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62a3e4f0c5
RITEM. Note that it must be able to code symbol numbers as positive number, and the negation of rule numbers as negative numbers. Adjust all dependencies (pretty many). * src/reduce.c (rule): Remove this `short *' pointer: use item_number_t. * src/system.h (MINSHORT, MAXSHORT): Remove. Include `limits.h'. Adjust dependencies to using SHRT_MAX and SHRT_MIN. (shortcpy): Remove. (MAXTABLE): Move to... * src/output.c (MAXTABLE): here. (prepare_rules): Use output_int_table to output rhs. * data/bison.simple, data/bison.c++: Adjust. * tests/torture.at (Big triangle): Move the limit from 254 to 500. * tests/regression.at (Web2c Actions): Ajust. Trying with bigger grammars shows various phenomena: at 3000 (28Mb of grammar file) bison is killed by my system, at 2000 (12Mb) bison passes, but produces negative #line number, once fixed, GCC is killed while compiling 14Mb, at 1500 (6.7 Mb of grammar, 8.2Mb of C), it passes. * src/state.h (state_h): Code input lines on ints, not shorts.
134 lines
3.4 KiB
C
134 lines
3.4 KiB
C
/* Part of the bison parser generator,
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Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Bison 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 2, or (at your option)
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any later version.
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Bison 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 Bison; see the file COPYING. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* Set up NULLABLE, a vector saying which nonterminals can expand into
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the null string. NULLABLE[I - NTOKENS] is nonzero if symbol I can
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do so. */
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#include "system.h"
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#include "getargs.h"
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#include "symtab.h"
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#include "types.h"
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#include "gram.h"
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#include "reduce.h"
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#include "nullable.h"
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char *nullable = NULL;
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static void
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nullable_print (FILE *out)
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{
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int i;
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fputs ("NULLABLE\n", out);
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for (i = ntokens; i < nsyms; i++)
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fprintf (out, "\t%s: %s\n", symbols[i]->tag, nullable[i] ? "yes" : "no");
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fputs ("\n\n", out);
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}
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void
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set_nullable (void)
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{
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int ruleno;
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short *s1;
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short *s2;
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shorts *p;
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short *squeue = XCALLOC (short, nvars);
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short *rcount = XCALLOC (short, nrules + 1);
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/* RITEM contains all the rules, including useless productions.
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Hence we must allocate room for useless nonterminals too. */
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shorts **rsets = XCALLOC (shorts *, nvars) - ntokens;
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/* This is said to be more elements than we actually use.
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Supposedly NRITEMS - NRULES is enough. But why take the risk? */
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shorts *relts = XCALLOC (shorts, nritems + nvars + 1);
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if (trace_flag)
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fprintf (stderr, "Entering set_nullable\n");
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nullable = XCALLOC (char, nvars) - ntokens;
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s1 = s2 = squeue;
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p = relts;
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for (ruleno = 1; ruleno < nrules + 1; ++ruleno)
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if (rules[ruleno].useful)
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{
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if (rules[ruleno].rhs[0] >= 0)
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{
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/* This rule has a non empty RHS. */
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item_number_t *r;
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int any_tokens = 0;
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for (r = rules[ruleno].rhs; *r >= 0; ++r)
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if (ISTOKEN (*r))
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any_tokens = 1;
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/* This rule has only nonterminals: schedule it for the second
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pass. */
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if (!any_tokens)
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for (r = rules[ruleno].rhs; *r >= 0; ++r)
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{
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rcount[ruleno]++;
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p->next = rsets[*r];
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p->value = ruleno;
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rsets[*r] = p;
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p++;
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}
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}
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else
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{
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/* This rule has an empty RHS. */
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assert (rules[ruleno].rhs[0] == -ruleno);
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if (rules[ruleno].useful && !nullable[rules[ruleno].lhs->number])
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{
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nullable[rules[ruleno].lhs->number] = 1;
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*s2++ = rules[ruleno].lhs->number;
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}
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}
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}
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while (s1 < s2)
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for (p = rsets[*s1++]; p; p = p->next)
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{
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ruleno = p->value;
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if (--rcount[ruleno] == 0)
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if (rules[ruleno].useful && !nullable[rules[ruleno].lhs->number])
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{
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nullable[rules[ruleno].lhs->number] = 1;
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*s2++ = rules[ruleno].lhs->number;
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}
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}
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XFREE (squeue);
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XFREE (rcount);
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XFREE (rsets + ntokens);
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XFREE (relts);
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if (trace_flag)
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nullable_print (stderr);
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}
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void
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free_nullable (void)
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{
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XFREE (nullable + ntokens);
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}
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