/* dfa - DFA construction routines */ /*- * 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/ncvs/src/usr.bin/lex/dfa.c,v 1.1.1.2 1996/06/19 20:26:04 nate Exp $ */ #include "flexdef.h" /* declare functions that have forward references */ void dump_associated_rules PROTO((FILE*, int)); void dump_transitions PROTO((FILE*, int[])); void sympartition PROTO((int[], int, int[], int[])); int symfollowset PROTO((int[], int, int, int[])); /* check_for_backing_up - check a DFA state for backing up * * synopsis * void check_for_backing_up( int ds, int state[numecs] ); * * ds is the number of the state to check and state[] is its out-transitions, * indexed by equivalence class. */ void check_for_backing_up( ds, state ) int ds; int state[]; { if ( (reject && ! dfaacc[ds].dfaacc_set) || (! reject && ! dfaacc[ds].dfaacc_state) ) { /* state is non-accepting */ ++num_backing_up; if ( backing_up_report ) { fprintf( backing_up_file, _( "State #%d is non-accepting -\n" ), ds ); /* identify the state */ dump_associated_rules( backing_up_file, ds ); /* Now identify it further using the out- and * jam-transitions. */ dump_transitions( backing_up_file, state ); putc( '\n', backing_up_file ); } } } /* check_trailing_context - check to see if NFA state set constitutes * "dangerous" trailing context * * synopsis * void check_trailing_context( int nfa_states[num_states+1], int num_states, * int accset[nacc+1], int nacc ); * * NOTES * Trailing context is "dangerous" if both the head and the trailing * part are of variable size \and/ there's a DFA state which contains * both an accepting state for the head part of the rule and NFA states * which occur after the beginning of the trailing context. * * When such a rule is matched, it's impossible to tell if having been * in the DFA state indicates the beginning of the trailing context or * further-along scanning of the pattern. In these cases, a warning * message is issued. * * nfa_states[1 .. num_states] is the list of NFA states in the DFA. * accset[1 .. nacc] is the list of accepting numbers for the DFA state. */ void check_trailing_context( nfa_states, num_states, accset, nacc ) int *nfa_states, num_states; int *accset; int nacc; { register int i, j; for ( i = 1; i <= num_states; ++i ) { int ns = nfa_states[i]; register int type = state_type[ns]; register int ar = assoc_rule[ns]; if ( type == STATE_NORMAL || rule_type[ar] != RULE_VARIABLE ) { /* do nothing */ } else if ( type == STATE_TRAILING_CONTEXT ) { /* Potential trouble. Scan set of accepting numbers * for the one marking the end of the "head". We * assume that this looping will be fairly cheap * since it's rare that an accepting number set * is large. */ for ( j = 1; j <= nacc; ++j ) if ( accset[j] & YY_TRAILING_HEAD_MASK ) { line_warning( _( "dangerous trailing context" ), rule_linenum[ar] ); return; } } } } /* dump_associated_rules - list the rules associated with a DFA state * * Goes through the set of NFA states associated with the DFA and * extracts the first MAX_ASSOC_RULES unique rules, sorts them, * and writes a report to the given file. */ void dump_associated_rules( file, ds ) FILE *file; int ds; { register int i, j; register int num_associated_rules = 0; int rule_set[MAX_ASSOC_RULES + 1]; int *dset = dss[ds]; int size = dfasiz[ds]; for ( i = 1; i <= size; ++i ) { register int rule_num = rule_linenum[assoc_rule[dset[i]]]; for ( j = 1; j <= num_associated_rules; ++j ) if ( rule_num == rule_set[j] ) break; if ( j > num_associated_rules ) { /* new rule */ if ( num_associated_rules < MAX_ASSOC_RULES ) rule_set[++num_associated_rules] = rule_num; } } bubble( rule_set, num_associated_rules ); fprintf( file, _( " associated rule line numbers:" ) ); for ( i = 1; i <= num_associated_rules; ++i ) { if ( i % 8 == 1 ) putc( '\n', file ); fprintf( file, "\t%d", rule_set[i] ); } putc( '\n', file ); } /* dump_transitions - list the transitions associated with a DFA state * * synopsis * dump_transitions( FILE *file, int state[numecs] ); * * Goes through the set of out-transitions and lists them in human-readable * form (i.e., not as equivalence classes); also lists jam transitions * (i.e., all those which are not out-transitions, plus EOF). The dump * is done to the given file. */ void dump_transitions( file, state ) FILE *file; int state[]; { register int i, ec; int out_char_set[CSIZE]; for ( i = 0; i < csize; ++i ) { ec = ABS( ecgroup[i] ); out_char_set[i] = state[ec]; } fprintf( file, _( " out-transitions: " ) ); list_character_set( file, out_char_set ); /* now invert the members of the set to get the jam transitions */ for ( i = 0; i < csize; ++i ) out_char_set[i] = ! out_char_set[i]; fprintf( file, _( "\n jam-transitions: EOF " ) ); list_character_set( file, out_char_set ); putc( '\n', file ); } /* epsclosure - construct the epsilon closure of a set of ndfa states * * synopsis * int *epsclosure( int t[num_states], int *numstates_addr, * int accset[num_rules+1], int *nacc_addr, * int *hashval_addr ); * * NOTES * The epsilon closure is the set of all states reachable by an arbitrary * number of epsilon transitions, which themselves do not have epsilon * transitions going out, unioned with the set of states which have non-null * accepting numbers. t is an array of size numstates of nfa state numbers. * Upon return, t holds the epsilon closure and *numstates_addr is updated. * accset holds a list of the accepting numbers, and the size of accset is * given by *nacc_addr. t may be subjected to reallocation if it is not * large enough to hold the epsilon closure. * * hashval is the hash value for the dfa corresponding to the state set. */ int *epsclosure( t, ns_addr, accset, nacc_addr, hv_addr ) int *t, *ns_addr, accset[], *nacc_addr, *hv_addr; { register int stkpos, ns, tsp; int numstates = *ns_addr, nacc, hashval, transsym, nfaccnum; int stkend, nstate; static int did_stk_init = false, *stk; #define MARK_STATE(state) \ trans1[state] = trans1[state] - MARKER_DIFFERENCE; #define IS_MARKED(state) (trans1[state] < 0) #define UNMARK_STATE(state) \ trans1[state] = trans1[state] + MARKER_DIFFERENCE; #define CHECK_ACCEPT(state) \ { \ nfaccnum = accptnum[state]; \ if ( nfaccnum != NIL ) \ accset[++nacc] = nfaccnum; \ } #define DO_REALLOCATION \ { \ current_max_dfa_size += MAX_DFA_SIZE_INCREMENT; \ ++num_reallocs; \ t = reallocate_integer_array( t, current_max_dfa_size ); \ stk = reallocate_integer_array( stk, current_max_dfa_size ); \ } \ #define PUT_ON_STACK(state) \ { \ if ( ++stkend >= current_max_dfa_size ) \ DO_REALLOCATION \ stk[stkend] = state; \ MARK_STATE(state) \ } #define ADD_STATE(state) \ { \ if ( ++numstates >= current_max_dfa_size ) \ DO_REALLOCATION \ t[numstates] = state; \ hashval += state; \ } #define STACK_STATE(state) \ { \ PUT_ON_STACK(state) \ CHECK_ACCEPT(state) \ if ( nfaccnum != NIL || transchar[state] != SYM_EPSILON ) \ ADD_STATE(state) \ } if ( ! did_stk_init ) { stk = allocate_integer_array( current_max_dfa_size ); did_stk_init = true; } nacc = stkend = hashval = 0; for ( nstate = 1; nstate <= numstates; ++nstate ) { ns = t[nstate]; /* The state could be marked if we've already pushed it onto * the stack. */ if ( ! IS_MARKED(ns) ) { PUT_ON_STACK(ns) CHECK_ACCEPT(ns) hashval += ns; } } for ( stkpos = 1; stkpos <= stkend; ++stkpos ) { ns = stk[stkpos]; transsym = transchar[ns]; if ( transsym == SYM_EPSILON ) { tsp = trans1[ns] + MARKER_DIFFERENCE; if ( tsp != NO_TRANSITION ) { if ( ! IS_MARKED(tsp) ) STACK_STATE(tsp) tsp = trans2[ns]; if ( tsp != NO_TRANSITION && ! IS_MARKED(tsp) ) STACK_STATE(tsp) } } } /* Clear out "visit" markers. */ for ( stkpos = 1; stkpos <= stkend; ++stkpos ) { if ( IS_MARKED(stk[stkpos]) ) UNMARK_STATE(stk[stkpos]) else flexfatal( _( "consistency check failed in epsclosure()" ) ); } *ns_addr = numstates; *hv_addr = hashval; *nacc_addr = nacc; return t; } /* increase_max_dfas - increase the maximum number of DFAs */ void increase_max_dfas() { current_max_dfas += MAX_DFAS_INCREMENT; ++num_reallocs; base = reallocate_integer_array( base, current_max_dfas ); def = reallocate_integer_array( def, current_max_dfas ); dfasiz = reallocate_integer_array( dfasiz, current_max_dfas ); accsiz = reallocate_integer_array( accsiz, current_max_dfas ); dhash = reallocate_integer_array( dhash, current_max_dfas ); dss = reallocate_int_ptr_array( dss, current_max_dfas ); dfaacc = reallocate_dfaacc_union( dfaacc, current_max_dfas ); if ( nultrans ) nultrans = reallocate_integer_array( nultrans, current_max_dfas ); } /* ntod - convert an ndfa to a dfa * * Creates the dfa corresponding to the ndfa we've constructed. The * dfa starts out in state #1. */ void ntod() { int *accset, ds, nacc, newds; int sym, hashval, numstates, dsize; int num_full_table_rows; /* used only for -f */ int *nset, *dset; int targptr, totaltrans, i, comstate, comfreq, targ; int symlist[CSIZE + 1]; int num_start_states; int todo_head, todo_next; /* Note that the following are indexed by *equivalence classes* * and not by characters. Since equivalence classes are indexed * beginning with 1, even if the scanner accepts NUL's, this * means that (since every character is potentially in its own * equivalence class) these arrays must have room for indices * from 1 to CSIZE, so their size must be CSIZE + 1. */ int duplist[CSIZE + 1], state[CSIZE + 1]; int targfreq[CSIZE + 1], targstate[CSIZE + 1]; accset = allocate_integer_array( num_rules + 1 ); nset = allocate_integer_array( current_max_dfa_size ); /* The "todo" queue is represented by the head, which is the DFA * state currently being processed, and the "next", which is the * next DFA state number available (not in use). We depend on the * fact that snstods() returns DFA's \in increasing order/, and thus * need only know the bounds of the dfas to be processed. */ todo_head = todo_next = 0; for ( i = 0; i <= csize; ++i ) { duplist[i] = NIL; symlist[i] = false; } for ( i = 0; i <= num_rules; ++i ) accset[i] = NIL; if ( trace ) { dumpnfa( scset[1] ); fputs( _( "\n\nDFA Dump:\n\n" ), stderr ); } inittbl(); /* Check to see whether we should build a separate table for * transitions on NUL characters. We don't do this for full-speed * (-F) scanners, since for them we don't have a simple state * number lying around with which to index the table. We also * don't bother doing it for scanners unless (1) NUL is in its own * equivalence class (indicated by a positive value of * ecgroup[NUL]), (2) NUL's equivalence class is the last * equivalence class, and (3) the number of equivalence classes is * the same as the number of characters. This latter case comes * about when useecs is false or when it's true but every character * still manages to land in its own class (unlikely, but it's * cheap to check for). If all these things are true then the * character code needed to represent NUL's equivalence class for * indexing the tables is going to take one more bit than the * number of characters, and therefore we won't be assured of * being able to fit it into a YY_CHAR variable. This rules out * storing the transitions in a compressed table, since the code * for interpreting them uses a YY_CHAR variable (perhaps it * should just use an integer, though; this is worth pondering ... * ###). * * Finally, for full tables, we want the number of entries in the * table to be a power of two so the array references go fast (it * will just take a shift to compute the major index). If * encoding NUL's transitions in the table will spoil this, we * give it its own table (note that this will be the case if we're * not using equivalence classes). */ /* Note that the test for ecgroup[0] == numecs below accomplishes * both (1) and (2) above */ if ( ! fullspd && ecgroup[0] == numecs ) { /* NUL is alone in its equivalence class, which is the * last one. */ int use_NUL_table = (numecs == csize); if ( fulltbl && ! use_NUL_table ) { /* We still may want to use the table if numecs * is a power of 2. */ int power_of_two; for ( power_of_two = 1; power_of_two <= csize; power_of_two *= 2 ) if ( numecs == power_of_two ) { use_NUL_table = true; break; } } if ( use_NUL_table ) nultrans = allocate_integer_array( current_max_dfas ); /* From now on, nultrans != nil indicates that we're * saving null transitions for later, separate encoding. */ } if ( fullspd ) { for ( i = 0; i <= numecs; ++i ) state[i] = 0; place_state( state, 0, 0 ); dfaacc[0].dfaacc_state = 0; } 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; } } } } }