X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/9222837b2743308e4971fc0ad299ca2f73fb20ae..78bcec17c82fe777c90f86717773de35bb5018e7:/src/nullable.c diff --git a/src/nullable.c b/src/nullable.c index b3686646..c0b60f64 100644 --- a/src/nullable.c +++ b/src/nullable.c @@ -1,5 +1,5 @@ /* Part of the bison parser generator, - Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc. + Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -26,12 +26,18 @@ #include "system.h" #include "getargs.h" #include "symtab.h" -#include "types.h" #include "gram.h" #include "reduce.h" #include "nullable.h" -char *nullable = NULL; +/* Linked list of rules. */ +typedef struct rule_list_s +{ + struct rule_list_s *next; + rule_t *value; +} rule_list_t; + +bool *nullable = NULL; static void nullable_print (FILE *out) @@ -44,31 +50,28 @@ nullable_print (FILE *out) } void -set_nullable (void) +nullable_compute (void) { rule_number_t ruleno; symbol_number_t *s1; symbol_number_t *s2; - shorts *p; + rule_list_t *p; symbol_number_t *squeue = XCALLOC (symbol_number_t, nvars); - short *rcount = XCALLOC (short, nrules + 1); + short *rcount = XCALLOC (short, nrules); /* RITEM contains all the rules, including useless productions. Hence we must allocate room for useless nonterminals too. */ - shorts **rsets = XCALLOC (shorts *, nvars) - ntokens; + rule_list_t **rsets = XCALLOC (rule_list_t *, nvars) - ntokens; /* This is said to be more elements than we actually use. Supposedly NRITEMS - NRULES is enough. But why take the risk? */ - shorts *relts = XCALLOC (shorts, nritems + nvars + 1); - - if (trace_flag) - fprintf (stderr, "Entering set_nullable\n"); + rule_list_t *relts = XCALLOC (rule_list_t, nritems + nvars + 1); - nullable = XCALLOC (char, nvars) - ntokens; + nullable = XCALLOC (bool, nvars) - ntokens; s1 = s2 = squeue; p = relts; - for (ruleno = 1; ruleno < nrules + 1; ++ruleno) + for (ruleno = 0; ruleno < nrules; ++ruleno) if (rules[ruleno].useful) { rule_t *rule = &rules[ruleno]; @@ -88,7 +91,7 @@ set_nullable (void) { rcount[ruleno]++; p->next = rsets[*r]; - p->value = ruleno; + p->value = rule; rsets[*r] = p; p++; } @@ -96,7 +99,7 @@ set_nullable (void) else { /* This rule has an empty RHS. */ - assert (rule_number_of_item_number (rule->rhs[0]) == ruleno); + assert (item_number_as_rule_number (rule->rhs[0]) == ruleno); if (rule->useful && !nullable[rule->lhs->number]) { nullable[rule->lhs->number] = 1; @@ -108,12 +111,12 @@ set_nullable (void) while (s1 < s2) for (p = rsets[*s1++]; p; p = p->next) { - ruleno = p->value; - if (--rcount[ruleno] == 0) - if (rules[ruleno].useful && !nullable[rules[ruleno].lhs->number]) + rule_t *rule = p->value; + if (--rcount[rule->number] == 0) + if (rule->useful && !nullable[rule->lhs->number]) { - nullable[rules[ruleno].lhs->number] = 1; - *s2++ = rules[ruleno].lhs->number; + nullable[rule->lhs->number] = 1; + *s2++ = rule->lhs->number; } } @@ -122,13 +125,13 @@ set_nullable (void) XFREE (rsets + ntokens); XFREE (relts); - if (trace_flag) + if (trace_flag & trace_sets) nullable_print (stderr); } void -free_nullable (void) +nullable_free (void) { XFREE (nullable + ntokens); }