* src/nullable.c (nullable_print): New.

[bison.git] / src / nullable.c

diff --git a/src/nullable.c b/src/nullable.c
index ec614595e60fb36c4ea66b241fae83aff931172f..c207924dc8328a9770263d2313451c8e38b66748 100644 (file)
--- a/src/nullable.c
+++ b/src/nullable.c
@@ -25,28 +25,35 @@
 
 #include "system.h"
 #include "getargs.h"
+#include "reader.h"
 #include "types.h"
 #include "gram.h"
 #include "nullable.h"
 
 char *nullable = NULL;
 
+static void
+nullable_print (FILE *out)
+{
+  int i;
+  fputs ("NULLABLE\n", out);
+  for (i = ntokens; i < nsyms; i++)
+    fprintf (out, "\t%s: %s\n", tags[i], nullable[i] ? "yes" : "no");
+  fputs ("\n\n", out);
+}
+
 void
 set_nullable (void)
 {
   short *r;
   short *s1;
   short *s2;
-  int ruleno;
-  int symbol;
   shorts *p;
 
   short *squeue;
   short *rcount;
   shorts **rsets;
   shorts *relts;
-  char any_tokens;
-  short *r1;
 
   if (trace_flag)
     fprintf (stderr, "Entering set_nullable\n");
@@ -69,7 +76,7 @@ set_nullable (void)
     {
       if (*r < 0)
        {
-         symbol = rule_table[-(*r++)].lhs;
+         int symbol = rule_table[-(*r++)].lhs;
          if (symbol >= 0 && !nullable[symbol])
            {
              nullable[symbol] = 1;
@@ -78,17 +85,16 @@ set_nullable (void)
        }
       else
        {
-         r1 = r;
-         any_tokens = 0;
+         int any_tokens = 0;
+         int symbol;
+         short *r1 = r;
          for (symbol = *r++; symbol > 0; symbol = *r++)
-           {
-             if (ISTOKEN (symbol))
-               any_tokens = 1;
-           }
+           if (ISTOKEN (symbol))
+             any_tokens = 1;
 
          if (!any_tokens)
            {
-             ruleno = -symbol;
+             int ruleno = -symbol;
              r = r1;
              for (symbol = *r++; symbol > 0; symbol = *r++)
                {
@@ -107,11 +113,11 @@ set_nullable (void)
       p = rsets[*s1++];
       while (p)
        {
-         ruleno = p->value;
+         int ruleno = p->value;
          p = p->next;
          if (--rcount[ruleno] == 0)
            {
-             symbol = rule_table[ruleno].lhs;
+             int symbol = rule_table[ruleno].lhs;
              if (symbol >= 0 && !nullable[symbol])
                {
                  nullable[symbol] = 1;
@@ -125,6 +131,9 @@ set_nullable (void)
   XFREE (rcount);
   XFREE (rsets + ntokens);
   XFREE (relts);
+
+  if (trace_flag)
+    nullable_print (stderr);
 }