h limits.h locale.h nl_types.h malloc.h stddef.h \
 stdlib.h string.h unistd.h sys/param.h])
diff --git a/m4/intdiv0.m4 b/m4/intdiv0.m4
new file mode 100644
index 0000000..55dddcf
--- /dev/null
+++ b/m4/intdiv0.m4
@@ -0,0 +1,72 @@
+# intdiv0.m4 serial 1 (gettext-0.11.3)
+dnl Copyright (C) 2002 Free Software Foundation, Inc.
+dnl This file is free software, distributed under the terms of the GNU
+dnl General Public License.  As a special exception to the GNU General
+dnl Public License, this file may be distributed as part of a program
+dnl that contains a configuration script generated by Autoconf, under
+dnl the same distribution terms as the rest of that program.
+
+dnl From Bruno Haible.
+
+AC_DEFUN([gt_INTDIV0],
+[
+  AC_REQUIRE([AC_PROG_CC])dnl
+  AC_REQUIRE([AC_CANONICAL_HOST])dnl
+
+  AC_CACHE_CHECK([whether integer division by zero raises SIGFPE],
+    gt_cv_int_divbyzero_sigfpe,
+    [
+      AC_TRY_RUN([
+#include <stdlib.h>
+#include <signal.h>
+
+static void
+#ifdef __cplusplus
+sigfpe_handler (int sig)
+#else
+sigfpe_handler (sig) int sig;
+#endif
+{
+  /* Exit with code 0 if SIGFPE, with code 1 if any other signal.  */
+  exit (sig != SIGFPE);
+}
+
+int x = 1;
+int y = 0;
+int z;
+int nan;
+
+int main ()
+{
+  signal (SIGFPE, sigfpe_handler);
+/* IRIX and AIX (when "xlc -qcheck" is used) yield signal SIGTRAP.  */
+#if (defined (__sgi) || defined (_AIX)) && defined (SIGTRAP)
+  signal (SIGTRAP, sigfpe_handler);
+#endif
+/* Linux/SPARC yields signal SIGILL.  */
+#if defined (__sparc__) && defined (__linux__)
+  signal (SIGILL, sigfpe_handler);
+#endif
+
+  z = x / y;
+  nan = y / y;
+  exit (1);
+}
+], gt_cv_int_divbyzero_sigfpe=yes, gt_cv_int_divbyzero_sigfpe=no,
+        [
+          # Guess based on the CPU.
+          case "$host_cpu" in
+            alpha* | i[34567]86 | m68k | s390*)
+              gt_cv_int_divbyzero_sigfpe="guessing yes";;
+            *)
+              gt_cv_int_divbyzero_sigfpe="guessing no";;
+          esac
+        ])
+    ])
+  case "$gt_cv_int_divbyzero_sigfpe" in
+    *yes) value=1;;
+    *) value=0;;
+  esac
+  AC_DEFINE_UNQUOTED(INTDIV0_RAISES_SIGFPE, $value,
+    [Define if integer division by zero raises signal SIGFPE.])
+])
diff --git a/src/ChangeLog b/src/ChangeLog
index 3f9355d..6a95a35 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2002-06-07  Bruno Haible  <bruno@clisp.org>
+
+	* msgfmt.c (install_sigfpe_handler): Assume the signal is always
+	SIGFPE, regardless of the platform.
+	(uninstall_sigfpe_handler): Likewise.
+
 2002-05-29  Bruno Haible  <bruno@clisp.org>
 
 	* dir-list.h (dir_list_save_reset, dir_list_restore): New declarations.
diff --git a/src/msgfmt.c b/src/msgfmt.c
index f8883f9..058178d 100644
--- a/src/msgfmt.c
+++ b/src/msgfmt.c
@@ -720,10 +720,6 @@ install_sigfpe_handler ()
   sigaction (SIGFPE, &action, (struct sigaction *) NULL);
 #else
   signal (SIGFPE, sigfpe_handler);
-  /* Irix and AIX send SIGTRAP, not SIGFPE.  */
-# if (defined (__sgi) || defined (_AIX)) && defined (SIGTRAP)
-  signal (SIGTRAP, sigfpe_handler);
-# endif
 #endif
 }
 
@@ -738,10 +734,6 @@ uninstall_sigfpe_handler ()
   sigaction (SIGFPE, &action, (struct sigaction *) NULL);
 #else
   signal (SIGFPE, SIG_DFL);
-  /* Irix and AIX send SIGTRAP, not SIGFPE.  */
-# if (defined (__sgi) || defined (_AIX)) && defined (SIGTRAP)
-  signal (SIGTRAP, SIG_DFL);
-# endif
 #endif
 }