Merge remote-tracking branch 'origin/maint'

[bison.git] / src / derives.c

diff --git a/src/derives.c b/src/derives.c
index ec7173d95b9433756b5a79c3497a73231d8be03c..890239295d9587738ca8fade57cc80ddd4b4e755 100644 (file)
--- a/src/derives.c
+++ b/src/derives.c
@@ -1,112 +1,120 @@
 /* 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, 2000-2003, 2005, 2009-2012 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
+   This program is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by
    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.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.

 
 

-   Bison is distributed in the hope that it will be useful,
+   This program 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
    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, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 

+#include <config.h>
+#include "system.h"

 
 

-/* set_derives finds, for each variable (nonterminal), which rules can
-   derive it.  It sets up the value of derives so that derives[i -
-   ntokens] points to a vector of rule numbers, terminated with -1.
-   */
+#include "getargs.h"

 
 

-#include "system.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"

 
 

-short **derives;
+/* Linked list of rule numbers.  */
+typedef struct rule_list
+{
+  struct rule_list *next;
+  rule *value;
+} rule_list;

 
 

-#if TRACE
+rule ***derives;

 
 static void
 print_derives (void)
 {
   int i;
 
 static void
 print_derives (void)
 {
   int i;

-  short *sp;

 
 

-  fputs ("\n\n\nDERIVES\n\n", stderr);
+  fputs ("DERIVES\n", stderr);

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

-      fprintf (stderr, "%s derives", tags[i]);
-      for (sp = derives[i]; *sp > 0; sp++)
-       fprintf (stderr, "  %d", *sp);
-      putc ('\n', stderr);
+      rule **rp;
+      fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
+      for (rp = derives[i - ntokens]; *rp; ++rp)
+        {
+          fprintf (stderr, "\t\t%3d ", (*rp)->user_number);
+          rule_rhs_print (*rp, stderr);
+          fprintf (stderr, "\n");
+        }

     }
 
     }
 

-  putc ('\n', stderr);
+  fputs ("\n\n", stderr);

 }
 
 }
 

-#endif

 
 void
 
 void

-set_derives (void)
+derives_compute (void)

 {
 {

-  int i;
-  int lhs;
-  shorts *p;
-  short *q;
-  shorts **dset;
-  shorts *delts;
+  symbol_number i;
+  rule_number r;
+  rule **q;

 
 

-  dset = XCALLOC (shorts *, nvars) - ntokens;
-  delts = XCALLOC (shorts, nrules + 1);
+  /* DSET[NTERM - NTOKENS] -- A linked list of the numbers of the rules
+     whose LHS is NTERM.  */
+  rule_list **dset = xcalloc (nvars, sizeof *dset);

 
 

-  p = delts;
-  for (i = nrules; i > 0; i--)
+  /* 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 = xnmalloc (nrules, sizeof *delts);
+
+  for (r = nrules - 1; r >= 0; --r)

     {
     {

-      lhs = rule_table[i].lhs;
-      if (lhs >= 0)
-       {
-         p->next = dset[lhs];
-         p->value = i;
-         dset[lhs] = p;
-         p++;
-       }
+      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;

     }
 
     }
 

-  derives = XCALLOC (short *, nvars) - ntokens;
-  q = XCALLOC (short, nvars + nrules);
+  /* DSET contains what we need under the form of a linked list.  Make
+     it a single array.  */
+
+  derives = xnmalloc (nvars, sizeof *derives);
+  q = xnmalloc (nvars + nrules, sizeof *q);

 
   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)
       while (p)

-       {
-         *q++ = p->value;
-         p = p->next;
-       }
-      *q++ = -1;
+        {
+          *q++ = p->value;
+          p = p->next;
+        }
+      *q++ = NULL;

     }
 
     }
 

-#if TRACE
-  print_derives ();
-#endif
+  if (trace_flag & trace_sets)
+    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);
+  free (derives[0]);
+  free (derives);

 }
 }