--- gforth/engine/signals.c	2001/09/15 20:40:47	1.12
+++ gforth/engine/signals.c	2003/01/19 23:35:34	1.21
@@ -1,6 +1,6 @@
 /* signal handling
 
-  Copyright (C) 1995,1996,1997,1998,2000 Free Software Foundation, Inc.
+  Copyright (C) 1995-2003 Free Software Foundation, Inc.
 
   This file is part of Gforth.
 
@@ -21,8 +21,8 @@
 */
 
 
-#define _GNU_SOURCE
-
+#include "config.h"
+#include "forth.h"
 #include <stdio.h>
 #include <setjmp.h>
 #include <string.h>
@@ -31,11 +31,14 @@
 #include <sys/ioctl.h>
 #endif
 /* #include <asm/signal.h> */
+#include <sys/types.h>
 #include <signal.h>
-#include "config.h"
-#include "forth.h"
 #include "io.h"
 
+#ifndef HAVE_STACK_T
+/* Darwin uses "struct sigaltstack" instead of "stack_t" */
+typedef struct sigaltstack stack_t;
+#endif
 
 #define DEFAULTCOLS 80
 #if defined(MSDOS) || defined (_WIN32)
@@ -52,6 +55,10 @@ UCell rows=DEFAULTROWS;
 /* systems that don't have SA_NODEFER hopefully don't block anyway */
 #endif
 
+#ifndef SA_ONSTACK
+#define SA_ONSTACK 0
+#endif
+
 #ifdef SA_SIGINFO
 void install_signal_handler(int sig, void (*handler)(int, siginfo_t *, void *))
      /* installs three-argument signal handler for sig */
@@ -60,7 +67,7 @@ void install_signal_handler(int sig, voi
 
   action.sa_sigaction=handler;
   sigemptyset(&action.sa_mask);
-  action.sa_flags=SA_RESTART|SA_NODEFER|SA_SIGINFO; /* pass siginfo */
+  action.sa_flags=SA_RESTART|SA_NODEFER|SA_SIGINFO|SA_ONSTACK; /* pass siginfo */
   sigaction(sig, &action, NULL);
 }
 #endif
@@ -73,7 +80,7 @@ Sigfunc *bsd_signal(int signo, Sigfunc *
 
   act.sa_handler=func;
   sigemptyset(&act.sa_mask);
-  act.sa_flags=SA_NODEFER;
+  act.sa_flags=SA_NODEFER; /* SA_ONSTACK does not work for graceful_exit */
   if (sigaction(signo,&act,&oact) < 0)
     return SIG_ERR;
   else
@@ -114,14 +121,20 @@ static void fpe_handler(int sig, siginfo
   int code;
 
   switch(info->si_code) {
+#ifdef FPE_INTDIV
   case FPE_INTDIV: code=-10; break; /* integer divide by zero */
+#endif
+#ifdef FPE_INTOVF
   case FPE_INTOVF: code=-11; break; /* integer overflow */
+#endif
   case FPE_FLTDIV: code=-42; break; /* floating point divide by zero */
   case FPE_FLTOVF: code=-43; break; /* floating point overflow  */
   case FPE_FLTUND: code=-54; break; /* floating point underflow  */
   case FPE_FLTRES: code=-41; break; /* floating point inexact result  */
+#if 0 /* defined by Unix95, but unnecessary */
   case FPE_FLTINV: /* invalid floating point operation  */
   case FPE_FLTSUB: /* subscript out of range  */
+#endif
   default: code=-55; break;
   }
   longjmp(throw_jmp_buf,code);
@@ -356,6 +369,18 @@ void install_signal_handlers(void)
   };
   int i;
   void (*throw_handler)() = die_on_signal ? graceful_exit : signal_throw;
+#ifdef SIGSTKSZ 
+  stack_t sigstack;
+  int sas_retval=-1;
+
+  sigstack.ss_size=SIGSTKSZ;
+  if ((sigstack.ss_sp = my_alloc(sigstack.ss_size)) != NULL) {
+    sigstack.ss_flags=0;
+    sas_retval=sigaltstack(&sigstack,(stack_t *)0);
+  }
+  if (debug)
+    fprintf(stderr,"sigaltstack: %s\n",strerror(sas_retval));
+#endif
 
 #define DIM(X)		(sizeof (X) / sizeof *(X))
 /*
@@ -367,8 +392,10 @@ void install_signal_handlers(void)
   for (i = 0; i < DIM (sigs_to_quit); i++)
     bsd_signal(sigs_to_quit [i], graceful_exit);
 #ifdef SA_SIGINFO
-  install_signal_handler(SIGFPE, fpe_handler);
-  install_signal_handler(SIGSEGV, segv_handler);
+  if (!die_on_signal) {
+    install_signal_handler(SIGFPE, fpe_handler);
+    install_signal_handler(SIGSEGV, segv_handler);
+  }
 #endif
 #ifdef SIGCONT
     bsd_signal(SIGCONT, termprep);