X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/68cae94e0b4e83246787fc5a413f085513ae9160..33f7f342c349a8bdb87bbb6b420ae56133115221:/src/tables.c
diff --git a/src/tables.c b/src/tables.c
index c938139b..f99f07b2 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"
@@ -86,7 +84,7 @@ int nvectors;
static base_number **froms;
static base_number **tos;
static unsigned int **conflict_tos;
-static int *tally;
+static size_t *tally;
static base_number *width;
@@ -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;
@@ -137,11 +135,11 @@ int high;
state_number *yydefgoto;
rule_number *yydefact;
-/*----------------------------------------------------------------.
-| If TABLE (and CHECK) appear to be small to be addressed at |
-| DESIRED, grow them. Note that TABLE[DESIRED] is to be used, so |
-| the desired size is at least DESIRED + 1. |
-`----------------------------------------------------------------*/
+/*-------------------------------------------------------------------.
+| If TABLE, CONFLICT_TABLE, and CHECK are too small to be addressed |
+| at DESIRED, grow them. TABLE[DESIRED] can be used, so the desired |
+| size is at least DESIRED + 1. |
+`-------------------------------------------------------------------*/
static void
table_grow (int desired)
@@ -153,11 +151,11 @@ table_grow (int desired)
if (trace_flag & trace_resource)
fprintf (stderr, "growing table and check from: %d to %d\n",
- old_size, table_size);
+ old_size, table_size);
table = xnrealloc (table, table_size, sizeof *table);
conflict_table = xnrealloc (conflict_table, table_size,
- sizeof *conflict_table);
+ sizeof *conflict_table);
check = xnrealloc (check, table_size, sizeof *check);
for (/* Nothing. */; old_size < table_size; ++old_size)
@@ -173,12 +171,12 @@ 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 |
-| reductions that are alternatives to the shift or reduction |
+| 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 |
+| reductions followed by a 0 in CONFLICT_LIST, updating |
| CONFLICT_LIST_CNT, and storing an index to the start of the list |
-| back into CONFLROW. |
+| back into CONFLROW. |
`-------------------------------------------------------------------*/
static void
@@ -193,41 +191,41 @@ conflict_row (state *s)
for (j = 0; j < ntokens; j += 1)
if (conflrow[j])
{
- conflrow[j] = conflict_list_cnt;
-
- /* 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)
- && (actrow[j]
- != rule_number_as_item_number (reds->rules[i]->number)))
- {
- assert (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);
- conflict_list[conflict_list_cnt] = 0;
- conflict_list_cnt += 1;
- conflict_list_free -= 1;
+ conflrow[j] = conflict_list_cnt;
+
+ /* 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->lookahead_tokens[i], j)
+ && (actrow[j]
+ != rule_number_as_item_number (reds->rules[i]->number)))
+ {
+ 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. */
+ aver (0 < conflict_list_free);
+ conflict_list[conflict_list_cnt] = 0;
+ conflict_list_cnt += 1;
+ conflict_list_free -= 1;
}
}
/*------------------------------------------------------------------.
| 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 |
-| ACTION_NUMBER_MINIMUM, a very negative number, means this |
-| situation is an error. The parser recognizes this value |
-| specially. |
+| ACTION_NUMBER_MINIMUM, a very negative number, means this |
+| 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;
@@ -252,27 +250,27 @@ 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
- rule) */
+ 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)
- {
- /* and record this rule as the rule to use if that
- token follows. */
- if (actrow[j] != 0)
- {
- conflicted = true;
- conflrow[j] = 1;
- }
- actrow[j] = rule_number_as_item_number (reds->rules[i]->number);
- }
+ /* and find each token which the rule finds acceptable
+ to come next */
+ BITSET_FOR_EACH (biter, reds->lookahead_tokens[i], j, 0)
+ {
+ /* and record this rule as the rule to use if that
+ token follows. */
+ if (actrow[j] != 0)
+ {
+ conflicted = true;
+ conflrow[j] = 1;
+ }
+ actrow[j] = rule_number_as_item_number (reds->rules[i]->number);
+ }
}
/* Now see which tokens are allowed for shifts in this state. For
@@ -284,16 +282,16 @@ action_row (state *s)
state *shift_state = trans->states[i];
if (actrow[sym] != 0)
- {
- conflicted = true;
- conflrow[sym] = 1;
- }
+ {
+ conflicted = true;
+ conflrow[sym] = 1;
+ }
actrow[sym] = state_number_as_int (shift_state->number);
/* Do not use any default reduction if there is a shift for
- error */
+ error */
if (sym == errtoken->number)
- nodefault = true;
+ nodefault = true;
}
/* See which tokens are an explicit error in this state (due to
@@ -305,62 +303,74 @@ 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-reduction");
+ if (STRNEQ (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;
- for (i = 0; i < reds->num; i++)
- {
- int count = 0;
- rule *r = reds->rules[i];
- symbol_number j;
-
- for (j = 0; j < ntokens; j++)
- if (actrow[j] == rule_number_as_item_number (r->number))
- count++;
-
- if (count > max)
- {
- max = count;
- default_rule = r;
- }
- }
-
- /* GLR parsers need space for conflict lists, so we can't
- default conflicted entries. For non-conflicted entries
- or as long as we are not building a GLR parser,
- actions that match the default are replaced with zero,
- which means "use the default". */
-
- if (max > 0)
- {
- int j;
- for (j = 0; j < ntokens; j++)
- if (actrow[j] == rule_number_as_item_number (default_rule->number)
- && ! (nondeterministic_parser && conflrow[j]))
- actrow[j] = 0;
- }
- }
+ {
+ int max = 0;
+ for (i = 0; i < reds->num; i++)
+ {
+ int count = 0;
+ rule *r = reds->rules[i];
+ symbol_number j;
+
+ for (j = 0; j < ntokens; j++)
+ if (actrow[j] == rule_number_as_item_number (r->number))
+ count++;
+
+ if (count > max)
+ {
+ max = count;
+ default_reduction = r;
+ }
+ }
+
+ /* GLR parsers need space for conflict lists, so we can't
+ default conflicted entries. For non-conflicted entries
+ or as long as we are not building a GLR parser,
+ actions that match the default are replaced with zero,
+ which means "use the default". */
+
+ if (max > 0)
+ {
+ int j;
+ for (j = 0; j < ntokens; j++)
+ 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;
+ actrow[i] = 0;
if (conflicted)
conflict_row (s);
- return default_rule;
+ return default_reduction;
}
@@ -372,45 +382,40 @@ static void
save_row (state_number s)
{
symbol_number i;
- int count;
- base_number *sp;
- base_number *sp1;
- base_number *sp2;
- unsigned int *sp3;
/* Number of non default actions in S. */
- count = 0;
+ size_t count = 0;
for (i = 0; i < ntokens; i++)
if (actrow[i] != 0)
count++;
- if (count == 0)
- return;
-
- /* Allocate non defaulted actions. */
- froms[s] = sp = sp1 = xnmalloc (count, sizeof *sp1);
- tos[s] = sp2 = xnmalloc (count, sizeof *sp2);
- conflict_tos[s] = sp3 =
- nondeterministic_parser ? xnmalloc (count, sizeof *sp3) : NULL;
-
- /* Store non defaulted actions. */
- for (i = 0; i < ntokens; i++)
- if (actrow[i] != 0)
- {
- *sp1++ = i;
- *sp2++ = actrow[i];
- if (nondeterministic_parser)
- *sp3++ = conflrow[i];
- }
-
- tally[s] = count;
- width[s] = sp1[-1] - sp[0] + 1;
+ if (count)
+ {
+ /* Allocate non defaulted actions. */
+ base_number *sp1 = froms[s] = xnmalloc (count, sizeof *sp1);
+ base_number *sp2 = tos[s] = xnmalloc (count, sizeof *sp2);
+ unsigned int *sp3 = conflict_tos[s] =
+ nondeterministic_parser ? xnmalloc (count, sizeof *sp3) : NULL;;
+
+ /* Store non defaulted actions. */
+ for (i = 0; i < ntokens; i++)
+ if (actrow[i] != 0)
+ {
+ *sp1++ = i;
+ *sp2++ = actrow[i];
+ if (nondeterministic_parser)
+ *sp3++ = conflrow[i];
+ }
+
+ tally[s] = count;
+ width[s] = sp1[-1] - froms[s][0] + 1;
+ }
}
/*------------------------------------------------------------------.
| 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. |
@@ -419,10 +424,6 @@ save_row (state_number s)
static void
token_actions (void)
{
- state_number i;
- symbol_number j;
- rule_number r;
-
int nconflict = nondeterministic_parser ? conflicts_total_count () : 0;
yydefact = xnmalloc (nstates, sizeof *yydefact);
@@ -436,28 +437,34 @@ token_actions (void)
/* Find the rules which are reduced. */
if (!nondeterministic_parser)
- for (r = 0; r < nrules; ++r)
- rules[r].useful = false;
-
- for (i = 0; i < nstates; ++i)
{
- rule *default_rule = action_row (states[i]);
- yydefact[i] = default_rule ? default_rule->number + 1 : 0;
- save_row (i);
-
- /* Now that the parser was computed, we can find which rules are
- really reduced, and which are not because of SR or RR
- conflicts. */
- if (!nondeterministic_parser)
- {
- for (j = 0; j < ntokens; ++j)
- if (actrow[j] < 0 && actrow[j] != ACTION_NUMBER_MINIMUM)
- rules[item_number_as_rule_number (actrow[j])].useful = true;
- if (yydefact[i])
- rules[yydefact[i] - 1].useful = true;
- }
+ rule_number r;
+ for (r = 0; r < nrules; ++r)
+ rules[r].useful = false;
}
+ {
+ state_number i;
+ for (i = 0; i < nstates; ++i)
+ {
+ 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
+ really reduced, and which are not because of SR or RR
+ conflicts. */
+ if (!nondeterministic_parser)
+ {
+ symbol_number j;
+ for (j = 0; j < ntokens; ++j)
+ if (actrow[j] < 0 && actrow[j] != ACTION_NUMBER_MINIMUM)
+ rules[item_number_as_rule_number (actrow[j])].useful = true;
+ if (yydefact[i])
+ rules[yydefact[i] - 1].useful = true;
+ }
+ }
+ }
free (actrow);
free (conflrow);
}
@@ -476,38 +483,33 @@ static void
save_column (symbol_number sym, state_number default_state)
{
goto_number i;
- base_number *sp;
- base_number *sp1;
- base_number *sp2;
- int count;
- vector_number symno = symbol_number_to_vector_number (sym);
-
goto_number begin = goto_map[sym - ntokens];
goto_number end = goto_map[sym - ntokens + 1];
/* Number of non default GOTO. */
- count = 0;
+ size_t count = 0;
for (i = begin; i < end; i++)
if (to_state[i] != default_state)
count++;
- if (count == 0)
- return;
-
- /* Allocate room for non defaulted gotos. */
- froms[symno] = sp = sp1 = xnmalloc (count, sizeof *sp1);
- tos[symno] = sp2 = xnmalloc (count, sizeof *sp2);
-
- /* Store the state numbers of the non defaulted gotos. */
- for (i = begin; i < end; i++)
- if (to_state[i] != default_state)
- {
- *sp1++ = from_state[i];
- *sp2++ = to_state[i];
- }
-
- tally[symno] = count;
- width[symno] = sp1[-1] - sp[0] + 1;
+ if (count)
+ {
+ /* Allocate room for non defaulted gotos. */
+ vector_number symno = symbol_number_to_vector_number (sym);
+ base_number *sp1 = froms[symno] = xnmalloc (count, sizeof *sp1);
+ base_number *sp2 = tos[symno] = xnmalloc (count, sizeof *sp2);
+
+ /* Store the state numbers of the non defaulted gotos. */
+ for (i = begin; i < end; i++)
+ if (to_state[i] != default_state)
+ {
+ *sp1++ = from_state[i];
+ *sp2++ = to_state[i];
+ }
+
+ tally[symno] = count;
+ width[symno] = sp1[-1] - froms[symno][0] + 1;
+ }
}
@@ -537,8 +539,8 @@ default_goto (symbol_number sym, size_t state_count[])
for (s = 0; s < nstates; s++)
if (state_count[s] > max)
{
- max = state_count[s];
- default_state = s;
+ max = state_count[s];
+ default_state = s;
}
return default_state;
@@ -586,29 +588,29 @@ sort_actions (void)
nentries = 0;
for (i = 0; i < nvectors; i++)
- if (tally[i] > 0)
+ if (0 < tally[i])
{
- int k;
- int t = tally[i];
- int w = width[i];
- int j = nentries - 1;
+ int k;
+ size_t t = tally[i];
+ int w = width[i];
+ int j = nentries - 1;
- while (j >= 0 && (width[order[j]] < w))
- j--;
+ while (0 <= j && width[order[j]] < w)
+ j--;
- while (j >= 0 && (width[order[j]] == w) && (tally[order[j]] < t))
- j--;
+ while (0 <= j && width[order[j]] == w && tally[order[j]] < t)
+ j--;
- for (k = nentries - 1; k > j; k--)
- order[k + 1] = order[k];
+ for (k = nentries - 1; k > j; k--)
+ order[k + 1] = order[k];
- order[j + 1] = i;
- nentries++;
+ order[j + 1] = i;
+ nentries++;
}
}
-/* If VECTOR is a state which actions (reflected by FROMS, TOS, TALLY
+/* If VECTOR is a state whose actions (reflected by FROMS, TOS, TALLY
and WIDTH of VECTOR) are common to a previous state, return this
state number.
@@ -618,7 +620,7 @@ static state_number
matching_state (vector_number vector)
{
vector_number i = order[vector];
- int t;
+ size_t t;
int w;
int prev;
@@ -634,8 +636,8 @@ matching_state (vector_number vector)
{
int j;
for (j = 0; j < t; j += 1)
- if (conflict_tos[i][j] != 0)
- return -1;
+ if (conflict_tos[i][j] != 0)
+ return -1;
}
for (prev = vector - 1; prev >= 0; prev--)
@@ -645,17 +647,18 @@ matching_state (vector_number vector)
int match = 1;
/* Given how ORDER was computed, if the WIDTH or TALLY is
- different, there cannot be a matching state. */
+ different, there cannot be a matching state. */
if (width[j] != w || tally[j] != t)
- return -1;
+ return -1;
for (k = 0; match && k < t; k++)
- if (tos[j][k] != tos[i][k] || froms[j][k] != froms[i][k]
- || (conflict_tos[j] != NULL && conflict_tos[j][k] != 0))
- match = 0;
+ if (tos[j][k] != tos[i][k]
+ || froms[j][k] != froms[i][k]
+ || (conflict_tos[j] != NULL && conflict_tos[j][k] != 0))
+ match = 0;
if (match)
- return j;
+ return j;
}
return -1;
@@ -665,57 +668,59 @@ matching_state (vector_number vector)
static base_number
pack_vector (vector_number vector)
{
+ base_number res;
vector_number i = order[vector];
- int j;
- int t = tally[i];
- int loc = 0;
+ size_t t = tally[i];
base_number *from = froms[i];
base_number *to = tos[i];
unsigned int *conflict_to = conflict_tos[i];
- assert (t);
+ aver (t != 0);
- for (j = lowzero - from[0]; ; j++)
+ for (res = lowzero - from[0]; ; res++)
{
- int k;
bool ok = true;
-
- assert (j < table_size);
-
- for (k = 0; ok && k < t; k++)
- {
- loc = j + state_number_as_int (from[k]);
- if (table_size <= loc)
- table_grow (loc);
-
- if (table[loc] != 0)
- ok = false;
- }
-
- for (k = 0; ok && k < vector; k++)
- if (pos[k] == j)
- ok = false;
+ aver (res < table_size);
+ {
+ int k;
+ for (k = 0; ok && k < t; k++)
+ {
+ int loc = res + state_number_as_int (from[k]);
+ if (table_size <= loc)
+ table_grow (loc);
+
+ if (table[loc] != 0)
+ ok = false;
+ }
+
+ if (ok)
+ for (k = 0; k < vector; k++)
+ if (pos[k] == res)
+ ok = false;
+ }
if (ok)
- {
- for (k = 0; k < t; k++)
- {
- loc = j + from[k];
- table[loc] = to[k];
- if (nondeterministic_parser && conflict_to != NULL)
- conflict_table[loc] = conflict_to[k];
- check[loc] = from[k];
- }
-
- while (table[lowzero] != 0)
- lowzero++;
-
- if (loc > high)
- high = loc;
-
- assert (BASE_MINIMUM <= j && j <= BASE_MAXIMUM);
- return j;
- }
+ {
+ int loc;
+ int k;
+ for (k = 0; k < t; k++)
+ {
+ loc = res + state_number_as_int (from[k]);
+ table[loc] = to[k];
+ if (nondeterministic_parser && conflict_to != NULL)
+ conflict_table[loc] = conflict_to[k];
+ check[loc] = from[k];
+ }
+
+ while (table[lowzero] != 0)
+ lowzero++;
+
+ if (high < loc)
+ high = loc;
+
+ aver (BASE_MINIMUM <= res && res <= BASE_MAXIMUM);
+ return res;
+ }
}
}
@@ -773,11 +778,11 @@ pack_table (void)
base_number place;
if (s < 0)
- /* A new set of state actions, or a nonterminal. */
- place = pack_vector (i);
+ /* A new set of state actions, or a nonterminal. */
+ place = pack_vector (i);
else
- /* Action of I were already coded for S. */
- place = base[s];
+ /* Action of I were already coded for S. */
+ place = base[s];
pos[i] = place;
base[order[i]] = place;
@@ -806,7 +811,7 @@ tables_generate (void)
correlated. In particular the signedness is not taken into
account. But it's not useless. */
verify (sizeof nstates <= sizeof nvectors
- && sizeof nvars <= sizeof nvectors);
+ && sizeof nvars <= sizeof nvectors);
nvectors = state_number_as_int (nstates) + nvars;