flexdef.h

Flex词法/语法分析器源码

/* flexdef - definitions file for flex */

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Vern Paxson.
 * 
 * The United States Government has rights in this work pursuant
 * to contract no. DE-AC03-76SF00098 between the United States
 * Department of Energy and the University of California.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/* @(#) $Header: /home/daffy/u0/vern/flex/RCS/flexdef.h,v 2.53 95/04/20 11:17:36 vern Exp $ (LBL) */

#include <stdio.h>
#include <ctype.h>

#include "config.h"

#ifdef __TURBOC__
#define HAVE_STRING_H 1
#define MS_DOS 1
#ifndef __STDC__
#define __STDC__ 1
#endif
 #pragma warn -pro
 #pragma warn -rch
 #pragma warn -use
 #pragma warn -aus
 #pragma warn -par
 #pragma warn -pia
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif

#ifdef STDC_HEADERS
#include <stdlib.h>
#endif

/* As an aid for the internationalization patch to flex, which
 * is maintained outside this distribution for copyright reasons.
 */
#define _(String) (String)

/* Always be prepared to generate an 8-bit scanner. */
#define CSIZE 256
#define Char unsigned char

/* Size of input alphabet - should be size of ASCII set. */
#ifndef DEFAULT_CSIZE
#define DEFAULT_CSIZE 128
#endif

#ifndef PROTO
#if __STDC__
#define PROTO(proto) proto
#else
#define PROTO(proto) ()
#endif
#endif

#ifdef VMS
#ifndef __VMS_POSIX
#define unlink remove
#define SHORT_FILE_NAMES
#endif
#endif

#ifdef MS_DOS
#define SHORT_FILE_NAMES
#endif


/* Maximum line length we'll have to deal with. */
#define MAXLINE 2048

#ifndef MIN
#define MIN(x,y) ((x) < (y) ? (x) : (y))
#endif
#ifndef MAX
#define MAX(x,y) ((x) > (y) ? (x) : (y))
#endif
#ifndef ABS
#define ABS(x) ((x) < 0 ? -(x) : (x))
#endif


/* ANSI C does not guarantee that isascii() is defined */
#ifndef isascii
#define isascii(c) ((c) <= 0177)
#endif


#define true 1
#define false 0
#define unspecified -1


/* Special chk[] values marking the slots taking by end-of-buffer and action
 * numbers.
 */
#define EOB_POSITION -1
#define ACTION_POSITION -2

/* Number of data items per line for -f output. */
#define NUMDATAITEMS 10

/* Number of lines of data in -f output before inserting a blank line for
 * readability.
 */
#define NUMDATALINES 10

/* transition_struct_out() definitions. */
#define TRANS_STRUCT_PRINT_LENGTH 14

/* Returns true if an nfa state has an epsilon out-transition slot
 * that can be used.  This definition is currently not used.
 */
#define FREE_EPSILON(state) \
	(transchar[state] == SYM_EPSILON && \
	 trans2[state] == NO_TRANSITION && \
	 finalst[state] != state)

/* Returns true if an nfa state has an epsilon out-transition character
 * and both slots are free
 */
#define SUPER_FREE_EPSILON(state) \
	(transchar[state] == SYM_EPSILON && \
	 trans1[state] == NO_TRANSITION) \

/* Maximum number of NFA states that can comprise a DFA state.  It's real
 * big because if there's a lot of rules, the initial state will have a
 * huge epsilon closure.
 */
#define INITIAL_MAX_DFA_SIZE 750
#define MAX_DFA_SIZE_INCREMENT 750


/* A note on the following masks.  They are used to mark accepting numbers
 * as being special.  As such, they implicitly limit the number of accepting
 * numbers (i.e., rules) because if there are too many rules the rule numbers
 * will overload the mask bits.  Fortunately, this limit is \large/ (0x2000 ==
 * 8192) so unlikely to actually cause any problems.  A check is made in
 * new_rule() to ensure that this limit is not reached.
 */

/* Mask to mark a trailing context accepting number. */
#define YY_TRAILING_MASK 0x2000

/* Mask to mark the accepting number of the "head" of a trailing context
 * rule.
 */
#define YY_TRAILING_HEAD_MASK 0x4000

/* Maximum number of rules, as outlined in the above note. */
#define MAX_RULE (YY_TRAILING_MASK - 1)


/* NIL must be 0.  If not, its special meaning when making equivalence classes
 * (it marks the representative of a given e.c.) will be unidentifiable.
 */
#define NIL 0

#define JAM -1	/* to mark a missing DFA transition */
#define NO_TRANSITION NIL
#define UNIQUE -1	/* marks a symbol as an e.c. representative */
#define INFINITY -1	/* for x{5,} constructions */

#define INITIAL_MAX_CCLS 100	/* max number of unique character classes */
#define MAX_CCLS_INCREMENT 100

/* Size of table holding members of character classes. */
#define INITIAL_MAX_CCL_TBL_SIZE 500
#define MAX_CCL_TBL_SIZE_INCREMENT 250

#define INITIAL_MAX_RULES 100	/* default maximum number of rules */
#define MAX_RULES_INCREMENT 100

#define INITIAL_MNS 2000	/* default maximum number of nfa states */
#define MNS_INCREMENT 1000	/* amount to bump above by if it's not enough */

#define INITIAL_MAX_DFAS 1000	/* default maximum number of dfa states */
#define MAX_DFAS_INCREMENT 1000

#define JAMSTATE -32766	/* marks a reference to the state that always jams */

/* Maximum number of NFA states. */
#define MAXIMUM_MNS 31999

/* Enough so that if it's subtracted from an NFA state number, the result
 * is guaranteed to be negative.
 */
#define MARKER_DIFFERENCE (MAXIMUM_MNS+2)

/* Maximum number of nxt/chk pairs for non-templates. */
#define INITIAL_MAX_XPAIRS 2000
#define MAX_XPAIRS_INCREMENT 2000

/* Maximum number of nxt/chk pairs needed for templates. */
#define INITIAL_MAX_TEMPLATE_XPAIRS 2500
#define MAX_TEMPLATE_XPAIRS_INCREMENT 2500

#define SYM_EPSILON (CSIZE + 1)	/* to mark transitions on the symbol epsilon */

#define INITIAL_MAX_SCS 40	/* maximum number of start conditions */
#define MAX_SCS_INCREMENT 40	/* amount to bump by if it's not enough */

#define ONE_STACK_SIZE 500	/* stack of states with only one out-transition */
#define SAME_TRANS -1	/* transition is the same as "default" entry for state */

/* The following percentages are used to tune table compression:

 * The percentage the number of out-transitions a state must be of the
 * number of equivalence classes in order to be considered for table
 * compaction by using protos.
 */
#define PROTO_SIZE_PERCENTAGE 15

/* The percentage the number of homogeneous out-transitions of a state
 * must be of the number of total out-transitions of the state in order
 * that the state's transition table is first compared with a potential 
 * template of the most common out-transition instead of with the first
 * proto in the proto queue.
 */
#define CHECK_COM_PERCENTAGE 50

/* The percentage the number of differences between a state's transition
 * table and the proto it was first compared with must be of the total
 * number of out-transitions of the state in order to keep the first
 * proto as a good match and not search any further.
 */
#define FIRST_MATCH_DIFF_PERCENTAGE 10

/* The percentage the number of differences between a state's transition
 * table and the most similar proto must be of the state's total number
 * of out-transitions to use the proto as an acceptable close match.
 */
#define ACCEPTABLE_DIFF_PERCENTAGE 50

/* The percentage the number of homogeneous out-transitions of a state
 * must be of the number of total out-transitions of the state in order
 * to consider making a template from the state.
 */
#define TEMPLATE_SAME_PERCENTAGE 60

/* The percentage the number of differences between a state's transition
 * table and the most similar proto must be of the state's total number
 * of out-transitions to create a new proto from the state.
 */
#define NEW_PROTO_DIFF_PERCENTAGE 20

/* The percentage the total number of out-transitions of a state must be
 * of the number of equivalence classes in order to consider trying to
 * fit the transition table into "holes" inside the nxt/chk table.
 */
#define INTERIOR_FIT_PERCENTAGE 15

/* Size of region set aside to cache the complete transition table of
 * protos on the proto queue to enable quick comparisons.
 */
#define PROT_SAVE_SIZE 2000

#define MSP 50	/* maximum number of saved protos (protos on the proto queue) */

/* Maximum number of out-transitions a state can have that we'll rummage
 * around through the interior of the internal fast table looking for a
 * spot for it.
 */
#define MAX_XTIONS_FULL_INTERIOR_FIT 4

/* Maximum number of rules which will be reported as being associated
 * with a DFA state.
 */
#define MAX_ASSOC_RULES 100

/* Number that, if used to subscript an array, has a good chance of producing
 * an error; should be small enough to fit into a short.
 */
#define BAD_SUBSCRIPT -32767

/* Absolute value of largest number that can be stored in a short, with a
 * bit of slop thrown in for general paranoia.
 */
#define MAX_SHORT 32700


/* Declarations for global variables. */

/* Variables for symbol tables:
 * sctbl - start-condition symbol table
 * ndtbl - name-definition symbol table
 * ccltab - character class text symbol table
 */

struct hash_entry
	{
	struct hash_entry *prev, *next;
	char *name;
	char *str_val;
	int int_val;
	} ;

typedef struct hash_entry **hash_table;

#define NAME_TABLE_HASH_SIZE 101
#define START_COND_HASH_SIZE 101
#define CCL_HASH_SIZE 101

extern struct hash_entry *ndtbl[NAME_TABLE_HASH_SIZE]; 
extern struct hash_entry *sctbl[START_COND_HASH_SIZE];
extern struct hash_entry *ccltab[CCL_HASH_SIZE];


/* Variables for flags:
 * printstats - if true (-v), dump statistics
 * syntaxerror - true if a syntax error has been found
 * eofseen - true if we've seen an eof in the input file
 * ddebug - if true (-d), make a "debug" scanner
 * trace - if true (-T), trace processing
 * nowarn - if true (-w), do not generate warnings
 * spprdflt - if true (-s), suppress the default rule
 * interactive - if true (-I), generate an interactive scanner