X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/da2a7671e11663b9ad941aa3e1f3014d6ad950cb..63951be29fcb8e21146a9377176d53d509c575ca:/src/tables.c diff --git a/src/tables.c b/src/tables.c index ba2c7a0e..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 - 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., 59 Temple Place - Suite 330, Boston, MA - 02111-1307, 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" @@ -42,13 +40,15 @@ Of course vector_number_t ought to be wide enough to contain state_number and symbol_number. */ -typedef short int vector_number; +typedef int vector_number; +#if 0 /* Not currently used. */ static inline vector_number state_number_to_vector_number (state_number s) { return s; } +#endif static inline vector_number symbol_number_to_vector_number (symbol_number sym) @@ -84,7 +84,7 @@ int nvectors; static base_number **froms; static base_number **tos; static unsigned int **conflict_tos; -static short int *tally; +static int *tally; static base_number *width; @@ -94,8 +94,8 @@ static base_number *width; If N = MIN, stands for `raise a syntax error'. If N > 0, stands for `shift SYMBOL and go to n'. If N < 0, stands for `reduce -N'. */ -typedef short int action_number; -#define ACTION_NUMBER_MINIMUM SHRT_MIN +typedef int action_number; +#define ACTION_NUMBER_MINIMUM INT_MIN static action_number *actrow; @@ -125,7 +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; @@ -171,7 +171,7 @@ table_grow (int desired) /*-------------------------------------------------------------------. | For GLR parsers, for each conflicted token in S, as indicated | -| by non-zero entries in CONFLROW, create a list of possible | +| by non-zero entries in CONFLROW, create a list of possible | | reductions that are alternatives to the shift or reduction | | currently recorded for that token in S. Store the alternative | | reductions followed by a 0 in CONFLICT_LIST, updating | @@ -196,20 +196,18 @@ conflict_row (state *s) /* Find all reductions for token J, and record all that do not match ACTROW[J]. */ for (i = 0; i < reds->num; i += 1) - if (bitset_test (reds->look_ahead_tokens[i], j) + if (bitset_test (reds->lookahead_tokens[i], j) && (actrow[j] != rule_number_as_item_number (reds->rules[i]->number))) { - if (conflict_list_free <= 0) - abort (); + 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. */ - if (conflict_list_free <= 0) - abort (); + aver (0 < conflict_list_free); conflict_list[conflict_list_cnt] = 0; conflict_list_cnt += 1; conflict_list_free -= 1; @@ -219,7 +217,7 @@ conflict_row (state *s) /*------------------------------------------------------------------. | Decide what to do for each type of token if seen as the | -| look-ahead in specified state. The value returned is used as the | +| lookahead in specified state. The value returned is used as the | | default action (yydefact) for the state. In addition, ACTROW is | | filled with what to do for each kind of token, index by symbol | | number, with zero meaning do the default action. The value | @@ -227,7 +225,7 @@ conflict_row (state *s) | situation is an error. The parser recognizes this value | | specially. | | | -| This is where conflicts are resolved. The loop over look-ahead | +| This is where conflicts are resolved. The loop over lookahead | | rules considered lower-numbered rules last, and the last rule | | considered that likes a token gets to handle it. | | | @@ -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; @@ -252,17 +250,17 @@ action_row (state *s) for (i = 0; i < ntokens; i++) actrow[i] = conflrow[i] = 0; - if (reds->look_ahead_tokens) + if (reds->lookahead_tokens) { int j; bitset_iterator biter; /* loop over all the rules available here which require - look-ahead (in reverse order to give precedence to the first + lookahead (in reverse order to give precedence to the first rule) */ for (i = reds->num - 1; i >= 0; --i) /* and find each token which the rule finds acceptable to come next */ - BITSET_FOR_EACH (biter, reds->look_ahead_tokens[i], j, 0) + BITSET_FOR_EACH (biter, reds->lookahead_tokens[i], j, 0) { /* and record this rule as the rule to use if that token follows. */ @@ -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; } @@ -410,7 +420,7 @@ save_row (state_number s) /*------------------------------------------------------------------. | Figure out the actions for the specified state, indexed by | -| look-ahead token type. | +| lookahead token type. | | | | The YYDEFACT table is output now. The detailed info is saved for | | putting into YYTABLE later. | @@ -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 @@ -516,14 +526,14 @@ save_column (symbol_number sym, state_number default_state) `-------------------------------------------------------------*/ static state_number -default_goto (symbol_number sym, short int state_count[]) +default_goto (symbol_number sym, size_t state_count[]) { state_number s; goto_number i; goto_number m = goto_map[sym - ntokens]; goto_number n = goto_map[sym - ntokens + 1]; state_number default_state = -1; - int max = 0; + size_t max = 0; if (m == n) return -1; @@ -558,7 +568,7 @@ static void goto_actions (void) { symbol_number i; - short int *state_count = xnmalloc (nstates, sizeof *state_count); + size_t *state_count = xnmalloc (nstates, sizeof *state_count); yydefgoto = xnmalloc (nvars, sizeof *yydefgoto); /* For a given nterm I, STATE_COUNT[S] is the number of times there @@ -673,16 +683,14 @@ pack_vector (vector_number vector) base_number *to = tos[i]; unsigned int *conflict_to = conflict_tos[i]; - if (!t) - abort (); + aver (t != 0); for (j = lowzero - from[0]; ; j++) { int k; bool ok = true; - if (table_size <= j) - abort (); + aver (j < table_size); for (k = 0; ok && k < t; k++) { @@ -715,8 +723,7 @@ pack_vector (vector_number vector) if (loc > high) high = loc; - if (! (BASE_MINIMUM <= j && j <= BASE_MAXIMUM)) - abort (); + aver (BASE_MINIMUM <= j && j <= BASE_MAXIMUM); return j; } } @@ -808,9 +815,8 @@ tables_generate (void) /* This is a poor way to make sure the sizes are properly correlated. In particular the signedness is not taken into account. But it's not useless. */ - verify (sizes_are_properly_correlated, - (sizeof nstates <= sizeof nvectors - && sizeof nvars <= sizeof nvectors)); + verify (sizeof nstates <= sizeof nvectors + && sizeof nvars <= sizeof nvectors); nvectors = state_number_as_int (nstates) + nvars;