cli-script.c

这个是LINUX下的GDB调度工具的源码

/* GDB CLI command scripting.

   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
   1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2004 Free Software
   Foundation, Inc.

   This file is part of GDB.

   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.  */

#include "defs.h"
#include "value.h"
#include "language.h"		/* For value_true */
#include <ctype.h>

#include "ui-out.h"
#include "gdb_string.h"

#include "top.h"
#include "cli/cli-cmds.h"
#include "cli/cli-decode.h"
#include "cli/cli-script.h"

/* Prototypes for local functions */

static enum command_control_type
	recurse_read_control_structure (struct command_line *current_cmd);

static char *insert_args (char *line);

static struct cleanup * setup_user_args (char *p);

static void validate_comname (char *);

/* Level of control structure.  */
static int control_level;

/* Source command state variable. */
static int source_error_allocated;

/* Structure for arguments to user defined functions.  */
#define MAXUSERARGS 10
struct user_args
  {
    struct user_args *next;
    struct
      {
	char *arg;
	int len;
      }
    a[MAXUSERARGS];
    int count;
  }
 *user_args;


/* Allocate, initialize a new command line structure for one of the
   control commands (if/while).  */

static struct command_line *
build_command_line (enum command_control_type type, char *args)
{
  struct command_line *cmd;

  if (args == NULL)
    error ("if/while commands require arguments.\n");

  cmd = (struct command_line *) xmalloc (sizeof (struct command_line));
  cmd->next = NULL;
  cmd->control_type = type;

  cmd->body_count = 1;
  cmd->body_list
    = (struct command_line **) xmalloc (sizeof (struct command_line *)
					* cmd->body_count);
  memset (cmd->body_list, 0, sizeof (struct command_line *) * cmd->body_count);
  cmd->line = savestring (args, strlen (args));
  return cmd;
}

/* Build and return a new command structure for the control commands
   such as "if" and "while".  */

static struct command_line *
get_command_line (enum command_control_type type, char *arg)
{
  struct command_line *cmd;
  struct cleanup *old_chain = NULL;

  /* Allocate and build a new command line structure.  */
  cmd = build_command_line (type, arg);

  old_chain = make_cleanup_free_command_lines (&cmd);

  /* Read in the body of this command.  */
  if (recurse_read_control_structure (cmd) == invalid_control)
    {
      warning ("error reading in control structure\n");
      do_cleanups (old_chain);
      return NULL;
    }

  discard_cleanups (old_chain);
  return cmd;
}

/* Recursively print a command (including full control structures).  */

void
print_command_lines (struct ui_out *uiout, struct command_line *cmd,
		     unsigned int depth)
{
  struct command_line *list;

  list = cmd;
  while (list)
    {

      if (depth)
	ui_out_spaces (uiout, 2 * depth);

      /* A simple command, print it and continue.  */
      if (list->control_type == simple_control)
	{
	  ui_out_field_string (uiout, NULL, list->line);
	  ui_out_text (uiout, "\n");
	  list = list->next;
	  continue;
	}

      /* loop_continue to jump to the start of a while loop, print it
         and continue. */
      if (list->control_type == continue_control)
	{
	  ui_out_field_string (uiout, NULL, "loop_continue");
	  ui_out_text (uiout, "\n");
	  list = list->next;
	  continue;
	}

      /* loop_break to break out of a while loop, print it and continue.  */
      if (list->control_type == break_control)
	{
	  ui_out_field_string (uiout, NULL, "loop_break");
	  ui_out_text (uiout, "\n");
	  list = list->next;
	  continue;
	}

      /* A while command.  Recursively print its subcommands and continue.  */
      if (list->control_type == while_control)
	{
	  ui_out_field_fmt (uiout, NULL, "while %s", list->line);
	  ui_out_text (uiout, "\n");
	  print_command_lines (uiout, *list->body_list, depth + 1);
	  if (depth)
	    ui_out_spaces (uiout, 2 * depth);
	  ui_out_field_string (uiout, NULL, "end");
	  ui_out_text (uiout, "\n");
	  list = list->next;
	  continue;
	}

      /* An if command.  Recursively print both arms before continueing.  */
      if (list->control_type == if_control)
	{
	  ui_out_field_fmt (uiout, NULL, "if %s", list->line);
	  ui_out_text (uiout, "\n");
	  /* The true arm. */
	  print_command_lines (uiout, list->body_list[0], depth + 1);

	  /* Show the false arm if it exists.  */
	  if (list->body_count == 2)
	    {
	      if (depth)
		ui_out_spaces (uiout, 2 * depth);
	      ui_out_field_string (uiout, NULL, "else");
	      ui_out_text (uiout, "\n");
	      print_command_lines (uiout, list->body_list[1], depth + 1);
	    }

	  if (depth)
	    ui_out_spaces (uiout, 2 * depth);
	  ui_out_field_string (uiout, NULL, "end");
	  ui_out_text (uiout, "\n");
	  list = list->next;
	  continue;
	}

      /* ignore illegal command type and try next */
      list = list->next;
    }				/* while (list) */
}

/* Handle pre-post hooks.  */

static void
clear_hook_in_cleanup (void *data)
{
  struct cmd_list_element *c = data;
  c->hook_in = 0; /* Allow hook to work again once it is complete */
}

void
execute_cmd_pre_hook (struct cmd_list_element *c)
{
  if ((c->hook_pre) && (!c->hook_in))
    {
      struct cleanup *cleanups = make_cleanup (clear_hook_in_cleanup, c);
      c->hook_in = 1; /* Prevent recursive hooking */
      execute_user_command (c->hook_pre, (char *) 0);
      do_cleanups (cleanups);
    }
}

void
execute_cmd_post_hook (struct cmd_list_element *c)
{
  if ((c->hook_post) && (!c->hook_in))
    {
      struct cleanup *cleanups = make_cleanup (clear_hook_in_cleanup, c);
      c->hook_in = 1; /* Prevent recursive hooking */
      execute_user_command (c->hook_post, (char *) 0);
      do_cleanups (cleanups);
    }
}

/* Execute the command in CMD.  */
static void
do_restore_user_call_depth (void * call_depth)
{	
  int * depth = call_depth;
  /* We will be returning_to_top_level() at this point, so we want to
     reset our depth. */
  (*depth) = 0;
}


void
execute_user_command (struct cmd_list_element *c, char *args)
{
  struct command_line *cmdlines;
  struct cleanup *old_chain;
  enum command_control_type ret;
  static int user_call_depth = 0;
  extern int max_user_call_depth;

  old_chain = setup_user_args (args);

  cmdlines = c->user_commands;
  if (cmdlines == 0)
    /* Null command */
    return;

  if (++user_call_depth > max_user_call_depth)
    error ("Max user call depth exceeded -- command aborted\n");

  old_chain = make_cleanup (do_restore_user_call_depth, &user_call_depth);

  /* Set the instream to 0, indicating execution of a
     user-defined function.  */
  old_chain = make_cleanup (do_restore_instream_cleanup, instream);
  instream = (FILE *) 0;
  while (cmdlines)
    {
      ret = execute_control_command (cmdlines);
      if (ret != simple_control && ret != break_control)
	{
	  warning ("Error in control structure.\n");
	  break;
	}
      cmdlines = cmdlines->next;
    }
  do_cleanups (old_chain);

  user_call_depth--;
}

enum command_control_type
execute_control_command (struct command_line *cmd)
{
  struct expression *expr;
  struct command_line *current;
  struct cleanup *old_chain = make_cleanup (null_cleanup, 0);
  struct value *val;
  struct value *val_mark;
  int loop;
  enum command_control_type ret;
  char *new_line;

  /* Start by assuming failure, if a problem is detected, the code
     below will simply "break" out of the switch.  */
  ret = invalid_control;

  switch (cmd->control_type)
    {
    case simple_control:
      /* A simple command, execute it and return.  */
      new_line = insert_args (cmd->line);
      if (!new_line)
	break;
      make_cleanup (free_current_contents, &new_line);
      execute_command (new_line, 0);
      ret = cmd->control_type;
      break;

    case continue_control:
    case break_control:
      /* Return for "continue", and "break" so we can either
         continue the loop at the top, or break out.  */
      ret = cmd->control_type;
      break;

    case while_control:
      {
	/* Parse the loop control expression for the while statement.  */
	new_line = insert_args (cmd->line);
	if (!new_line)
	  break;
	make_cleanup (free_current_contents, &new_line);
	expr = parse_expression (new_line);
	make_cleanup (free_current_contents, &expr);

	ret = simple_control;
	loop = 1;

	/* Keep iterating so long as the expression is true.  */
	while (loop == 1)
	  {
	    int cond_result;

	    QUIT;

	    /* Evaluate the expression.  */
	    val_mark = value_mark ();
	    val = evaluate_expression (expr);
	    cond_result = value_true (val);
	    value_free_to_mark (val_mark);

	    /* If the value is false, then break out of the loop.  */
	    if (!cond_result)
	      break;

	    /* Execute the body of the while statement.  */
	    current = *cmd->body_list;
	    while (current)
	      {
		ret = execute_control_command (current);

		/* If we got an error, or a "break" command, then stop
		   looping.  */
		if (ret == invalid_control || ret == break_control)
		  {
		    loop = 0;
		    break;
		  }

		/* If we got a "continue" command, then restart the loop
		   at this point.  */
		if (ret == continue_control)
		  break;

		/* Get the next statement.  */
		current = current->next;
	      }
	  }

	/* Reset RET so that we don't recurse the break all the way down.  */
	if (ret == break_control)
	  ret = simple_control;

	break;
      }

    case if_control:
      {
	new_line = insert_args (cmd->line);
	if (!new_line)
	  break;
	make_cleanup (free_current_contents, &new_line);
	/* Parse the conditional for the if statement.  */
	expr = parse_expression (new_line);
	make_cleanup (free_current_contents, &expr);

	current = NULL;
	ret = simple_control;

	/* Evaluate the conditional.  */
	val_mark = value_mark ();
	val = evaluate_expression (expr);

	/* Choose which arm to take commands from based on the value of the
	   conditional expression.  */
	if (value_true (val))
	  current = *cmd->body_list;
	else if (cmd->body_count == 2)
	  current = *(cmd->body_list + 1);
	value_free_to_mark (val_mark);

	/* Execute commands in the given arm.  */
	while (current)
	  {
	    ret = execute_control_command (current);

	    /* If we got an error, get out.  */
	    if (ret != simple_control)
	      break;

	    /* Get the next statement in the body.  */
	    current = current->next;
	  }

	break;
      }

    default:
      warning ("Invalid control type in command structure.");
      break;
    }

  do_cleanups (old_chain);

  return ret;
}

/* "while" command support.  Executes a body of statements while the