From 7c6b64d02355fa26b3a256906327ab3edbbee8b7 Mon Sep 17 00:00:00 2001
From: Akim Demaille <akim@epita.fr>
Date: Sat, 29 Dec 2001 14:16:16 +0000
Subject: [PATCH] * src/lalr.c (lookaheads_print): New. (lalr): Call it when
 --trace-flag. * tests/sets.at (Nullable): Adjust: when tracing, the
 lookaheads are dumped.

---
 ChangeLog     |  8 ++++++++
 src/lalr.c    | 29 +++++++++++++++++++++++++++++
 tests/sets.at |  6 ++++++
 3 files changed, 43 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index e16dafb4..e335f058 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2001-12-29  Akim Demaille  <akim@epita.fr>
+
+	* src/lalr.c (lookaheads_print): New.
+	(lalr): Call it when --trace-flag.
+	* tests/sets.at (Nullable): Adjust: when tracing, the lookaheads
+	are dumped.
+
+	
 2001-12-29  Akim Demaille  <akim@epita.fr>
 
 	* src/derives.c (print_derives): Be sure to use `>= 0', not `> 0',
diff --git a/src/lalr.c b/src/lalr.c
index 660088cd..36a8607c 100644
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -24,6 +24,7 @@
    tokens they accept.  */
 
 #include "system.h"
+#include "reader.h"
 #include "types.h"
 #include "LR0.h"
 #include "gram.h"
@@ -546,6 +547,31 @@ initialize_lookaheads (void)
     }
 }
 
+
+/*---------------------------------------.
+| Output the lookaheads for each state.  |
+`---------------------------------------*/
+
+static void
+lookaheads_print (FILE *out)
+{
+  int i, j, k;
+  fprintf (out, "Lookaheads: BEGIN\n");
+  for (i = 0; i < nstates; ++i)
+    {
+      fprintf (out, "State %d: %d lookaheads\n",
+	       i, state_table[i]->nlookaheads);
+
+      for (j = 0; j < state_table[i]->nlookaheads; ++j)
+	for (k = 0; k < ntokens; ++k)
+	  if (BITISSET (LA (state_table[i]->lookaheadsp + j), j))
+	    fprintf (out, "   on %d (%s) -> rule %d\n",
+		     k, tags[k],
+		     -LAruleno[state_table[i]->lookaheadsp + j] - 1);
+    }
+  fprintf (out, "Lookaheads: END\n");
+}
+
 void
 lalr (void)
 {
@@ -558,4 +584,7 @@ lalr (void)
   build_relations ();
   compute_FOLLOWS ();
   compute_lookaheads ();
+
+  if (trace_flag)
+    lookaheads_print (stderr);
 }
diff --git a/tests/sets.at b/tests/sets.at
index 61bfd623..f1c16dcf 100644
--- a/tests/sets.at
+++ b/tests/sets.at
@@ -157,6 +157,12 @@ transpose: input
 transpose: output
   0:
 
+Lookaheads: BEGIN
+State 0: 0 lookaheads
+State 1: 0 lookaheads
+State 2: 0 lookaheads
+State 3: 0 lookaheads
+Lookaheads: END
 ]])
 
 AT_CLEANUP
-- 
2.45.2