X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/742e4900c8b05c8c1f56985288141c890f1e9c73..e34e97bcd736ab3193bfd3abd4162db3b159836d:/src/tables.c diff --git a/src/tables.c b/src/tables.c index 000d027c..eb827b76 100644 --- a/src/tables.c +++ b/src/tables.c @@ -1,30 +1,27 @@ /* Output the generated parsing program for Bison. - Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004, - 2005 Free Software Foundation, Inc. + Copyright (C) 1984, 1986, 1989, 1992, 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 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. + 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 3 of the License, or + (at your option) any later version. - Bison 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. + 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., 51 Franklin Street, Fifth Floor, Boston, MA - 02110-1301, USA. */ + along with this program. If not, see . */ #include #include "system.h" #include -#include #include "complain.h" #include "conflicts.h" @@ -32,6 +29,7 @@ #include "getargs.h" #include "gram.h" #include "lalr.h" +#include "muscle-tab.h" #include "reader.h" #include "symtab.h" #include "tables.h" @@ -127,7 +125,7 @@ static int table_size = 32768; base_number *table; base_number *check; /* The value used in TABLE to denote explicit syntax errors - (%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MININUM, + (%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MINIMUM, but in order to keep small tables, renumbered as TABLE_ERROR, which is the smallest (non error) value minus 1. */ base_number table_ninf = 0; @@ -202,14 +200,14 @@ conflict_row (state *s) && (actrow[j] != rule_number_as_item_number (reds->rules[i]->number))) { - assert (0 < conflict_list_free); + aver (0 < conflict_list_free); conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1; conflict_list_cnt += 1; conflict_list_free -= 1; } /* Leave a 0 at the end. */ - assert (0 < conflict_list_free); + aver (0 < conflict_list_free); conflict_list[conflict_list_cnt] = 0; conflict_list_cnt += 1; conflict_list_free -= 1; @@ -241,7 +239,7 @@ static rule * action_row (state *s) { int i; - rule *default_rule = NULL; + rule *default_reduction = NULL; reductions *reds = s->reductions; transitions *trans = s->transitions; errs *errp = s->errs; @@ -305,13 +303,24 @@ action_row (state *s) actrow[sym->number] = ACTION_NUMBER_MINIMUM; } + /* Turn off default reductions where requested by the user. See + state_lookahead_tokens_count in lalr.c to understand when states are + labeled as consistent. */ + { + char *default_reductions = + muscle_percent_define_get ("lr.default-reductions"); + if (0 != strcmp (default_reductions, "most") && !s->consistent) + nodefault = true; + free (default_reductions); + } + /* Now find the most common reduction and make it the default action for this state. */ if (reds->num >= 1 && !nodefault) { if (s->consistent) - default_rule = reds->rules[0]; + default_reduction = reds->rules[0]; else { int max = 0; @@ -328,7 +337,7 @@ action_row (state *s) if (count > max) { max = count; - default_rule = r; + default_reduction = r; } } @@ -342,17 +351,18 @@ action_row (state *s) { int j; for (j = 0; j < ntokens; j++) - if (actrow[j] == rule_number_as_item_number (default_rule->number) + if (actrow[j] + == rule_number_as_item_number (default_reduction->number) && ! (nondeterministic_parser && conflrow[j])) actrow[j] = 0; } } } - /* If have no default rule, the default is an error. + /* If have no default reduction, the default is an error. So replace any action which says "error" with "use default". */ - if (!default_rule) + if (!default_reduction) for (i = 0; i < ntokens; i++) if (actrow[i] == ACTION_NUMBER_MINIMUM) actrow[i] = 0; @@ -360,7 +370,7 @@ action_row (state *s) if (conflicted) conflict_row (s); - return default_rule; + return default_reduction; } @@ -441,8 +451,8 @@ token_actions (void) for (i = 0; i < nstates; ++i) { - rule *default_rule = action_row (states[i]); - yydefact[i] = default_rule ? default_rule->number + 1 : 0; + rule *default_reduction = action_row (states[i]); + yydefact[i] = default_reduction ? default_reduction->number + 1 : 0; save_row (i); /* Now that the parser was computed, we can find which rules are @@ -673,14 +683,14 @@ pack_vector (vector_number vector) base_number *to = tos[i]; unsigned int *conflict_to = conflict_tos[i]; - assert (t); + aver (t != 0); for (j = lowzero - from[0]; ; j++) { int k; bool ok = true; - assert (j < table_size); + aver (j < table_size); for (k = 0; ok && k < t; k++) { @@ -713,7 +723,7 @@ pack_vector (vector_number vector) if (loc > high) high = loc; - assert (BASE_MINIMUM <= j && j <= BASE_MAXIMUM); + aver (BASE_MINIMUM <= j && j <= BASE_MAXIMUM); return j; } }