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/* parser.c - the part of the parser that can return partial tokens */
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2005,2007,2009 Free Software Foundation, Inc.
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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#include <grub/parser.h>
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#include <grub/misc.h>
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/* All the possible state transitions on the command line. If a
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transition can not be found, it is assumed that there is no
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transition and keep_value is assumed to be 1. */
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static struct grub_parser_state_transition state_transitions[] = {
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{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_QUOTE, '\'', 0},
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{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_DQUOTE, '\"', 0},
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{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_VAR, '$', 0},
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{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_ESC, '\\', 0},
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{GRUB_PARSER_STATE_ESC, GRUB_PARSER_STATE_TEXT, 0, 1},
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{GRUB_PARSER_STATE_QUOTE, GRUB_PARSER_STATE_TEXT, '\'', 0},
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{GRUB_PARSER_STATE_DQUOTE, GRUB_PARSER_STATE_TEXT, '\"', 0},
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{GRUB_PARSER_STATE_DQUOTE, GRUB_PARSER_STATE_QVAR, '$', 0},
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{GRUB_PARSER_STATE_VAR, GRUB_PARSER_STATE_VARNAME2, '{', 0},
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{GRUB_PARSER_STATE_VAR, GRUB_PARSER_STATE_VARNAME, 0, 1},
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{GRUB_PARSER_STATE_VARNAME, GRUB_PARSER_STATE_TEXT, ' ', 1},
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{GRUB_PARSER_STATE_VARNAME2, GRUB_PARSER_STATE_TEXT, '}', 0},
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{GRUB_PARSER_STATE_QVAR, GRUB_PARSER_STATE_QVARNAME2, '{', 0},
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{GRUB_PARSER_STATE_QVAR, GRUB_PARSER_STATE_QVARNAME, 0, 1},
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{GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_TEXT, '\"', 0},
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{GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_DQUOTE, ' ', 1},
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{GRUB_PARSER_STATE_QVARNAME2, GRUB_PARSER_STATE_DQUOTE, '}', 0},
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/* Determines the state following STATE, determined by C. */
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grub_parser_cmdline_state (grub_parser_state_t state, char c, char *result)
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struct grub_parser_state_transition *transition;
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struct grub_parser_state_transition default_transition;
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default_transition.to_state = state;
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default_transition.keep_value = 1;
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/* Look for a good translation. */
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for (transition = state_transitions; transition->from_state; transition++)
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if (transition->from_state != state)
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/* An exact match was found, use it. */
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if (transition->input == c)
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if (transition->input == ' ' && !grub_isalpha (c)
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&& !grub_isdigit (c) && c != '_')
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/* A less perfect match was found, use this one if no exact
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match can be found. */
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if (transition->input == 0)
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if (!transition->from_state)
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transition = &default_transition;
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if (transition->keep_value)
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return transition->to_state;
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grub_parser_split_cmdline (const char *cmdline, grub_reader_getline_t getline,
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int *argc, char ***argv)
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grub_parser_state_t state = GRUB_PARSER_STATE_TEXT;
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/* XXX: Fixed size buffer, perhaps this buffer should be dynamically
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char *rd = (char *) cmdline;
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auto int check_varstate (grub_parser_state_t s);
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int check_varstate (grub_parser_state_t s)
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return (s == GRUB_PARSER_STATE_VARNAME
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|| s == GRUB_PARSER_STATE_VARNAME2
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|| s == GRUB_PARSER_STATE_QVARNAME
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|| s == GRUB_PARSER_STATE_QVARNAME2);
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auto void add_var (grub_parser_state_t newstate);
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void add_var (grub_parser_state_t newstate)
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/* Check if a variable was being read in and the end of the name
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if (!(check_varstate (state) && !check_varstate (newstate)))
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val = grub_env_get (varname);
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/* Insert the contents of the variable in the buffer. */
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grub_parser_state_t newstate;
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newstate = grub_parser_cmdline_state (state, *rd, &use);
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/* If a variable was being processed and this character does
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not describe the variable anymore, write the variable to
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if (check_varstate (newstate))
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if (newstate == GRUB_PARSER_STATE_TEXT
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&& state != GRUB_PARSER_STATE_ESC && use == ' ')
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/* Don't add more than one argument if multiple
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if (bp != buffer && *(bp - 1))
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while (state != GRUB_PARSER_STATE_TEXT && !check_varstate (state));
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/* A special case for when the last character was part of a
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add_var (GRUB_PARSER_STATE_TEXT);
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if (bp != buffer && *(bp - 1))
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/* Reserve memory for the return values. */
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args = grub_malloc (bp - buffer);
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grub_memcpy (args, buffer, bp - buffer);
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*argv = grub_malloc (sizeof (char *) * (*argc + 1));
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/* The arguments are separated with 0's, setup argv so it points to
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for (i = 0; i < *argc; i++)
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grub_parser_execute (char *source)
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auto grub_err_t getline (char **line, int cont);
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grub_err_t getline (char **line, int cont __attribute__ ((unused)))
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p = grub_strchr (source, '\n');
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*line = grub_strndup (source, p - source);
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*line = grub_strdup (source);
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source = p ? p + 1 : 0;
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grub_rescue_parse_line (line, getline);