X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/779e7ceb9395424c2cf90d43c75302ababc8ee72..f6df83b4e80b2a53c08b5dc654e247076a3b9b03:/src/nullable.c?ds=sidebyside diff --git a/src/nullable.c b/src/nullable.c index d65c4f2b..b3769fe4 100644 --- a/src/nullable.c +++ b/src/nullable.c @@ -1,30 +1,29 @@ /* Calculate which nonterminals can expand into the null string for Bison. - Copyright (C) 1984, 1989, 2000, 2001, 2002, 2003, 2004 Free - Software Foundation, Inc. + Copyright (C) 1984, 1989, 2000-2006, 2009-2012 Free Software + Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. - Bison is free software; you can redistribute it and/or modify + This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. - Bison is distributed in the hope that it will be useful, + This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with Bison; see the file COPYING. If not, write to - the Free Software Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. */ + along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* Set up NULLABLE, a vector saying which nonterminals can expand into the null string. NULLABLE[I - NTOKENS] is nonzero if symbol I can do so. */ +#include <config.h> #include "system.h" #include "getargs.h" @@ -48,8 +47,8 @@ nullable_print (FILE *out) int i; fputs ("NULLABLE\n", out); for (i = ntokens; i < nsyms; i++) - fprintf (out, "\t%s: %s\n", symbols[i]->tag, - nullable[i - ntokens] ? "yes" : "no"); + fprintf (out, " %s: %s\n", symbols[i]->tag, + nullable[i - ntokens] ? "yes" : "no"); fputs ("\n\n", out); } @@ -61,16 +60,16 @@ nullable_compute (void) symbol_number *s2; rule_list *p; - symbol_number *squeue = CALLOC (squeue, nvars); - short int *rcount = CALLOC (rcount, nrules); + symbol_number *squeue = xnmalloc (nvars, sizeof *squeue); + size_t *rcount = xcalloc (nrules, sizeof *rcount); /* RITEM contains all the rules, including useless productions. Hence we must allocate room for useless nonterminals too. */ - rule_list **rsets = CALLOC (rsets, nvars); + rule_list **rsets = xcalloc (nvars, sizeof *rsets); /* This is said to be more elements than we actually use. Supposedly NRITEMS - NRULES is enough. But why take the risk? */ - rule_list *relts = CALLOC (relts, nritems + nvars + 1); + rule_list *relts = xnmalloc (nritems + nvars + 1, sizeof *relts); - CALLOC (nullable, nvars); + nullable = xcalloc (nvars, sizeof *nullable); s1 = s2 = squeue; p = relts; @@ -78,58 +77,58 @@ nullable_compute (void) for (ruleno = 0; ruleno < nrules; ++ruleno) if (rules[ruleno].useful) { - rule *rules_ruleno = &rules[ruleno]; - if (rules_ruleno->rhs[0] >= 0) - { - /* This rule has a non empty RHS. */ - item_number *rp = NULL; - bool any_tokens = false; - for (rp = rules_ruleno->rhs; *rp >= 0; ++rp) - if (ISTOKEN (*rp)) - any_tokens = true; - - /* This rule has only nonterminals: schedule it for the second - pass. */ - if (!any_tokens) - for (rp = rules_ruleno->rhs; *rp >= 0; ++rp) - { - rcount[ruleno]++; - p->next = rsets[*rp - ntokens]; - p->value = rules_ruleno; - rsets[*rp - ntokens] = p; - p++; - } - } - else - { - /* This rule has an empty RHS. */ - if (item_number_as_rule_number (rules_ruleno->rhs[0]) != ruleno) - abort (); - if (rules_ruleno->useful - && ! nullable[rules_ruleno->lhs->number - ntokens]) - { - nullable[rules_ruleno->lhs->number - ntokens] = true; - *s2++ = rules_ruleno->lhs->number; - } - } + rule *rules_ruleno = &rules[ruleno]; + if (rules_ruleno->rhs[0] >= 0) + { + /* This rule has a non empty RHS. */ + item_number *rp = NULL; + bool any_tokens = false; + for (rp = rules_ruleno->rhs; *rp >= 0; ++rp) + if (ISTOKEN (*rp)) + any_tokens = true; + + /* This rule has only nonterminals: schedule it for the second + pass. */ + if (!any_tokens) + for (rp = rules_ruleno->rhs; *rp >= 0; ++rp) + { + rcount[ruleno]++; + p->next = rsets[*rp - ntokens]; + p->value = rules_ruleno; + rsets[*rp - ntokens] = p; + p++; + } + } + else + { + /* This rule has an empty RHS. */ + aver (item_number_as_rule_number (rules_ruleno->rhs[0]) + == ruleno); + if (rules_ruleno->useful + && ! nullable[rules_ruleno->lhs->number - ntokens]) + { + nullable[rules_ruleno->lhs->number - ntokens] = true; + *s2++ = rules_ruleno->lhs->number; + } + } } while (s1 < s2) for (p = rsets[*s1++ - ntokens]; p; p = p->next) { - rule *r = p->value; - if (--rcount[r->number] == 0) - if (r->useful && ! nullable[r->lhs->number - ntokens]) - { - nullable[r->lhs->number - ntokens] = true; - *s2++ = r->lhs->number; - } + rule *r = p->value; + if (--rcount[r->number] == 0) + if (r->useful && ! nullable[r->lhs->number - ntokens]) + { + nullable[r->lhs->number - ntokens] = true; + *s2++ = r->lhs->number; + } } - XFREE (squeue); - XFREE (rcount); - XFREE (rsets); - XFREE (relts); + free (squeue); + free (rcount); + free (rsets); + free (relts); if (trace_flag & trace_sets) nullable_print (stderr); @@ -139,5 +138,5 @@ nullable_compute (void) void nullable_free (void) { - XFREE (nullable); + free (nullable); }