cli-script.c

这个是LINUX下的GDB调度工具的源码

	  ret = recurse_read_control_structure (next);
	  control_level--;

	  if (ret != simple_control)
	    break;
	}
    }

  dont_repeat ();

  return ret;
}

/* Read lines from the input stream and accumulate them in a chain of
   struct command_line's, which is then returned.  For input from a
   terminal, the special command "end" is used to mark the end of the
   input, and is not included in the returned chain of commands. */

#define END_MESSAGE "End with a line saying just \"end\"."

struct command_line *
read_command_lines (char *prompt_arg, int from_tty)
{
  struct command_line *head, *tail, *next;
  struct cleanup *old_chain;
  enum command_control_type ret;
  enum misc_command_type val;

  control_level = 0;
  if (deprecated_readline_begin_hook)
    {
      /* Note - intentional to merge messages with no newline */
      (*deprecated_readline_begin_hook) ("%s  %s\n", prompt_arg, END_MESSAGE);
    }
  else if (from_tty && input_from_terminal_p ())
    {
      printf_unfiltered ("%s\n%s\n", prompt_arg, END_MESSAGE);
      gdb_flush (gdb_stdout);
    }

  head = tail = NULL;
  old_chain = NULL;

  while (1)
    {
      val = read_next_line (&next);

      /* Ignore blank lines or comments.  */
      if (val == nop_command)
	continue;

      if (val == end_command)
	{
	  ret = simple_control;
	  break;
	}

      if (val != ok_command)
	{
	  ret = invalid_control;
	  break;
	}

      if (next->control_type == while_control
	  || next->control_type == if_control)
	{
	  control_level++;
	  ret = recurse_read_control_structure (next);
	  control_level--;

	  if (ret == invalid_control)
	    break;
	}

      if (tail)
	{
	  tail->next = next;
	}
      else
	{
	  head = next;
	  old_chain = make_cleanup_free_command_lines (&head);
	}
      tail = next;
    }

  dont_repeat ();

  if (head)
    {
      if (ret != invalid_control)
	{
	  discard_cleanups (old_chain);
	}
      else
	do_cleanups (old_chain);
    }

  if (deprecated_readline_end_hook)
    {
      (*deprecated_readline_end_hook) ();
    }
  return (head);
}

/* Free a chain of struct command_line's.  */

void
free_command_lines (struct command_line **lptr)
{
  struct command_line *l = *lptr;
  struct command_line *next;
  struct command_line **blist;
  int i;

  while (l)
    {
      if (l->body_count > 0)
	{
	  blist = l->body_list;
	  for (i = 0; i < l->body_count; i++, blist++)
	    free_command_lines (blist);
	}
      next = l->next;
      xfree (l->line);
      xfree (l);
      l = next;
    }
  *lptr = NULL;
}

static void
do_free_command_lines_cleanup (void *arg)
{
  free_command_lines (arg);
}

struct cleanup *
make_cleanup_free_command_lines (struct command_line **arg)
{
  return make_cleanup (do_free_command_lines_cleanup, arg);
}

struct command_line *
copy_command_lines (struct command_line *cmds)
{
  struct command_line *result = NULL;

  if (cmds)
    {
      result = (struct command_line *) xmalloc (sizeof (struct command_line));

      result->next = copy_command_lines (cmds->next);
      result->line = xstrdup (cmds->line);
      result->control_type = cmds->control_type;
      result->body_count = cmds->body_count;
      if (cmds->body_count > 0)
        {
          int i;

          result->body_list = (struct command_line **)
            xmalloc (sizeof (struct command_line *) * cmds->body_count);

          for (i = 0; i < cmds->body_count; i++)
            result->body_list[i] = copy_command_lines (cmds->body_list[i]);
        }
      else
        result->body_list = NULL;
    }

  return result;
}

static void
validate_comname (char *comname)
{
  char *p;

  if (comname == 0)
    error_no_arg ("name of command to define");

  p = comname;
  while (*p)
    {
      if (!isalnum (*p) && *p != '-' && *p != '_')
	error ("Junk in argument list: \"%s\"", p);
      p++;
    }
}

/* This is just a placeholder in the command data structures.  */
static void
user_defined_command (char *ignore, int from_tty)
{
}

void
define_command (char *comname, int from_tty)
{
#define MAX_TMPBUF 128   
  enum cmd_hook_type
    {
      CMD_NO_HOOK = 0,
      CMD_PRE_HOOK,
      CMD_POST_HOOK
    };
  struct command_line *cmds;
  struct cmd_list_element *c, *newc, *oldc, *hookc = 0;
  char *tem = comname;
  char *tem2; 
  char tmpbuf[MAX_TMPBUF];
  int  hook_type      = CMD_NO_HOOK;
  int  hook_name_size = 0;
   
#define	HOOK_STRING	"hook-"
#define	HOOK_LEN 5
#define HOOK_POST_STRING "hookpost-"
#define HOOK_POST_LEN    9

  validate_comname (comname);

  /* Look it up, and verify that we got an exact match.  */
  c = lookup_cmd (&tem, cmdlist, "", -1, 1);
  if (c && strcmp (comname, c->name) != 0)
    c = 0;

  if (c)
    {
      int q;
      if (c->class == class_user || c->class == class_alias)
	q = query ("Redefine command \"%s\"? ", c->name);
      else
	q = query ("Really redefine built-in command \"%s\"? ", c->name);
      if (!q)
	error ("Command \"%s\" not redefined.", c->name);
    }

  /* If this new command is a hook, then mark the command which it
     is hooking.  Note that we allow hooking `help' commands, so that
     we can hook the `stop' pseudo-command.  */

  if (!strncmp (comname, HOOK_STRING, HOOK_LEN))
    {
       hook_type      = CMD_PRE_HOOK;
       hook_name_size = HOOK_LEN;
    }
  else if (!strncmp (comname, HOOK_POST_STRING, HOOK_POST_LEN))
    {
      hook_type      = CMD_POST_HOOK;
      hook_name_size = HOOK_POST_LEN;
    }
   
  if (hook_type != CMD_NO_HOOK)
    {
      /* Look up cmd it hooks, and verify that we got an exact match.  */
      tem = comname + hook_name_size;
      hookc = lookup_cmd (&tem, cmdlist, "", -1, 0);
      if (hookc && strcmp (comname + hook_name_size, hookc->name) != 0)
	hookc = 0;
      if (!hookc)
	{
	  warning ("Your new `%s' command does not hook any existing command.",
		   comname);
	  if (!query ("Proceed? "))
	    error ("Not confirmed.");
	}
    }

  comname = savestring (comname, strlen (comname));

  /* If the rest of the commands will be case insensitive, this one
     should behave in the same manner. */
  for (tem = comname; *tem; tem++)
    if (isupper (*tem))
      *tem = tolower (*tem);

  sprintf (tmpbuf, "Type commands for definition of \"%s\".", comname);
  cmds = read_command_lines (tmpbuf, from_tty);

  if (c && c->class == class_user)
    free_command_lines (&c->user_commands);

  newc = add_cmd (comname, class_user, user_defined_command,
		  (c && c->class == class_user)
		  ? c->doc : savestring ("User-defined.", 13), &cmdlist);
  newc->user_commands = cmds;

  /* If this new command is a hook, then mark both commands as being
     tied.  */
  if (hookc)
    {
      switch (hook_type)
        {
        case CMD_PRE_HOOK:
          hookc->hook_pre  = newc;  /* Target gets hooked.  */
          newc->hookee_pre = hookc; /* We are marked as hooking target cmd. */
          break;
        case CMD_POST_HOOK:
          hookc->hook_post  = newc;  /* Target gets hooked.  */
          newc->hookee_post = hookc; /* We are marked as hooking target cmd. */
          break;
        default:
          /* Should never come here as hookc would be 0. */
	  internal_error (__FILE__, __LINE__, "bad switch");
        }
    }
}

void
document_command (char *comname, int from_tty)
{
  struct command_line *doclines;
  struct cmd_list_element *c;
  char *tem = comname;
  char tmpbuf[128];

  validate_comname (comname);

  c = lookup_cmd (&tem, cmdlist, "", 0, 1);

  if (c->class != class_user)
    error ("Command \"%s\" is built-in.", comname);

  sprintf (tmpbuf, "Type documentation for \"%s\".", comname);
  doclines = read_command_lines (tmpbuf, from_tty);

  if (c->doc)
    xfree (c->doc);

  {
    struct command_line *cl1;
    int len = 0;

    for (cl1 = doclines; cl1; cl1 = cl1->next)
      len += strlen (cl1->line) + 1;

    c->doc = (char *) xmalloc (len + 1);
    *c->doc = 0;

    for (cl1 = doclines; cl1; cl1 = cl1->next)
      {
	strcat (c->doc, cl1->line);
	if (cl1->next)
	  strcat (c->doc, "\n");
      }
  }

  free_command_lines (&doclines);
}

struct source_cleanup_lines_args
{
  int old_line;
  char *old_file;
  char *old_pre_error;
  char *old_error_pre_print;
};

static void
source_cleanup_lines (void *args)
{
  struct source_cleanup_lines_args *p =
  (struct source_cleanup_lines_args *) args;
  source_line_number = p->old_line;
  source_file_name = p->old_file;
  source_pre_error = p->old_pre_error;
  error_pre_print = p->old_error_pre_print;
}

static void
do_fclose_cleanup (void *stream)
{
  fclose (stream);
}

/* Used to implement source_command */

void
script_from_file (FILE *stream, char *file)
{
  struct cleanup *old_cleanups;
  struct source_cleanup_lines_args old_lines;
  int needed_length;

  if (stream == NULL)
    {
      internal_error (__FILE__, __LINE__, "called with NULL file pointer!");
    }

  old_cleanups = make_cleanup (do_fclose_cleanup, stream);

  old_lines.old_line = source_line_number;
  old_lines.old_file = source_file_name;
  old_lines.old_pre_error = source_pre_error;
  old_lines.old_error_pre_print = error_pre_print;
  make_cleanup (source_cleanup_lines, &old_lines);
  source_line_number = 0;
  source_file_name = file;
  source_pre_error = error_pre_print == NULL ? "" : error_pre_print;
  source_pre_error = savestring (source_pre_error, strlen (source_pre_error));
  make_cleanup (xfree, source_pre_error);
  /* This will get set every time we read a line.  So it won't stay "" for
     long.  */
  error_pre_print = "";

  needed_length = strlen (source_file_name) + strlen (source_pre_error) + 80;
  if (source_error_allocated < needed_length)
    {
      source_error_allocated *= 2;
      if (source_error_allocated < needed_length)
	source_error_allocated = needed_length;
      if (source_error == NULL)
	source_error = xmalloc (source_error_allocated);
      else
	source_error = xrealloc (source_error, source_error_allocated);
    }

  read_command_file (stream);

  do_cleanups (old_cleanups);
}

void
show_user_1 (struct cmd_list_element *c, struct ui_file *stream)
{
  struct command_line *cmdlines;

  cmdlines = c->user_commands;
  if (!cmdlines)
    return;
  fputs_filtered ("User command ", stream);
  fputs_filtered (c->name, stream);
  fputs_filtered (":\n", stream);

  print_command_lines (uiout, cmdlines, 1);
  fputs_filtered ("\n", stream);
}