* tests/calc.at (AT_CHECK_CALC): Adjust: there are now additional

`Error:' lines.
* data/bison.simple (yystos) [YYDEBUG]: New.
(yyparse) [YYDEBUG]: Display the symbols which are popped during
error recovery.
* tests/regression.at (Web2c Actions): Adjust: yystos is output now.

ChangeLog

@@ -1,3 +1,12 @@
+2002-05-26  Akim Demaille  <akim@epita.fr>
+
+	* tests/calc.at (AT_CHECK_CALC): Adjust: there are now additional
+	`Error:' lines.
+	* data/bison.simple (yystos) [YYDEBUG]: New.
+	(yyparse) [YYDEBUG]: Display the symbols which are popped during
+	error recovery.
+	* tests/regression.at (Web2c Actions): Adjust: yystos is output now.
+
 2002-05-25  Akim Demaille  <akim@epita.fr>
 
 	* doc/bison.texinfo (Debugging): Split into...

NEWS

@@ -26,6 +26,9 @@ Changes in version 1.49b:
   and has long been required by POSIX.  For more details, please see
   <http://mail.gnu.org/pipermail/bug-bison/2002-May/001452.html>.
 
+* Traces
+  Popped tokens and nonterminals are now reported.
+
 * Large grammars
   Large grammars are now supported (large token numbers, large grammar
   size (= sum of the LHS and RHS lengths), large LALR tables).

data/bison.simple

@@ -362,7 +362,7 @@ static const b4_uint_type(b4_rline_max) yyrline[[]] =
 };
 #endif
 
-#if (YYDEBUG) || YYERROR_VERBOSE
+#if YYDEBUG || YYERROR_VERBOSE
 /* YYTNME[[SYMBOL-NUM]] -- String name of the symbol SYMBOL-NUM.
    First, the terminals, then, starting at YYNTOKENS, nonterminals. */
 static const char *const yytname[[]] =
@@ -389,9 +389,9 @@ static const b4_uint_type(b4_r2_max) yyr2[[]] =
   b4_r2
 };
 
-/* YYDEFACT[[S]] -- default rule to reduce with in state S when YYTABLE
+/* YYDEFACT[[STATE-NAME]] -- Default rule to reduce with in state
-   doesn't specify something else to do.  Zero means the default is an
+   STATE-NUM when YYTABLE doesn't specify something else to do.  Zero
-   error.  */
+   means the default is an error.  */
 static const short yydefact[[]] =
 {
   b4_defact
@@ -429,6 +429,14 @@ static const short yycheck[[]] =
   b4_check
 };
 
+#if YYDEBUG
+/* YYSTOS[[STATE-NUM]] -- The (internal number of the) accessing
+   symbol of state STATE-NUM.  */
+static const b4_uint_type(b4_stos_max) yystos[[]] =
+{
+  b4_stos
+};
+#endif
 
 #if ! defined (YYSIZE_T) && defined (__SIZE_TYPE__)
 # define YYSIZE_T __SIZE_TYPE__
@@ -1137,6 +1145,27 @@ yyerrlab1:
       /* Pop the current state because it cannot handle the error token.  */
       if (yyssp == yyss)
 	YYABORT;
+
+#if YYDEBUG
+      if (yydebug)
+	{
+	  if (yystos[yystate] < YYNTOKENS)
+	    {
+	      YYFPRINTF (stderr, "Error: popping token %d (%s",
+			 yytoknum[yystos[yystate]], yytname[yystos[yystate]]);
+# ifdef YYPRINT
+	      YYPRINT (stderr, yytoknum[yystos[yystate]], *yyvsp);
+# endif
+	      YYFPRINTF (stderr, ")\n");
+	    }
+	  else
+	    {
+	      YYFPRINTF (stderr, "Error: popping nonterminal (%s)\n",
+			 yytname[yystos[yystate]]);
+	    }
+	}
+#endif
+
       yyvsp--;
       yystate = *--yyssp;
 #if YYLSP_NEEDED

tests/calc.at

@@ -1,5 +1,5 @@
 # Checking the output filenames.                         -*- Autotest -*-
-# Copyright 2000, 2001 Free Software Foundation, Inc.
+# Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -406,18 +406,18 @@ _AT_CHECK_CALC([$1],
 (2^2)^3 = 64], [486])
 
 # Some parse errors.
-_AT_CHECK_CALC_ERROR([$1], [0 0], [10],
+_AT_CHECK_CALC_ERROR([$1], [0 0], [11],
                      [1.3-1.4: parse error, unexpected "number"])
-_AT_CHECK_CALC_ERROR([$1], [1//2], [13],
+_AT_CHECK_CALC_ERROR([$1], [1//2], [15],
                      [1.3-1.4: parse error, unexpected '/', expecting "number" or '-' or '('])
 _AT_CHECK_CALC_ERROR([$1], [error], [4],
                      [1.1-1.2: parse error, unexpected $undefined., expecting "number" or '-' or '\n' or '('])
-_AT_CHECK_CALC_ERROR([$1], [1 = 2 = 3], [19],
+_AT_CHECK_CALC_ERROR([$1], [1 = 2 = 3], [22],
                      [1.7-1.8: parse error, unexpected '='])
 _AT_CHECK_CALC_ERROR([$1],
                      [
 +1],
-                     [13],
+                     [14],
                      [2.1-2.2: parse error, unexpected '+'])
 # Exercise error messages with EOF: work on an empty file.
 _AT_CHECK_CALC_ERROR([$1],
@@ -430,7 +430,7 @@ _AT_CHECK_CALC_ERROR([$1],
 # associated to `error'.
 _AT_CHECK_CALC_ERROR([$1],
                      [(1 ++ 2) + (0 0) = 1],
-                     [76],
+                     [82],
 [1.5-1.6: parse error, unexpected '+', expecting "number" or '-' or '('
 1.15-1.16: parse error, unexpected "number"
 calc: error: 0 != 1])

tests/regression.at

@@ -1,5 +1,5 @@
 # Bison Regressions.                               -*- Autotest -*-
-# Copyright 2001, 2002 Free Software Foundation, Inc.
+# Copyright (C) 2001, 2002 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -549,6 +549,11 @@ static const short yycheck[] =
 {
        7,     3,     9,     4,     0,    -1,     6,     5
 };
+static const unsigned char yystos[] =
+{
+       0,     3,     8,     9,    10,     4,     0,     6,    11,     5,
+       8,     8
+};
 ]])
 
 AT_CLEANUP