breakpoint.c

早期freebsd实现

     char *arg;
     int from_tty;
{
  break_command_1 (arg, 0, from_tty);
}

static void
tbreak_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  break_command_1 (arg, 1, from_tty);
}

/* ARGSUSED */
static void
watch_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  struct breakpoint *b;
  struct symtab_and_line sal;
  struct expression *exp;
  struct block *exp_valid_block;
  struct value *val;

  sal.pc = 0;
  sal.symtab = NULL;
  sal.line = 0;
  
  /* Parse arguments.  */
  innermost_block = NULL;
  exp = parse_expression (arg);
  exp_valid_block = innermost_block;
  val = evaluate_expression (exp);
  release_value (val);

  /* Now set up the breakpoint.  */
  b = set_raw_breakpoint (sal);
  set_breakpoint_count (breakpoint_count + 1);
  b->number = breakpoint_count;
  b->type = bp_watchpoint;
  b->disposition = donttouch;
  b->exp = exp;
  b->exp_valid_block = exp_valid_block;
  b->val = val;
  b->cond = 0;
  b->cond_string = NULL;
  mention (b);
}

/*
 * Helper routine for the until_command routine in infcmd.c.  Here
 * because it uses the mechanisms of breakpoints.
 */
/* ARGSUSED */
void
until_break_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  FRAME prev_frame = get_prev_frame (selected_frame);
  struct breakpoint *breakpoint;
  struct cleanup *old_chain;

  clear_proceed_status ();

  /* Set a breakpoint where the user wants it and at return from
     this function */
  
  if (default_breakpoint_valid)
    sals = decode_line_1 (&arg, 1, default_breakpoint_symtab,
			  default_breakpoint_line);
  else
    sals = decode_line_1 (&arg, 1, (struct symtab *)NULL, 0);
  
  if (sals.nelts != 1)
    error ("Couldn't get information on specified line.");
  
  sal = sals.sals[0];
  free ((PTR)sals.sals);		/* malloc'd, so freed */
  
  if (*arg)
    error ("Junk at end of arguments.");
  
  resolve_sal_pc (&sal);
  
  breakpoint = set_momentary_breakpoint (sal, selected_frame, bp_until);
  
  old_chain = make_cleanup(delete_breakpoint, breakpoint);

  /* Keep within the current frame */
  
  if (prev_frame)
    {
      struct frame_info *fi;
      
      fi = get_frame_info (prev_frame);
      sal = find_pc_line (fi->pc, 0);
      sal.pc = fi->pc;
      breakpoint = set_momentary_breakpoint (sal, prev_frame, bp_until);
      make_cleanup(delete_breakpoint, breakpoint);
    }
  
  proceed (-1, -1, 0);
  do_cleanups(old_chain);
}

#if 0
/* These aren't used; I don't konw what they were for.  */
/* Set a breakpoint at the catch clause for NAME.  */
static int
catch_breakpoint (name)
     char *name;
{
}

static int
disable_catch_breakpoint ()
{
}

static int
delete_catch_breakpoint ()
{
}

static int
enable_catch_breakpoint ()
{
}
#endif /* 0 */

struct sal_chain
{
  struct sal_chain *next;
  struct symtab_and_line sal;
};

#if 0
/* This isn't used; I don't know what it was for.  */
/* For each catch clause identified in ARGS, run FUNCTION
   with that clause as an argument.  */
static struct symtabs_and_lines
map_catch_names (args, function)
     char *args;
     int (*function)();
{
  register char *p = args;
  register char *p1;
  struct symtabs_and_lines sals;
#if 0
  struct sal_chain *sal_chain = 0;
#endif

  if (p == 0)
    error_no_arg ("one or more catch names");

  sals.nelts = 0;
  sals.sals = NULL;

  while (*p)
    {
      p1 = p;
      /* Don't swallow conditional part.  */
      if (p1[0] == 'i' && p1[1] == 'f'
	  && (p1[2] == ' ' || p1[2] == '\t'))
	break;

      if (isalpha (*p1))
	{
	  p1++;
	  while (isalnum (*p1) || *p1 == '_' || *p1 == '$')
	    p1++;
	}

      if (*p1 && *p1 != ' ' && *p1 != '\t')
	error ("Arguments must be catch names.");

      *p1 = 0;
#if 0
      if (function (p))
	{
	  struct sal_chain *next
	    = (struct sal_chain *)alloca (sizeof (struct sal_chain));
	  next->next = sal_chain;
	  next->sal = get_catch_sal (p);
	  sal_chain = next;
	  goto win;
	}
#endif
      printf ("No catch clause for exception %s.\n", p);
#if 0
    win:
#endif
      p = p1;
      while (*p == ' ' || *p == '\t') p++;
    }
}
#endif /* 0 */

/* This shares a lot of code with `print_frame_label_vars' from stack.c.  */

static struct symtabs_and_lines
get_catch_sals (this_level_only)
     int this_level_only;
{
  register struct blockvector *bl;
  register struct block *block;
  int index, have_default = 0;
  struct frame_info *fi;
  CORE_ADDR pc;
  struct symtabs_and_lines sals;
  struct sal_chain *sal_chain = 0;
  char *blocks_searched;

  /* Not sure whether an error message is always the correct response,
     but it's better than a core dump.  */
  if (selected_frame == NULL)
    error ("No selected frame.");
  block = get_frame_block (selected_frame);
  fi = get_frame_info (selected_frame);
  pc = fi->pc;

  sals.nelts = 0;
  sals.sals = NULL;

  if (block == 0)
    error ("No symbol table info available.\n");

  bl = blockvector_for_pc (BLOCK_END (block) - 4, &index);
  blocks_searched = (char *) alloca (BLOCKVECTOR_NBLOCKS (bl) * sizeof (char));
  memset (blocks_searched, 0, BLOCKVECTOR_NBLOCKS (bl) * sizeof (char));

  while (block != 0)
    {
      CORE_ADDR end = BLOCK_END (block) - 4;
      int last_index;

      if (bl != blockvector_for_pc (end, &index))
	error ("blockvector blotch");
      if (BLOCKVECTOR_BLOCK (bl, index) != block)
	error ("blockvector botch");
      last_index = BLOCKVECTOR_NBLOCKS (bl);
      index += 1;

      /* Don't print out blocks that have gone by.  */
      while (index < last_index
	     && BLOCK_END (BLOCKVECTOR_BLOCK (bl, index)) < pc)
	index++;

      while (index < last_index
	     && BLOCK_END (BLOCKVECTOR_BLOCK (bl, index)) < end)
	{
	  if (blocks_searched[index] == 0)
	    {
	      struct block *b = BLOCKVECTOR_BLOCK (bl, index);
	      int nsyms;
	      register int i;
	      register struct symbol *sym;

	      nsyms = BLOCK_NSYMS (b);

	      for (i = 0; i < nsyms; i++)
		{
		  sym = BLOCK_SYM (b, i);
		  if (! strcmp (SYMBOL_NAME (sym), "default"))
		    {
		      if (have_default)
			continue;
		      have_default = 1;
		    }
		  if (SYMBOL_CLASS (sym) == LOC_LABEL)
		    {
		      struct sal_chain *next = (struct sal_chain *)
			alloca (sizeof (struct sal_chain));
		      next->next = sal_chain;
		      next->sal = find_pc_line (SYMBOL_VALUE_ADDRESS (sym), 0);
		      sal_chain = next;
		    }
		}
	      blocks_searched[index] = 1;
	    }
	  index++;
	}
      if (have_default)
	break;
      if (sal_chain && this_level_only)
	break;

      /* After handling the function's top-level block, stop.
	 Don't continue to its superblock, the block of
	 per-file symbols.  */
      if (BLOCK_FUNCTION (block))
	break;
      block = BLOCK_SUPERBLOCK (block);
    }

  if (sal_chain)
    {
      struct sal_chain *tmp_chain;

      /* Count the number of entries.  */
      for (index = 0, tmp_chain = sal_chain; tmp_chain;
	   tmp_chain = tmp_chain->next)
	index++;

      sals.nelts = index;
      sals.sals = (struct symtab_and_line *)
	xmalloc (index * sizeof (struct symtab_and_line));
      for (index = 0; sal_chain; sal_chain = sal_chain->next, index++)
	sals.sals[index] = sal_chain->sal;
    }

  return sals;
}

/* Commands to deal with catching exceptions.  */

static void
catch_command_1 (arg, tempflag, from_tty)
     char *arg;
     int tempflag;
     int from_tty;
{
  /* First, translate ARG into something we can deal with in terms
     of breakpoints.  */

  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  register struct expression *cond = 0;
  register struct breakpoint *b;
  char *save_arg;
  int i;

  sal.line = sal.pc = sal.end = 0;
  sal.symtab = 0;

  /* If no arg given, or if first arg is 'if ', all active catch clauses
     are breakpointed. */

  if (!arg || (arg[0] == 'i' && arg[1] == 'f' 
	       && (arg[2] == ' ' || arg[2] == '\t')))
    {
      /* Grab all active catch clauses.  */
      sals = get_catch_sals (0);
    }
  else
    {
      /* Grab selected catch clauses.  */
      error ("catch NAME not implemeneted");
#if 0
      /* This isn't used; I don't know what it was for.  */
      sals = map_catch_names (arg, catch_breakpoint);
#endif
    }

  if (! sals.nelts) 
    return;

  save_arg = arg;
  for (i = 0; i < sals.nelts; i++)
    {
      resolve_sal_pc (&sals.sals[i]);
      
      while (arg && *arg)
	{
	  if (arg[0] == 'i' && arg[1] == 'f'
	      && (arg[2] == ' ' || arg[2] == '\t'))
	    cond = parse_exp_1 ((arg += 2, &arg), 
				block_for_pc (sals.sals[i].pc), 0);
	  else
	    error ("Junk at end of arguments.");
	}
      arg = save_arg;
    }

  for (i = 0; i < sals.nelts; i++)
    {
      sal = sals.sals[i];

      if (from_tty)
	describe_other_breakpoints (sal.pc);

      b = set_raw_breakpoint (sal);
      set_breakpoint_count (breakpoint_count + 1);
      b->number = breakpoint_count;
      b->type = bp_breakpoint;
      b->cond = cond;
      b->enable = enabled;
      b->disposition = tempflag ? delete : donttouch;

      printf ("Breakpoint %d at %s", b->number, local_hex_string(b->address));
      if (b->symtab)
	printf (": file %s, line %d.", b->symtab->filename, b->line_number);
      printf ("\n");
    }

  if (sals.nelts > 1)
    {
      printf ("Multiple breakpoints were set.\n");
      printf ("Use the \"delete\" command to delete unwanted breakpoints.\n");
    }
  free ((PTR)sals.sals);
}

#if 0
/* These aren't used; I don't know what they were for.  */
/* Disable breakpoints on all catch clauses described in ARGS.  */
static void
disable_catch (args)
     char *args;
{
  /* Map the disable command to catch clauses described in ARGS.  */
}

/* Enable breakpoints on all catch clauses described in ARGS.  */
static void
enable_catch (args)
     char *args;
{
  /* Map the disable command to catch clauses described in ARGS.  */
}

/* Delete breakpoints on all catch clauses in the active scope.  */
static void
delete_catch (args)
     char *args;
{
  /* Map the delete command to catch clauses described in ARGS.  */
}
#endif /* 0 */

static void
catch_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  catch_command_1 (arg, 0, from_tty);
}

static void
clear_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  register struct breakpoint *b, *b1;
  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  register struct breakpoint *found;
  int i;

  if (arg)
    {
      sals = decode_line_spec (arg, 1);
    }
  else
    {
      sals.sals = (struct symtab_and_line *) xmalloc (sizeof (struct symtab_and_line));
      sal.line = default_breakpoint_line;
      sal.symtab = default_breakpoint_symtab;
      sal.pc = 0;
      if (sal.symtab == 0)
	error ("No source file specified.");

      sals.sals[0] = sal;
      sals.nelts = 1;
    }

  for (i = 0; i < sals.nelts; i++)
    {
      /* If exact pc given, clear bpts at that pc.
	 But if sal.pc is zero, clear all bpts on specified line.  */
      sal = sals.sals[i];
      found = (struct breakpoint *) 0;
      while (breakpoint_chain
	     && (sal.pc ? breakpoint_chain->address == sal.pc
		 : (breakpoint_chain->symtab == sal.symtab
		    && breakpoint_chain->line_number == sal.line)))
	{
	  b1 = breakpoint_chain;
	  breakpoint_chain = b1->next;
	  b1->next = found;
	  found = b1;
	}

      ALL_BREAKPOINTS (b)
	while (b->next
	       && b->next->type != bp_watchpoint
	       && (sal.pc ? b->next->address == sal.pc
		   : (b->next->symtab == sal.symtab
		      && b->next->line_number == sal.line)))
	  {
	    b1 = b->next;
	    b->next = b1->next;
	    b1->next = found;
	    found = b1;
	  }

      if (found == 0)
	{
	  if (arg)
	    error ("No breakpoint at %s.", arg);
	  else
	    error ("No breakpoint at this line.");
	}

      if (found->next) from_tty = 1; /* Always report if deleted more than one */
      if (from_tty) printf ("Deleted breakpoint%s ", found->next ? "s" : "");
      while (found)
	{
	  if (from_tty) printf ("%d ", found->number);
	  b1 = found->next;
	  delete_breakpoint (found);
	  found = b1;
	}
      if (from_tty) putchar ('\n');
    }
  free ((PTR)sals.sals);
}

/* Delete breakpoint in BS if they are `delete' breakpoints.
   This is called after any breakpoint is hit, or after errors.  */