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. */
+/* Set of all nonterminals which are not useless. */
+static BSet N;
-static BSet N, P, V, V1;
+/* Set of all rules which have no useless nonterminals in their RHS. */
+static BSet P;
+
+/* Set of all accessible symbols. */
+static BSet V;
+
+/* Set of symbols used to define rule precedence (so they are
+ `useless', but no warning should be issued). */
+static BSet V1;
static int nuseful_productions;
static int nuseless_productions;
static int nuseful_nonterminals;
-static int nuseless_nonterminals;
+int nuseless_nonterminals;
\f
static bool
bits_equal (BSet L, BSet R, int n)
static void
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;
+ /* This is turned off because we would need to change the numbers in
+ the case statements in the actions file.
- np = 0;
- ni = 0;
- for (pn = 1; pn <= nrules; pn++)
- {
+ 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)
{
- rule_table[np].lhs = rule_table[pn].lhs;
- rline[np] = rline[pn];
- rule_table[np].prec = rule_table[pn].prec;
+ 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;
+ rule_table[np].rhs = rule_table[pn].rhs;
if (rule_table[np].rhs != ni)
{
pi = rule_table[np].rhs;
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))
- {
- rule_table[pn].lhs = -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;
-
- /* Create a map of nonterminal number to new nonterminal
- number. -1 in the map means it was useless and is being
- eliminated. */
-
- nontermmap = XCALLOC (short, nvars) - ntokens;
- for (i = ntokens; i < nsyms; i++)
- nontermmap[i] = -1;
- n = ntokens;
- for (i = ntokens; i < nsyms; i++)
- if (BITISSET (V, i))
- nontermmap[i] = n++;
+/*------------------------------.
+| Remove useless nonterminals. |
+`------------------------------*/
- /* Shuffle elements of tables indexed by symbol number. */
+static void
+nonterminals_reduce (void)
+{
+ int i, n;
+ rule r;
- for (i = ntokens; i < nsyms; i++)
- {
- n = nontermmap[i];
- if (n >= 0)
- {
- sassoc[n] = sassoc[i];
- sprec[n] = sprec[i];
- tags[n] = tags[i];
- }
- }
+ /* Map the nonterminals to their new index: useful first, useless
+ afterwards. Kept for later report. */
- /* Replace all symbol numbers in valid data structures. */
+ 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);
+ }
+
+ /* Replace all symbol numbers in valid data structures. */
- for (i = 1; i <= nrules; i++)
- {
- /* Ignore the rules disabled above. */
- if (rule_table[i].lhs >= 0)
- 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];
- }
+ 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];
+ }
- for (r = ritem; *r; r++)
- if (ISVAR (*r))
- *r = nontermmap[*r];
+ for (r = ritem; *r; r++)
+ if (ISVAR (*r))
+ *r = nontermmap[*r];
- start_symbol = nontermmap[start_symbol];
+ start_symbol = nontermmap[start_symbol];
- nsyms -= nuseless_nonterminals;
- nvars -= nuseless_nonterminals;
+ nsyms -= nuseless_nonterminals;
+ nvars -= nuseless_nonterminals;
- free (&nontermmap[ntokens]);
- }
+ free (nontermmap + ntokens);
}
-/*-----------------------------------------------------------------.
-| Ouput the detailed results of the reductions. For FILE.output. |
-`-----------------------------------------------------------------*/
+/*------------------------------------------------------------------.
+| Output the detailed results of the reductions. For FILE.output. |
+`------------------------------------------------------------------*/
void
reduce_output (FILE *out)
{
- int i;
- rule r;
- bool b;
-
if (nuseless_nonterminals > 0)
{
- fprintf (out, _("Useless nonterminals:"));
- fprintf (out, "\n\n");
- for (i = ntokens; i < nsyms; i++)
- if (!BITISSET (V, i))
- fprintf (out, " %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++)
- {
+
+ {
+ bool b = FALSE;
+ int i;
+ for (i = 0; i < ntokens; i++)
if (!BITISSET (V, i) && !BITISSET (V1, i))
{
if (!b)
- {
- fprintf (out, "\n\n");
- fprintf (out, _("Terminals which are not used:"));
- fprintf (out, "\n\n");
- b = TRUE;
- }
+ 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 (out, "\n\n");
- fprintf (out, _("Useless rules:"));
- fprintf (out, "\n\n");
+ int i;
+ fprintf (out, "%s\n\n", _("Useless rules:"));
for (i = 1; i <= nrules; i++)
- if (!BITISSET (P, i))
+ if (!rule_table[i].useful)
{
- fprintf (out, "#%-4d ", i);
- fprintf (out, "%s :\t", tags[rule_table[i].lhs]);
+ rule r;
+ fprintf (out, "#%-4d ", i - 1);
+ fprintf (out, "%s:", tags[rule_table[i].lhs]);
for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
fprintf (out, " %s", tags[*r]);
- fprintf (out, ";\n");
+ fputs (";\n", out);
}
+ fputs ("\n\n", out);
}
- if (nuseless_nonterminals > 0 || nuseless_productions > 0 || b)
- fprintf (out, "\n\n");
}
\f
static void
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) Lhs : (@Rhs) Ritems [Num?]\n");
+ fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
for (i = 1; i <= nrules; i++)
{
- fprintf (out, "%-5d(%5d%5d)%5d : (@%-5d)",
+ 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].lhs,
- rule_table[i].rhs);
+ 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, "%5d", *r);
- fprintf (out, " [%d]\n", -(*r));
+ fprintf (out, "%3d", *r);
+ fprintf (out, " [%d]\n", -(*r));
}
fprintf (out, "\n\n");
fprintf (out, "Rules interpreted\n-----------------\n\n");
tags[start_symbol]);
reduce_grammar_tables ();
+ if (nuseless_nonterminals > 0)
+ nonterminals_reduce ();
if (trace_flag)
{
projects / bison.git / blobdiff