/* Grammar reduction for Bison.
- Copyright (C) 1988, 1989 Free Software Foundation, Inc.
+ Copyright 1988, 1989, 2000, 2001 Free Software Foundation, Inc.
-This file is part of Bison, the GNU Compiler Compiler.
+ 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.
+ 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.
-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.
+ 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.
-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, 675 Mass Ave, Cambridge, MA 02139, USA. */
+ 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. */
-/*
- * Reduce the grammar: Find and eliminate unreachable terminals,
- * nonterminals, and productions. David S. Bakin.
- */
+/* Reduce the grammar: Find and eliminate unreachable terminals,
+ nonterminals, and productions. David S. Bakin. */
-/*
- * Don't eliminate unreachable terminals: They may be used by the user's
- * parser.
- */
+/* Don't eliminate unreachable terminals: They may be used by the
+ user's parser. */
-#include <stdio.h>
#include "system.h"
+#include "getargs.h"
#include "files.h"
#include "gram.h"
-#include "machine.h"
-#include "alloc.h"
+#include "complain.h"
+#include "reduce.h"
+#include "reader.h"
+#include "getargs.h"
-
-extern char **tags; /* reader.c */
-extern int verboseflag; /* getargs.c */
-static int statisticsflag; /* XXXXXXX */
-
-#ifndef TRUE
-#define TRUE (1)
-#define FALSE (0)
-#endif
-typedef int bool;
typedef unsigned *BSet;
-typedef short *rule;
-
+typedef short *rule;
-/*
- * N is set of all nonterminals which are not useless. P is set of all rules
- * which have no useless nonterminals in their RHS. V is the set of all
- * accessible symbols.
- */
-static BSet N, P, V, V1;
+/* Set of all nonterminals which are not useless. */
+static BSet N;
-static int nuseful_productions, nuseless_productions,
- nuseful_nonterminals, nuseless_nonterminals;
+/* Set of all rules which have no useless nonterminals in their RHS. */
+static BSet P;
+/* Set of all accessible symbols. */
+static BSet V;
-static void useless_nonterminals();
-static void inaccessable_symbols();
-static void reduce_grammar_tables();
-static void print_results();
-static void print_notices();
-void dump_grammar();
+/* Set of symbols used to define rule precedence (so they are
+ `useless', but no warning should be issued). */
+static BSet V1;
-extern void fatals ();
+static int nuseful_productions;
+static int nuseless_productions;
+static int nuseful_nonterminals;
+int nuseless_nonterminals;
\f
-
-bool
-bits_equal (L, R, n)
-BSet L;
-BSet R;
-int n;
+static bool
+bits_equal (BSet L, BSet R, int n)
{
int i;
}
-int
-nbits (i)
-unsigned i;
+static int
+nbits (unsigned i)
{
int count = 0;
- while (i != 0) {
- i ^= (i & ((unsigned) (- (int) i)));
- ++count;
- }
+ while (i != 0)
+ {
+ i ^= (i & ((unsigned) (-(int) i)));
+ ++count;
+ }
return count;
}
-int
-bits_size (S, n)
-BSet S;
-int n;
+static int
+bits_size (BSet S, int n)
{
int i, count = 0;
for (i = n - 1; i >= 0; i--)
- count += nbits(S[i]);
+ count += nbits (S[i]);
return count;
}
\f
-void
-reduce_grammar ()
-{
- bool reduced;
-
- /* Allocate the global sets used to compute the reduced grammar */
-
- N = NEW2(WORDSIZE(nvars), unsigned);
- P = NEW2(WORDSIZE(nrules + 1), unsigned);
- V = NEW2(WORDSIZE(nsyms), unsigned);
- V1 = NEW2(WORDSIZE(nsyms), unsigned);
-
- useless_nonterminals();
- inaccessable_symbols();
-
- reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
-
- if (verboseflag)
- print_results();
-
- if (reduced == FALSE)
- goto done_reducing;
-
- print_notices();
-
- if (!BITISSET(N, start_symbol - ntokens))
- fatals(_("Start symbol %s does not derive any sentence"),
- tags[start_symbol]);
-
- reduce_grammar_tables();
- /* if (verboseflag) {
- fprintf(foutput, "REDUCED GRAMMAR\n\n");
- dump_grammar();
- }
- */
-
- /**/ statisticsflag = FALSE; /* someday getopts should handle this */
- if (statisticsflag == TRUE)
- fprintf(stderr,
- _("reduced %s defines %d terminal%s, %d nonterminal%s\
-, and %d production%s.\n"), infile,
- ntokens, (ntokens == 1 ? "" : "s"),
- nvars, (nvars == 1 ? "" : "s"),
- nrules, (nrules == 1 ? "" : "s"));
-
- done_reducing:
-
- /* Free the global sets used to compute the reduced grammar */
-
- FREE(N);
- FREE(V);
- FREE(P);
-
-}
-\f
-/*
- * Another way to do this would be with a set for each production and then do
- * subset tests against N, but even for the C grammar the whole reducing
- * process takes only 2 seconds on my 8Mhz AT.
- */
+/*-------------------------------------------------------------------.
+| Another way to do this would be with a set for each production and |
+| then do subset tests against N0, but even for the C grammar the |
+| whole reducing process takes only 2 seconds on my 8Mhz AT. |
+`-------------------------------------------------------------------*/
static bool
-useful_production (i, N)
-int i;
-BSet N;
+useful_production (int i, BSet N0)
{
- rule r;
+ rule r;
short n;
- /*
- * A production is useful if all of the nonterminals in its RHS
- * appear in the set of useful nonterminals.
- */
+ /* A production is useful if all of the nonterminals in its appear
+ in the set of useful nonterminals. */
- for (r = &ritem[rrhs[i]]; *r > 0; r++)
- if (ISVAR(n = *r))
- if (!BITISSET(N, n - ntokens))
+ for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
+ if (ISVAR (n = *r))
+ if (!BITISSET (N0, n - ntokens))
return FALSE;
return TRUE;
}
-/* Remember that rules are 1-origin, symbols are 0-origin. */
+/*---------------------------------------------------------.
+| Remember that rules are 1-origin, symbols are 0-origin. |
+`---------------------------------------------------------*/
static void
-useless_nonterminals ()
+useless_nonterminals (void)
{
BSet Np, Ns;
- int i, n;
-
- /*
- * N is set as built. Np is set being built this iteration. P is set
- * of all productions which have a RHS all in N.
- */
-
- Np = NEW2(WORDSIZE(nvars), unsigned);
-
- /*
- * The set being computed is a set of nonterminals which can derive
- * the empty string or strings consisting of all terminals. At each
- * iteration a nonterminal is added to the set if there is a
- * production with that nonterminal as its LHS for which all the
- * nonterminals in its RHS are already in the set. Iterate until the
- * set being computed remains unchanged. Any nonterminals not in the
- * set at that point are useless in that they will never be used in
- * deriving a sentence of the language.
- *
- * This iteration doesn't use any special traversal over the
- * productions. A set is kept of all productions for which all the
- * nonterminals in the RHS are in useful. Only productions not in
- * this set are scanned on each iteration. At the end, this set is
- * saved to be used when finding useful productions: only productions
- * in this set will appear in the final grammar.
- */
-
- n = 0;
+ int i;
+
+ /* N is set as built. Np is set being built this iteration. P is
+ set of all productions which have a RHS all in N. */
+
+ Np = XCALLOC (unsigned, WORDSIZE (nvars));
+
+ /* The set being computed is a set of nonterminals which can derive
+ the empty string or strings consisting of all terminals. At each
+ iteration a nonterminal is added to the set if there is a
+ production with that nonterminal as its LHS for which all the
+ nonterminals in its RHS are already in the set. Iterate until
+ the set being computed remains unchanged. Any nonterminals not
+ in the set at that point are useless in that they will never be
+ used in deriving a sentence of the language.
+
+ This iteration doesn't use any special traversal over the
+ productions. A set is kept of all productions for which all the
+ nonterminals in the RHS are in useful. Only productions not in
+ this set are scanned on each iteration. At the end, this set is
+ saved to be used when finding useful productions: only
+ productions in this set will appear in the final grammar. */
+
while (1)
{
- for (i = WORDSIZE(nvars) - 1; i >= 0; i--)
+ for (i = WORDSIZE (nvars) - 1; i >= 0; i--)
Np[i] = N[i];
for (i = 1; i <= nrules; i++)
{
- if (!BITISSET(P, i))
+ if (!BITISSET (P, i))
{
- if (useful_production(i, N))
+ if (useful_production (i, N))
{
- SETBIT(Np, rlhs[i] - ntokens);
- SETBIT(P, i);
+ SETBIT (Np, rule_table[i].lhs - ntokens);
+ SETBIT (P, i);
}
}
}
- if (bits_equal(N, Np, WORDSIZE(nvars)))
+ if (bits_equal (N, Np, WORDSIZE (nvars)))
break;
Ns = Np;
Np = N;
N = Ns;
}
- FREE(N);
+ XFREE (N);
N = Np;
}
-\f
+
+
static void
-inaccessable_symbols ()
+inaccessable_symbols (void)
{
- BSet Vp, Vs, Pp;
- int i, n;
+ BSet Vp, Vs, Pp;
+ int i;
short t;
- rule r;
-
- /*
- * Find out which productions are reachable and which symbols are
- * used. Starting with an empty set of productions and a set of
- * symbols which only has the start symbol in it, iterate over all
- * productions until the set of productions remains unchanged for an
- * iteration. For each production which has a LHS in the set of
- * reachable symbols, add the production to the set of reachable
- * productions, and add all of the nonterminals in the RHS of the
- * production to the set of reachable symbols.
- *
- * Consider only the (partially) reduced grammar which has only
- * nonterminals in N and productions in P.
- *
- * The result is the set P of productions in the reduced grammar, and
- * the set V of symbols in the reduced grammar.
- *
- * Although this algorithm also computes the set of terminals which are
- * reachable, no terminal will be deleted from the grammar. Some
- * terminals might not be in the grammar but might be generated by
- * semantic routines, and so the user might want them available with
- * specified numbers. (Is this true?) However, the nonreachable
- * terminals are printed (if running in verbose mode) so that the user
- * can know.
- */
-
- Vp = NEW2(WORDSIZE(nsyms), unsigned);
- Pp = NEW2(WORDSIZE(nrules + 1), unsigned);
+ rule r;
- /* If the start symbol isn't useful, then nothing will be useful. */
- if (!BITISSET(N, start_symbol - ntokens))
- goto end_iteration;
+ /* Find out which productions are reachable and which symbols are
+ used. Starting with an empty set of productions and a set of
+ symbols which only has the start symbol in it, iterate over all
+ productions until the set of productions remains unchanged for an
+ iteration. For each production which has a LHS in the set of
+ reachable symbols, add the production to the set of reachable
+ productions, and add all of the nonterminals in the RHS of the
+ production to the set of reachable symbols.
- SETBIT(V, start_symbol);
+ Consider only the (partially) reduced grammar which has only
+ nonterminals in N and productions in P.
- n = 0;
- while (1)
+ The result is the set P of productions in the reduced grammar,
+ and the set V of symbols in the reduced grammar.
+
+ Although this algorithm also computes the set of terminals which
+ are reachable, no terminal will be deleted from the grammar. Some
+ terminals might not be in the grammar but might be generated by
+ semantic routines, and so the user might want them available with
+ specified numbers. (Is this true?) However, the nonreachable
+ terminals are printed (if running in verbose mode) so that the
+ user can know. */
+
+ Vp = XCALLOC (unsigned, WORDSIZE (nsyms));
+ Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
+
+ /* If the start symbol isn't useful, then nothing will be useful. */
+ if (BITISSET (N, start_symbol - ntokens))
{
- for (i = WORDSIZE(nsyms) - 1; i >= 0; i--)
- Vp[i] = V[i];
- for (i = 1; i <= nrules; i++)
+ SETBIT (V, start_symbol);
+
+ while (1)
{
- if (!BITISSET(Pp, i) && BITISSET(P, i) &&
- BITISSET(V, rlhs[i]))
+ for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
+ Vp[i] = V[i];
+ for (i = 1; i <= nrules; i++)
{
- for (r = &ritem[rrhs[i]]; *r >= 0; r++)
+ if (!BITISSET (Pp, i)
+ && BITISSET (P, i)
+ && BITISSET (V, rule_table[i].lhs))
{
- if (ISTOKEN(t = *r)
- || BITISSET(N, t - ntokens))
- {
- SETBIT(Vp, t);
- }
+ for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
+ if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
+ SETBIT (Vp, t);
+ SETBIT (Pp, i);
}
- SETBIT(Pp, i);
}
+ if (bits_equal (V, Vp, WORDSIZE (nsyms)))
+ break;
+ Vs = Vp;
+ Vp = V;
+ V = Vs;
}
- if (bits_equal(V, Vp, WORDSIZE(nsyms)))
- {
- break;
- }
- Vs = Vp;
- Vp = V;
- V = Vs;
}
- end_iteration:
- FREE(V);
+ XFREE (V);
V = Vp;
/* Tokens 0, 1, and 2 are internal to Bison. Consider them useful. */
- SETBIT(V, 0); /* end-of-input token */
- SETBIT(V, 1); /* error token */
- SETBIT(V, 2); /* some undefined token */
+ SETBIT (V, 0); /* end-of-input token */
+ SETBIT (V, 1); /* error token */
+ SETBIT (V, 2); /* some undefined token */
- FREE(P);
+ XFREE (P);
P = Pp;
- nuseful_productions = bits_size(P, WORDSIZE(nrules + 1));
+ nuseful_productions = bits_size (P, WORDSIZE (nrules + 1));
nuseless_productions = nrules - nuseful_productions;
nuseful_nonterminals = 0;
for (i = ntokens; i < nsyms; i++)
- if (BITISSET(V, i))
+ if (BITISSET (V, i))
nuseful_nonterminals++;
nuseless_nonterminals = nvars - nuseful_nonterminals;
/* A token that was used in %prec should not be warned about. */
for (i = 1; i < nrules; i++)
- if (rprecsym[i] != 0)
- SETBIT(V1, rprecsym[i]);
+ if (rule_table[i].precsym != 0)
+ SETBIT (V1, rule_table[i].precsym);
}
-\f
+
static void
-reduce_grammar_tables ()
+reduce_grammar_tables (void)
{
-/* This is turned off because we would need to change the numbers
- in the case statements in the actions file. */
-#if 0
- /* remove useless productions */
- if (nuseless_productions > 0)
- {
- short np, pn, ni, pi;
-
- np = 0;
- ni = 0;
- for (pn = 1; pn <= nrules; pn++)
- {
- if (BITISSET(P, pn))
+ /* This is turned off because we would need to change the numbers in
+ the case statements in the actions file.
+
+ We don't disable it via CPP so that it is still checked with the
+ rest of the code, to avoid its becoming completely obsolete.
+
+ FIXME: I think the comment above demonstrates this code must be
+ turned off for *semantic* parser, not in the general case. Try
+ to understand this better --akim. */
+
+ if (0)
+ /* remove useless productions */
+ if (nuseless_productions > 0)
+ {
+ short np, pn, ni, pi;
+
+ np = 0;
+ ni = 0;
+ for (pn = 1; pn <= nrules; pn++)
+ if (BITISSET (P, pn))
{
np++;
if (pn != np)
{
- rlhs[np] = rlhs[pn];
- rline[np] = rline[pn];
- rprec[np] = rprec[pn];
- rassoc[np] = rassoc[pn];
- rrhs[np] = rrhs[pn];
- if (rrhs[np] != ni)
+ rule_table[np].lhs = rule_table[pn].lhs;
+ rule_table[np].line = rule_table[pn].line;
+ rule_table[np].prec = rule_table[pn].prec;
+ rule_table[np].assoc = rule_table[pn].assoc;
+ rule_table[np].rhs = rule_table[pn].rhs;
+ if (rule_table[np].rhs != ni)
{
- pi = rrhs[np];
- rrhs[np] = ni;
+ pi = rule_table[np].rhs;
+ rule_table[np].rhs = ni;
while (ritem[pi] >= 0)
ritem[ni++] = ritem[pi++];
ritem[ni++] = -np;
}
- } else {
+ }
+ else
+ {
while (ritem[ni++] >= 0);
}
}
- }
- ritem[ni] = 0;
- nrules -= nuseless_productions;
- nitems = ni;
- /*
- * Is it worth it to reduce the amount of memory for the
- * grammar? Probably not.
- */
+ ritem[ni] = 0;
+ nrules -= nuseless_productions;
+ nitems = ni;
- }
-#endif /* 0 */
- /* Disable useless productions,
- since they may contain useless nonterms
- that would get mapped below to -1 and confuse everyone. */
+ /* Is it worth it to reduce the amount of memory for the
+ grammar? Probably not. */
+ }
+
+ /* Disable useless productions. */
if (nuseless_productions > 0)
{
int pn;
-
for (pn = 1; pn <= nrules; pn++)
- {
- if (!BITISSET(P, pn))
- {
- rlhs[pn] = -1;
- }
- }
+ rule_table[pn].useful = BITISSET (P, pn);
}
+}
- /* remove useless symbols */
- if (nuseless_nonterminals > 0)
- {
- int i, n;
-/* short j; JF unused */
- short *nontermmap;
- rule r;
+/*------------------------------.
+| Remove useless nonterminals. |
+`------------------------------*/
- /*
- * create a map of nonterminal number to new nonterminal
- * number. -1 in the map means it was useless and is being
- * eliminated.
- */
+static void
+nonterminals_reduce (void)
+{
+ int i, n;
+ rule r;
- nontermmap = NEW2(nvars, short) - ntokens;
- for (i = ntokens; i < nsyms; i++)
- nontermmap[i] = -1;
+ /* Map the nonterminals to their new index: useful first, useless
+ afterwards. Kept for later report. */
- n = ntokens;
- for (i = ntokens; i < nsyms; i++)
- if (BITISSET(V, i))
- nontermmap[i] = n++;
+ short *nontermmap = XCALLOC (short, nvars) - ntokens;
+ n = ntokens;
+ for (i = ntokens; i < nsyms; i++)
+ if (BITISSET (V, i))
+ nontermmap[i] = n++;
+ for (i = ntokens; i < nsyms; i++)
+ if (!BITISSET (V, i))
+ nontermmap[i] = n++;
+
+
+ /* Shuffle elements of tables indexed by symbol number. */
+ {
+ short *sassoc_sorted = XMALLOC (short, nvars) - ntokens;
+ short *sprec_sorted = XMALLOC (short, nvars) - ntokens;
+ char **tags_sorted = XMALLOC (char *, nvars) - ntokens;
+
+ for (i = ntokens; i < nsyms; i++)
+ {
+ n = nontermmap[i];
+ sassoc_sorted[n] = sassoc[i];
+ sprec_sorted[n] = sprec[i];
+ tags_sorted[n] = tags[i];
+ }
+ for (i = ntokens; i < nsyms; i++)
+ {
+ sassoc[i] = sassoc_sorted[i];
+ sprec[i] = sprec_sorted[i];
+ tags[i] = tags_sorted[i];
+ }
+ free (sassoc_sorted + ntokens);
+ free (sprec_sorted + ntokens);
+ free (tags_sorted + ntokens);
+ }
- /* Shuffle elements of tables indexed by symbol number. */
+ /* Replace all symbol numbers in valid data structures. */
- for (i = ntokens; i < nsyms; i++)
- {
- n = nontermmap[i];
- if (n >= 0)
- {
- sassoc[n] = sassoc[i];
- sprec[n] = sprec[i];
- tags[n] = tags[i];
- } else {
- free(tags[i]);
- }
- }
+ for (i = 1; i <= nrules; i++)
+ {
+ rule_table[i].lhs = nontermmap[rule_table[i].lhs];
+ if (ISVAR (rule_table[i].precsym))
+ /* Can this happen? */
+ rule_table[i].precsym = nontermmap[rule_table[i].precsym];
+ }
- /* Replace all symbol numbers in valid data structures. */
+ for (r = ritem; *r; r++)
+ if (ISVAR (*r))
+ *r = nontermmap[*r];
- for (i = 1; i <= nrules; i++)
- {
- /* Ignore the rules disabled above. */
- if (rlhs[i] >= 0)
- rlhs[i] = nontermmap[rlhs[i]];
- if (ISVAR (rprecsym[i]))
- /* Can this happen? */
- rprecsym[i] = nontermmap[rprecsym[i]];
- }
+ start_symbol = nontermmap[start_symbol];
- for (r = ritem; *r; r++)
- if (ISVAR(*r))
- *r = nontermmap[*r];
+ nsyms -= nuseless_nonterminals;
+ nvars -= nuseless_nonterminals;
- start_symbol = nontermmap[start_symbol];
+ free (nontermmap + ntokens);
+}
- nsyms -= nuseless_nonterminals;
- nvars -= nuseless_nonterminals;
- free(&nontermmap[ntokens]);
- }
-}
-\f
-static void
-print_results ()
-{
- int i;
-/* short j; JF unused */
- rule r;
- bool b;
+/*------------------------------------------------------------------.
+| Output the detailed results of the reductions. For FILE.output. |
+`------------------------------------------------------------------*/
+void
+reduce_output (FILE *out)
+{
if (nuseless_nonterminals > 0)
{
- fprintf(foutput, _("Useless nonterminals:\n\n"));
- for (i = ntokens; i < nsyms; i++)
- if (!BITISSET(V, i))
- fprintf(foutput, " %s\n", tags[i]);
+ int i;
+ fprintf (out, "%s\n\n", _("Useless nonterminals:"));
+ for (i = 0; i < nuseless_nonterminals; ++i)
+ fprintf (out, " %s\n", tags[nsyms + i]);
+ fputs ("\n\n", out);
}
- b = FALSE;
- for (i = 0; i < ntokens; i++)
- {
- if (!BITISSET(V, i) && !BITISSET(V1, i))
+
+ {
+ bool b = FALSE;
+ int i;
+ for (i = 0; i < ntokens; i++)
+ if (!BITISSET (V, i) && !BITISSET (V1, i))
{
if (!b)
- {
- fprintf(foutput, _("\n\nTerminals which are not used:\n\n"));
- b = TRUE;
- }
- fprintf(foutput, " %s\n", tags[i]);
+ fprintf (out, "%s\n\n", _("Terminals which are not used:"));
+ b = TRUE;
+ fprintf (out, " %s\n", tags[i]);
}
- }
+ if (b)
+ fputs ("\n\n", out);
+ }
if (nuseless_productions > 0)
{
- fprintf(foutput, _("\n\nUseless rules:\n\n"));
+ int i;
+ fprintf (out, "%s\n\n", _("Useless rules:"));
for (i = 1; i <= nrules; i++)
- {
- if (!BITISSET(P, i))
- {
- fprintf(foutput, "#%-4d ", i);
- fprintf(foutput, "%s :\t", tags[rlhs[i]]);
- for (r = &ritem[rrhs[i]]; *r >= 0; r++)
- {
- fprintf(foutput, " %s", tags[*r]);
- }
- fprintf(foutput, ";\n");
- }
- }
+ if (!rule_table[i].useful)
+ {
+ rule r;
+ fprintf (out, "#%-4d ", i);
+ fprintf (out, "%s:", tags[rule_table[i].lhs]);
+ for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
+ fprintf (out, " %s", tags[*r]);
+ fputs (";\n", out);
+ }
+ fputs ("\n\n", out);
}
- if (nuseless_nonterminals > 0 || nuseless_productions > 0 || b)
- fprintf(foutput, "\n\n");
}
\f
-void
-dump_grammar ()
+static void
+dump_grammar (FILE *out)
{
int i;
rule r;
- fprintf(foutput,
- "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nitems = %d\n\n",
- ntokens, nvars, nsyms, nrules, nitems);
- fprintf(foutput, _("Variables\n---------\n\n"));
- fprintf(foutput, _("Value Sprec Sassoc Tag\n"));
+ fprintf (out, "REDUCED GRAMMAR\n\n");
+ fprintf (out,
+ "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nitems = %d\n\n",
+ ntokens, nvars, nsyms, nrules, nitems);
+ fprintf (out, "Variables\n---------\n\n");
+ fprintf (out, "Value Sprec Sassoc Tag\n");
for (i = ntokens; i < nsyms; i++)
- fprintf(foutput, "%5d %5d %5d %s\n",
- i, sprec[i], sassoc[i], tags[i]);
- fprintf(foutput, "\n\n");
- fprintf(foutput, _("Rules\n-----\n\n"));
+ fprintf (out, "%5d %5d %5d %s\n", i, sprec[i], sassoc[i], tags[i]);
+ fprintf (out, "\n\n");
+ fprintf (out, "Rules\n-----\n\n");
+ fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
for (i = 1; i <= nrules; i++)
{
- fprintf(foutput, "%-5d(%5d%5d)%5d : (@%-5d)",
- i, rprec[i], rassoc[i], rlhs[i], rrhs[i]);
- for (r = &ritem[rrhs[i]]; *r > 0; r++)
- fprintf(foutput, "%5d", *r);
- fprintf(foutput, " [%d]\n", -(*r));
+ int rhs_count = 0;
+ /* Find the last RHS index in ritems. */
+ for (r = &ritem[rule_table[i].rhs]; *r > 0; ++r)
+ ++rhs_count;
+ fprintf (out, "%3d (%2d, %2d, %2d, %2d-%2d) %2d ->",
+ i,
+ rule_table[i].prec, rule_table[i].assoc, rule_table[i].useful,
+ rule_table[i].rhs, rule_table[i].rhs + rhs_count - 1,
+ rule_table[i].lhs);
+ /* Dumped the RHS. */
+ for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
+ fprintf (out, "%3d", *r);
+ fprintf (out, " [%d]\n", -(*r));
}
- fprintf(foutput, "\n\n");
- fprintf(foutput, _("Rules interpreted\n-----------------\n\n"));
+ fprintf (out, "\n\n");
+ fprintf (out, "Rules interpreted\n-----------------\n\n");
for (i = 1; i <= nrules; i++)
{
- fprintf(foutput, "%-5d %s :", i, tags[rlhs[i]]);
- for (r = &ritem[rrhs[i]]; *r > 0; r++)
- fprintf(foutput, " %s", tags[*r]);
- fprintf(foutput, "\n");
+ fprintf (out, "%-5d %s :", i, tags[rule_table[i].lhs]);
+ for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
+ fprintf (out, " %s", tags[*r]);
+ fputc ('\n', out);
}
- fprintf(foutput, "\n\n");
+ fprintf (out, "\n\n");
}
+
+/*-------------------------------.
+| Report the results to STDERR. |
+`-------------------------------*/
+
static void
-print_notices ()
+reduce_print (void)
{
- extern int fixed_outfiles;
-
- if (fixed_outfiles && nuseless_productions)
- fprintf(stderr, _("%d rules never reduced\n"), nuseless_productions);
+ 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 contains "), infile);
+ fprintf (stderr, _("%s contains "), infile);
if (nuseless_nonterminals > 0)
- {
- fprintf(stderr, _("%d useless nonterminal%s"),
- nuseless_nonterminals,
- (nuseless_nonterminals == 1 ? "" : "s"));
- }
+ 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, _(" and "));
if (nuseless_productions > 0)
+ fprintf (stderr, ngettext ("%d useless rule",
+ "%d useless rules",
+ nuseless_productions),
+ nuseless_productions);
+ fprintf (stderr, "\n");
+ fflush (stderr);
+}
+\f
+void
+reduce_grammar (void)
+{
+ bool reduced;
+
+ /* Allocate the global sets used to compute the reduced grammar */
+
+ N = XCALLOC (unsigned, WORDSIZE (nvars));
+ P = XCALLOC (unsigned, WORDSIZE (nrules + 1));
+ V = XCALLOC (unsigned, WORDSIZE (nsyms));
+ V1 = XCALLOC (unsigned, WORDSIZE (nsyms));
+
+ useless_nonterminals ();
+ inaccessable_symbols ();
+
+ reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
+
+ if (!reduced)
+ return;
+
+ reduce_print ();
+
+ if (!BITISSET (N, start_symbol - ntokens))
+ fatal (_("Start symbol %s does not derive any sentence"),
+ tags[start_symbol]);
+
+ reduce_grammar_tables ();
+ if (nuseless_nonterminals > 0)
+ nonterminals_reduce ();
+
+ if (trace_flag)
{
- fprintf(stderr, _("%d useless rule%s"),
- nuseless_productions,
- (nuseless_productions == 1 ? "" : "s"));
+ dump_grammar (stderr);
+
+ fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\
+, and %d productions.\n",
+ infile, ntokens, nvars, nrules);
}
- fprintf(stderr, "\n");
- fflush(stderr);
+}
+
+
+/*-----------------------------------------------------------.
+| Free the global sets used to compute the reduced grammar. |
+`-----------------------------------------------------------*/
+
+void
+reduce_free (void)
+{
+ XFREE (N);
+ XFREE (V);
+ XFREE (V1);
+ XFREE (P);
}
projects / bison.git / blobdiff