2002-04-07 Akim Demaille <akim@epita.fr>
- Remove the useless rules from the parser.
+ * src/LR0.c (allocate_itemsets): Don't loop over ritem: loop over
+ the RHS of the rules.
+ * src/output.c (output_gram): Likewise.
- * src/gram.h, src/gram.c (rules_swap, rule_rhs_length): New.
- (ritem_longest_rhs): Use the latter.
+2002-04-07 Akim Demaille <akim@epita.fr>
+
+ * src/gram.h (rule_t): `lhs' is now a pointer to the symbol's
+ bucket.
+ Adjust all dependencies.
+ * src/reduce.c (nonterminals_reduce): Don't forget to renumber the
+ `number' of the buckets too.
+ * src/gram.h: Include `symtab.h'.
+ (associativity): Move to...
+ * src/symtab.h: here.
+ No longer include `gram.h'.
+
+
+2002-04-07 Akim Demaille <akim@epita.fr>
+
+ * src/gram.h, src/gram.c (rules_rhs_length): New.
+ (ritem_longest_rhs): Use it.
* src/gram.h (rule_t): `number' is a new member.
* src/reader.c (packgram): Set it.
* src/reduce.c (reduce_grammar_tables): Move the useless rules at
the usefulness of a rule, as useless rules are beyond `nrules + 1'.
* tests/reduce.at (Reduced Automaton): New test.
-diff -x *.po -ur -x testsuite bison-1.49a/NEWS bison/NEWS
---- bison-1.49a/NEWS Sun Apr 7 17:36:56 2002
-+++ bison/NEWS Sun Apr 7 18:19:39 2002
-@@ -3,6 +3,10 @@
-
- Changes in version 1.49a:
-
-+* Useless rules are actually removed.
-+ Before, Bison reported the useless rules, but, although not used,
-+ included them in the parsers.
-+
- * False `Token not used' report fixed.
- On a grammar such as
-
-diff -x *.po -ur -x testsuite bison-1.49a/src/gram.c bison/src/gram.c
---- bison-1.49a/src/gram.c Sun Apr 7 17:36:56 2002
-+++ bison/src/gram.c Sun Apr 7 18:19:39 2002
-@@ -1,5 +1,5 @@
- /* Allocate input grammar variables for bison,
-- Copyright 1984, 1986, 1989, 2001 Free Software Foundation, Inc.
-+ Copyright 1984, 1986, 1989, 2001, 2002 Free Software Foundation, Inc.
-
- This file is part of Bison, the GNU Compiler Compiler.
-
-@@ -51,6 +51,51 @@
- int error_token_number;
-
-
-+/*----------------------------------.
-+| Swap the rules number R1 and R2. |
-+`----------------------------------*/
-+
-+void
-+rules_swap (int r1, int r2)
-+{
-+ /* The easy part: swap the immediate contents of the structures. */
-+ {
-+ rule_t rule = rules[r1];
-+ rules[r1] = rules[r2];
-+ rules[r2] = rule;
-+ }
-+
-+ /* The first negative number in the RHS is the rule number. */
-+ {
-+ short *rhsp;
-+ for (rhsp = rules[r1].rhs; *rhsp >= 0; ++rhsp)
-+ /* Nothing. */;
-+ assert (*rhsp == -r2);
-+ *rhsp = -r1;
-+
-+ for (rhsp = rules[r2].rhs; *rhsp >= 0; ++rhsp)
-+ /* Nothing. */;
-+ assert (*rhsp == -r1);
-+ *rhsp = -r2;
-+ }
-+}
-+
-+
-+/*--------------------------------------.
-+| Return the number of symbols in RHS. |
-+`--------------------------------------*/
-+
-+int
-+rule_rhs_length (rule_t *rule)
-+{
-+ int res = 0;
-+ short *rhsp;
-+ for (rhsp = rule->rhs; *rhsp >= 0; ++rhsp)
-+ ++res;
-+ return res;
-+}
-+
-+
- /*------------------------.
- | Dump RITEM for traces. |
- `------------------------*/
-@@ -76,23 +121,15 @@
- size_t
- ritem_longest_rhs (void)
- {
-- int length;
-- int max;
-+ int max = 0;
- int i;
-
-- length = 0;
-- max = 0;
-- for (i = 0; i < nritems; ++i)
-- if (ritem[i] >= 0)
-- {
-- length++;
-- }
-- else
-- {
-- if (length > max)
-- max = length;
-- length = 0;
-- }
-+ for (i = 1; i < nrules + 1; ++i)
-+ {
-+ int length = rule_rhs_length (&rules[i]);
-+ if (length > max)
-+ max = length;
-+ }
-
- return max;
- }
-diff -x *.po -ur -x testsuite bison-1.49a/src/gram.h bison/src/gram.h
---- bison-1.49a/src/gram.h Sun Apr 7 17:55:00 2002
-+++ bison/src/gram.h Sun Apr 7 18:19:39 2002
-@@ -124,6 +124,10 @@
-
- typedef struct rule_s
- {
-+ /* The number of the rule in the source. It is usually the index in
-+ RULES too, except if there are useless rules. */
-+ short number;
-+
- short lhs;
- short *rhs;
- short prec;
-@@ -166,6 +170,11 @@
-
- extern int error_token_number;
-
-+/* Swap two rules. */
-+void rules_swap PARAMS ((int r1, int r2));
-+
-+/* Report the length of the RHS. */
-+int rule_rhs_length PARAMS ((rule_t *rule));
-
- /* Dump RITEM for traces. */
- void ritem_print PARAMS ((FILE *out));
-diff -x *.po -ur -x testsuite bison-1.49a/src/print.c bison/src/print.c
---- bison-1.49a/src/print.c Sun Apr 7 17:55:00 2002
-+++ bison/src/print.c Sun Apr 7 18:19:39 2002
-@@ -366,19 +366,17 @@
- fprintf (out, "%s\n\n", _("Grammar"));
- fprintf (out, " %s\n", _("Number, Line, Rule"));
- for (i = 1; i < nrules + 1; i++)
-- /* Don't print rules disabled in reduce_grammar_tables. */
-- if (rules[i].useful)
-- {
-- fprintf (out, _(" %3d %3d %s ->"),
-- i - 1, rules[i].line, escape (symbols[rules[i].lhs]->tag));
-- rule = rules[i].rhs;
-- if (*rule >= 0)
-- while (*rule >= 0)
-- fprintf (out, " %s", escape (symbols[*rule++]->tag));
-- else
-- fprintf (out, " /* %s */", _("empty"));
-- fputc ('\n', out);
-- }
-+ {
-+ fprintf (out, _(" %3d %3d %s ->"),
-+ i - 1, rules[i].line, escape (symbols[rules[i].lhs]->tag));
-+ rule = rules[i].rhs;
-+ if (*rule >= 0)
-+ while (*rule >= 0)
-+ fprintf (out, " %s", escape (symbols[*rule++]->tag));
-+ else
-+ fprintf (out, " /* %s */", _("empty"));
-+ fputc ('\n', out);
-+ }
- fputs ("\n\n", out);
-
-
-diff -x *.po -ur -x testsuite bison-1.49a/src/reader.c bison/src/reader.c
---- bison-1.49a/src/reader.c Sun Apr 7 17:56:13 2002
-+++ bison/src/reader.c Sun Apr 7 18:19:39 2002
-@@ -1687,6 +1687,7 @@
- while (p)
- {
- bucket *ruleprec = p->ruleprec;
-+ rules[ruleno].number = ruleno;
- rules[ruleno].lhs = p->sym->number;
- rules[ruleno].rhs = ritem + itemno;
- rules[ruleno].line = p->line;
-diff -x *.po -ur -x testsuite bison-1.49a/src/reduce.c bison/src/reduce.c
---- bison-1.49a/src/reduce.c Sun Apr 7 17:55:00 2002
-+++ bison/src/reduce.c Sun Apr 7 18:19:39 2002
-@@ -220,70 +220,59 @@
- bitset_set (V1, rules[i].precsym);
- }
-
-+
-+/*-------------------------------------------------------------------.
-+| Put the useless productions at the end of RULES, and adjust NRULES |
-+| accordingly. |
-+`-------------------------------------------------------------------*/
-+
- 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.
--
-- 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 + 1; pn++)
-- if (bitset_test (P, pn))
-- {
-- np++;
-- if (pn != np)
-- {
-- rules[np].lhs = rules[pn].lhs;
-- rules[np].line = rules[pn].line;
-- rules[np].prec = rules[pn].prec;
-- rules[np].assoc = rules[pn].assoc;
-- rules[np].rhs = rules[pn].rhs;
-- if (rules[np].rhs - ritem != ni)
-- {
-- pi = rules[np].rhs - ritem;
-- rules[np].rhs = ritem + ni;
-- while (ritem[pi] >= 0)
-- ritem[ni++] = ritem[pi++];
-- ritem[ni++] = -np;
-- }
-- }
-- else
-- {
-- while (ritem[ni++] >= 0)
-- /* Nothing. */;
-- }
-- }
--
-- ritem[ni] = 0;
-- nrules -= nuseless_productions;
-- nitems = ni;
-- nritems = ni;
--
-- /* Is it worth it to reduce the amount of memory for the
-- grammar? Probably not. */
-- }
--
-- /* Disable useless productions. */
-+ /* Flag useless productions. */
- if (nuseless_productions > 0)
- {
- int pn;
- for (pn = 1; pn < nrules + 1; pn++)
- rules[pn].useful = bitset_test (P, pn);
- }
-+
-+ /* Map the nonterminals to their new index: useful first, useless
-+ afterwards. Kept for later report. */
-+ if (nuseless_productions > 0)
-+ {
-+ short *map = XCALLOC (short, nrules + 1) - 1;
-+ int useful = 1;
-+ int useless = nrules + 1 - nuseless_productions;
-+ int i;
-+ for (i = 1; i < nrules + 1; ++i)
-+ map[i] = rules[i].useful ? useful++ : useless++;
-+
-+ /* Shuffle elements of tables indexed by symbol number. */
-+ for (i = 1; i < nrules + 1; ++i)
-+ if (i != map[i])
-+ {
-+ int j = map[i];
-+ rules_swap (i, map[i]);
-+ map[i] = map[j];
-+ map[j] = j;
-+ }
-+
-+ free (map + 1);
-+ nrules -= nuseless_productions;
-+ }
-+
-+ /* Adjust NRITEMS and NITEMS. */
-+ {
-+ int r;
-+ int length;
-+ for (r = nrules + 1; r < nrules + 1 + nuseless_productions; ++r)
-+ {
-+ length = rule_rhs_length (&rules[r]);
-+ nritems -= length + 1;
-+ nitems -= length + 1;
-+ }
-+ }
- }
-
-
-@@ -378,16 +367,15 @@
- {
- int i;
- fprintf (out, "%s\n\n", _("Useless rules:"));
-- for (i = 1; i < nrules + 1; i++)
-- if (!rules[i].useful)
-- {
-- rule r;
-- fprintf (out, "#%-4d ", i - 1);
-- fprintf (out, "%s:", symbols[rules[i].lhs]->tag);
-- for (r = rules[i].rhs; *r >= 0; r++)
-- fprintf (out, " %s", symbols[*r]->tag);
-- fputs (";\n", out);
-- }
-+ for (i = nrules + 1; i < nuseless_productions + nrules + 1; i++)
-+ {
-+ rule r;
-+ fprintf (out, "#%-4d ", rules[i].number - 1);
-+ fprintf (out, "%s:", symbols[rules[i].lhs]->tag);
-+ for (r = rules[i].rhs; *r >= 0; r++)
-+ fprintf (out, " %s", symbols[*r]->tag);
-+ fputs (";\n", out);
-+ }
- fputs ("\n\n", out);
- }
- }
-@@ -411,7 +399,7 @@
- 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 + 1; i++)
-+ for (i = 1; i < nrules + nuseless_productions + 1; i++)
- {
- int rhs_count = 0;
- /* Find the last RHS index in ritems. */
-@@ -429,7 +417,7 @@
- }
- fprintf (out, "\n\n");
- fprintf (out, "Rules interpreted\n-----------------\n\n");
-- for (i = 1; i < nrules + 1; i++)
-+ for (i = 1; i < nrules + nuseless_productions + 1; i++)
- {
- fprintf (out, "%-5d %s :", i, symbols[rules[i].lhs]->tag);
- for (r = rules[i].rhs; *r >= 0; r++)
-diff -x *.po -ur -x testsuite bison-1.49a/tests/reduce.at bison/tests/reduce.at
---- bison-1.49a/tests/reduce.at Sun Apr 7 17:36:56 2002
-+++ bison/tests/reduce.at Sun Apr 7 18:19:39 2002
-@@ -174,6 +174,89 @@
-
-
- ## ------------------- ##
-+## Reduced Automaton. ##
-+## ------------------- ##
-+
-+# Check that the automaton is that as the for the grammar reduced by
-+# hand.
-+
-+AT_SETUP([Reduced Automaton])
-+
-+# The non reduced grammar.
-+# ------------------------
-+AT_DATA([[not-reduced.y]],
-+[[/* A useless token. */
-+%token useless_token
-+/* A useful one. */
-+%token useful
-+%verbose
-+%output="not-reduced.c"
-+
-+%%
-+
-+exp: useful { /* A useful action. */ }
-+ | non_productive { /* A non productive action. */ }
-+ ;
-+
-+not_reachable: useful { /* A not reachable action. */ }
-+ ;
-+
-+non_productive: non_productive useless_token
-+ { /* Another non productive action. */ }
-+ ;
-+]])
-+
-+AT_CHECK([[bison not-reduced.y]], 0, [],
-+[[not-reduced.y contains 2 useless nonterminals and 3 useless rules
-+]])
-+
-+AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' not-reduced.output]], 0,
-+[[Useless nonterminals:
-+ not_reachable
-+ non_productive
-+Terminals which are not used:
-+ useless_token
-+Useless rules:
-+#2 exp: non_productive;
-+#3 not_reachable: useful;
-+#4 non_productive: non_productive useless_token;
-+]])
-+
-+# The reduced grammar.
-+# --------------------
-+AT_DATA([[reduced.y]],
-+[[/* A useless token. */
-+%token useless_token
-+/* A useful one. */
-+%token useful
-+%verbose
-+%output="reduced.c"
-+
-+%%
-+
-+exp: useful { /* A useful action. */ }
-+// | non_productive { /* A non productive action. */ } */
-+ ;
-+
-+//not_reachable: useful { /* A not reachable action. */ }
-+// ;
-+
-+//non_productive: non_productive useless_token
-+// { /* Another non productive action. */ }
-+// ;
-+]])
-+
-+AT_CHECK([[bison reduced.y]])
-+
-+# Comparing the parsers.
-+cp reduced.c expout
-+AT_CHECK([sed 's/not-reduced/reduced/g' not-reduced.c], 0, [expout])
-+
-+AT_CLEANUP
-+
-+
-+
-+## ------------------- ##
- ## Underivable Rules. ##
- ## ------------------- ##
-
2002-04-07 Akim Demaille <akim@epita.fr>
* src/reduce.c (inaccessable_symbols): Fix a buglet: because of a
lacking `+ 1' to nrules, Bison reported as useless a token if it
was used solely to set the precedence of the last rule...
-
2002-04-07 Akim Demaille <akim@epita.fr>
* data/bison.c++, data/bison.simple: Don't output the current file
name in #line, to avoid useless diffs between two identical
outputs under different names.
-
2002-04-07 Akim Demaille <akim@epita.fr>
* src/closure.c, src/print.c, src/reader.c, src/reduce.c:
Normalize loops to using `< nrules + 1', not `<= nrules'.
-
2002-04-07 Akim Demaille <akim@epita.fr>
* TODO: Update.
-
2002-04-07 Akim Demaille <akim@epita.fr>
* src/output.c, src/reader.c, src/symtab.c, src/symtab.h: Rename
bucket.value as bucket.number.
-
2002-04-07 Akim Demaille <akim@epita.fr>
* src/closure.c, src/derives.c, src/gram.h, src/lalr.c,
YYERROR_VERBOSE is nonzero, not whether it is defined.
Merge changes from bison-1_29-branch.
-
+
2002-03-20 Paul Eggert <eggert@twinsun.com>
Merge fixes from Debian bison_1.34-1.diff.
* src/reader.c (parse_union_decl): Define the muscle stype_line.
* data/bison.simple, data/bison.c++: Use it.
-
2002-03-19 Akim Demaille <akim@epita.fr>
* tests/regression.at (%nonassoc and eof, Unresolved SR Conflicts)
projects / bison.git / blobdiff