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1098 lines
25 KiB
C
1098 lines
25 KiB
C
/* dfa - DFA construction routines */
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/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Vern Paxson.
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*
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* The United States Government has rights in this work pursuant
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* to contract no. DE-AC03-76SF00098 between the United States
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* Department of Energy and the University of California.
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*
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* Redistribution and use in source and binary forms are permitted provided
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* that: (1) source distributions retain this entire copyright notice and
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* comment, and (2) distributions including binaries display the following
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* acknowledgement: ``This product includes software developed by the
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* University of California, Berkeley and its contributors'' in the
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* documentation or other materials provided with the distribution and in
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* all advertising materials mentioning features or use of this software.
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* Neither the name of the University nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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/* $Header: /home/daffy/u0/vern/flex/RCS/dfa.c,v 2.26 95/04/20 13:53:14 vern Exp $ */
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "flexdef.h"
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/* declare functions that have forward references */
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void dump_associated_rules PROTO((FILE*, int));
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void dump_transitions PROTO((FILE*, int[]));
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void sympartition PROTO((int[], int, int[], int[]));
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int symfollowset PROTO((int[], int, int, int[]));
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/* check_for_backing_up - check a DFA state for backing up
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*
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* synopsis
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* void check_for_backing_up( int ds, int state[numecs] );
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*
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* ds is the number of the state to check and state[] is its out-transitions,
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* indexed by equivalence class.
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*/
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void check_for_backing_up( ds, state )
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int ds;
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int state[];
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{
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if ( (reject && ! dfaacc[ds].dfaacc_set) ||
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(! reject && ! dfaacc[ds].dfaacc_state) )
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{ /* state is non-accepting */
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++num_backing_up;
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if ( backing_up_report )
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{
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fprintf( backing_up_file,
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_( "State #%d is non-accepting -\n" ), ds );
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/* identify the state */
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dump_associated_rules( backing_up_file, ds );
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/* Now identify it further using the out- and
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* jam-transitions.
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*/
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dump_transitions( backing_up_file, state );
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putc( '\n', backing_up_file );
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}
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}
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}
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/* check_trailing_context - check to see if NFA state set constitutes
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* "dangerous" trailing context
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*
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* synopsis
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* void check_trailing_context( int nfa_states[num_states+1], int num_states,
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* int accset[nacc+1], int nacc );
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*
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* NOTES
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* Trailing context is "dangerous" if both the head and the trailing
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* part are of variable size \and/ there's a DFA state which contains
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* both an accepting state for the head part of the rule and NFA states
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* which occur after the beginning of the trailing context.
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*
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* When such a rule is matched, it's impossible to tell if having been
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* in the DFA state indicates the beginning of the trailing context or
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* further-along scanning of the pattern. In these cases, a warning
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* message is issued.
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*
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* nfa_states[1 .. num_states] is the list of NFA states in the DFA.
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* accset[1 .. nacc] is the list of accepting numbers for the DFA state.
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*/
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void check_trailing_context( nfa_states, num_states, accset, nacc )
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int *nfa_states, num_states;
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int *accset;
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int nacc;
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{
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register int i, j;
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for ( i = 1; i <= num_states; ++i )
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{
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int ns = nfa_states[i];
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register int type = state_type[ns];
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register int ar = assoc_rule[ns];
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if ( type == STATE_NORMAL || rule_type[ar] != RULE_VARIABLE )
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{ /* do nothing */
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}
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else if ( type == STATE_TRAILING_CONTEXT )
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{
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/* Potential trouble. Scan set of accepting numbers
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* for the one marking the end of the "head". We
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* assume that this looping will be fairly cheap
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* since it's rare that an accepting number set
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* is large.
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*/
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for ( j = 1; j <= nacc; ++j )
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if ( accset[j] & YY_TRAILING_HEAD_MASK )
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{
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line_warning(
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_( "dangerous trailing context" ),
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rule_linenum[ar] );
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return;
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}
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}
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}
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}
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/* dump_associated_rules - list the rules associated with a DFA state
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*
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* Goes through the set of NFA states associated with the DFA and
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* extracts the first MAX_ASSOC_RULES unique rules, sorts them,
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* and writes a report to the given file.
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*/
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void dump_associated_rules( file, ds )
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FILE *file;
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int ds;
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{
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register int i, j;
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register int num_associated_rules = 0;
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int rule_set[MAX_ASSOC_RULES + 1];
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int *dset = dss[ds];
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int size = dfasiz[ds];
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for ( i = 1; i <= size; ++i )
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{
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register int rule_num = rule_linenum[assoc_rule[dset[i]]];
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for ( j = 1; j <= num_associated_rules; ++j )
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if ( rule_num == rule_set[j] )
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break;
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if ( j > num_associated_rules )
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{ /* new rule */
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if ( num_associated_rules < MAX_ASSOC_RULES )
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rule_set[++num_associated_rules] = rule_num;
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}
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}
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bubble( rule_set, num_associated_rules );
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fprintf( file, _( " associated rule line numbers:" ) );
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for ( i = 1; i <= num_associated_rules; ++i )
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{
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if ( i % 8 == 1 )
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putc( '\n', file );
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fprintf( file, "\t%d", rule_set[i] );
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}
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putc( '\n', file );
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}
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/* dump_transitions - list the transitions associated with a DFA state
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*
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* synopsis
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* dump_transitions( FILE *file, int state[numecs] );
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*
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* Goes through the set of out-transitions and lists them in human-readable
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* form (i.e., not as equivalence classes); also lists jam transitions
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* (i.e., all those which are not out-transitions, plus EOF). The dump
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* is done to the given file.
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*/
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void dump_transitions( file, state )
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FILE *file;
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int state[];
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{
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register int i, ec;
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int out_char_set[CSIZE];
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for ( i = 0; i < csize; ++i )
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{
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ec = ABS( ecgroup[i] );
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out_char_set[i] = state[ec];
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}
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fprintf( file, _( " out-transitions: " ) );
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list_character_set( file, out_char_set );
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/* now invert the members of the set to get the jam transitions */
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for ( i = 0; i < csize; ++i )
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out_char_set[i] = ! out_char_set[i];
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fprintf( file, _( "\n jam-transitions: EOF " ) );
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list_character_set( file, out_char_set );
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putc( '\n', file );
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}
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/* epsclosure - construct the epsilon closure of a set of ndfa states
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*
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* synopsis
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* int *epsclosure( int t[num_states], int *numstates_addr,
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* int accset[num_rules+1], int *nacc_addr,
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* int *hashval_addr );
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*
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* NOTES
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* The epsilon closure is the set of all states reachable by an arbitrary
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* number of epsilon transitions, which themselves do not have epsilon
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* transitions going out, unioned with the set of states which have non-null
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* accepting numbers. t is an array of size numstates of nfa state numbers.
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* Upon return, t holds the epsilon closure and *numstates_addr is updated.
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* accset holds a list of the accepting numbers, and the size of accset is
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* given by *nacc_addr. t may be subjected to reallocation if it is not
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* large enough to hold the epsilon closure.
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*
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* hashval is the hash value for the dfa corresponding to the state set.
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*/
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int *epsclosure( t, ns_addr, accset, nacc_addr, hv_addr )
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int *t, *ns_addr, accset[], *nacc_addr, *hv_addr;
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{
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register int stkpos, ns, tsp;
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int numstates = *ns_addr, nacc, hashval, transsym, nfaccnum;
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int stkend, nstate;
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static int did_stk_init = false, *stk;
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#define MARK_STATE(state) \
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trans1[state] = trans1[state] - MARKER_DIFFERENCE;
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#define IS_MARKED(state) (trans1[state] < 0)
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#define UNMARK_STATE(state) \
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trans1[state] = trans1[state] + MARKER_DIFFERENCE;
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#define CHECK_ACCEPT(state) \
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{ \
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nfaccnum = accptnum[state]; \
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if ( nfaccnum != NIL ) \
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accset[++nacc] = nfaccnum; \
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}
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#define DO_REALLOCATION \
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{ \
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current_max_dfa_size += MAX_DFA_SIZE_INCREMENT; \
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++num_reallocs; \
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t = reallocate_integer_array( t, current_max_dfa_size ); \
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stk = reallocate_integer_array( stk, current_max_dfa_size ); \
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} \
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#define PUT_ON_STACK(state) \
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{ \
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if ( ++stkend >= current_max_dfa_size ) \
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DO_REALLOCATION \
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stk[stkend] = state; \
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MARK_STATE(state) \
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}
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#define ADD_STATE(state) \
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{ \
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if ( ++numstates >= current_max_dfa_size ) \
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DO_REALLOCATION \
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t[numstates] = state; \
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hashval += state; \
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}
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#define STACK_STATE(state) \
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{ \
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PUT_ON_STACK(state) \
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CHECK_ACCEPT(state) \
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if ( nfaccnum != NIL || transchar[state] != SYM_EPSILON ) \
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ADD_STATE(state) \
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}
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if ( ! did_stk_init )
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{
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stk = allocate_integer_array( current_max_dfa_size );
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did_stk_init = true;
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}
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nacc = stkend = hashval = 0;
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for ( nstate = 1; nstate <= numstates; ++nstate )
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{
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ns = t[nstate];
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/* The state could be marked if we've already pushed it onto
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* the stack.
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*/
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if ( ! IS_MARKED(ns) )
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{
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PUT_ON_STACK(ns)
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CHECK_ACCEPT(ns)
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hashval += ns;
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}
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}
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for ( stkpos = 1; stkpos <= stkend; ++stkpos )
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{
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ns = stk[stkpos];
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transsym = transchar[ns];
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if ( transsym == SYM_EPSILON )
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{
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tsp = trans1[ns] + MARKER_DIFFERENCE;
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if ( tsp != NO_TRANSITION )
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{
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if ( ! IS_MARKED(tsp) )
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STACK_STATE(tsp)
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tsp = trans2[ns];
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if ( tsp != NO_TRANSITION && ! IS_MARKED(tsp) )
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STACK_STATE(tsp)
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}
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}
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}
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/* Clear out "visit" markers. */
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for ( stkpos = 1; stkpos <= stkend; ++stkpos )
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{
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if ( IS_MARKED(stk[stkpos]) )
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UNMARK_STATE(stk[stkpos])
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else
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flexfatal(
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_( "consistency check failed in epsclosure()" ) );
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}
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*ns_addr = numstates;
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*hv_addr = hashval;
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*nacc_addr = nacc;
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return t;
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}
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/* increase_max_dfas - increase the maximum number of DFAs */
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void increase_max_dfas()
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{
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current_max_dfas += MAX_DFAS_INCREMENT;
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++num_reallocs;
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base = reallocate_integer_array( base, current_max_dfas );
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def = reallocate_integer_array( def, current_max_dfas );
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dfasiz = reallocate_integer_array( dfasiz, current_max_dfas );
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accsiz = reallocate_integer_array( accsiz, current_max_dfas );
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dhash = reallocate_integer_array( dhash, current_max_dfas );
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dss = reallocate_int_ptr_array( dss, current_max_dfas );
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dfaacc = reallocate_dfaacc_union( dfaacc, current_max_dfas );
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if ( nultrans )
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nultrans =
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reallocate_integer_array( nultrans, current_max_dfas );
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}
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/* ntod - convert an ndfa to a dfa
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*
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* Creates the dfa corresponding to the ndfa we've constructed. The
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* dfa starts out in state #1.
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*/
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void ntod()
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{
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int *accset, ds, nacc, newds;
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int sym, hashval, numstates, dsize;
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int num_full_table_rows; /* used only for -f */
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int *nset, *dset;
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int targptr, totaltrans, i, comstate, comfreq, targ;
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int symlist[CSIZE + 1];
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int num_start_states;
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int todo_head, todo_next;
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/* Note that the following are indexed by *equivalence classes*
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* and not by characters. Since equivalence classes are indexed
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* beginning with 1, even if the scanner accepts NUL's, this
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* means that (since every character is potentially in its own
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* equivalence class) these arrays must have room for indices
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* from 1 to CSIZE, so their size must be CSIZE + 1.
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*/
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int duplist[CSIZE + 1], state[CSIZE + 1];
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int targfreq[CSIZE + 1], targstate[CSIZE + 1];
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accset = allocate_integer_array( num_rules + 1 );
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nset = allocate_integer_array( current_max_dfa_size );
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/* The "todo" queue is represented by the head, which is the DFA
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* state currently being processed, and the "next", which is the
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* next DFA state number available (not in use). We depend on the
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* fact that snstods() returns DFA's \in increasing order/, and thus
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* need only know the bounds of the dfas to be processed.
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*/
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todo_head = todo_next = 0;
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for ( i = 0; i <= csize; ++i )
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{
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duplist[i] = NIL;
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symlist[i] = false;
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}
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for ( i = 0; i <= num_rules; ++i )
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accset[i] = NIL;
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if ( trace )
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{
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dumpnfa( scset[1] );
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fputs( _( "\n\nDFA Dump:\n\n" ), stderr );
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}
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inittbl();
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/* Check to see whether we should build a separate table for
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* transitions on NUL characters. We don't do this for full-speed
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* (-F) scanners, since for them we don't have a simple state
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* number lying around with which to index the table. We also
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* don't bother doing it for scanners unless (1) NUL is in its own
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* equivalence class (indicated by a positive value of
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* ecgroup[NUL]), (2) NUL's equivalence class is the last
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* equivalence class, and (3) the number of equivalence classes is
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* the same as the number of characters. This latter case comes
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* about when useecs is false or when it's true but every character
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* still manages to land in its own class (unlikely, but it's
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* cheap to check for). If all these things are true then the
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* character code needed to represent NUL's equivalence class for
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* indexing the tables is going to take one more bit than the
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* number of characters, and therefore we won't be assured of
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* being able to fit it into a YY_CHAR variable. This rules out
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* storing the transitions in a compressed table, since the code
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* for interpreting them uses a YY_CHAR variable (perhaps it
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* should just use an integer, though; this is worth pondering ...
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* ###).
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*
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* Finally, for full tables, we want the number of entries in the
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* table to be a power of two so the array references go fast (it
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* will just take a shift to compute the major index). If
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* encoding NUL's transitions in the table will spoil this, we
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* give it its own table (note that this will be the case if we're
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* not using equivalence classes).
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*/
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/* Note that the test for ecgroup[0] == numecs below accomplishes
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* both (1) and (2) above
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*/
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if ( ! fullspd && ecgroup[0] == numecs )
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{
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/* NUL is alone in its equivalence class, which is the
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* last one.
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*/
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int use_NUL_table = (numecs == csize);
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if ( fulltbl && ! use_NUL_table )
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{
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/* We still may want to use the table if numecs
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* is a power of 2.
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*/
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int power_of_two;
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for ( power_of_two = 1; power_of_two <= csize;
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power_of_two *= 2 )
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if ( numecs == power_of_two )
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{
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use_NUL_table = true;
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break;
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}
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}
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if ( use_NUL_table )
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nultrans = allocate_integer_array( current_max_dfas );
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/* From now on, nultrans != nil indicates that we're
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* saving null transitions for later, separate encoding.
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*/
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}
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if ( fullspd )
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{
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for ( i = 0; i <= numecs; ++i )
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state[i] = 0;
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place_state( state, 0, 0 );
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dfaacc[0].dfaacc_state = 0;
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}
|
|
|
|
else if ( fulltbl )
|
|
{
|
|
if ( nultrans )
|
|
/* We won't be including NUL's transitions in the
|
|
* table, so build it for entries from 0 .. numecs - 1.
|
|
*/
|
|
num_full_table_rows = numecs;
|
|
|
|
else
|
|
/* Take into account the fact that we'll be including
|
|
* the NUL entries in the transition table. Build it
|
|
* from 0 .. numecs.
|
|
*/
|
|
num_full_table_rows = numecs + 1;
|
|
|
|
/* Unless -Ca, declare it "short" because it's a real
|
|
* long-shot that that won't be large enough.
|
|
*/
|
|
out_str_dec( "static yyconst %s yy_nxt[][%d] =\n {\n",
|
|
/* '}' so vi doesn't get too confused */
|
|
long_align ? "long" : "short", num_full_table_rows );
|
|
|
|
outn( " {" );
|
|
|
|
/* Generate 0 entries for state #0. */
|
|
for ( i = 0; i < num_full_table_rows; ++i )
|
|
mk2data( 0 );
|
|
|
|
dataflush();
|
|
outn( " },\n" );
|
|
}
|
|
|
|
/* Create the first states. */
|
|
|
|
num_start_states = lastsc * 2;
|
|
|
|
for ( i = 1; i <= num_start_states; ++i )
|
|
{
|
|
numstates = 1;
|
|
|
|
/* For each start condition, make one state for the case when
|
|
* we're at the beginning of the line (the '^' operator) and
|
|
* one for the case when we're not.
|
|
*/
|
|
if ( i % 2 == 1 )
|
|
nset[numstates] = scset[(i / 2) + 1];
|
|
else
|
|
nset[numstates] =
|
|
mkbranch( scbol[i / 2], scset[i / 2] );
|
|
|
|
nset = epsclosure( nset, &numstates, accset, &nacc, &hashval );
|
|
|
|
if ( snstods( nset, numstates, accset, nacc, hashval, &ds ) )
|
|
{
|
|
numas += nacc;
|
|
totnst += numstates;
|
|
++todo_next;
|
|
|
|
if ( variable_trailing_context_rules && nacc > 0 )
|
|
check_trailing_context( nset, numstates,
|
|
accset, nacc );
|
|
}
|
|
}
|
|
|
|
if ( ! fullspd )
|
|
{
|
|
if ( ! snstods( nset, 0, accset, 0, 0, &end_of_buffer_state ) )
|
|
flexfatal(
|
|
_( "could not create unique end-of-buffer state" ) );
|
|
|
|
++numas;
|
|
++num_start_states;
|
|
++todo_next;
|
|
}
|
|
|
|
while ( todo_head < todo_next )
|
|
{
|
|
targptr = 0;
|
|
totaltrans = 0;
|
|
|
|
for ( i = 1; i <= numecs; ++i )
|
|
state[i] = 0;
|
|
|
|
ds = ++todo_head;
|
|
|
|
dset = dss[ds];
|
|
dsize = dfasiz[ds];
|
|
|
|
if ( trace )
|
|
fprintf( stderr, _( "state # %d:\n" ), ds );
|
|
|
|
sympartition( dset, dsize, symlist, duplist );
|
|
|
|
for ( sym = 1; sym <= numecs; ++sym )
|
|
{
|
|
if ( symlist[sym] )
|
|
{
|
|
symlist[sym] = 0;
|
|
|
|
if ( duplist[sym] == NIL )
|
|
{
|
|
/* Symbol has unique out-transitions. */
|
|
numstates = symfollowset( dset, dsize,
|
|
sym, nset );
|
|
nset = epsclosure( nset, &numstates,
|
|
accset, &nacc, &hashval );
|
|
|
|
if ( snstods( nset, numstates, accset,
|
|
nacc, hashval, &newds ) )
|
|
{
|
|
totnst = totnst + numstates;
|
|
++todo_next;
|
|
numas += nacc;
|
|
|
|
if (
|
|
variable_trailing_context_rules &&
|
|
nacc > 0 )
|
|
check_trailing_context(
|
|
nset, numstates,
|
|
accset, nacc );
|
|
}
|
|
|
|
state[sym] = newds;
|
|
|
|
if ( trace )
|
|
fprintf( stderr, "\t%d\t%d\n",
|
|
sym, newds );
|
|
|
|
targfreq[++targptr] = 1;
|
|
targstate[targptr] = newds;
|
|
++numuniq;
|
|
}
|
|
|
|
else
|
|
{
|
|
/* sym's equivalence class has the same
|
|
* transitions as duplist(sym)'s
|
|
* equivalence class.
|
|
*/
|
|
targ = state[duplist[sym]];
|
|
state[sym] = targ;
|
|
|
|
if ( trace )
|
|
fprintf( stderr, "\t%d\t%d\n",
|
|
sym, targ );
|
|
|
|
/* Update frequency count for
|
|
* destination state.
|
|
*/
|
|
|
|
i = 0;
|
|
while ( targstate[++i] != targ )
|
|
;
|
|
|
|
++targfreq[i];
|
|
++numdup;
|
|
}
|
|
|
|
++totaltrans;
|
|
duplist[sym] = NIL;
|
|
}
|
|
}
|
|
|
|
if ( caseins && ! useecs )
|
|
{
|
|
register int j;
|
|
|
|
for ( i = 'A', j = 'a'; i <= 'Z'; ++i, ++j )
|
|
{
|
|
if ( state[i] == 0 && state[j] != 0 )
|
|
/* We're adding a transition. */
|
|
++totaltrans;
|
|
|
|
else if ( state[i] != 0 && state[j] == 0 )
|
|
/* We're taking away a transition. */
|
|
--totaltrans;
|
|
|
|
state[i] = state[j];
|
|
}
|
|
}
|
|
|
|
numsnpairs += totaltrans;
|
|
|
|
if ( ds > num_start_states )
|
|
check_for_backing_up( ds, state );
|
|
|
|
if ( nultrans )
|
|
{
|
|
nultrans[ds] = state[NUL_ec];
|
|
state[NUL_ec] = 0; /* remove transition */
|
|
}
|
|
|
|
if ( fulltbl )
|
|
{
|
|
outn( " {" );
|
|
|
|
/* Supply array's 0-element. */
|
|
if ( ds == end_of_buffer_state )
|
|
mk2data( -end_of_buffer_state );
|
|
else
|
|
mk2data( end_of_buffer_state );
|
|
|
|
for ( i = 1; i < num_full_table_rows; ++i )
|
|
/* Jams are marked by negative of state
|
|
* number.
|
|
*/
|
|
mk2data( state[i] ? state[i] : -ds );
|
|
|
|
dataflush();
|
|
outn( " },\n" );
|
|
}
|
|
|
|
else if ( fullspd )
|
|
place_state( state, ds, totaltrans );
|
|
|
|
else if ( ds == end_of_buffer_state )
|
|
/* Special case this state to make sure it does what
|
|
* it's supposed to, i.e., jam on end-of-buffer.
|
|
*/
|
|
stack1( ds, 0, 0, JAMSTATE );
|
|
|
|
else /* normal, compressed state */
|
|
{
|
|
/* Determine which destination state is the most
|
|
* common, and how many transitions to it there are.
|
|
*/
|
|
|
|
comfreq = 0;
|
|
comstate = 0;
|
|
|
|
for ( i = 1; i <= targptr; ++i )
|
|
if ( targfreq[i] > comfreq )
|
|
{
|
|
comfreq = targfreq[i];
|
|
comstate = targstate[i];
|
|
}
|
|
|
|
bldtbl( state, ds, totaltrans, comstate, comfreq );
|
|
}
|
|
}
|
|
|
|
if ( fulltbl )
|
|
dataend();
|
|
|
|
else if ( ! fullspd )
|
|
{
|
|
cmptmps(); /* create compressed template entries */
|
|
|
|
/* Create tables for all the states with only one
|
|
* out-transition.
|
|
*/
|
|
while ( onesp > 0 )
|
|
{
|
|
mk1tbl( onestate[onesp], onesym[onesp], onenext[onesp],
|
|
onedef[onesp] );
|
|
--onesp;
|
|
}
|
|
|
|
mkdeftbl();
|
|
}
|
|
|
|
flex_free( (void *) accset );
|
|
flex_free( (void *) nset );
|
|
}
|
|
|
|
|
|
/* snstods - converts a set of ndfa states into a dfa state
|
|
*
|
|
* synopsis
|
|
* is_new_state = snstods( int sns[numstates], int numstates,
|
|
* int accset[num_rules+1], int nacc,
|
|
* int hashval, int *newds_addr );
|
|
*
|
|
* On return, the dfa state number is in newds.
|
|
*/
|
|
|
|
int snstods( sns, numstates, accset, nacc, hashval, newds_addr )
|
|
int sns[], numstates, accset[], nacc, hashval, *newds_addr;
|
|
{
|
|
int didsort = 0;
|
|
register int i, j;
|
|
int newds, *oldsns;
|
|
|
|
for ( i = 1; i <= lastdfa; ++i )
|
|
if ( hashval == dhash[i] )
|
|
{
|
|
if ( numstates == dfasiz[i] )
|
|
{
|
|
oldsns = dss[i];
|
|
|
|
if ( ! didsort )
|
|
{
|
|
/* We sort the states in sns so we
|
|
* can compare it to oldsns quickly.
|
|
* We use bubble because there probably
|
|
* aren't very many states.
|
|
*/
|
|
bubble( sns, numstates );
|
|
didsort = 1;
|
|
}
|
|
|
|
for ( j = 1; j <= numstates; ++j )
|
|
if ( sns[j] != oldsns[j] )
|
|
break;
|
|
|
|
if ( j > numstates )
|
|
{
|
|
++dfaeql;
|
|
*newds_addr = i;
|
|
return 0;
|
|
}
|
|
|
|
++hshcol;
|
|
}
|
|
|
|
else
|
|
++hshsave;
|
|
}
|
|
|
|
/* Make a new dfa. */
|
|
|
|
if ( ++lastdfa >= current_max_dfas )
|
|
increase_max_dfas();
|
|
|
|
newds = lastdfa;
|
|
|
|
dss[newds] = allocate_integer_array( numstates + 1 );
|
|
|
|
/* If we haven't already sorted the states in sns, we do so now,
|
|
* so that future comparisons with it can be made quickly.
|
|
*/
|
|
|
|
if ( ! didsort )
|
|
bubble( sns, numstates );
|
|
|
|
for ( i = 1; i <= numstates; ++i )
|
|
dss[newds][i] = sns[i];
|
|
|
|
dfasiz[newds] = numstates;
|
|
dhash[newds] = hashval;
|
|
|
|
if ( nacc == 0 )
|
|
{
|
|
if ( reject )
|
|
dfaacc[newds].dfaacc_set = (int *) 0;
|
|
else
|
|
dfaacc[newds].dfaacc_state = 0;
|
|
|
|
accsiz[newds] = 0;
|
|
}
|
|
|
|
else if ( reject )
|
|
{
|
|
/* We sort the accepting set in increasing order so the
|
|
* disambiguating rule that the first rule listed is considered
|
|
* match in the event of ties will work. We use a bubble
|
|
* sort since the list is probably quite small.
|
|
*/
|
|
|
|
bubble( accset, nacc );
|
|
|
|
dfaacc[newds].dfaacc_set = allocate_integer_array( nacc + 1 );
|
|
|
|
/* Save the accepting set for later */
|
|
for ( i = 1; i <= nacc; ++i )
|
|
{
|
|
dfaacc[newds].dfaacc_set[i] = accset[i];
|
|
|
|
if ( accset[i] <= num_rules )
|
|
/* Who knows, perhaps a REJECT can yield
|
|
* this rule.
|
|
*/
|
|
rule_useful[accset[i]] = true;
|
|
}
|
|
|
|
accsiz[newds] = nacc;
|
|
}
|
|
|
|
else
|
|
{
|
|
/* Find lowest numbered rule so the disambiguating rule
|
|
* will work.
|
|
*/
|
|
j = num_rules + 1;
|
|
|
|
for ( i = 1; i <= nacc; ++i )
|
|
if ( accset[i] < j )
|
|
j = accset[i];
|
|
|
|
dfaacc[newds].dfaacc_state = j;
|
|
|
|
if ( j <= num_rules )
|
|
rule_useful[j] = true;
|
|
}
|
|
|
|
*newds_addr = newds;
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
/* symfollowset - follow the symbol transitions one step
|
|
*
|
|
* synopsis
|
|
* numstates = symfollowset( int ds[current_max_dfa_size], int dsize,
|
|
* int transsym, int nset[current_max_dfa_size] );
|
|
*/
|
|
|
|
int symfollowset( ds, dsize, transsym, nset )
|
|
int ds[], dsize, transsym, nset[];
|
|
{
|
|
int ns, tsp, sym, i, j, lenccl, ch, numstates, ccllist;
|
|
|
|
numstates = 0;
|
|
|
|
for ( i = 1; i <= dsize; ++i )
|
|
{ /* for each nfa state ns in the state set of ds */
|
|
ns = ds[i];
|
|
sym = transchar[ns];
|
|
tsp = trans1[ns];
|
|
|
|
if ( sym < 0 )
|
|
{ /* it's a character class */
|
|
sym = -sym;
|
|
ccllist = cclmap[sym];
|
|
lenccl = ccllen[sym];
|
|
|
|
if ( cclng[sym] )
|
|
{
|
|
for ( j = 0; j < lenccl; ++j )
|
|
{
|
|
/* Loop through negated character
|
|
* class.
|
|
*/
|
|
ch = ccltbl[ccllist + j];
|
|
|
|
if ( ch == 0 )
|
|
ch = NUL_ec;
|
|
|
|
if ( ch > transsym )
|
|
/* Transsym isn't in negated
|
|
* ccl.
|
|
*/
|
|
break;
|
|
|
|
else if ( ch == transsym )
|
|
/* next 2 */ goto bottom;
|
|
}
|
|
|
|
/* Didn't find transsym in ccl. */
|
|
nset[++numstates] = tsp;
|
|
}
|
|
|
|
else
|
|
for ( j = 0; j < lenccl; ++j )
|
|
{
|
|
ch = ccltbl[ccllist + j];
|
|
|
|
if ( ch == 0 )
|
|
ch = NUL_ec;
|
|
|
|
if ( ch > transsym )
|
|
break;
|
|
else if ( ch == transsym )
|
|
{
|
|
nset[++numstates] = tsp;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
else if ( sym >= 'A' && sym <= 'Z' && caseins )
|
|
flexfatal(
|
|
_( "consistency check failed in symfollowset" ) );
|
|
|
|
else if ( sym == SYM_EPSILON )
|
|
{ /* do nothing */
|
|
}
|
|
|
|
else if ( ABS( ecgroup[sym] ) == transsym )
|
|
nset[++numstates] = tsp;
|
|
|
|
bottom: ;
|
|
}
|
|
|
|
return numstates;
|
|
}
|
|
|
|
|
|
/* sympartition - partition characters with same out-transitions
|
|
*
|
|
* synopsis
|
|
* sympartition( int ds[current_max_dfa_size], int numstates,
|
|
* int symlist[numecs], int duplist[numecs] );
|
|
*/
|
|
|
|
void sympartition( ds, numstates, symlist, duplist )
|
|
int ds[], numstates;
|
|
int symlist[], duplist[];
|
|
{
|
|
int tch, i, j, k, ns, dupfwd[CSIZE + 1], lenccl, cclp, ich;
|
|
|
|
/* Partitioning is done by creating equivalence classes for those
|
|
* characters which have out-transitions from the given state. Thus
|
|
* we are really creating equivalence classes of equivalence classes.
|
|
*/
|
|
|
|
for ( i = 1; i <= numecs; ++i )
|
|
{ /* initialize equivalence class list */
|
|
duplist[i] = i - 1;
|
|
dupfwd[i] = i + 1;
|
|
}
|
|
|
|
duplist[1] = NIL;
|
|
dupfwd[numecs] = NIL;
|
|
|
|
for ( i = 1; i <= numstates; ++i )
|
|
{
|
|
ns = ds[i];
|
|
tch = transchar[ns];
|
|
|
|
if ( tch != SYM_EPSILON )
|
|
{
|
|
if ( tch < -lastccl || tch >= csize )
|
|
{
|
|
flexfatal(
|
|
_( "bad transition character detected in sympartition()" ) );
|
|
}
|
|
|
|
if ( tch >= 0 )
|
|
{ /* character transition */
|
|
int ec = ecgroup[tch];
|
|
|
|
mkechar( ec, dupfwd, duplist );
|
|
symlist[ec] = 1;
|
|
}
|
|
|
|
else
|
|
{ /* character class */
|
|
tch = -tch;
|
|
|
|
lenccl = ccllen[tch];
|
|
cclp = cclmap[tch];
|
|
mkeccl( ccltbl + cclp, lenccl, dupfwd,
|
|
duplist, numecs, NUL_ec );
|
|
|
|
if ( cclng[tch] )
|
|
{
|
|
j = 0;
|
|
|
|
for ( k = 0; k < lenccl; ++k )
|
|
{
|
|
ich = ccltbl[cclp + k];
|
|
|
|
if ( ich == 0 )
|
|
ich = NUL_ec;
|
|
|
|
for ( ++j; j < ich; ++j )
|
|
symlist[j] = 1;
|
|
}
|
|
|
|
for ( ++j; j <= numecs; ++j )
|
|
symlist[j] = 1;
|
|
}
|
|
|
|
else
|
|
for ( k = 0; k < lenccl; ++k )
|
|
{
|
|
ich = ccltbl[cclp + k];
|
|
|
|
if ( ich == 0 )
|
|
ich = NUL_ec;
|
|
|
|
symlist[ich] = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|