multistart: adjust computation of initial core and adjust reports

Currently the core of the initial state is limited to the single rule
on $accept.

* src/lr0.c (generate_states): There may now be several rules on
$accept.

* src/graphviz.c (conclude_red): Recognize "final" transitions by the
fact that we reduce to "$accept".
* src/print.c (print_reduction): Likewise.
* src/print-xml.c (print_reduction): Likewise.

src/graphviz.c

@@ -101,6 +101,7 @@ no_reduce_bitset_init (state const *s, bitset *no_reduce_set)
       bitset_set (*no_reduce_set, s->errs->symbols[n]->content->number);
 }
 
+/* Show the reductions from state SOURCE on rule RULENO. */
 static void
 conclude_red (struct obstack *out, int source, rule_number ruleno,
               bool enabled, bool first, FILE *fout)
@@ -112,8 +113,6 @@ conclude_red (struct obstack *out, int source, rule_number ruleno,
   else
     {
       char const *ed = enabled ? "" : "d";
-      char const *color = enabled ? ruleno ? "3" : "1" : "5";
-
       /* First, build the edge's head. The name of reduction nodes is "nRm",
          with n the source state and m the rule number. This is because we
          don't want all the reductions bearing a same rule number to point to
@@ -136,11 +135,16 @@ conclude_red (struct obstack *out, int source, rule_number ruleno,
       /* Build the associated diamond representation of the target rule. */
       fprintf (fout, " \"%dR%d%s\" [label=\"",
                source, ruleno, ed);
-      if (ruleno)
-        fprintf (fout, "R%d", ruleno);
-      else
+      bool final = rules[ruleno].lhs->symbol == acceptsymbol;
+      if (final)
         fprintf (fout, "Acc");
+      else
+        fprintf (fout, "R%d", ruleno);
 
+      char const *color
+        = !enabled ? "5"
+        : final    ? "1"
+        :            "3";
       fprintf (fout, "\", fillcolor=%s, shape=diamond, style=filled]\n",
                color);
     }

src/lr0.c

@@ -395,9 +395,10 @@ generate_states (void)
   /* Create the initial state, whose accessing symbol (by convention)
      is 0, aka $end.  */
   {
-    /* The items of its core.  */
-    kernel_size[0] = 1;
-    kernel_base[0][0] = 0;
+    /* The items of its core: beginning of all the rules of $accept.  */
+    kernel_size[0] = 0;
+    for (rule_number r = 0; r < nrules && rules[r].lhs->symbol == acceptsymbol; ++r)
+      kernel_base[0][kernel_size[0]++] = rules[r].rhs - ritem;
     state_list_append (0, kernel_size[0], kernel_base[0]);
   }
 

src/print-xml.c

@@ -216,17 +216,18 @@ static void
 print_reduction (FILE *out, int level, char const *lookahead,
                  rule *r, bool enabled)
 {
-  if (r->number)
+  const bool final = r->lhs->symbol == acceptsymbol;
+  if (final)
+    xml_printf (out, level,
+                "<reduction symbol=\"%s\" rule=\"accept\" enabled=\"%s\"/>",
+                xml_escape (lookahead),
+                enabled ? "true" : "false");
+  else
     xml_printf (out, level,
                 "<reduction symbol=\"%s\" rule=\"%d\" enabled=\"%s\"/>",
                 xml_escape (lookahead),
                 r->number,
                 enabled ? "true" : "false");
-  else
-    xml_printf (out, level,
-                "<reduction symbol=\"%s\" rule=\"accept\" enabled=\"%s\"/>",
-                xml_escape (lookahead),
-                enabled ? "true" : "false");
 }
 
 

src/print.c

@@ -196,11 +196,12 @@ print_reduction (FILE *out, size_t width,
     fputc (' ', out);
   if (!enabled)
     fputc ('[', out);
-  if (r->number)
+  const bool final = r->lhs->symbol == acceptsymbol;
+  if (final)
+    fprintf (out, _("accept"));
+  else
     fprintf (out, _("reduce using rule %d (%s)"), r->number,
              r->lhs->symbol->tag);
-  else
-    fprintf (out, _("accept"));
   if (!enabled)
     fputc (']', out);
   fputc ('\n', out);