/* Grammar reduction for Bison.
- Copyright (C) 1988, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+ Copyright (C) 1988, 1989, 2000, 2001, 2002, 2003, 2005, 2006,
+ 2007, 2008 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
+ 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 2, or (at your option)
- any later version.
+ 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,
+ 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 <http://www.gnu.org/licenses/>. */
/* Reduce the grammar: Find and eliminate unreachable terminals,
/* Don't eliminate unreachable terminals: They may be used by the
user's parser. */
+#include <config.h>
#include "system.h"
#include <bitset.h>
#include "files.h"
#include "getargs.h"
#include "gram.h"
+#include "print-xml.h"
#include "reader.h"
#include "reduce.h"
#include "symtab.h"
rule_number r;
for (r = 0; r < nrules; r++)
rules[r].useful = bitset_test (P, r);
- grammar_rules_never_reduced_report (_("useless rule"));
+ grammar_rules_useless_report (_("rule useless in grammar"));
}
/* Map the nonterminals to their new index: useful first, useless
{
int useful = 0;
int useless = nrules - nuseless_productions;
- rule *rules_sorted = XMALLOC (rule, nrules);
+ rule *rules_sorted = xnmalloc (nrules, sizeof *rules_sorted);
rule_number r;
for (r = 0; r < nrules; ++r)
rules_sorted[rules[r].useful ? useful++ : useless++] = rules[r];
/* Adjust NRITEMS. */
{
- int r;
+ rule_number r;
int length;
for (r = nrules; r < nrules + nuseless_productions; ++r)
{
/* Map the nonterminals to their new index: useful first, useless
afterwards. Kept for later report. */
- symbol_number *nontermmap = XCALLOC (symbol_number, nvars) - ntokens;
+ symbol_number *nontermmap = xnmalloc (nvars, sizeof *nontermmap);
n = ntokens;
for (i = ntokens; i < nsyms; i++)
if (bitset_test (V, i))
- nontermmap[i] = n++;
+ nontermmap[i - ntokens] = n++;
for (i = ntokens; i < nsyms; i++)
if (!bitset_test (V, i))
{
- nontermmap[i] = n++;
- warn_at (symbols[i]->location, _("useless nonterminal: %s"),
+ nontermmap[i - ntokens] = n++;
+ warn_at (symbols[i]->location, _("nonterminal useless in grammar: %s"),
symbols[i]->tag);
}
/* Shuffle elements of tables indexed by symbol number. */
{
- symbol **symbols_sorted = XMALLOC (symbol *, nvars) - ntokens;
+ symbol **symbols_sorted = xnmalloc (nvars, sizeof *symbols_sorted);
for (i = ntokens; i < nsyms; i++)
- symbols[i]->number = nontermmap[i];
+ symbols[i]->number = nontermmap[i - ntokens];
for (i = ntokens; i < nsyms; i++)
- symbols_sorted[nontermmap[i]] = symbols[i];
+ symbols_sorted[nontermmap[i - ntokens] - ntokens] = symbols[i];
for (i = ntokens; i < nsyms; i++)
- symbols[i] = symbols_sorted[i];
- free (symbols_sorted + ntokens);
+ symbols[i] = symbols_sorted[i - ntokens];
+ free (symbols_sorted);
}
{
item_number *rhsp;
for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
if (ISVAR (*rhsp))
- *rhsp = symbol_number_as_item_number (nontermmap[*rhsp]);
+ *rhsp = symbol_number_as_item_number (nontermmap[*rhsp
+ - ntokens]);
}
- accept->number = nontermmap[accept->number];
+ accept->number = nontermmap[accept->number - ntokens];
}
nsyms -= nuseless_nonterminals;
nvars -= nuseless_nonterminals;
- free (nontermmap + ntokens);
+ free (nontermmap);
}
if (nuseless_nonterminals > 0)
{
int i;
- fprintf (out, "%s\n\n", _("Useless nonterminals"));
+ fprintf (out, "%s\n\n", _("Nonterminals useless in grammar"));
for (i = 0; i < nuseless_nonterminals; ++i)
fprintf (out, " %s\n", symbols[nsyms + i]->tag);
fputs ("\n\n", out);
bool b = false;
int i;
for (i = 0; i < ntokens; i++)
- if (!bitset_test (V, i) && !bitset_test (V1, i))
+ if (reduce_token_unused_in_grammar (i))
{
if (!b)
- fprintf (out, "%s\n\n", _("Terminals which are not used"));
+ fprintf (out, "%s\n\n", _("Terminals unused in grammar"));
b = true;
fprintf (out, " %s\n", symbols[i]->tag);
}
}
if (nuseless_productions > 0)
- grammar_rules_partial_print (out, _("Useless rules"),
- rule_useless_p);
+ grammar_rules_partial_print (out, _("Rules useless in grammar"),
+ rule_useless_in_grammar_p);
}
\f
-
-
-
/*-------------------------------.
| Report the results to STDERR. |
`-------------------------------*/
static void
reduce_print (void)
{
- if (yacc_flag && nuseless_productions)
- fprintf (stderr, ngettext ("%d rule never reduced\n",
- "%d rules never reduced\n",
- nuseless_productions),
- nuseless_productions);
-
- fprintf (stderr, "%s: %s: ", grammar_file, _("warning"));
-
if (nuseless_nonterminals > 0)
- fprintf (stderr, ngettext ("%d useless nonterminal",
- "%d useless nonterminals",
- nuseless_nonterminals),
- nuseless_nonterminals);
-
- if (nuseless_nonterminals > 0 && nuseless_productions > 0)
- fprintf (stderr, _(" and "));
-
+ {
+ fprintf (stderr, "%s: %s: ", grammar_file, _("warning"));
+ fprintf (stderr, ngettext ("%d nonterminal useless in grammar",
+ "%d nonterminals useless in grammar",
+ nuseless_nonterminals),
+ nuseless_nonterminals);
+ fprintf (stderr, "\n");
+ }
if (nuseless_productions > 0)
- fprintf (stderr, ngettext ("%d useless rule",
- "%d useless rules",
- nuseless_productions),
- nuseless_productions);
- fprintf (stderr, "\n");
- fflush (stderr);
+ {
+ fprintf (stderr, "%s: %s: ", grammar_file, _("warning"));
+ fprintf (stderr, ngettext ("%d rule useless in grammar",
+ "%d rules useless in grammar",
+ nuseless_productions),
+ nuseless_productions);
+ fprintf (stderr, "\n");
+ }
}
\f
void
useless_nonterminals ();
inaccessable_symbols ();
- reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
+ reduced = (nuseless_nonterminals + nuseless_productions > 0);
if (!reduced)
return;
}
}
+bool
+reduce_token_unused_in_grammar (symbol_number i)
+{
+ aver (i < ntokens);
+ return !bitset_test (V, i) && !bitset_test (V1, i);
+}
+
+bool
+reduce_nonterminal_useless_in_grammar (symbol_number i)
+{
+ aver (ntokens <= i && i < nsyms + nuseless_nonterminals);
+ return nsyms <= i;
+}
/*-----------------------------------------------------------.
| Free the global sets used to compute the reduced grammar. |
projects / bison.git / blobdiff