Accept a token number in a %left, %right, or %nonassoc for POSIX

conformance. Reported by Tim Josling at <http://lists.gnu.org/archive/html/bug-bison/2008-01/msg00010.html>. * NEWS (2.3a+): Mention. * doc/bison.texinfo (Precedence Decl): Describe how literal strings and code numbers are treated by precedence declarations. * src/parse-gram.y (precedence_declaration): Use symbols.prec instead of symbols.1. (symbols.prec): New, just like symbols.1 but uses symbol.prec instead of symbol. (symbol.prec): New, just like symbol but allows INT. * src/symtab.c (symbol_user_token_number_set): Remove an aver that no longer holds. * tests/regression.at (Token number in precedence declaration): New test case.
2026-03-09 12:23:04 +00:00 · 2008-02-17 00:18:36 +00:00
parent 80d2c3adcc
commit ab7f29f8f9
7 changed files with 365 additions and 225 deletions
--- a/18
+++ b/18
@@ -1,3 +1,21 @@
+2008-02-16  Joel E. Denny  <jdenny@ces.clemson.edu>
+
+	Accept a token number in a %left, %right, or %nonassoc for POSIX
+	conformance.  Reported by Tim Josling at
+	<http://lists.gnu.org/archive/html/bug-bison/2008-01/msg00010.html>.
+	* NEWS (2.3a+): Mention.
+	* doc/bison.texinfo (Precedence Decl): Describe how literal strings
+	and code numbers are treated by precedence declarations.
+	* src/parse-gram.y (precedence_declaration): Use symbols.prec instead
+	of symbols.1.
+	(symbols.prec): New, just like symbols.1 but uses symbol.prec instead
+	of symbol.
+	(symbol.prec): New, just like symbol but allows INT.
+	* src/symtab.c (symbol_user_token_number_set): Remove an aver that no
+	longer holds.
+	* tests/regression.at (Token number in precedence declaration): New
+	test case.
+
 2008-02-06  Juan Manuel Guerrero  <juan.guerrero@gmx.de>

 	DJGPP specific issues.
--- a/6
+++ b/6
@@ -154,6 +154,10 @@ Changes in version 2.3a+ (????-??-??):
  See the section `Freeing Discarded Symbols' in the Bison manual for further
  details.

+* %left, %right, and %nonassoc can now declare token numbers.  This is required
+  by POSIX.  However, see the end of section `Operator Precedence' in the Bison
+  manual for a caveat concerning the treatment of literal strings.
+
 Changes in version 2.3a, 2006-09-13:

 * Instead of %union, you can define and use your own union type
@@ -978,7 +982,7 @@ End:
 -----

 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
-2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Compiler Compiler.

--- a/doc/bison.texinfo
+++ b/doc/bison.texinfo
@@ -34,7 +34,8 @@ This manual is for @acronym{GNU} Bison (version @value{VERSION},
@value{UPDATED}), the @acronym{GNU} parser generator.

 Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1995, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
+Foundation, Inc.

@quotation
 Permission is granted to copy, distribute and/or modify this document
@@ -4088,7 +4089,7 @@ once.  These are called @dfn{precedence declarations}.
@xref{Precedence, ,Operator Precedence}, for general information on
 operator precedence.

-The syntax of a precedence declaration is the same as that of
+The syntax of a precedence declaration is nearly the same as that of
@code{%token}: either

@example
@@ -4126,6 +4127,18 @@ When two tokens declared in different precedence declarations associate,
 the one declared later has the higher precedence and is grouped first.
@end itemize

+For backward compatibility, there is a confusing difference between the
+argument lists of @code{%token} and precedence declarations.
+Only a @code{%token} can associate a literal string with a token type name.
+A precedence declaration always interprets a literal string as a reference to a
+separate token.
+For example:
+
+@example
+%left  OR "<="         // Does not declare an alias.
+%left  OR 134 "<=" 135 // Declares 134 for OR and 135 for "<=".
+@end example
+
@node Union Decl
@subsection The Collection of Value Types
@cindex declaring value types
--- a/src/parse-gram.c
+++ b/src/parse-gram.c
@@ -73,8 +73,8 @@
 #line 1 "parse-gram.y"
 /* Bison Grammar Parser                             -*- C -*-

-   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation,
-   Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
+   Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

@@ -552,16 +552,16 @@ union yyalloc
 /* YYFINAL -- State number of the termination state.  */
 #define YYFINAL  3
 /* YYLAST -- Last index in YYTABLE.  */
-#define YYLAST   155
+#define YYLAST   156

 /* YYNTOKENS -- Number of terminals.  */
 #define YYNTOKENS  57
 /* YYNNTS -- Number of nonterminals.  */
-#define YYNNTS  31
+#define YYNNTS  33
 /* YYNRULES -- Number of rules.  */
-#define YYNRULES  101
+#define YYNRULES  105
 /* YYNRULES -- Number of states.  */
-#define YYNSTATES  139
+#define YYNSTATES  143

 /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
 #define YYUNDEFTOK  2
@@ -618,42 +618,43 @@ static const yytype_uint16 yyprhs[] =
      81,    84,    86,    88,    90,    92,    94,    96,    99,   103,
     107,   109,   111,   114,   118,   119,   121,   125,   126,   130,
     131,   135,   139,   143,   145,   147,   149,   150,   152,   154,
-     157,   159,   162,   164,   166,   168,   170,   172,   174,   177,
-     180,   184,   186,   189,   191,   194,   196,   199,   202,   203,
-     207,   209,   213,   216,   217,   220,   223,   227,   231,   235,
-     237,   239,   240,   242,   244,   246,   248,   250,   252,   254,
-     256,   257
+     157,   159,   162,   164,   167,   169,   172,   174,   176,   178,
+     180,   182,   184,   187,   190,   194,   196,   199,   201,   204,
+     206,   209,   212,   213,   217,   219,   223,   226,   227,   230,
+     233,   237,   241,   245,   247,   249,   250,   252,   254,   256,
+     258,   260,   262,   264,   266,   267
 };

 /* YYRHS -- A `-1'-separated list of the rules' RHS.  */
 static const yytype_int8 yyrhs[] =
 {
-      58,     0,    -1,    59,    49,    74,    87,    -1,    -1,    59,
-      60,    -1,    61,    -1,    51,    -1,    17,    -1,    19,    80,
-      81,    -1,    20,    -1,    20,     3,    -1,    21,    -1,    22,
+      58,     0,    -1,    59,    49,    76,    89,    -1,    -1,    59,
+      60,    -1,    61,    -1,    51,    -1,    17,    -1,    19,    82,
+      83,    -1,    20,    -1,    20,     3,    -1,    21,    -1,    22,
       4,    -1,    23,     4,    -1,    24,     3,    -1,    24,    46,
       3,    -1,    25,    -1,    26,    43,    -1,    27,     3,    -1,
      28,    43,    -1,    29,    -1,    30,     3,    -1,    30,    46,
       3,    -1,    32,    -1,    33,    -1,    34,     3,    -1,    34,
      46,     3,    -1,    35,    43,    -1,    36,    -1,    37,     3,
      -1,    38,     3,    -1,    40,    -1,    41,    -1,    42,    -1,
-      52,    -1,    66,    -1,    63,    -1,    39,    85,    -1,     8,
-      43,    70,    -1,     9,    43,    70,    -1,    18,    -1,    31,
-      -1,    16,    82,    -1,    16,    47,    82,    -1,    -1,    47,
-      -1,    56,    62,    82,    -1,    -1,     6,    64,    73,    -1,
-      -1,     5,    65,    73,    -1,     7,    53,    69,    -1,    67,
+      52,    -1,    66,    -1,    63,    -1,    39,    87,    -1,     8,
+      43,    72,    -1,     9,    43,    72,    -1,    18,    -1,    31,
+      -1,    16,    84,    -1,    16,    47,    84,    -1,    -1,    47,
+      -1,    56,    62,    84,    -1,    -1,     6,    64,    75,    -1,
+      -1,     5,    65,    75,    -1,     7,    53,    71,    -1,    67,
      68,    69,    -1,    10,    -1,    11,    -1,    12,    -1,    -1,
-      53,    -1,    85,    -1,    69,    85,    -1,    71,    -1,    70,
-      71,    -1,    85,    -1,    53,    -1,    54,    -1,    55,    -1,
-      53,    -1,    83,    -1,    83,     4,    -1,    83,    86,    -1,
-      83,     4,    86,    -1,    72,    -1,    73,    72,    -1,    75,
-      -1,    74,    75,    -1,    76,    -1,    61,    52,    -1,     1,
-      52,    -1,    -1,    84,    77,    78,    -1,    79,    -1,    78,
-      50,    79,    -1,    78,    52,    -1,    -1,    79,    85,    -1,
-      79,    43,    -1,    79,    13,    85,    -1,    79,    14,     4,
-      -1,    79,    15,    53,    -1,    47,    -1,     3,    -1,    -1,
+      53,    -1,    70,    -1,    69,    70,    -1,    87,    -1,    87,
+       4,    -1,    87,    -1,    71,    87,    -1,    73,    -1,    72,
+      73,    -1,    87,    -1,    53,    -1,    54,    -1,    55,    -1,
+      53,    -1,    85,    -1,    85,     4,    -1,    85,    88,    -1,
+      85,     4,    88,    -1,    74,    -1,    75,    74,    -1,    77,
+      -1,    76,    77,    -1,    78,    -1,    61,    52,    -1,     1,
+      52,    -1,    -1,    86,    79,    80,    -1,    81,    -1,    80,
+      50,    81,    -1,    80,    52,    -1,    -1,    81,    87,    -1,
+      81,    43,    -1,    81,    13,    87,    -1,    81,    14,     4,
+      -1,    81,    15,    53,    -1,    47,    -1,     3,    -1,    -1,
       3,    -1,    43,    -1,    47,    -1,    44,    -1,    48,    -1,
-      83,    -1,    86,    -1,     3,    -1,    -1,    49,    45,    -1
+      85,    -1,    88,    -1,     3,    -1,    -1,    49,    45,    -1
 };

 /* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
@@ -665,11 +666,11 @@ static const yytype_uint16 yyrline[] =
     283,   307,   308,   309,   310,   314,   315,   316,   320,   327,
     334,   338,   342,   349,   364,   365,   369,   381,   381,   386,
     386,   391,   402,   417,   418,   419,   423,   424,   429,   431,
-     436,   437,   441,   442,   443,   444,   449,   454,   459,   465,
-     471,   482,   483,   492,   493,   499,   500,   501,   508,   508,
-     512,   513,   514,   519,   520,   522,   524,   526,   528,   538,
-     539,   545,   548,   557,   577,   579,   588,   593,   594,   599,
-     606,   608
+     436,   437,   442,   444,   449,   450,   454,   455,   456,   457,
+     462,   467,   472,   478,   484,   495,   496,   505,   506,   512,
+     513,   514,   521,   521,   525,   526,   527,   532,   533,   535,
+     537,   539,   541,   551,   552,   558,   561,   570,   590,   592,
+     601,   606,   607,   612,   619,   621
 };
 #endif

@@ -695,10 +696,11 @@ static const char *const yytname[] =
  "prologue_declarations", "prologue_declaration", "grammar_declaration",
  "union_name", "symbol_declaration", "$@1", "$@2",
  "precedence_declaration", "precedence_declarator", "type.opt",
-  "symbols.1", "generic_symlist", "generic_symlist_item", "symbol_def",
-  "symbol_defs.1", "grammar", "rules_or_grammar_declaration", "rules",
-  "$@3", "rhses.1", "rhs", "variable", "content.opt", "braceless", "id",
-  "id_colon", "symbol", "string_as_id", "epilogue.opt", 0
+  "symbols.prec", "symbol.prec", "symbols.1", "generic_symlist",
+  "generic_symlist_item", "symbol_def", "symbol_defs.1", "grammar",
+  "rules_or_grammar_declaration", "rules", "$@3", "rhses.1", "rhs",
+  "variable", "content.opt", "braceless", "id", "id_colon", "symbol",
+  "string_as_id", "epilogue.opt", 0
 };
 #endif

@@ -725,11 +727,11 @@ static const yytype_uint8 yyr1[] =
      60,    60,    60,    60,    60,    61,    61,    61,    61,    61,
      61,    61,    61,    61,    62,    62,    61,    64,    63,    65,
      63,    63,    66,    67,    67,    67,    68,    68,    69,    69,
-      70,    70,    71,    71,    71,    71,    72,    72,    72,    72,
-      72,    73,    73,    74,    74,    75,    75,    75,    77,    76,
-      78,    78,    78,    79,    79,    79,    79,    79,    79,    80,
-      80,    81,    81,    82,    83,    83,    84,    85,    85,    86,
-      87,    87
+      70,    70,    71,    71,    72,    72,    73,    73,    73,    73,
+      74,    74,    74,    74,    74,    75,    75,    76,    76,    77,
+      77,    77,    79,    78,    80,    80,    80,    81,    81,    81,
+      81,    81,    81,    82,    82,    83,    83,    84,    85,    85,
+      86,    87,    87,    88,    89,    89
 };

 /* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
@@ -741,11 +743,11 @@ static const yytype_uint8 yyr2[] =
       2,     1,     1,     1,     1,     1,     1,     2,     3,     3,
       1,     1,     2,     3,     0,     1,     3,     0,     3,     0,
       3,     3,     3,     1,     1,     1,     0,     1,     1,     2,
-       1,     2,     1,     1,     1,     1,     1,     1,     2,     2,
-       3,     1,     2,     1,     2,     1,     2,     2,     0,     3,
-       1,     3,     2,     0,     2,     2,     3,     3,     3,     1,
-       1,     0,     1,     1,     1,     1,     1,     1,     1,     1,
-       0,     2
+       1,     2,     1,     2,     1,     2,     1,     1,     1,     1,
+       1,     1,     2,     2,     3,     1,     2,     1,     2,     1,
+       2,     2,     0,     3,     1,     3,     2,     0,     2,     2,
+       3,     3,     3,     1,     1,     0,     1,     1,     1,     1,
+       1,     1,     1,     1,     0,     2
 };

 /* YYDEFACT[STATE-NAME] -- Default rule to reduce with in state
@@ -758,24 +760,25 @@ static const yytype_uint8 yydefact[] =
       0,    16,     0,     0,     0,    20,     0,    41,    23,    24,
       0,     0,    28,     0,     0,     0,    31,    32,    33,     0,
       6,    34,    44,     4,     5,    36,    35,    56,     0,     0,
-       0,     0,     0,    93,     0,    42,    90,    89,    91,    10,
+       0,     0,     0,    97,     0,    42,    94,    93,    95,    10,
      12,    13,    14,     0,    17,    18,    19,    21,     0,    25,
-       0,    27,    29,    30,    99,    95,    94,    97,    37,    98,
-       0,    96,     0,     0,    73,    75,    78,    45,     0,    57,
-       0,    66,    71,    50,    67,    48,    51,    58,    63,    64,
-      65,    38,    60,    62,    39,    43,    92,     8,    15,    22,
-      26,    77,    76,     0,    74,     2,    83,    46,    52,    72,
-      68,    69,    59,    61,   101,    79,    80,    70,    83,    82,
-       0,     0,     0,    85,    84,    81,    86,    87,    88
+       0,    27,    29,    30,   103,    99,    98,   101,    37,   102,
+       0,   100,     0,     0,    77,    79,    82,    45,     0,    57,
+       0,    70,    75,    50,    71,    48,    51,    62,    67,    68,
+      69,    38,    64,    66,    39,    43,    96,     8,    15,    22,
+      26,    81,    80,     0,    78,     2,    87,    46,    52,    58,
+      60,    76,    72,    73,    63,    65,   105,    83,    84,    59,
+      61,    74,    87,    86,     0,     0,     0,    89,    88,    85,
+      90,    91,    92
 };

 /* YYDEFGOTO[NTERM-NUM].  */
-static const yytype_int8 yydefgoto[] =
+static const yytype_int16 yydefgoto[] =
 {
      -1,     1,     2,    43,    82,    88,    45,    49,    48,    46,
-      47,    90,    96,   101,   102,    92,    93,    83,    84,    85,
-     116,   125,   126,    58,   107,    55,    77,    86,   103,    79,
-     115
+      47,    90,   118,   119,    96,   101,   102,    92,    93,    83,
+      84,    85,   116,   127,   128,    58,   107,    55,    77,    86,
+     103,    79,   115
 };

 /* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
@@ -783,54 +786,55 @@ static const yytype_int8 yydefgoto[] =
 #define YYPACT_NINF -60
 static const yytype_int16 yypact[] =
 {
-     -60,    18,    96,   -60,   -60,   -60,   -16,    17,    24,   -60,
+     -60,    18,   100,   -60,   -60,   -60,   -16,    24,    27,   -60,
     -60,   -60,    -8,   -60,   -60,    11,    70,   -60,    71,    80,
-       2,   -60,    46,    87,    49,   -60,    31,   -60,   -60,   -60,
-      40,    50,   -60,    91,    93,     0,   -60,   -60,   -60,    15,
-     -60,   -60,    51,   -60,   -60,   -60,   -60,    44,    12,    12,
-       0,    25,    25,   -60,    56,   -60,   -60,   -60,   106,   -60,
-     -60,   -60,   -60,   107,   -60,   -60,   -60,   -60,   108,   -60,
-     136,   -60,   -60,   -60,   -60,   -60,   -60,   -60,   -60,   -60,
-      88,   -60,    89,     1,   -60,   -60,   -60,   -60,    56,   -60,
+       2,   -60,    46,    87,    48,   -60,    31,   -60,   -60,   -60,
+      40,    49,   -60,    91,    92,     0,   -60,   -60,   -60,    15,
+     -60,   -60,    50,   -60,   -60,   -60,   -60,    43,    12,    12,
+       0,    25,    25,   -60,    55,   -60,   -60,   -60,    97,   -60,
+     -60,   -60,   -60,    98,   -60,   -60,   -60,   -60,    99,   -60,
+     110,   -60,   -60,   -60,   -60,   -60,   -60,   -60,   -60,   -60,
+      51,   -60,    62,     1,   -60,   -60,   -60,   -60,    55,   -60,
       0,   -60,   -60,    12,    84,    12,     0,   -60,   -60,   -60,
     -60,    25,   -60,   -60,    25,   -60,   -60,   -60,   -60,   -60,
-     -60,   -60,   -60,    97,   -60,   -60,   -60,   -60,     0,   -60,
-     140,   -60,   -60,   -60,   -60,    14,    38,   -60,   -60,   -60,
-       0,   142,    98,   -60,   -60,    38,   -60,   -60,   -60
+     -60,   -60,   -60,   101,   -60,   -60,   -60,   -60,     0,   -60,
+     111,   -60,   140,   -60,   -60,   -60,   -60,    10,    38,   -60,
+     -60,   -60,   -60,   -60,     0,   141,    94,   -60,   -60,    38,
+     -60,   -60,   -60
 };

 /* YYPGOTO[NTERM-NUM].  */
 static const yytype_int16 yypgoto[] =
 {
-     -60,   -60,   -60,   -60,   147,   -60,   -60,   -60,   -60,   -60,
-     -60,   -60,    54,   101,   -59,   -25,   105,   -60,    67,   -60,
-     -60,   -60,    27,   -60,   -60,   -50,   -19,   -60,   -35,   -58,
-     -60
+     -60,   -60,   -60,   -60,   142,   -60,   -60,   -60,   -60,   -60,
+     -60,   -60,   -60,    30,   -60,   102,   -59,   -27,   104,   -60,
+      67,   -60,   -60,   -60,    23,   -60,   -60,   -50,   -19,   -60,
+     -35,   -58,   -60
 };

 /* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
   positive, shift that token.  If negative, reduce the rule which
   number is the opposite.  If zero, do what YYDEFACT says.
   If YYTABLE_NINF, syntax error.  */
-#define YYTABLE_NINF -101
+#define YYTABLE_NINF -105
 static const yytype_int16 yytable[] =
 {
-      78,  -100,    80,    74,   105,    62,     4,     5,     6,     7,
+      78,  -104,    80,    74,   105,    62,     4,     5,     6,     7,
       8,     9,    10,    11,    56,    97,    80,    12,     3,    14,
       4,     5,     6,     7,     8,     9,    10,    11,    74,    94,
-      94,    12,    27,    14,    67,    53,   121,    50,   117,    54,
-      35,    74,   123,    69,    75,   123,    27,    76,    63,    81,
-     113,   130,   131,   132,    35,    97,    75,    42,    57,    76,
-      51,   122,   127,    81,   128,    91,   129,    52,   119,    75,
-     119,    42,    76,    59,    94,    60,    94,    68,    98,    99,
-     100,   133,    75,   122,    61,    76,    70,    74,   120,    64,
-      65,   134,    66,    71,    72,   136,    73,    89,    87,    53,
-     134,     4,     5,     6,     7,     8,     9,    10,    11,   106,
-     108,   109,    12,    13,    14,    15,    16,    17,    18,    19,
-      20,    21,    22,    23,    24,    25,    26,    27,    28,    29,
-      30,    31,    32,    33,    34,    35,    36,    37,    38,   110,
-     111,   112,   124,    74,   118,    39,   137,    40,    41,    44,
-     114,   138,    42,   104,    95,   135
+      94,    12,    27,    14,    67,    53,   123,    50,   117,    54,
+      35,    74,   125,    69,    75,   125,    27,    76,    63,    81,
+     113,   134,   135,   136,    35,   120,    75,    42,    57,    76,
+     132,   124,   133,    81,   131,    91,   121,    51,   121,    75,
+      52,    42,    76,    59,    94,    60,    94,    68,    98,    99,
+     100,   137,    75,   120,    61,    76,    70,    74,   122,    64,
+      65,    66,    71,   138,    72,    73,    89,    87,    53,   140,
+     106,   108,   109,   111,   138,     4,     5,     6,     7,     8,
+       9,    10,    11,   110,   112,   130,    12,    13,    14,    15,
+      16,    17,    18,    19,    20,    21,    22,    23,    24,    25,
+      26,    27,    28,    29,    30,    31,    32,    33,    34,    35,
+      36,    37,    38,    74,    44,   141,   126,   142,   129,    39,
+     114,    40,    41,    95,   104,   139,    42
 };

 static const yytype_uint8 yycheck[] =
@@ -841,16 +845,16 @@ static const yytype_uint8 yycheck[] =
      49,    16,    31,    18,     3,    43,    94,    53,    88,    47,
      39,     3,   101,     3,    44,   104,    31,    47,    46,    48,
      49,    13,    14,    15,    39,    90,    44,    56,    47,    47,
-      43,    96,   120,    48,    50,    53,    52,    43,    93,    44,
-      95,    56,    47,     3,    93,     4,    95,    46,    53,    54,
+      50,    96,    52,    48,   122,    53,    93,    43,    95,    44,
+      43,    56,    47,     3,    93,     4,    95,    46,    53,    54,
      55,    43,    44,   118,     4,    47,    46,     3,     4,    43,
-       3,   126,    43,    43,     3,   130,     3,    53,    47,    43,
-     135,     5,     6,     7,     8,     9,    10,    11,    12,     3,
-       3,     3,    16,    17,    18,    19,    20,    21,    22,    23,
-      24,    25,    26,    27,    28,    29,    30,    31,    32,    33,
-      34,    35,    36,    37,    38,    39,    40,    41,    42,     3,
-      52,    52,    45,     3,    90,    49,     4,    51,    52,     2,
-      83,    53,    56,    52,    49,   128
+       3,    43,    43,   128,     3,     3,    53,    47,    43,   134,
+       3,     3,     3,    52,   139,     5,     6,     7,     8,     9,
+      10,    11,    12,     3,    52,     4,    16,    17,    18,    19,
+      20,    21,    22,    23,    24,    25,    26,    27,    28,    29,
+      30,    31,    32,    33,    34,    35,    36,    37,    38,    39,
+      40,    41,    42,     3,     2,     4,    45,    53,   118,    49,
+      83,    51,    52,    49,    52,   132,    56
 };

 /* YYSTOS[STATE-NUM] -- The (internal number of the) accessing
@@ -862,15 +866,16 @@ static const yytype_uint8 yystos[] =
      24,    25,    26,    27,    28,    29,    30,    31,    32,    33,
      34,    35,    36,    37,    38,    39,    40,    41,    42,    49,
      51,    52,    56,    60,    61,    63,    66,    67,    65,    64,
-      53,    43,    43,    43,    47,    82,     3,    47,    80,     3,
+      53,    43,    43,    43,    47,    84,     3,    47,    82,     3,
       4,     4,     3,    46,    43,     3,    43,     3,    46,     3,
-      46,    43,     3,     3,     3,    44,    47,    83,    85,    86,
-       1,    48,    61,    74,    75,    76,    84,    47,    62,    53,
-      68,    53,    72,    73,    83,    73,    69,    85,    53,    54,
-      55,    70,    71,    85,    70,    82,     3,    81,     3,     3,
-       3,    52,    52,    49,    75,    87,    77,    82,    69,    72,
-       4,    86,    85,    71,    45,    78,    79,    86,    50,    52,
-      13,    14,    15,    43,    85,    79,    85,     4,    53
+      46,    43,     3,     3,     3,    44,    47,    85,    87,    88,
+       1,    48,    61,    76,    77,    78,    86,    47,    62,    53,
+      68,    53,    74,    75,    85,    75,    71,    87,    53,    54,
+      55,    72,    73,    87,    72,    84,     3,    83,     3,     3,
+       3,    52,    52,    49,    77,    89,    79,    84,    69,    70,
+      87,    74,     4,    88,    87,    73,    45,    80,    81,    70,
+       4,    88,    50,    52,    13,    14,    15,    43,    87,    81,
+      87,     4,    53
 };

 #define yyerrok		(yyerrstatus = 0)
@@ -1025,7 +1030,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fputs (quotearg_style (c_quoting_style, (yyvaluep->chars)), stderr); };

 /* Line 22 of yacc.c  */
-#line 1029 "parse-gram.c"
+#line 1034 "parse-gram.c"
 	break;
      case 4: /* "\"integer\"" */

@@ -1034,7 +1039,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fprintf (stderr, "%d", (yyvaluep->integer)); };

 /* Line 22 of yacc.c  */
-#line 1038 "parse-gram.c"
+#line 1043 "parse-gram.c"
 	break;
      case 43: /* "\"{...}\"" */

@@ -1043,7 +1048,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fprintf (stderr, "{\n%s\n}", (yyvaluep->code)); };

 /* Line 22 of yacc.c  */
-#line 1047 "parse-gram.c"
+#line 1052 "parse-gram.c"
 	break;
      case 44: /* "\"char\"" */

@@ -1052,7 +1057,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fputs (char_name ((yyvaluep->character)), stderr); };

 /* Line 22 of yacc.c  */
-#line 1056 "parse-gram.c"
+#line 1061 "parse-gram.c"
 	break;
      case 45: /* "\"epilogue\"" */

@@ -1061,7 +1066,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fprintf (stderr, "{\n%s\n}", (yyvaluep->chars)); };

 /* Line 22 of yacc.c  */
-#line 1065 "parse-gram.c"
+#line 1070 "parse-gram.c"
 	break;
      case 47: /* "\"identifier\"" */

@@ -1070,7 +1075,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fputs ((yyvaluep->uniqstr), stderr); };

 /* Line 22 of yacc.c  */
-#line 1074 "parse-gram.c"
+#line 1079 "parse-gram.c"
 	break;
      case 48: /* "\"identifier:\"" */

@@ -1079,7 +1084,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fprintf (stderr, "%s:", (yyvaluep->uniqstr)); };

 /* Line 22 of yacc.c  */
-#line 1083 "parse-gram.c"
+#line 1088 "parse-gram.c"
 	break;
      case 51: /* "\"%{...%}\"" */

@@ -1088,7 +1093,7 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fprintf (stderr, "{\n%s\n}", (yyvaluep->chars)); };

 /* Line 22 of yacc.c  */
-#line 1092 "parse-gram.c"
+#line 1097 "parse-gram.c"
 	break;
      case 53: /* "\"type\"" */

@@ -1097,70 +1102,70 @@ yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp)
 	{ fprintf (stderr, "<%s>", (yyvaluep->uniqstr)); };

 /* Line 22 of yacc.c  */
-#line 1101 "parse-gram.c"
+#line 1106 "parse-gram.c"
 	break;
-      case 80: /* "variable" */
+      case 82: /* "variable" */

 /* Line 22 of yacc.c  */
 #line 189 "parse-gram.y"
 	{ fputs ((yyvaluep->uniqstr), stderr); };

 /* Line 22 of yacc.c  */
-#line 1110 "parse-gram.c"
+#line 1115 "parse-gram.c"
 	break;
-      case 81: /* "content.opt" */
+      case 83: /* "content.opt" */

 /* Line 22 of yacc.c  */
 #line 184 "parse-gram.y"
 	{ fprintf (stderr, "{\n%s\n}", (yyvaluep->chars)); };

 /* Line 22 of yacc.c  */
-#line 1119 "parse-gram.c"
+#line 1124 "parse-gram.c"
 	break;
-      case 82: /* "braceless" */
+      case 84: /* "braceless" */

 /* Line 22 of yacc.c  */
 #line 184 "parse-gram.y"
 	{ fprintf (stderr, "{\n%s\n}", (yyvaluep->chars)); };

 /* Line 22 of yacc.c  */
-#line 1128 "parse-gram.c"
+#line 1133 "parse-gram.c"
 	break;
-      case 83: /* "id" */
+      case 85: /* "id" */

 /* Line 22 of yacc.c  */
 #line 196 "parse-gram.y"
 	{ fprintf (stderr, "%s", (yyvaluep->symbol)->tag); };

 /* Line 22 of yacc.c  */
-#line 1137 "parse-gram.c"
+#line 1142 "parse-gram.c"
 	break;
-      case 84: /* "id_colon" */
+      case 86: /* "id_colon" */

 /* Line 22 of yacc.c  */
 #line 197 "parse-gram.y"
 	{ fprintf (stderr, "%s:", (yyvaluep->symbol)->tag); };

 /* Line 22 of yacc.c  */
-#line 1146 "parse-gram.c"
+#line 1151 "parse-gram.c"
 	break;
-      case 85: /* "symbol" */
+      case 87: /* "symbol" */

 /* Line 22 of yacc.c  */
 #line 196 "parse-gram.y"
 	{ fprintf (stderr, "%s", (yyvaluep->symbol)->tag); };

 /* Line 22 of yacc.c  */
-#line 1155 "parse-gram.c"
+#line 1160 "parse-gram.c"
 	break;
-      case 86: /* "string_as_id" */
+      case 88: /* "string_as_id" */

 /* Line 22 of yacc.c  */
 #line 196 "parse-gram.y"
 	{ fprintf (stderr, "%s", (yyvaluep->symbol)->tag); };

 /* Line 22 of yacc.c  */
-#line 1164 "parse-gram.c"
+#line 1169 "parse-gram.c"
 	break;
      default:
 	break;
@@ -1612,10 +1617,10 @@ YYLTYPE yylloc;
  YYSIZE_T yymsg_alloc = sizeof yymsgbuf;
 #endif

-  /* Three stacks and their tools:
-     `yyss': related to states,
-     `yyvs': related to semantic values,
-     `yyls': related to locations.
+  /* The stacks and their tools:
+     `yyss' is related to states.
+     `yyvs' is related to semantic values.
+     `yyls' is related to locations.

     Refer to the stacks thru separate pointers, to allow yyoverflow
     to reallocate them elsewhere.  */
@@ -1684,7 +1689,7 @@ YYLTYPE yylloc;
 }

 /* Line 22 of yacc.c  */
-#line 1688 "parse-gram.c"
+#line 1693 "parse-gram.c"
  yylsp[0] = yylloc;
  goto yysetstate;

@@ -2334,68 +2339,96 @@ yyreduce:

 /* Line 22 of yacc.c  */
 #line 436 "parse-gram.y"
-    { (yyval.list) = (yyvsp[(1) - (1)].list); }
+    { (yyval.symbol) = (yyvsp[(1) - (1)].symbol); }
    break;

  case 61:

 /* Line 22 of yacc.c  */
 #line 437 "parse-gram.y"
-    { (yyval.list) = symbol_list_prepend ((yyvsp[(1) - (2)].list), (yyvsp[(2) - (2)].list)); }
+    { (yyval.symbol) = (yyvsp[(1) - (2)].symbol); symbol_user_token_number_set ((yyvsp[(1) - (2)].symbol), (yyvsp[(2) - (2)].integer), (yylsp[(2) - (2)])); }
    break;

  case 62:

 /* Line 22 of yacc.c  */
-#line 441 "parse-gram.y"
+#line 443 "parse-gram.y"
    { (yyval.list) = symbol_list_sym_new ((yyvsp[(1) - (1)].symbol), (yylsp[(1) - (1)])); }
    break;

  case 63:

 /* Line 22 of yacc.c  */
-#line 442 "parse-gram.y"
-    { (yyval.list) = symbol_list_type_new ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
+#line 445 "parse-gram.y"
+    { (yyval.list) = symbol_list_prepend ((yyvsp[(1) - (2)].list), symbol_list_sym_new ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)]))); }
    break;

  case 64:

 /* Line 22 of yacc.c  */
-#line 443 "parse-gram.y"
-    { (yyval.list) = symbol_list_default_tagged_new ((yylsp[(1) - (1)])); }
+#line 449 "parse-gram.y"
+    { (yyval.list) = (yyvsp[(1) - (1)].list); }
    break;

  case 65:

 /* Line 22 of yacc.c  */
-#line 444 "parse-gram.y"
-    { (yyval.list) = symbol_list_default_tagless_new ((yylsp[(1) - (1)])); }
+#line 450 "parse-gram.y"
+    { (yyval.list) = symbol_list_prepend ((yyvsp[(1) - (2)].list), (yyvsp[(2) - (2)].list)); }
    break;

  case 66:

 /* Line 22 of yacc.c  */
-#line 450 "parse-gram.y"
-    {
-       current_type = (yyvsp[(1) - (1)].uniqstr);
-       tag_seen = true;
-     }
+#line 454 "parse-gram.y"
+    { (yyval.list) = symbol_list_sym_new ((yyvsp[(1) - (1)].symbol), (yylsp[(1) - (1)])); }
    break;

  case 67:

 /* Line 22 of yacc.c  */
 #line 455 "parse-gram.y"
+    { (yyval.list) = symbol_list_type_new ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
+    break;
+
+  case 68:
+
+/* Line 22 of yacc.c  */
+#line 456 "parse-gram.y"
+    { (yyval.list) = symbol_list_default_tagged_new ((yylsp[(1) - (1)])); }
+    break;
+
+  case 69:
+
+/* Line 22 of yacc.c  */
+#line 457 "parse-gram.y"
+    { (yyval.list) = symbol_list_default_tagless_new ((yylsp[(1) - (1)])); }
+    break;
+
+  case 70:
+
+/* Line 22 of yacc.c  */
+#line 463 "parse-gram.y"
+    {
+       current_type = (yyvsp[(1) - (1)].uniqstr);
+       tag_seen = true;
+     }
+    break;
+
+  case 71:
+
+/* Line 22 of yacc.c  */
+#line 468 "parse-gram.y"
    {
       symbol_class_set ((yyvsp[(1) - (1)].symbol), current_class, (yylsp[(1) - (1)]), true);
       symbol_type_set ((yyvsp[(1) - (1)].symbol), current_type, (yylsp[(1) - (1)]));
     }
    break;

-  case 68:
+  case 72:

 /* Line 22 of yacc.c  */
-#line 460 "parse-gram.y"
+#line 473 "parse-gram.y"
    {
      symbol_class_set ((yyvsp[(1) - (2)].symbol), current_class, (yylsp[(1) - (2)]), true);
      symbol_type_set ((yyvsp[(1) - (2)].symbol), current_type, (yylsp[(1) - (2)]));
@@ -2403,10 +2436,10 @@ yyreduce:
    }
    break;

-  case 69:
+  case 73:

 /* Line 22 of yacc.c  */
-#line 466 "parse-gram.y"
+#line 479 "parse-gram.y"
    {
      symbol_class_set ((yyvsp[(1) - (2)].symbol), current_class, (yylsp[(1) - (2)]), true);
      symbol_type_set ((yyvsp[(1) - (2)].symbol), current_type, (yylsp[(1) - (2)]));
@@ -2414,10 +2447,10 @@ yyreduce:
    }
    break;

-  case 70:
+  case 74:

 /* Line 22 of yacc.c  */
-#line 472 "parse-gram.y"
+#line 485 "parse-gram.y"
    {
      symbol_class_set ((yyvsp[(1) - (3)].symbol), current_class, (yylsp[(1) - (3)]), true);
      symbol_type_set ((yyvsp[(1) - (3)].symbol), current_type, (yylsp[(1) - (3)]));
@@ -2426,98 +2459,98 @@ yyreduce:
    }
    break;

-  case 77:
+  case 81:

 /* Line 22 of yacc.c  */
-#line 502 "parse-gram.y"
+#line 515 "parse-gram.y"
    {
      yyerrok;
    }
    break;

-  case 78:
+  case 82:

 /* Line 22 of yacc.c  */
-#line 508 "parse-gram.y"
+#line 521 "parse-gram.y"
    { current_lhs = (yyvsp[(1) - (1)].symbol); current_lhs_location = (yylsp[(1) - (1)]); }
    break;

-  case 80:
-
-/* Line 22 of yacc.c  */
-#line 512 "parse-gram.y"
-    { grammar_current_rule_end ((yylsp[(1) - (1)])); }
-    break;
-
-  case 81:
-
-/* Line 22 of yacc.c  */
-#line 513 "parse-gram.y"
-    { grammar_current_rule_end ((yylsp[(3) - (3)])); }
-    break;
-
-  case 83:
-
-/* Line 22 of yacc.c  */
-#line 519 "parse-gram.y"
-    { grammar_current_rule_begin (current_lhs, current_lhs_location); }
-    break;
-
  case 84:

 /* Line 22 of yacc.c  */
-#line 521 "parse-gram.y"
-    { grammar_current_rule_symbol_append ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)])); }
+#line 525 "parse-gram.y"
+    { grammar_current_rule_end ((yylsp[(1) - (1)])); }
    break;

  case 85:

 /* Line 22 of yacc.c  */
-#line 523 "parse-gram.y"
-    { grammar_current_rule_action_append ((yyvsp[(2) - (2)].code), (yylsp[(2) - (2)])); }
-    break;
-
-  case 86:
-
-/* Line 22 of yacc.c  */
-#line 525 "parse-gram.y"
-    { grammar_current_rule_prec_set ((yyvsp[(3) - (3)].symbol), (yylsp[(3) - (3)])); }
+#line 526 "parse-gram.y"
+    { grammar_current_rule_end ((yylsp[(3) - (3)])); }
    break;

  case 87:

 /* Line 22 of yacc.c  */
-#line 527 "parse-gram.y"
-    { grammar_current_rule_dprec_set ((yyvsp[(3) - (3)].integer), (yylsp[(3) - (3)])); }
+#line 532 "parse-gram.y"
+    { grammar_current_rule_begin (current_lhs, current_lhs_location); }
    break;

  case 88:

 /* Line 22 of yacc.c  */
-#line 529 "parse-gram.y"
-    { grammar_current_rule_merge_set ((yyvsp[(3) - (3)].uniqstr), (yylsp[(3) - (3)])); }
+#line 534 "parse-gram.y"
+    { grammar_current_rule_symbol_append ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)])); }
+    break;
+
+  case 89:
+
+/* Line 22 of yacc.c  */
+#line 536 "parse-gram.y"
+    { grammar_current_rule_action_append ((yyvsp[(2) - (2)].code), (yylsp[(2) - (2)])); }
    break;

  case 90:

 /* Line 22 of yacc.c  */
-#line 539 "parse-gram.y"
-    { (yyval.uniqstr) = uniqstr_new ((yyvsp[(1) - (1)].chars)); }
+#line 538 "parse-gram.y"
+    { grammar_current_rule_prec_set ((yyvsp[(3) - (3)].symbol), (yylsp[(3) - (3)])); }
    break;

  case 91:

 /* Line 22 of yacc.c  */
-#line 545 "parse-gram.y"
+#line 540 "parse-gram.y"
+    { grammar_current_rule_dprec_set ((yyvsp[(3) - (3)].integer), (yylsp[(3) - (3)])); }
+    break;
+
+  case 92:
+
+/* Line 22 of yacc.c  */
+#line 542 "parse-gram.y"
+    { grammar_current_rule_merge_set ((yyvsp[(3) - (3)].uniqstr), (yylsp[(3) - (3)])); }
+    break;
+
+  case 94:
+
+/* Line 22 of yacc.c  */
+#line 552 "parse-gram.y"
+    { (yyval.uniqstr) = uniqstr_new ((yyvsp[(1) - (1)].chars)); }
+    break;
+
+  case 95:
+
+/* Line 22 of yacc.c  */
+#line 558 "parse-gram.y"
    {
      (yyval.chars) = "";
    }
    break;

-  case 93:
+  case 97:

 /* Line 22 of yacc.c  */
-#line 558 "parse-gram.y"
+#line 571 "parse-gram.y"
    {
      code_props plain_code;
      (yyvsp[(1) - (1)].code)[strlen ((yyvsp[(1) - (1)].code)) - 1] = '\n';
@@ -2528,17 +2561,17 @@ yyreduce:
    }
    break;

-  case 94:
+  case 98:

 /* Line 22 of yacc.c  */
-#line 578 "parse-gram.y"
+#line 591 "parse-gram.y"
    { (yyval.symbol) = symbol_from_uniqstr ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
    break;

-  case 95:
+  case 99:

 /* Line 22 of yacc.c  */
-#line 580 "parse-gram.y"
+#line 593 "parse-gram.y"
    {
      (yyval.symbol) = symbol_get (char_name ((yyvsp[(1) - (1)].character)), (yylsp[(1) - (1)]));
      symbol_class_set ((yyval.symbol), token_sym, (yylsp[(1) - (1)]), false);
@@ -2546,27 +2579,27 @@ yyreduce:
    }
    break;

-  case 96:
+  case 100:

 /* Line 22 of yacc.c  */
-#line 588 "parse-gram.y"
+#line 601 "parse-gram.y"
    { (yyval.symbol) = symbol_from_uniqstr ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
    break;

-  case 99:
+  case 103:

 /* Line 22 of yacc.c  */
-#line 600 "parse-gram.y"
+#line 613 "parse-gram.y"
    {
      (yyval.symbol) = symbol_get (quotearg_style (c_quoting_style, (yyvsp[(1) - (1)].chars)), (yylsp[(1) - (1)]));
      symbol_class_set ((yyval.symbol), token_sym, (yylsp[(1) - (1)]), false);
    }
    break;

-  case 101:
+  case 105:

 /* Line 22 of yacc.c  */
-#line 609 "parse-gram.y"
+#line 622 "parse-gram.y"
    {
      code_props plain_code;
      code_props_plain_init (&plain_code, (yyvsp[(2) - (2)].chars), (yylsp[(2) - (2)]));
@@ -2580,7 +2613,7 @@ yyreduce:


 /* Line 22 of yacc.c  */
-#line 2584 "parse-gram.c"
+#line 2617 "parse-gram.c"
      default: break;
    }
  YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyn], &yyval, &yyloc);
@@ -2799,7 +2832,7 @@ yyreturn:


 /* Line 22 of yacc.c  */
-#line 619 "parse-gram.y"
+#line 632 "parse-gram.y"



--- a/src/parse-gram.y
+++ b/src/parse-gram.y
@@ -1,7 +1,7 @@
 %{/* Bison Grammar Parser                             -*- C -*-

-   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation,
-   Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
+   Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

@@ -192,12 +192,12 @@ static int current_prec = 0;
 %type <integer> INT
 %printer { fprintf (stderr, "%d", $$); } INT

-%type <symbol> id id_colon symbol string_as_id
+%type <symbol> id id_colon symbol symbol.prec string_as_id
 %printer { fprintf (stderr, "%s", $$->tag); } id symbol string_as_id
 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon

 %type <assoc> precedence_declarator
-%type <list>  symbols.1 generic_symlist generic_symlist_item
+%type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
 %%

 input:
@@ -399,7 +399,7 @@ symbol_declaration:
 ;

 precedence_declaration:
-  precedence_declarator type.opt symbols.1
+  precedence_declarator type.opt symbols.prec
    {
      symbol_list *list;
      ++current_prec;
@@ -424,6 +424,19 @@ type.opt:
 | TYPE           { current_type = $1; tag_seen = true; }
 ;

+/* Just like symbols.1 but accept INT for the sake of POSIX.  */
+symbols.prec:
+  symbol.prec
+    { $$ = symbol_list_sym_new ($1, @1); }
+| symbols.prec symbol.prec
+    { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
+;
+
+symbol.prec:
+    symbol { $$ = $1; }
+  | symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
+  ;
+
 /* One or more symbols to be %typed. */
 symbols.1:
  symbol
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -1,7 +1,7 @@
 /* Symbol table manager for Bison.

-   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2006, 2007 Free
-   Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2006, 2007, 2008
+   Free Software Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

@@ -358,8 +358,6 @@ symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
 {
  int *user_token_numberp;

-  aver (sym->class == token_sym);
-
  if (sym->user_token_number != USER_NUMBER_ALIAS)
    user_token_numberp = &sym->user_token_number;
  else
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -1,6 +1,6 @@
 # Bison Regressions.                               -*- Autotest -*-

-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software
+# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
 # Foundation, Inc.

 # This program is free software: you can redistribute it and/or modify
@@ -1181,3 +1181,64 @@ state 2
 ]])

 AT_CLEANUP
+
+
+
+## ---------------------------------------- ##
+## Token number in precedence declaration.  ##
+## ---------------------------------------- ##
+
+AT_SETUP([[Token number in precedence declaration.]])
+
+# POSIX says token numbers can be declared in %left, %right, and %nonassoc, but
+# we lost this in Bison 1.50.
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+  #include <stdio.h>
+  void yyerror (char const *);
+  int yylex (void);
+%}
+
+%error-verbose
+%left TK1 1 TK2 2 "tok alias" 3
+
+%%
+
+start: TK1 sr_conflict "tok alias" ;
+
+sr_conflict:
+  TK2
+  | TK2 "tok alias"
+  ;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+int
+yylex (void)
+{
+  static int const input[] = { 1, 2, 3, 0 };
+  static int const *inputp = input;
+  return *inputp++;
+}
+
+int
+main (void)
+{
+  return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o input.c input.y]], [[0]],,
+[[input.y:24.5-19: warning: rule useless in parser due to conflicts: sr_conflict: TK2 "tok alias"
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]])
+
+AT_CLEANUP