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

[bison.git] / src / derives.c

diff --git a/src/derives.c b/src/derives.c
index 8ca038f85bd4bd495c42cb8da5efee74109506eb..da881ecc521e8277974e22adcb88a24c6c39b94b 100644 (file)
--- a/src/derives.c
+++ b/src/derives.c
@@ -1,5 +1,7 @@
 /* Match rules with nonterminals for bison,
 /* Match rules with nonterminals for bison,

-   Copyright 1984, 1989, 2000, 2001  Free Software Foundation, Inc.
+
+   Copyright (C) 1984, 1989, 2000, 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.
 


@@ -20,13 +22,22 @@
 
 
 #include "system.h"
 
 
 #include "system.h"

+

 #include "getargs.h"
 #include "getargs.h"

-#include "types.h"
-#include "reader.h"
-#include "gram.h"
+

 #include "derives.h"
 #include "derives.h"

+#include "gram.h"
+#include "reader.h"
+#include "symtab.h"
+
+/* Linked list of rule numbers.  */
+typedef struct rule_list
+{
+  struct rule_list *next;
+  rule *value;
+} rule_list;

 
 

-short **derives = NULL;
+rule ***derives = NULL;

 
 static void
 print_derives (void)
 
 static void
 print_derives (void)


@@ -37,15 +48,12 @@ print_derives (void)
 
   for (i = ntokens; i < nsyms; i++)
     {
 
   for (i = ntokens; i < nsyms; i++)
     {

-      short *sp;
-      fprintf (stderr, "\t%s derives\n", tags[i]);
-      for (sp = derives[i]; *sp > 0; sp++)
+      rule **rp;
+      fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
+      for (rp = derives[i - ntokens]; *rp; ++rp)

        {
        {

-         short *rhsp;
-         fprintf (stderr, "\t\t%d:", *sp);
-         for (rhsp = ritem + rule_table[*sp].rhs; *rhsp >= 0; ++rhsp)
-           fprintf (stderr, " %s", tags[*rhsp]);
-         fprintf (stderr, " (rule %d)\n", -*rhsp - 1);
+         fprintf (stderr, "\t\t%3d ", (*rp)->user_number);
+         rule_rhs_print (*rp, stderr);

        }
     }
 
        }
     }
 


@@ -54,53 +62,60 @@ print_derives (void)
 
 
 void
 
 
 void

-set_derives (void)
+derives_compute (void)

 {
 {

-  int i;
-  shorts *p;
-  short *q;
-  shorts **dset;
-  shorts *delts;
-
-  dset = XCALLOC (shorts *, nvars) - ntokens;
-  delts = XCALLOC (shorts, nrules + 1);
-
-  p = delts;
-  for (i = nrules; i > 0; i--)
-    if (rule_table[i].useful)
-      {
-       int lhs = rule_table[i].lhs;
-       p->next = dset[lhs];
-       p->value = i;
-       dset[lhs] = p;
-       p++;
-      }
-
-  derives = XCALLOC (short *, nvars) - ntokens;
-  q = XCALLOC (short, nvars + nrules);
+  symbol_number i;
+  int r;
+  rule **q;
+
+  /* DSET[NTERM - NTOKENS] -- A linked list of the numbers of the rules
+     whose LHS is NTERM.  */
+  rule_list **dset = CALLOC (dset, nvars);
+
+  /* DELTS[RULE] -- There are NRULES rule number to attach to nterms.
+     Instead of performing NRULES allocations for each, have an array
+     indexed by rule numbers.  */
+  rule_list *delts = CALLOC (delts, nrules);
+
+  for (r = nrules - 1; r >= 0; --r)
+    {
+      symbol_number lhs = rules[r].lhs->number;
+      rule_list *p = &delts[r];
+      /* A new LHS is found.  */
+      p->next = dset[lhs - ntokens];
+      p->value = &rules[r];
+      dset[lhs - ntokens] = p;
+    }
+
+  /* DSET contains what we need under the form of a linked list.  Make
+     it a single array.  */
+
+  CALLOC (derives, nvars);
+  CALLOC (q, nvars + nrules);

 
   for (i = ntokens; i < nsyms; i++)
     {
 
   for (i = ntokens; i < nsyms; i++)
     {

-      derives[i] = q;
-      p = dset[i];
+      rule_list *p = dset[i - ntokens];
+      derives[i - ntokens] = q;

       while (p)
        {
          *q++ = p->value;
          p = p->next;
        }
       while (p)
        {
          *q++ = p->value;
          p = p->next;
        }

-      *q++ = -1;
+      *q++ = NULL;

     }
 
     }
 

-  if (trace_flag)
+  if (trace_flag & trace_sets)

     print_derives ();
 
     print_derives ();
 

-  XFREE (dset + ntokens);
-  XFREE (delts);
+  free (dset);
+  free (delts);

 }
 
 }
 

+

 void
 void

-free_derives (void)
+derives_free (void)

 {
 {

-  XFREE (derives[ntokens]);
-  XFREE (derives + ntokens);
+  XFREE (derives[0]);
+  XFREE (derives);

 }
 }