lalr: more debug traces

[Akim Demaille]

commit 59bec5fade53bb6d84754457b43b49e037616a48
Author: Akim Demaille <address@hidden>
Date:   Sun Feb 24 19:00:41 2019 +0100

    lalr: more debug traces
    
    I need to be able to read includes and goto_follows.
    
    * src/relation.h, src/relation.c (relation_print): Provide a means to
    pretty-print the nodes of the relation.
    * src/lalr.c (goto_print, follows_print): New.
    (set_goto_map): Use goto_print.
    (build_relations): Show INCLUDES.
    (compute_FOLLOWS): Rename as...
    (compute_follows): this.
    Show FOLLOWS.

diff --git a/src/ielr.c b/src/ielr.c
index 47ce38c3..a1f146b9 100644
--- a/src/ielr.c
+++ b/src/ielr.c
@@ -198,7 +198,7 @@ ielr_compute_internal_follow_edges (bitset 
ritem_sees_lookahead_set,
   if (trace_flag & trace_ielr)
     {
       fprintf (stderr, "internal_follow_edges:\n");
-      relation_print (*edgesp, ngotos, stderr);
+      relation_print (*edgesp, ngotos, NULL, stderr);
     }
 }
 
@@ -305,7 +305,7 @@ ielr_compute_always_follows (goto_number ***edgesp,
   if (trace_flag & trace_ielr)
     {
       fprintf (stderr, "always follow edges:\n");
-      relation_print (*edgesp, ngotos, stderr);
+      relation_print (*edgesp, ngotos, NULL, stderr);
       fprintf (stderr, "always_follows:\n");
       debug_bitsetv (*always_followsp);
     }
diff --git a/src/lalr.c b/src/lalr.c
index 40f1502d..46cf01e5 100644
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -67,6 +67,15 @@ size_t nLA;
 static goto_number **includes;
 static goto_list **lookback;
 
+static void
+goto_print (goto_number i, FILE* out)
+{
+  const state_number src = from_state[i];
+  const state_number dst = to_state[i];
+  symbol_number var = states[dst]->accessing_symbol;
+  fprintf (out,
+           "goto[%ld] = (%d, %s, %d)", i, src, symbols[var]->tag, dst);
+}
 
 void
 set_goto_map (void)
@@ -117,6 +126,13 @@ set_goto_map (void)
     }
 
   free (temp_map);
+
+  if (trace_flag & trace_automaton)
+    for (int i = 0; i < ngotos; ++i)
+      {
+        goto_print (i, stderr);
+        fputc ('\n', stderr);
+      }
 }
 
 
@@ -140,7 +156,7 @@ map_goto (state_number src, symbol_number sym)
     }
 }
 
-
+/* Build goto_follows. */
 static void
 initialize_F (void)
 {
@@ -181,7 +197,6 @@ initialize_F (void)
 
   for (goto_number i = 0; i < ngotos; ++i)
     free (reads[i]);
-
   free (reads);
   free (edge);
 }
@@ -198,7 +213,8 @@ add_lookback_edge (state *s, rule const *r, goto_number 
gotono)
 }
 
 
-
+/* Compute INCLUDES and LOOKBACK.  Corresponds to step E in Sec. 6 of
+   [DeRemer 1982].  */
 static void
 build_relations (void)
 {
@@ -265,18 +281,42 @@ build_relations (void)
   free (path);
 
   relation_transpose (&includes, ngotos);
+  if (trace_flag & trace_automaton)
+    {
+      fprintf (stderr, "includes:\n");
+      relation_print (includes, ngotos, goto_print, stderr);
+    }
 }
 
+/* Print FOLLOWS for debugging.  */
+static void
+follows_print (FILE* out)
+{
+  for (goto_number i = 0; i < ngotos; ++i)
+    {
+      fputs ("FOLLOWS[", out);
+      goto_print (i, out);
+      fputs ("] =", out);
+      bitset_iterator iter;
+      symbol_number sym;
+      BITSET_FOR_EACH (iter, goto_follows[i], sym, 0)
+        {
+          fputc (' ', out);
+          symbol_print (symbols[sym], out);
+        }
+      fputc ('\n', out);
+    }
+}
 
-
+/* Compute FOLLOWS from INCLUDES, and free INCLUDES.  */
 static void
-compute_FOLLOWS (void)
+compute_follows (void)
 {
   relation_digraph (includes, ngotos, &goto_follows);
-
+  if (trace_flag & trace_sets)
+    follows_print (stderr);
   for (goto_number i = 0; i < ngotos; ++i)
     free (includes[i]);
-
   free (includes);
 }
 
@@ -291,7 +331,6 @@ compute_lookahead_tokens (void)
   /* Free LOOKBACK. */
   for (size_t i = 0; i < nLA; ++i)
     LIST_FREE (goto_list, lookback[i]);
-
   free (lookback);
 }
 
@@ -421,7 +460,7 @@ lalr (void)
   initialize_F ();
   lookback = xcalloc (nLA, sizeof *lookback);
   build_relations ();
-  compute_FOLLOWS ();
+  compute_follows ();
   compute_lookahead_tokens ();
 
   if (trace_flag & trace_sets)
diff --git a/src/lalr.h b/src/lalr.h
index 84a66f7c..1ef3c40c 100644
--- a/src/lalr.h
+++ b/src/lalr.h
@@ -102,5 +102,4 @@ goto_number map_goto (state_number src, symbol_number sym);
 /* goto_follows[i] is the set of tokens following goto i.  */
 extern bitsetv goto_follows;
 
-
 #endif /* !LALR_H_ */
diff --git a/src/relation.c b/src/relation.c
index abee524d..57c14292 100644
--- a/src/relation.c
+++ b/src/relation.c
@@ -27,14 +27,25 @@
 #include "relation.h"
 
 void
-relation_print (relation r, relation_node size, FILE *out)
+relation_print (relation r, relation_node size,
+                relation_node_print print, FILE *out)
 {
-  for (relation_node i = 0; i < size; ++i)
+  for (size_t i = 0; i < size; ++i)
     {
-      fprintf (out, "%3lu: ", (unsigned long) i);
+      if (print)
+        print (i, out);
+      else
+        fprintf (out, "%3lu", (unsigned long) i);
+      fputc (':', out);
       if (r[i])
         for (relation_node j = 0; r[i][j] != END_NODE; ++j)
-          fprintf (out, "%3lu ", (unsigned long) r[i][j]);
+          {
+            fputc (' ', out);
+            if (print)
+              print (r[i][j], out);
+            else
+              fprintf (out, "%3lu", (unsigned long) r[i][j]);
+          }
       fputc ('\n', out);
     }
   fputc ('\n', out);
@@ -58,10 +69,8 @@ static bitsetv F;
 static void
 traverse (relation_node i)
 {
-  relation_node height;
-
   vertices[++top] = i;
-  indexes[i] = height = top;
+  relation_node height = indexes[i] = top;
 
   if (R[i])
     for (relation_node j = 0; R[i][j] != END_NODE; ++j)
@@ -116,30 +125,30 @@ relation_digraph (relation r, relation_node size, bitsetv 
*function)
 `-------------------------------------------*/
 
 void
-relation_transpose (relation *R_arg, relation_node n)
+relation_transpose (relation *R_arg, relation_node size)
 {
   relation r = *R_arg;
 
   if (trace_flag & trace_sets)
     {
       fputs ("relation_transpose: input\n", stderr);
-      relation_print (r, n, stderr);
+      relation_print (r, size, NULL, stderr);
     }
 
   /* Count. */
   /* NEDGES[I] -- total size of NEW_R[I]. */
-  size_t *nedges = xcalloc (n, sizeof *nedges);
-  for (relation_node i = 0; i < n; i++)
+  size_t *nedges = xcalloc (size, sizeof *nedges);
+  for (relation_node i = 0; i < size; i++)
     if (r[i])
       for (relation_node j = 0; r[i][j] != END_NODE; ++j)
         ++nedges[r[i][j]];
 
   /* Allocate. */
   /* The result. */
-  relation new_R = xnmalloc (n, sizeof *new_R);
+  relation new_R = xnmalloc (size, sizeof *new_R);
   /* END_R[I] -- next entry of NEW_R[I]. */
-  relation end_R = xnmalloc (n, sizeof *end_R);
-  for (relation_node i = 0; i < n; i++)
+  relation end_R = xnmalloc (size, sizeof *end_R);
+  for (relation_node i = 0; i < size; i++)
     {
       relation_node *sp = NULL;
       if (nedges[i] > 0)
@@ -152,7 +161,7 @@ relation_transpose (relation *R_arg, relation_node n)
     }
 
   /* Store. */
-  for (relation_node i = 0; i < n; i++)
+  for (relation_node i = 0; i < size; i++)
     if (r[i])
       for (relation_node j = 0; r[i][j] != END_NODE; ++j)
         *end_R[r[i][j]]++ = i;
@@ -161,14 +170,14 @@ relation_transpose (relation *R_arg, relation_node n)
   free (end_R);
 
   /* Free the input: it is replaced with the result. */
-  for (relation_node i = 0; i < n; i++)
+  for (relation_node i = 0; i < size; i++)
     free (r[i]);
   free (r);
 
   if (trace_flag & trace_sets)
     {
       fputs ("relation_transpose: output\n", stderr);
-      relation_print (new_R, n, stderr);
+      relation_print (new_R, size, NULL, stderr);
     }
 
   *R_arg = new_R;
diff --git a/src/relation.h b/src/relation.h
index e6b59ff8..0edf59e1 100644
--- a/src/relation.h
+++ b/src/relation.h
@@ -33,9 +33,11 @@ typedef size_t relation_node;
 typedef relation_node *relation_nodes;
 typedef relation_nodes *relation;
 
+typedef void (relation_node_print) (relation_node node, FILE* out);
 
 /* Report a relation R that has SIZE vertices.  */
-void relation_print (relation r, relation_node size, FILE *out);
+void relation_print (relation r, size_t size,
+                     relation_node_print print, FILE *out);
 
 /* Compute the transitive closure of the FUNCTION on the relation R
    with SIZE vertices.
@@ -44,7 +46,7 @@ void relation_print (relation r, relation_node size, FILE 
*out);
    (unioned) with FUNCTION[NODE - 2].  */
 void relation_digraph (relation r, relation_node size, bitsetv *function);
 
-/* Destructively transpose *R_ARG, of size N.  */
-void relation_transpose (relation *R_arg, relation_node n);
+/* Destructively transpose *R_ARG, of size SIZE.  */
+void relation_transpose (relation *R_arg, relation_node size);
 
 #endif /* ! RELATION_H_ */