tmsim

  1/*
  2 * Copyright © 2016-2018 Sören Tempel
  3 *
  4 * This program is free software: you can redistribute it and/or
  5 * modify it under the terms of the GNU Affero General Public
  6 * License as published by the Free Software Foundation, either
  7 * version 3 of the License, or (at your option) any later version.
  8 *
  9 * This program is distributed in the hope that it will be useful,
 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 12 * Affero General Public License for more details.
 13 *
 14 * You should have received a copy of the GNU Affero General Public
 15 * License along with this program. If not, see
 16 * <http://www.gnu.org/licenses/>.
 17 */
 18
 19#ifndef TMSIM_SCANNER_H
 20#define TMSIM_SCANNER_H
 21
 22#include <pthread.h>
 23
 24#include <sys/types.h>
 25
 26#include "queue.h"
 27#include "token.h"
 28
 29/**
 30 * Can be used in conjunction with emit if the character in the input
 31 * string at the start position of this token should be used as the
 32 * value field of the enqueued token.
 33 *
 34 * @param SCANNER Scanner for which a value should be emitted.
 35 */
 36#define TOKAUTO(SCANNER) (SCANNER->input[scr->start])
 37
 38/**
 39 * Macro which must be used to return from a ::scanfn function. This
 40 * macro sets the state field of given scanner and returns afterwards.
 41 *
 42 * @param SCANNER Scanner for which state field should be modified.
 43 * @param FUNCTION Function pointer which should be used as the next
 44 * 	state.
 45 */
 46#define LEXRET(SCANNER, FUNCTION) \
 47	do { \
 48		SCANNER->state = FUNCTION; \
 49		return; \
 50	} while (0)
 51
 52enum {
 53	/**
 54	 * Passed to emit (as value) if the token doesn't have a
 55	 * meaningful character value.
 56	 */
 57	TOKNOP = 0,
 58
 59	/**
 60	 * Amount of bytes needed for a string representation of the
 61	 * ::tmname type plus one byte for null termination. This value
 62	 * is somewhat heuristic.
 63	 */
 64	STATELEN = 64,
 65};
 66
 67/**
 68 * Multithreaded lexer for the tmsim input files.
 69 */
 70typedef struct _scanner scanner;
 71
 72/**
 73 * Function pointer representing the current state of a ::scanner.
 74 */
 75typedef void (*scanfn)(scanner *scr);
 76
 77struct _scanner {
 78	/**
 79	 * Current state of the scanner. This field points to the
 80	 * function which should be invoked next for parsing the
 81	 * upcoming characters.
 82	 */
 83	scanfn state;
 84
 85	/**
 86	 * Thread used to perform lexical scanning of the input string.
 87	 */
 88	pthread_t thread;
 89
 90	/**
 91	 * Queue to which recognized tokens should be added.
 92	 */
 93	queue *tqueue;
 94
 95	char *input;  /**< Input string passed to ::scanstr. */
 96	size_t inlen; /**< Length of the input string. */
 97
 98	size_t pos;   /**< Current position in the input string. */
 99	size_t start; /**< Start position of current token in input string. */
100
101	unsigned int line;   /**< Line being analyzed currently. */
102	unsigned int column; /**< Column being analyzed currently. */
103};
104
105scanner *scanstr(char *, size_t);
106token *nexttoken(scanner *);
107void freescanner(scanner *);
108
109#endif