(inc_loc_): Stop program execution if the

program counter is incremented beyond the maximum address (3999).

1 files changed, 12 insertions, 12 deletions

diff --git a/mixlib/xmix_vm.h b/mixlib/xmix_vm.h
index 019dfd6..45805e8 100644
--- a/mixlib/xmix_vm.h
+++ b/mixlib/xmix_vm.h
@@ -2,24 +2,24 @@
  * This file contains internal declarations used in the implementation
  * of the mix_vm_t type.
  * ------------------------------------------------------------------
- *  $Id: xmix_vm.h,v 1.7 2002/03/24 00:23:28 jao Exp $
+ *  $Id: xmix_vm.h,v 1.8 2003/01/12 21:05:01 jao Exp $
  * ------------------------------------------------------------------
- * Copyright (C) 2000, 2002 Free Software Foundation, Inc.
- *  
+ * Copyright (C) 2000, 2002, 2003 Free Software Foundation, Inc.
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
- *  
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *  
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *  
+ *
  */
 
 
@@ -42,7 +42,7 @@ enum {
   MEM_CELLS_MAX_ = MIX_VM_CELL_NO - 1
 };
 
-struct mix_vm_t 
+struct mix_vm_t
 {
   mix_word_t reg[IREG_NO_+3];
   mix_word_t cell[MEM_CELLS_NO_];
@@ -50,7 +50,7 @@ struct mix_vm_t
   mix_cmpflag_t cmpflag;
   mix_short_t loc_count;
   mix_vm_status_t status;
-  mix_device_t * devices[BD_NO_]; 
+  mix_device_t * devices[BD_NO_];
   mix_address_t start_addr;	/* start address of loaded file */
   GTree *line_table;		/* source line no -> address  */
   GTree *address_table;		/* adress -> source line no */
@@ -107,15 +107,15 @@ do {						\
 #define set_loc_(vm,x)  (vm)->loc_count = (MEMOK_(x)? (x) : MIX_SHORT_ZERO)
 
 #define set_status_(vm,s) ((vm)->status = (s))
+#define is_halted_(vm) ((vm)->status == MIX_VM_HALT)
+#define halt_(vm,val) ((vm)->status = (val)? MIX_VM_HALT : MIX_VM_RUNNING)
 
 #define inc_loc_(vm)				\
 do {						\
-  if (vm->loc_count++ == MEM_CELLS_MAX_)	\
-    vm->loc_count = MIX_SHORT_ZERO;		\
+  if (++(vm->loc_count) == MEM_CELLS_NO_)	\
+    { vm->loc_count--; halt_(vm, TRUE); }	\
 } while(FALSE)
 
-#define is_halted_(vm) ((vm)->status == MIX_VM_HALT)
-#define halt_(vm,val) ((vm)->status = (val)? MIX_VM_HALT : MIX_VM_RUNNING)
 #define set_start_(vm,val) ((vm)->start_addr = (val))
 #define reset_loc_(vm) set_loc_ (vm, vm->start_addr)
 #define update_time_(vm,ins) mix_vm_clock_add_lapse (get_clock_(vm), ins)