* src/symtab.h (SUNDEF): New.

* src/symtab.c (bucket_new): Init user_token_number to SUNDEF to
stand for `uninitialized', instead of 0.
* src/reader.c (packsymbols, parse_thong_decl): Adjust.
* src/lex.c (lex): Adjust.
* tests/calc.at (_AT_DATA_CALC_Y): Declare a token for EOF.
Number it 0.
Let yylex return it instead of a plain 0.
Reported by Dick Streefland.

ChangeLog

@@ -1,3 +1,16 @@
+2001-11-02  Akim Demaille  <akim@epita.fr>
+
+	* src/symtab.h (SUNDEF): New.
+	* src/symtab.c (bucket_new): Init user_token_number to SUNDEF to
+	stand for `uninitialized', instead of 0.
+	* src/reader.c (packsymbols, parse_thong_decl): Adjust.
+	* src/lex.c (lex): Adjust.
+
+	* tests/calc.at (_AT_DATA_CALC_Y): Declare a token for EOF.
+	Number it 0.
+	Let yylex return it instead of a plain 0.
+	Reported by Dick Streefland.
+
 2001-11-02  Akim Demaille  <akim@epita.fr>
 
 	* tests/regression.at (Mixing %token styles): New test.

src/lex.c

@@ -446,7 +446,7 @@ lex (void)
 	token_buffer = obstack_finish (&token_obstack);
 	symval = getsym (token_buffer);
 	symval->class = token_sym;
-	if (!symval->user_token_number)
+	if (symval->user_token_number == SUNDEF)
 	  symval->user_token_number = code;
 	return tok_identifier;
       }

src/reader.c

@@ -724,7 +724,6 @@ token_buffer);
 	}
 
       prev = t;
-
     }
 }
 
@@ -852,7 +851,7 @@ parse_thong_decl (void)
   token_t token;
   struct bucket *symbol;
   char *typename = 0;
-  int usrtoknum = 0;
+  int usrtoknum = SUNDEF;
 
   token = lex ();		/* fetch typename or first token */
   if (token == tok_typename)
@@ -1724,6 +1723,9 @@ token_translations_init (void)
       /* A token string alias? */
       if (bp->user_token_number == SALIAS)
 	continue;
+
+      assert (bp->user_token_number != SUNDEF);
+
       /* A token which translation has already been set? */
       if (token_translations[bp->user_token_number] != 2)
 	complain (_("tokens %s and %s both assigned number %d"),
@@ -1810,7 +1812,7 @@ packsymbols (void)
 
       if (bp->class == token_sym)
 	{
-	  if (bp->user_token_number == 0)
+	  if (bp->user_token_number == SUNDEF)
 	    bp->user_token_number = ++last_user_token_number;
 	  if (bp->user_token_number > max_user_token_number)
 	    max_user_token_number = bp->user_token_number;

src/symtab.c

@@ -1,5 +1,5 @@
 /* Symbol table manager for Bison,
-   Copyright 1984, 1989, 2000 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -58,7 +58,7 @@ bucket_new (const char *tag, int hashval)
   res->value = 0;
   res->prec = 0;
   res->assoc = right_assoc;
-  res->user_token_number = 0;
+  res->user_token_number = SUNDEF;
   res->alias = NULL;
   res->class = unknown_sym;
 

src/symtab.h

@@ -1,5 +1,5 @@
 /* Definitions for symtab.c and callers, part of bison,
-   Copyright 1984, 1989, 1992, 2000 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 1992, 2000, 2001  Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -33,6 +33,7 @@ typedef enum
   nterm_sym		/* non-terminal */
 } symbol_class;
 
+#define SUNDEF  -1              /* For undefined user number. */
 #define SALIAS	-9991		/* for symbol generated with an alias */
 
 typedef struct bucket

tests/calc.at

@@ -64,7 +64,8 @@ static void yyungetc (int c);
 extern void perror (const char *s);
 %}
 
-/* BISON Declarations */
+/* Bison Declarations */
+%token CALC_EOF 0
 %token NUM
 
 %nonassoc '=' /* comparison	       */
@@ -204,7 +205,7 @@ yylex (void)
 
   /* Return end-of-file.  */
   if (c == EOF)
-    return 0;
+    return CALC_EOF;
 
   /* Return single chars. */
   return c;