gdb/mi/mi-parse.c

/* MI Command Set - MI parser.

   Copyright (C) 2000-2020 Free Software Foundation, Inc.

   Contributed by Cygnus Solutions (a Red Hat company).

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "mi-cmds.h"
#include "mi-parse.h"
#include "charset.h"

#include <ctype.h>
#include "cli/cli-utils.h"
#include "language.h"

static const char mi_no_values[] = "--no-values";
static const char mi_simple_values[] = "--simple-values";
static const char mi_all_values[] = "--all-values";

/* Like parse_escape, but leave the results as a host char, not a
   target char.  */

static int
mi_parse_escape (const char **string_ptr)
{
  int c = *(*string_ptr)++;

  switch (c)
    {
      case '\n':
	return -2;
      case 0:
	(*string_ptr)--;
	return 0;

      case '0':
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
	{
	  int i = host_hex_value (c);
	  int count = 0;

	  while (++count < 3)
	    {
	      c = (**string_ptr);
	      if (isdigit (c) && c != '8' && c != '9')
		{
		  (*string_ptr)++;
		  i *= 8;
		  i += host_hex_value (c);
		}
	      else
		{
		  break;
		}
	    }
	  return i;
	}

    case 'a':
      c = '\a';
      break;
    case 'b':
      c = '\b';
      break;
    case 'f':
      c = '\f';
      break;
    case 'n':
      c = '\n';
      break;
    case 'r':
      c = '\r';
      break;
    case 't':
      c = '\t';
      break;
    case 'v':
      c = '\v';
      break;

    default:
      break;
    }

  return c;
}

static void
mi_parse_argv (const char *args, struct mi_parse *parse)
{
  const char *chp = args;
  int argc = 0;
  char **argv = XNEWVEC (char *, argc + 1);

  argv[argc] = NULL;
  while (1)
    {
      char *arg;

      /* Skip leading white space.  */
      chp = skip_spaces (chp);
      /* Three possibilities: EOF, quoted string, or other text. */
      switch (*chp)
	{
	case '\0':
	  parse->argv = argv;
	  parse->argc = argc;
	  return;
	case '"':
	  {
	    /* A quoted string.  */
	    int len;
	    const char *start = chp + 1;

	    /* Determine the buffer size.  */
	    chp = start;
	    len = 0;
	    while (*chp != '\0' && *chp != '"')
	      {
		if (*chp == '\\')
		  {
		    chp++;
		    if (mi_parse_escape (&chp) <= 0)
		      {
			/* Do not allow split lines or "\000".  */
			freeargv (argv);
			return;
		      }
		  }
		else
		  chp++;
		len++;
	      }
	    /* Insist on a closing quote.  */
	    if (*chp != '"')
	      {
		freeargv (argv);
		return;
	      }
	    /* Insist on trailing white space.  */
	    if (chp[1] != '\0' && !isspace (chp[1]))
	      {
		freeargv (argv);
		return;
	      }
	    /* Create the buffer and copy characters in.  */
	    arg = XNEWVEC (char, len + 1);
	    chp = start;
	    len = 0;
	    while (*chp != '\0' && *chp != '"')
	      {
		if (*chp == '\\')
		  {
		    chp++;
		    arg[len] = mi_parse_escape (&chp);
		  }
		else
		  arg[len] = *chp++;
		len++;
	      }
	    arg[len] = '\0';
	    chp++;		/* That closing quote.  */
	    break;
	  }
	default:
	  {
	    /* An unquoted string.  Accumulate all non-blank
	       characters into a buffer.  */
	    int len;
	    const char *start = chp;

	    while (*chp != '\0' && !isspace (*chp))
	      {
		chp++;
	      }
	    len = chp - start;
	    arg = XNEWVEC (char, len + 1);
	    strncpy (arg, start, len);
	    arg[len] = '\0';
	    break;
	  }
	}
      /* Append arg to argv.  */
      argv = XRESIZEVEC (char *, argv, argc + 2);
      argv[argc++] = arg;
      argv[argc] = NULL;
    }
}

mi_parse::mi_parse ()
  : op (MI_COMMAND),
    command (NULL),
    token (NULL),
    cmd (NULL),
    cmd_start (NULL),
    args (NULL),
    argv (NULL),
    argc (0),
    all (0),
    thread_group (-1),
    thread (-1),
    frame (-1),
    language (language_unknown)
{
}

mi_parse::~mi_parse ()
{
  xfree (command);
  xfree (token);
  xfree (args);
  freeargv (argv);
}

std::unique_ptr<struct mi_parse>
mi_parse (const char *cmd, char **token)
{
  const char *chp;

  std::unique_ptr<struct mi_parse> parse (new struct mi_parse);

  /* Before starting, skip leading white space.  */
  cmd = skip_spaces (cmd);

  /* Find/skip any token and then extract it.  */
  for (chp = cmd; *chp >= '0' && *chp <= '9'; chp++)
    ;
  *token = (char *) xmalloc (chp - cmd + 1);
  memcpy (*token, cmd, (chp - cmd));
  (*token)[chp - cmd] = '\0';

  /* This wasn't a real MI command.  Return it as a CLI_COMMAND.  */
  if (*chp != '-')
    {
      chp = skip_spaces (chp);
      parse->command = xstrdup (chp);
      parse->op = CLI_COMMAND;

      return parse;
    }

  /* Extract the command.  */
  {
    const char *tmp = chp + 1;	/* discard ``-'' */

    for (; *chp && !isspace (*chp); chp++)
      ;
    parse->command = (char *) xmalloc (chp - tmp + 1);
    memcpy (parse->command, tmp, chp - tmp);
    parse->command[chp - tmp] = '\0';
  }

  /* Find the command in the MI table.  */
  parse->cmd = mi_lookup (parse->command);
  if (parse->cmd == NULL)
    throw_error (UNDEFINED_COMMAND_ERROR,
		 _("Undefined MI command: %s"), parse->command);

  /* Skip white space following the command.  */
  chp = skip_spaces (chp);

  /* Parse the --thread and --frame options, if present.  At present,
     some important commands, like '-break-*' are implemented by
     forwarding to the CLI layer directly.  We want to parse --thread
     and --frame here, so as not to leave those option in the string
     that will be passed to CLI.

     Same for the --language option.  */

  for (;;)
    {
      const char *option;
      size_t as = sizeof ("--all ") - 1;
      size_t tgs = sizeof ("--thread-group ") - 1;
      size_t ts = sizeof ("--thread ") - 1;
      size_t fs = sizeof ("--frame ") - 1;
      size_t ls = sizeof ("--language ") - 1;

      if (strncmp (chp, "--all ", as) == 0)
	{
	  parse->all = 1;
	  chp += as;
	}
      /* See if --all is the last token in the input.  */
      if (strcmp (chp, "--all") == 0)
	{
          parse->all = 1;
          chp += strlen (chp);
        }
      if (strncmp (chp, "--thread-group ", tgs) == 0)
	{
	  char *endp;

	  option = "--thread-group";
	  if (parse->thread_group != -1)
	    error (_("Duplicate '--thread-group' option"));
	  chp += tgs;
	  if (*chp != 'i')
	    error (_("Invalid thread group id"));
	  chp += 1;
	  parse->thread_group = strtol (chp, &endp, 10);
	  chp = endp;
	}
      else if (strncmp (chp, "--thread ", ts) == 0)
	{
	  char *endp;

	  option = "--thread";
	  if (parse->thread != -1)
	    error (_("Duplicate '--thread' option"));
	  chp += ts;
	  parse->thread = strtol (chp, &endp, 10);
	  chp = endp;
	}
      else if (strncmp (chp, "--frame ", fs) == 0)
	{
	  char *endp;

	  option = "--frame";
	  if (parse->frame != -1)
	    error (_("Duplicate '--frame' option"));
	  chp += fs;
	  parse->frame = strtol (chp, &endp, 10);
	  chp = endp;
	}
      else if (strncmp (chp, "--language ", ls) == 0)
	{
	  option = "--language";
	  chp += ls;
	  std::string lang_name = extract_arg (&chp);

	  parse->language = language_enum (lang_name.c_str ());
	  if (parse->language == language_unknown
	      || parse->language == language_auto)
	    error (_("Invalid --language argument: %s"), lang_name.c_str ());
	}
      else
	break;

      if (*chp != '\0' && !isspace (*chp))
	error (_("Invalid value for the '%s' option"), option);
      chp = skip_spaces (chp);
    }

  /* For new argv commands, attempt to return the parsed argument
     list.  */
  if (parse->cmd->argv_func != NULL)
    {
      mi_parse_argv (chp, parse.get ());
      if (parse->argv == NULL)
	error (_("Problem parsing arguments: %s %s"), parse->command, chp);
    }

  /* FIXME: DELETE THIS */
  /* For CLI commands, also return the remainder of the
     command line as a single string. */
  if (parse->cmd->cli.cmd != NULL)
    parse->args = xstrdup (chp);

  /* Fully parsed, flag as an MI command.  */
  parse->op = MI_COMMAND;
  return parse;
}

enum print_values
mi_parse_print_values (const char *name)
{
   if (strcmp (name, "0") == 0
       || strcmp (name, mi_no_values) == 0)
     return PRINT_NO_VALUES;
   else if (strcmp (name, "1") == 0
	    || strcmp (name, mi_all_values) == 0)
     return PRINT_ALL_VALUES;
   else if (strcmp (name, "2") == 0
	    || strcmp (name, mi_simple_values) == 0)
     return PRINT_SIMPLE_VALUES;
   else
     error (_("Unknown value for PRINT_VALUES: must be: \
0 or \"%s\", 1 or \"%s\", 2 or \"%s\""),
	    mi_no_values, mi_all_values, mi_simple_values);
}