parse.c

gcc-2.95.3 Linux下最常用的C编译器

	      low_bound = expr;
	      high_bound = NULL_TREE;
	    }
	  build_loop_iterator (loop_counter, low_bound,
			       NULL_TREE, high_bound,
			       going_down, 1, 0);
	}
    }
}

/* Matches: '(' <event list> ')' ':'.
   Or; returns NULL_EXPR. */

static tree
parse_delay_case_event_list ()
{
  tree event_list = NULL_TREE;
  tree event;
  if (! check_token (LPRN))
    return NULL_TREE;
  event = parse_expression ();
  if (PEEK_TOKEN () == ')' && PEEK_TOKEN1 () != ':')
    {
      /* Oops. */
      require (RPRN);
      pushback_paren_expr (event);
      return NULL_TREE;
    }
  for (;;)
    {
      if (! ignoring)
	event_list = tree_cons (NULL_TREE, event, event_list);
      if (! check_token (COMMA))
	break;
      event = parse_expression ();
    }
  expect (RPRN, "missing ')'");
  expect (COLON, "missing ':'");
  return ignoring ? error_mark_node : event_list;
}

static void
parse_delay_case_action (label)
     tree label;
{
  tree label_cnt = NULL_TREE, set_location, priority;
  tree combined_event_list = NULL_TREE;
  require (DELAY);
  require (CASE);
  PUSH_ACTION;
  pushlevel (1);
  expand_exit_needed = 0;
  if (check_token (SET))
    {
      set_location = parse_expression ();
      parse_semi_colon ();
    }
  else
    set_location = NULL_TREE;
  if (check_token (PRIORITY))
    {
      priority = parse_expression ();
      parse_semi_colon ();
    }
  else
    priority = NULL_TREE;
  if (! ignoring)
    label_cnt = build_delay_case_start (set_location, priority);
  for (;;)
    {
      tree event_list = parse_delay_case_event_list ();
      if (event_list)
	{
	  if (! ignoring )
	    { 
	      int if_or_elseif = combined_event_list == NULL_TREE;
	      build_delay_case_label (event_list, if_or_elseif);  
	      combined_event_list = chainon (combined_event_list, event_list);
	    }
	}
      else if (parse_action ())
	{
	  if (! ignoring)
	    {
	      expand_exit_needed = 1;
	      if (combined_event_list == NULL_TREE)
		error ("missing DELAY CASE alternative");
	    }
	}
      else
	break;
    }
  expect (ESAC, "missing 'ESAC' in DELAY CASE'");
  if (! ignoring)
    build_delay_case_end (combined_event_list);
  possibly_define_exit_label (label);
  poplevel (0, 0, 0); 
}

static void
parse_do_action (label)
     tree label;
{
  tree condition;
  int token;
  require (DO);
  if (check_token (WITH))
    {
      tree list = NULL_TREE;
      for (;;)
	{
	  tree name = parse_primval ();
	  if (! ignoring && TREE_CODE (name) != ERROR_MARK)
	    {
	      if (TREE_CODE (TREE_TYPE (name)) == REFERENCE_TYPE)
		name = convert (TREE_TYPE (TREE_TYPE (name)), name);
	      else
		{
		  int is_loc = chill_location (name);
		  if (is_loc == 1) /* This is probably not possible */
		    warning ("non-referable location in DO WITH");
		  
		  if (is_loc > 1)
		    name = build_chill_arrow_expr (name, 1);
		  name = decl_temp1 (get_identifier ("__with_element"),
				     TREE_TYPE (name),
				     0, name, 0, 0);
		  if (is_loc > 1)
		    name = build_chill_indirect_ref (name, NULL_TREE, 0);
		  
		}
	      if (TREE_CODE (TREE_TYPE (name)) != RECORD_TYPE)
		error ("WITH element must be of STRUCT mode");
	      else
		list = tree_cons (NULL_TREE, name, list);
	    }
	  if (! check_token (COMMA))
	    break;
	}
      pushlevel (1);
      push_action ();
      for (list = nreverse (list); list != NULL_TREE; list = TREE_CHAIN (list))
	shadow_record_fields (TREE_VALUE (list));

      parse_semi_colon ();
      parse_opt_actions ();
      expect (OD, "missing 'OD' in 'DO WITH'");
      if (! ignoring)
	emit_line_note (input_filename, lineno);
      possibly_define_exit_label (label);
      parse_opt_handler ();
      parse_opt_end_label_semi_colon (label);
      poplevel (0, 0, 0); 
      return;
    }
  token = PEEK_TOKEN();
  if (token != FOR && token != WHILE)
    {
      push_handler ();
      parse_opt_actions ();
      expect (OD, "Missing 'OD' after 'DO'");
      parse_opt_handler ();
      parse_opt_end_label_semi_colon (label);
      return;
    }
  if (! ignoring)
    emit_line_note (input_filename, lineno);
  push_loop_block ();
  if (check_token (FOR))
    {
      if (check_token (EVER))
	{
	  if (!ignoring)
	    build_loop_iterator (NULL_TREE, NULL_TREE,
				 NULL_TREE, NULL_TREE,
				 0, 0, 1);
	}
      else
	{
	  parse_iteration ();
	  while (check_token (COMMA))
	    parse_iteration ();
	}
    }
  else if (!ignoring)
    build_loop_iterator (NULL_TREE, NULL_TREE,
			 NULL_TREE, NULL_TREE,
			 0, 0, 1);
       
  begin_loop_scope ();
  if (! ignoring)
    build_loop_start (label);
  condition = check_token (WHILE) ? parse_expression () : NULL_TREE;
  if (! ignoring)
    top_loop_end_check (condition);
  parse_semi_colon ();
  parse_opt_actions ();
  if (! ignoring)
    build_loop_end (); 
  expect (OD, "Missing 'OD' after 'DO'");
  /* Note that the handler is inside the reach of the DO. */
  parse_opt_handler ();
  end_loop_scope (label);
  pop_loop_block ();
  parse_opt_end_label_semi_colon (label);
}

/* Matches: '(' <signal name> [ 'IN' <defining occurrence list> ']' ')' ':'
   or: '(' <buffer location> IN (defining occurrence> ')' ':'
   or: returns NULL_TREE. */

static tree
parse_receive_spec ()
{
  tree val;
  tree name_list = NULL_TREE;
  if (!check_token (LPRN))
    return NULL_TREE;
  val = parse_primval ();
  if (check_token (IN))
    {
#if 0
      if (flag_local_loop_counter)
	name_list = parse_defining_occurrence_list ();
      else
#endif
	{
	  for (;;)
	    {
	      tree loc = parse_primval ();
	      if (! ignoring)
		name_list = tree_cons (NULL_TREE, loc, name_list);
	      if (! check_token (COMMA))
		break;
	    }
	}
    }
  if (! check_token (RPRN))
    {
      error ("missing ')' in signal/buffer receive alternative");
      return NULL_TREE;
    }
  if (check_token (COLON))
    {
      if (ignoring || val == NULL_TREE || TREE_CODE (val) == ERROR_MARK)
	return error_mark_node;
      else
	return build_receive_case_label (val, name_list);
    }

  /* We saw: '(' <primitive value> ')' not followed by ':'.
     Presumably the start of an action.  Backup and fail. */
  if (name_list != NULL_TREE)
    error ("misplaced 'IN' in signal/buffer receive alternative");
  pushback_paren_expr (val);
  return NULL_TREE;
}

/* To understand the code generation for this, see ch-tasking.c,
   and the 2-page comments preceding the
   build_chill_receive_case_start () definition. */

static void
parse_receive_case_action (label)
     tree label;
{
  tree instance_location;
  tree have_else_actions;
  int spec_seen = 0;
  tree alt_list = NULL_TREE;
  require (RECEIVE);
  require (CASE);
  push_action ();
  pushlevel (1);
  if (! ignoring)
    {
      expand_exit_needed = 0;
    }

  if (check_token (SET))
    {
      instance_location = parse_expression ();
      parse_semi_colon ();
    }
  else
    instance_location = NULL_TREE;
  if (! ignoring)
    instance_location = build_receive_case_start (instance_location);

  for (;;)
    {
      tree receive_spec = parse_receive_spec ();
      if (receive_spec)
	{
	  if (! ignoring)
	    alt_list = tree_cons (NULL_TREE, receive_spec, alt_list);
	  spec_seen++;
	}
      else if (parse_action ())
	{
	  if (! spec_seen && pass == 1)
	    error ("missing RECEIVE alternative");
	  if (! ignoring)
	    expand_exit_needed = 1;
	  spec_seen = 1;
	}
      else
	break;
    }
  if (check_token (ELSE))
    {
      if (! ignoring)
	{
	  emit_line_note (input_filename, lineno); 
	  if (build_receive_case_if_generated ())
	    expand_start_else ();
	}
      parse_opt_actions ();
      have_else_actions = integer_one_node;
    }
  else
    have_else_actions = integer_zero_node;
  expect (ESAC, "missing 'ESAC' matching 'RECEIVE CASE'");
  if (! ignoring)
    {
      build_receive_case_end (nreverse (alt_list), have_else_actions);
    }
  possibly_define_exit_label (label);
  poplevel (0, 0, 0); 
}

static void
parse_send_action ()
{
  tree signal = NULL_TREE;
  tree buffer = NULL_TREE;
  tree value_list;
  tree with_expr, to_expr, priority;
  require (SEND);
  /* The tricky part is distinguishing between a SEND buffer action,
     and a SEND signal action. */
  if (pass != 2 || PEEK_TOKEN () != NAME)
    {
      /* If this is pass 2, it's a SEND buffer action.
	 If it's pass 1, we don't care. */
      buffer = parse_primval ();
    }
  else
    {
      /* We have to specifically check for signalname followed by
	 a '(', since we allow a signalname to be used (syntactically)
	 as a "function". */
      tree name = parse_name ();
      if (TREE_CODE (name) == TYPE_DECL && CH_DECL_SIGNAL (name))
	signal = name; /* It's a SEND signal action! */
      else
	{
	  /* It's not a legal SEND signal action.
	     Back up and try as a SEND buffer action. */
	  pushback_token (EXPR, name);
	  buffer = parse_primval ();
	}
    }
  if (check_token (LPRN))
    {
      value_list = NULL_TREE;
      for (;;)
	{
	  tree expr = parse_untyped_expr ();
	  if (! ignoring)
	    value_list = tree_cons (NULL_TREE, expr, value_list);
	  if (! check_token (COMMA))
	    break;
	}
      value_list = nreverse (value_list);
      expect (RPRN, "missing ')'");
    }
  else
    value_list = NULL_TREE;
  if (check_token (WITH))
    with_expr = parse_expression ();
  else
    with_expr = NULL_TREE;
  if (check_token (TO))
    to_expr = parse_expression ();
  else
    to_expr = NULL_TREE;
  if (check_token (PRIORITY))
    priority = parse_expression ();
  else
    priority = NULL_TREE;
  PUSH_ACTION;
  if (ignoring)
    return;

  if (signal)
    { /* It's a <send signal action>! */
      tree sigdesc = build_signal_descriptor (signal, value_list);
      if (sigdesc != NULL_TREE && TREE_CODE (sigdesc) != ERROR_MARK)
	{
	  tree sendto = to_expr ? to_expr : IDENTIFIER_SIGNAL_DEST (signal);
	  expand_send_signal (sigdesc, with_expr,
			      sendto, priority, DECL_NAME (signal));
	}
    }
  else
    {
      /* all checks are done in expand_send_buffer */
      expand_send_buffer (buffer, value_list, priority, with_expr, to_expr);
    }
}

static void
parse_start_action ()
{
  tree name, copy_number, param_list, startset;
  require (START);
  name = parse_name_string ();
  expect (LPRN, "missing '(' in START action");
  PUSH_ACTION;
  /* copy number is a required parameter */
  copy_number = parse_expression ();
  if (!ignoring
      && (copy_number == NULL_TREE 
	  || TREE_CODE (copy_number) == ERROR_MARK
	  || TREE_CODE (TREE_TYPE (copy_number)) != INTEGER_TYPE))
    {
      error ("PROCESS copy number must be integer");
      copy_number = integer_zero_node;
    }
  if (check_token (COMMA))
    param_list = parse_expr_list (); /* user parameters */
  else
    param_list = NULL_TREE;
  expect (RPRN, "missing ')'");
  startset = check_token (SET) ? parse_primval () : NULL;
  build_start_process (name, copy_number, param_list, startset);
}

static void
parse_opt_actions ()
{
  while (parse_action ()) ;
}

static int
parse_action ()
{
  tree label = NULL_TREE;
  tree expr, rhs, loclist;
  enum tree_code op;

  if (current_function_decl == global_function_decl
      && PEEK_TOKEN () != SC
      && PEEK_TOKEN () != END)
    seen_action = 1, build_constructor = 1;

  if (PEEK_TOKEN () == NAME && PEEK_TOKEN1 () == COLON)
    {
      label = parse_defining_occurrence ();
      require (COLON);
      INIT_ACTION;
      define_label (input_filename, lineno, label);
    }

  switch (PEEK_TOKEN ())
    {
    case AFTER:
      {
	int delay;
	require (AFTER);
	expr = parse_primval ();
	delay = check_token (DELAY);
	expect (IN, "missing 'IN'");
	push_action ();
	pushlevel (1);
	build_after_start (expr, delay);
	parse_opt_actions ();
	expect (TIMEOUT, "missing 'TIMEOUT'");
	build_after_timeout_start ();
	parse_opt_actions ();
	expect (END, "missing 'END'");
	build_after_end ();
	possibly_define_exit_label (label);
	poplevel (0, 0, 0); 
      }
      goto bracketed_action;
    case ASM_KEYWORD:
      parse_asm_action ();
      goto no_handler_action;
    case ASSERT:
      require (ASSERT);
      PUSH_ACTION;
      expr = parse_expression ();
      if (! ignoring)
	{ tree assertfail = ridpointers[(int) RID_ASSERTFAIL];
	  expr = build (TRUTH_ORIF_EXPR, void_type_node, expr,
			build_cause_exception (assertfail, 0));
	  expand_expr_stmt (fold (expr));
	}
      goto handler_action;
    case AT:
      require (AT);
      PUSH_ACTION;
      expr = parse_primval ();
      expect (IN, "missing 'IN'");
      pushlevel (1);
      if (! ignoring)
	build_at_action (expr);
      parse_opt_actions ();
      expect (TIMEOUT, "missing 'TIMEOUT'");
      if (! ignoring)
	expand_start_else ();
      parse_opt_actions ();
      expect (END, "missing 'END'");
      if (! ignoring)
	expand_end_cond ();
      possibly_define_exit_label (label);
      poplevel (0, 0, 0);
      goto bracketed_action;
    case BEGINTOKEN:
      parse_begin_end_block (label);
      return 1;
    case CASE:
      parse_case_action (label);
      goto bracketed_action;