X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/5fbb0954b861b5bff653e1b87a1bd5e0b328445d..c76e14da4bf475d4f85090d5fdde85d8dddb5833:/src/nullable.c?ds=sidebyside diff --git a/src/nullable.c b/src/nullable.c index ae02db75..635ea619 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. @@ -26,11 +26,17 @@ #include "system.h" #include "getargs.h" #include "symtab.h" -#include "types.h" #include "gram.h" #include "reduce.h" #include "nullable.h" +/* Linked list of rule numbers. */ +typedef struct rule_list_s +{ + struct rule_list_s *next; + rule_number_t value; +} rule_list_t; + char *nullable = NULL; static void @@ -46,19 +52,19 @@ nullable_print (FILE *out) void set_nullable (void) { - int ruleno; - token_number_t *s1; - token_number_t *s2; - shorts *p; + rule_number_t ruleno; + symbol_number_t *s1; + symbol_number_t *s2; + rule_list_t *p; - token_number_t *squeue = XCALLOC (token_number_t, nvars); + symbol_number_t *squeue = XCALLOC (symbol_number_t, nvars); short *rcount = XCALLOC (short, nrules + 1); /* 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); + rule_list_t *relts = XCALLOC (rule_list_t, nritems + nvars + 1); if (trace_flag) fprintf (stderr, "Entering set_nullable\n"); @@ -71,19 +77,20 @@ set_nullable (void) for (ruleno = 1; ruleno < nrules + 1; ++ruleno) if (rules[ruleno].useful) { - if (rules[ruleno].rhs[0] >= 0) + rule_t *rule = &rules[ruleno]; + if (rule->rhs[0] >= 0) { /* This rule has a non empty RHS. */ - item_number_t *r; + item_number_t *r = NULL; int any_tokens = 0; - for (r = rules[ruleno].rhs; *r >= 0; ++r) + for (r = rule->rhs; *r >= 0; ++r) if (ISTOKEN (*r)) any_tokens = 1; /* This rule has only nonterminals: schedule it for the second pass. */ if (!any_tokens) - for (r = rules[ruleno].rhs; *r >= 0; ++r) + for (r = rule->rhs; *r >= 0; ++r) { rcount[ruleno]++; p->next = rsets[*r]; @@ -95,11 +102,11 @@ set_nullable (void) else { /* This rule has an empty RHS. */ - assert (rules[ruleno].rhs[0] == -ruleno); - if (rules[ruleno].useful && !nullable[rules[ruleno].lhs->number]) + assert (rule_number_of_item_number (rule->rhs[0]) == ruleno); + 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; } } }