use autoconf to find a suitable signal function type

ChangeLog

@@ -1,3 +1,8 @@
+2010-09-30  Robert Larice
+ * configure.ac ,
+ * src/include/defines.h :
+    use autoconf to find a suitable signal function type
+
 2010-09-30  Robert Larice
  * src/xspice/icm/Makefile :
     use $(MAKE) instead of `make'

configure.ac

@@ -618,6 +618,13 @@ dnl Check for a few typdefs:
 AC_TYPE_PID_T
 AC_TYPE_SIGNAL
 
+dnl sighandler_t is the type of the signal handler on GNU variants,
+dnl sig_t is the type of a signal handler on 4.4BSD's,
+dnl other systems use __sighandler_t.
+AC_CHECK_TYPES([sighandler_t, sig_t, __sighandler_t], , ,
+   [#include <sys/types.h>
+    #include <signal.h> ])
+
 dnl Check for a few libraries and headers:
 AC_HEADER_DIRENT
 AC_CHECK_HEADERS(unistd.h ctype.h pwd.h fcntl.h sys/ioctl.h stropts.h)

src/include/defines.h

@@ -112,11 +112,15 @@
 
 
 #ifndef SIGNAL_FUNCTION
-#if defined(_MSC_VER) || defined(__MINGW32__) || defined(__CYGWIN__) || defined(__SUNPRO_C)
-#  define SIGNAL_FUNCTION RETSIGTYPE (*)(int)
-#else
+# ifdef HAVE_SIGHANDLER_T
 #  define SIGNAL_FUNCTION sighandler_t
-#endif
+# elif HAVE_SIG_T
+#  define SIGNAL_FUNCTION sig_t
+# elif HAVE___SIGHANDLER_T
+#  define SIGNAL_FUNCTION __sighandler_t
+# else
+#  define SIGNAL_FUNCTION RETSIGTYPE (*)(int)
+# endif
 #endif
 
 #define BSIZE_SP      512