* doc/bison.texinfo (Debugging): Split into...

[bison.git] / src / print_graph.c

diff --git a/src/print_graph.c b/src/print_graph.c
index 6de5b34dff8de143945a7a3edbc10bc5393c0e32..416c4fd2bb300bdf6357b072cc6e36c28a146eb6 100644 (file)
--- a/src/print_graph.c
+++ b/src/print_graph.c
@@ -47,7 +47,7 @@ escape (const char *s)
 
 /* This part will construct the label of nodes. */
 static void
-print_core (state_t *state, struct obstack *node_obstack)
+print_core (struct obstack *oout, state_t *state)
 {
   int i;
   item_number_t *sitems = state->items;
@@ -61,7 +61,7 @@ print_core (state_t *state, struct obstack *node_obstack)
       snritems = nritemset;
     }
 
-  obstack_fgrow1 (node_obstack, "state %2d\n", state->number);
+  obstack_fgrow1 (oout, "state %2d\n", state->number);
   for (i = 0; i < snritems; i++)
     {
       item_number_t *sp;
@@ -76,17 +76,43 @@ print_core (state_t *state, struct obstack *node_obstack)
       rule = -(*sp);
 
       if (i)
-       obstack_1grow (node_obstack, '\n');
-      obstack_fgrow1 (node_obstack, " %s -> ",
+       obstack_1grow (oout, '\n');
+      obstack_fgrow1 (oout, " %s -> ",
                      escape (rules[rule].lhs->tag));
 
       for (sp = rules[rule].rhs; sp < sp1; sp++)
-       obstack_fgrow1 (node_obstack, "%s ", escape (symbols[*sp]->tag));
+       obstack_fgrow1 (oout, "%s ", escape (symbols[*sp]->tag));
 
-      obstack_1grow (node_obstack, '.');
+      obstack_1grow (oout, '.');
 
       for (/* Nothing */; *sp >= 0; ++sp)
-       obstack_fgrow1 (node_obstack, " %s", escape (symbols[*sp]->tag));
+       obstack_fgrow1 (oout, " %s", escape (symbols[*sp]->tag));
+
+      /* Experimental feature: display the lookaheads. */
+      if (trace_flag && state->nlookaheads)
+       {
+         int j, k;
+         int nlookaheads = 0;
+         /* Look for lookaheads corresponding to this rule. */
+         for (j = 0; j < state->nlookaheads; ++j)
+           for (k = 0; k < ntokens; ++k)
+             if (bitset_test (LA[state->lookaheadsp + j], k)
+                 && LArule[state->lookaheadsp + j]->number == rule)
+               nlookaheads++;
+         if (nlookaheads)
+           {
+             obstack_sgrow (oout, "  [");
+             for (j = 0; j < state->nlookaheads; ++j)
+               for (k = 0; k < ntokens; ++k)
+                 if (bitset_test (LA[state->lookaheadsp + j], k)
+                     && LArule[state->lookaheadsp + j]->number == rule)
+                   obstack_fgrow2 (oout, "%s%s",
+                                   quotearg_style (escape_quoting_style,
+                                                   symbols[k]->tag),
+                                   --nlookaheads ? ", " : "");
+             obstack_sgrow (oout, "]");
+           }
+       }
     }
 }
 
@@ -114,7 +140,7 @@ print_actions (state_t *state, const char *node_name)
     if (!SHIFT_IS_DISABLED (shiftp, i))
       {
        int state1 = shiftp->shifts[i];
-       int symbol = states[state1]->accessing_symbol;
+       token_number_t symbol = states[state1]->accessing_symbol;
 
        new_edge (&edge);
 
@@ -154,7 +180,7 @@ print_state (state_t *state)
   new_node (&node);
   sprintf (name, "%d", state->number);
   node.title = name;
-  print_core (state, &node_obstack);
+  print_core (&node_obstack, state);
   obstack_1grow (&node_obstack, '\0');
   node.label = obstack_finish (&node_obstack);