keep track of runtime errors and correctly report them.

3 files changed, 115 insertions, 68 deletions

diff --git a/mixlib/xmix_vm.c b/mixlib/xmix_vm.c
index 718a9d3..ecb67c9 100644
--- a/mixlib/xmix_vm.c
+++ b/mixlib/xmix_vm.c
@@ -56,6 +56,20 @@ get_dev_ (mix_vm_t *vm, mix_fspec_t type)
   return vm->devices[type];
 }
 
+/* error macro */
+#define fail_if_not_(vm,cond,error)             \
+do {                                            \
+  if (!(cond))                                  \
+    {                                           \
+      set_last_error_ (vm, error);              \
+      return FALSE;                             \
+    }                                           \
+} while (FALSE)
+
+#define fail_(vm,error) fail_if_not_ (vm, FALSE, error)
+
+#define fail_unexpected_(vm) fail_ (vm, MIX_VM_ERROR_UNEXPECTED)
+
 /* Instruction handlers */
 
 static gboolean
@@ -136,7 +150,7 @@ spc_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
                mix_word_negative (num) : num);
       break;
     }
-  default: return FALSE;
+  default: fail_ (vm, MIX_VM_ERROR_BAD_FSPEC);
   }
   inc_loc_ (vm);
   return TRUE;
@@ -148,7 +162,8 @@ sla_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
   mix_short_t n = get_M_ (vm,ins);
 
   g_assert (ins->opcode == mix_opSLx);
-  g_return_val_if_fail (mix_short_is_positive (n), FALSE);
+
+  fail_if_not_ (vm, mix_short_is_positive (n), MIX_VM_ERROR_BAD_M);
 
   switch ( mix_ins_id_from_ins (*ins) ) {
   case mix_SLA:
@@ -174,7 +189,7 @@ sla_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
                                    &get_rA_ (vm), &get_rX_ (vm));
     break;
   default:
-    return FALSE;
+    fail_unexpected_ (vm);
   }
 
   inc_loc_ (vm);
@@ -189,16 +204,19 @@ mov_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
   guint k, delta = ins->fspec;
 
   g_assert (ins->opcode == mix_opMOVE);
-  g_return_val_if_fail (mix_short_is_positive (from), FALSE);
-  g_return_val_if_fail (mix_short_is_positive (to), FALSE);
-  g_return_val_if_fail (MEMOK_ (from + delta -1), FALSE);
-  g_return_val_if_fail (MEMOK_ (to + delta - 1), FALSE);
-
-  for (k = 0; k < delta; ++k)
-    set_cell_ (vm, to+k, get_cell_ (vm, from+k));
-  set_rI_ (vm, 1, to+delta);
-  inc_loc_ (vm);
-  return TRUE;
+  if (mix_short_is_positive (from)
+      && mix_short_is_positive (to)
+      && MEMOK_ (from + delta -1)
+      && MEMOK_ (to + delta - 1))
+    {
+      for (k = 0; k < delta; ++k)
+        set_cell_ (vm, to+k, get_cell_ (vm, from+k));
+      set_rI_ (vm, 1, to+delta);
+      inc_loc_ (vm);
+      return TRUE;
+    }
+  else
+    return FALSE;
 }
 
 static gboolean
@@ -258,8 +276,10 @@ static gboolean
 jbs_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
 {
   g_assert (ins->opcode == mix_opJBUS);
-  g_return_val_if_fail (ins->fspec < BD_NO_, TRUE);
-  g_return_val_if_fail (get_dev_ (vm, ins->fspec) != NULL, TRUE);
+  fail_if_not_ (vm, ins->fspec < BD_NO_, MIX_VM_ERROR_BAD_DEVICE_NO);
+  fail_if_not_ (vm, get_dev_ (vm, ins->fspec) != NULL,
+                MIX_VM_ERROR_BAD_DEVICE_NO);
+
   if ( mix_device_busy (get_dev_ (vm, ins->fspec)) ) {
     set_rJ_ (vm, get_loc_ (vm));
     set_loc_ (vm, get_M_ (vm, ins));
@@ -272,18 +292,19 @@ ioc_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
 {
   mix_address_t addr;
   mix_device_t *dev;
-  gboolean result;
 
   g_assert (ins->opcode == mix_opIOC);
+
   addr = get_M_ (vm, ins);
-  g_return_val_if_fail (ins->fspec < BD_NO_, TRUE);
+  fail_if_not_ (vm, ins->fspec < BD_NO_, MIX_VM_ERROR_BAD_DEVICE_NO);
+
   dev = get_dev_ (vm, ins->fspec);
-  g_return_val_if_fail (dev != NULL, TRUE);
-  result =
-    mix_device_ioc (dev, addr);
+  fail_if_not_ (vm, dev != NULL, MIX_VM_ERROR_BAD_DEVICE_NO);
+
+  fail_if_not_ (vm, mix_device_ioc (dev, addr), MIX_VM_ERROR_DEV_CTL);
 
   inc_loc_ (vm);
-  return result;
+  return TRUE;
 }
 
 static gboolean
@@ -291,21 +312,24 @@ inp_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
 {
   mix_address_t addr;
   mix_device_t *dev;
-  gboolean result;
 
   g_assert (ins->opcode == mix_opIN);
+  fail_if_not_ (vm, ins->fspec < BD_NO_, MIX_VM_ERROR_BAD_DEVICE_NO);
+
   addr = get_M_ (vm, ins);
-  g_return_val_if_fail (ins->fspec < BD_NO_, TRUE);
-  g_return_val_if_fail (MEMOK_ (addr), TRUE);
+  fail_if_not_ (vm, MEMOK_ (addr), MIX_VM_ERROR_BAD_ACCESS);
+
   dev = get_dev_ (vm, ins->fspec);
-  g_return_val_if_fail ( dev != NULL, TRUE);
-  g_return_val_if_fail (MEM_CELLS_NO_ - addr > mix_device_block_size (dev),
-			TRUE);
-  result =
-    mix_device_read (dev, get_cell_ptr_ (vm, addr));
+  fail_if_not_ (vm, dev != NULL, MIX_VM_ERROR_BAD_DEVICE_NO);
+
+  fail_if_not_ (vm, MEM_CELLS_NO_ - addr > mix_device_block_size (dev),
+                MIX_VM_ERROR_BAD_ACCESS);
+
+  fail_if_not_ (vm, mix_device_read (dev, get_cell_ptr_ (vm, addr)),
+                MIX_VM_ERROR_DEV_READ);
 
   inc_loc_ (vm);
-  return result;
+  return TRUE;
 }
 
 static gboolean
@@ -313,29 +337,35 @@ out_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
 {
   mix_address_t addr;
   mix_device_t *dev;
-  gboolean result;
 
   g_assert (ins->opcode == mix_opOUT);
+
+  fail_if_not_ (vm, ins->fspec < BD_NO_, MIX_VM_ERROR_BAD_DEVICE_NO);
+
   addr = get_M_ (vm, ins);
-  g_return_val_if_fail (ins->fspec < BD_NO_, TRUE);
-  g_return_val_if_fail (MEMOK_ (addr), TRUE);
+  fail_if_not_ (vm, MEMOK_ (addr), MIX_VM_ERROR_BAD_ACCESS);
+
   dev = get_dev_ (vm, ins->fspec);
-  g_return_val_if_fail ( dev != NULL, TRUE);
-  g_return_val_if_fail (MEM_CELLS_NO_ - addr > mix_device_block_size (dev),
-			TRUE);
-  result =
-    mix_device_write (dev, get_cell_ptr_ (vm, addr));
+  fail_if_not_ (vm, dev != NULL, MIX_VM_ERROR_BAD_DEVICE_NO);
+
+  fail_if_not_ (vm, MEM_CELLS_NO_ - addr > mix_device_block_size (dev),
+                MIX_VM_ERROR_BAD_ACCESS);
+
+  fail_if_not_ (vm, mix_device_write (dev, get_cell_ptr_ (vm, addr)),
+                MIX_VM_ERROR_DEV_WRITE);
 
   inc_loc_ (vm);
-  return result;
+  return TRUE;
 }
 
 static gboolean
 jrd_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
 {
   g_assert (ins->opcode == mix_opJRED);
-  g_return_val_if_fail (ins->fspec < BD_NO_, TRUE);
-  g_return_val_if_fail (get_dev_ (vm, ins->fspec) != NULL, TRUE);
+  fail_if_not_ (vm, ins->fspec < BD_NO_, MIX_VM_ERROR_BAD_DEVICE_NO);
+  fail_if_not_ (vm, get_dev_ (vm, ins->fspec) != NULL,
+                MIX_VM_ERROR_BAD_DEVICE_NO);
+
   inc_loc_ (vm);
   if ( !mix_device_busy (get_dev_ (vm, ins->fspec)) )
     {
@@ -353,7 +383,8 @@ jmp_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
   mix_ins_id_t id = mix_ins_id_from_ins (*ins);
 
   g_assert (ins->opcode == mix_opJMP);
-  g_return_val_if_fail (MEMOK_ (addr), FALSE);
+  fail_if_not_ (vm, MEMOK_ (addr), MIX_VM_ERROR_BAD_ACCESS);
+
   switch ( id ) {
   case mix_JMP:
   case mix_JSJ:
@@ -386,7 +417,7 @@ jmp_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
     jump = ( get_cmp_ (vm) != mix_GREAT );
     break;
   default:
-    return FALSE;
+    fail_unexpected_ (vm);
   }
 
   inc_loc_ (vm);
@@ -406,7 +437,7 @@ jpx_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
   mix_word_t val;
 
   g_assert (ins->opcode >= mix_opJAx || ins->opcode <= mix_opJXx);
-  g_return_val_if_fail (MEMOK_ (addr), FALSE);
+  fail_if_not_ (vm, MEMOK_ (addr), MIX_VM_ERROR_BAD_ACCESS);
 
   switch (ins->opcode) {
   case mix_opJAx: val = get_rA_ (vm); break;
@@ -448,7 +479,7 @@ jpx_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
       || mix_word_is_negative (val);
     break;
   default:
-    return FALSE;
+    fail_unexpected_ (vm);
   }
 
   inc_loc_ (vm);
@@ -509,7 +540,7 @@ ina_handler_ (mix_vm_t *vm, const mix_ins_t *ins)
     mix_word_reverse_sign (val);
     break;
   default:
-    return FALSE;
+    fail_unexpected_ (vm);
   }
   set_reg_ (vm, r, val);
   inc_loc_ (vm);
diff --git a/mixlib/xmix_vm.h b/mixlib/xmix_vm.h
index 45805e8..f4773eb 100644
--- a/mixlib/xmix_vm.h
+++ b/mixlib/xmix_vm.h
@@ -2,9 +2,9 @@
  * This file contains internal declarations used in the implementation
  * of the mix_vm_t type.
  * ------------------------------------------------------------------
- *  $Id: xmix_vm.h,v 1.8 2003/01/12 21:05:01 jao Exp $
+ *  $Id: xmix_vm.h,v 1.9 2004/06/06 19:53:13 jao Exp $
  * ------------------------------------------------------------------
- * Copyright (C) 2000, 2002, 2003 Free Software Foundation, Inc.
+ * Copyright (C) 2000, 2002, 2003, 2004 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
@@ -50,6 +50,7 @@ struct mix_vm_t
   mix_cmpflag_t cmpflag;
   mix_short_t loc_count;
   mix_vm_status_t status;
+  mix_vm_error_t last_error;
   mix_device_t * devices[BD_NO_];
   mix_address_t start_addr;	/* start address of loaded file */
   GTree *line_table;		/* source line no -> address  */
@@ -86,6 +87,8 @@ enum { A_ = 0, X_, J_, I1_, I2_, I3_, I4_, I5_, I6_ };
 #define get_pred_list_(vm) (vm->pred_list)
 #define get_address_list_(vm) (vm->address_list)
 #define get_status_(vm) (vm->status)
+#define get_last_error_(vm) (vm->last_error)
+#define set_last_error_(vm,error) ((vm)->last_error = (error))
 
 #define set_reg_(vm,r,x)			\
 do {						\
diff --git a/mixlib/xmix_vm_handlers.c b/mixlib/xmix_vm_handlers.c
index 4d0285f..a778750 100644
--- a/mixlib/xmix_vm_handlers.c
+++ b/mixlib/xmix_vm_handlers.c
@@ -1,9 +1,9 @@
 /* -*-c-*- -------------- xmix_vm_handlers.c :
  * Implementation of the functions declared in xmix_vm_handlers.h
  * ------------------------------------------------------------------
- * $Id: xmix_vm_handlers.c,v 1.7 2003/01/11 22:43:13 jao Exp $
+ * $Id: xmix_vm_handlers.c,v 1.8 2004/06/06 19:54:11 jao Exp $
  * ------------------------------------------------------------------
- * Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+ * Copyright (C) 2001, 2002, 2003, 2004 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
@@ -103,31 +103,42 @@ mix_vm_command_info_t commands_[] = {
 
 /* trace current instruction */
 static void
-trace_ (mix_vm_cmd_dispatcher_t *dis)
+do_trace_ (mix_vm_cmd_dispatcher_t *dis, gboolean error)
 {
   enum {BUFFER_LEN = 128};
   static gchar STRINS[BUFFER_LEN];
 
-  if (wants_logs_ (dis))
+  const mix_src_file_t *file = mix_vm_get_src_file (dis->vm);
+  const gchar *line = "\n";
+  mix_address_t loc = mix_vm_get_prog_count (dis->vm);
+  mix_word_t ins = mix_vm_get_addr_contents (dis->vm, loc);
+  mix_ins_t fins;
+  mix_word_to_ins_uncheck (ins, fins);
+  mix_ins_to_string_in_buffer (&fins, STRINS, BUFFER_LEN);
+
+  if (file != NULL)
     {
-      const mix_src_file_t *file = mix_vm_get_src_file (dis->vm);
-      const gchar *line = "\n";
-      mix_address_t loc = mix_vm_get_prog_count (dis->vm);
-      mix_word_t ins = mix_vm_get_addr_contents (dis->vm, loc);
-      mix_ins_t fins;
-      mix_word_to_ins_uncheck (ins, fins);
-      mix_ins_to_string_in_buffer (&fins, STRINS, BUFFER_LEN);
+      gulong b = mix_vm_get_break_lineno (dis->vm);
+      if (b > 0) line = mix_src_file_get_line (file, b);
+    }
 
-      if (file != NULL)
-	{
-	  gulong b = mix_vm_get_break_lineno (dis->vm);
-	  if (b > 0) line = mix_src_file_get_line (file, b);
-	}
+  if (!error)
+    log_message_ (dis, "%d: [%-15s]\t%s", (gint)loc, STRINS, line);
+  else
+    log_error_ (dis, "%d: [%-15s]\t%s", (gint)loc, STRINS, line);
+}
 
-      log_message_ (dis, "%d: [%-15s]\t%s", (gint)loc, STRINS, line);
+static void
+trace_ (mix_vm_cmd_dispatcher_t *dis)
+{
+  if (wants_logs_ (dis))
+    {
+      do_trace_ (dis, FALSE);
     }
 }
 
+#define trace_error_(dis)  do_trace_ (dis, TRUE)
+
 /* run a program tracing executed instructions */
 static int
 run_and_trace_ (mix_vm_cmd_dispatcher_t *dis)
@@ -328,12 +339,14 @@ cmd_run_ (mix_vm_cmd_dispatcher_t *dis, const gchar *arg)
 	}
       break;
     case MIX_VM_ERROR:
-      log_error_ (dis, _("... error executing loaded file"));
+      log_error_ (dis, _("%s:"), mix_vm_get_last_error_string (dis->vm));
+      trace_error_ (dis);
       break;
     default:
       g_assert_not_reached ();
       break;
     }
+
   if (wants_logs_ (dis)) print_time_ (dis);
 
   return TRUE;
@@ -373,8 +386,8 @@ cmd_next_ (mix_vm_cmd_dispatcher_t *dis, const gchar *arg)
 	}
       else if (k == MIX_VM_ERROR)
 	{
-	  log_error_ (dis, _("Error at address %d"),
-		      mix_vm_get_prog_count (dis->vm));
+	  log_error_ (dis, _("%s:"), mix_vm_get_last_error_string (dis->vm));
+          trace_error_ (dis);
 	  break;
 	}
     }