Do not let the scan-skel token buffer grow unboundedly in the usual case.

[bison.git] / src / gram.c

diff --git a/src/gram.c b/src/gram.c
index 9db02d8ba5a7f2b21d7bdc32d9ac881a60d6315d..cf5a946db983e698269f6f2fa1aaa1800ecbc3ad 100644 (file)
--- a/src/gram.c
+++ b/src/gram.c
@@ -1,5 +1,6 @@
-/* Allocate input grammar variables for bison,
-   Copyright 1984, 1986, 1989, 2001 Free Software Foundation, Inc.
+/* Allocate input grammar variables for Bison.
+
+   Copyright (C) 1984, 1986, 1989, 2001, 2002 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -20,35 +21,139 @@
 
 
 #include "system.h"
 
 
 #include "system.h"

+
+#include <quotearg.h>
+

 #include "gram.h"
 #include "reader.h"
 #include "gram.h"
 #include "reader.h"

+#include "reduce.h"
+#include "symtab.h"

 
 

-/* comments for these variables are in gram.h  */
+/* Comments for these variables are in gram.h.  */

 
 

-int nitems;
-int nrules;
-int nsyms;
-int ntokens;
-int nvars;
+item_number *ritem = NULL;
+unsigned int nritems = 0;

 
 

-short *ritem = NULL;
-rule_t *rule_table = NULL;
-short *rprec = NULL;
-short *rprecsym = NULL;
-short *sprec = NULL;
-short *rassoc = NULL;
-short *sassoc = NULL;
-short *token_translations = NULL;
+rule *rules = NULL;
+rule_number nrules = 0;

 
 

-int start_symbol;
+symbol **symbols = NULL;
+int nsyms = 0;
+int ntokens = 1;
+int nvars = 0;

 
 

-int max_user_token_number;
+symbol_number *token_translations = NULL;

 
 

-int semantic_parser;
+int max_user_token_number = 256;

 
 

-int pure_parser;
+int glr_parser = 0;
+int pure_parser = 0;

 
 

-int error_token_number;
+
+/*--------------------------------------------------------------.
+| Return true IFF the rule has a `number' smaller than NRULES.  |
+`--------------------------------------------------------------*/
+
+bool
+rule_useful_p (rule *r)
+{
+  return r->number < nrules;
+}
+
+
+/*-------------------------------------------------------------.
+| Return true IFF the rule has a `number' higher than NRULES.  |
+`-------------------------------------------------------------*/
+
+bool
+rule_useless_p (rule *r)
+{
+  return r->number >= nrules;
+}
+
+
+/*--------------------------------------------------------------------.
+| Return true IFF the rule is not flagged as useful *and* is useful.  |
+| In other words, it was discarded because of conflicts.              |
+`--------------------------------------------------------------------*/
+
+bool
+rule_never_reduced_p (rule *r)
+{
+  return !r->useful && r->number < nrules;
+}
+
+
+/*----------------------------------------------------------------.
+| Print this RULE's number and lhs on OUT.  If a PREVIOUS_LHS was |
+| already displayed (by a previous call for another rule), avoid  |
+| useless repetitions.                                            |
+`----------------------------------------------------------------*/
+
+void
+rule_lhs_print (rule *r, symbol *previous_lhs, FILE *out)
+{
+  fprintf (out, "  %3d ", r->number);
+  if (previous_lhs != r->lhs)
+    {
+      fprintf (out, "%s:", r->lhs->tag);
+    }
+  else
+    {
+      int n;
+      for (n = strlen (previous_lhs->tag); n > 0; --n)
+       fputc (' ', out);
+      fputc ('|', out);
+    }
+}
+
+
+/*--------------------------------------.
+| Return the number of symbols in RHS.  |
+`--------------------------------------*/
+
+int
+rule_rhs_length (rule *r)
+{
+  int res = 0;
+  item_number *rhsp;
+  for (rhsp = r->rhs; *rhsp >= 0; ++rhsp)
+    ++res;
+  return res;
+}
+
+
+/*-------------------------------.
+| Print this rule's RHS on OUT.  |
+`-------------------------------*/
+
+void
+rule_rhs_print (rule *r, FILE *out)
+{
+  if (*r->rhs >= 0)
+    {
+      item_number *rp;
+      for (rp = r->rhs; *rp >= 0; rp++)
+       fprintf (out, " %s", symbols[*rp]->tag);
+      fputc ('\n', out);
+    }
+  else
+    {
+      fprintf (out, " /* %s */\n", _("empty"));
+    }
+}
+
+
+/*-------------------------.
+| Print this rule on OUT.  |
+`-------------------------*/
+
+void
+rule_print (rule *r, FILE *out)
+{
+  fprintf (out, "%s:", r->lhs->tag);
+  rule_rhs_print (r, out);
+}

 
 
 /*------------------------.
 
 
 /*------------------------.


@@ -58,13 +163,13 @@ int error_token_number;
 void
 ritem_print (FILE *out)
 {
 void
 ritem_print (FILE *out)
 {

-  int i;
+  unsigned int i;

   fputs ("RITEM\n", out);
   fputs ("RITEM\n", out);

-  for (i = 0; ritem[i]; ++i)
-    if (ritem[i] > 0)
-      fprintf (out, "  %s", tags[ritem[i]]);
+  for (i = 0; i < nritems; ++i)
+    if (ritem[i] >= 0)
+      fprintf (out, "  %s", symbols[ritem[i]]->tag);

     else
     else

-      fprintf (out, "  (rule %d)\n", -ritem[i]);
+      fprintf (out, "  (rule %d)\n", item_number_as_rule_number (ritem[i]));

   fputs ("\n\n", out);
 }
 
   fputs ("\n\n", out);
 }
 


@@ -76,23 +181,158 @@ ritem_print (FILE *out)
 size_t
 ritem_longest_rhs (void)
 {
 size_t
 ritem_longest_rhs (void)
 {

-  short *itemp;
-  int length;
-  int max;
-
-  length = 0;
-  max = 0;
-  for (itemp = ritem; *itemp; itemp++)
-    if (*itemp > 0)
+  int max = 0;
+  rule_number r;
+
+  for (r = 0; r < nrules; ++r)
+    {
+      int length = rule_rhs_length (&rules[r]);
+      if (length > max)
+       max = length;
+    }
+
+  return max;
+}
+
+
+/*-----------------------------------------------------------------.
+| Print the grammar's rules that match FILTER on OUT under TITLE.  |
+`-----------------------------------------------------------------*/
+
+void
+grammar_rules_partial_print (FILE *out, const char *title,
+                            rule_filter filter)
+{
+  int r;
+  bool first = true;
+  symbol *previous_lhs = NULL;
+
+  /* rule # : LHS -> RHS */
+  for (r = 0; r < nrules + nuseless_productions; r++)
+    {
+      if (filter && !filter (&rules[r]))
+       continue;
+      if (first)
+       fprintf (out, "%s\n\n", title);
+      else if (previous_lhs && previous_lhs != rules[r].lhs)
+       fputc ('\n', out);
+      first = false;
+      rule_lhs_print (&rules[r], previous_lhs, out);
+      rule_rhs_print (&rules[r], out);
+      previous_lhs = rules[r].lhs;
+    }
+  if (!first)
+    fputs ("\n\n", out);
+}
+
+
+/*------------------------------------------.
+| Print the grammar's useful rules on OUT.  |
+`------------------------------------------*/
+
+void
+grammar_rules_print (FILE *out)
+{
+  grammar_rules_partial_print (out, _("Grammar"), rule_useful_p);
+}
+
+
+/*-------------------.
+| Dump the grammar.  |
+`-------------------*/
+
+void
+grammar_dump (FILE *out, const char *title)
+{
+  fprintf (out, "%s\n\n", title);
+  fprintf (out,
+          "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nritems = %d\n\n",
+          ntokens, nvars, nsyms, nrules, nritems);
+
+
+  fprintf (out, "Variables\n---------\n\n");
+  {
+    symbol_number i;
+    fprintf (out, "Value  Sprec  Sassoc  Tag\n");
+
+    for (i = ntokens; i < nsyms; i++)
+      fprintf (out, "%5d  %5d   %5d  %s\n",
+              i,
+              symbols[i]->prec, symbols[i]->assoc,
+              symbols[i]->tag);
+    fprintf (out, "\n\n");
+  }
+
+  fprintf (out, "Rules\n-----\n\n");
+  {
+    rule_number i;
+    fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
+    for (i = 0; i < nrules + nuseless_productions; i++)

       {
       {

-       length++;
+       rule *rule_i = &rules[i];
+       item_number *r = NULL;
+       unsigned int rhs_itemno = rule_i->rhs - ritem;
+       unsigned int rhs_count = 0;
+       /* Find the last RHS index in ritems. */
+       for (r = rule_i->rhs; *r >= 0; ++r)
+         ++rhs_count;
+       fprintf (out, "%3d (%2d, %2d, %2d, %2u-%2u)   %2d ->",
+                i,
+                rule_i->prec ? rule_i->prec->prec : 0,
+                rule_i->prec ? rule_i->prec->assoc : 0,
+                rule_i->useful,
+                rhs_itemno,
+                rhs_itemno + rhs_count - 1,
+                rule_i->lhs->number);
+       /* Dumped the RHS. */
+       for (r = rule_i->rhs; *r >= 0; r++)
+         fprintf (out, " %3d", *r);
+       fprintf (out, "  [%d]\n", item_number_as_rule_number (*r));

       }
       }

-    else
+  }
+  fprintf (out, "\n\n");
+
+  fprintf (out, "Rules interpreted\n-----------------\n\n");
+  {
+    rule_number r;
+    for (r = 0; r < nrules + nuseless_productions; r++)

       {
       {

-       if (length > max)
-         max = length;
-       length = 0;
+       fprintf (out, "%-5d  ", r);
+       rule_print (&rules[r], out);

       }
       }

+  }
+  fprintf (out, "\n\n");
+}

 
 

-  return max;
+
+/*------------------------------------------------------------------.
+| Report on STDERR the rules that are not flagged USEFUL, using the |
+| MESSAGE (which can be `useless rule' when invoked after grammar   |
+| reduction, or `never reduced' after conflicts were taken into     |
+| account).                                                         |
+`------------------------------------------------------------------*/
+
+void
+grammar_rules_never_reduced_report (const char *message)
+{
+  rule_number r;
+  for (r = 0; r < nrules ; ++r)
+    if (!rules[r].useful)
+      {
+       location_print (stderr, rules[r].location);
+       fprintf (stderr, ": %s: %s: ",
+                _("warning"), message);
+       rule_print (&rules[r], stderr);
+      }
+}
+
+void
+grammar_free (void)
+{
+  XFREE (ritem);
+  free (rules);
+  XFREE (token_translations);
+  /* Free the symbol table data structure.  */
+  symbols_free ();
+  free_merger_functions ();

 }
 }