# Bison Regressions. -*- Autotest -*-
-# Copyright (C) 2001, 2002, 2003, 2004, 2005 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
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
+# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
-
+#
# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-# 02110-1301, USA.
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
AT_BANNER([[Regression tests.]])
-## ------------------------- ##
-## Early token definitions. ##
-## ------------------------- ##
+## ------------------ ##
+## Trivial grammars. ##
+## ------------------ ##
+
+AT_SETUP([Trivial grammars])
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+void yyerror (char const *);
+int yylex (void);
+#define YYSTYPE int *
+%}
+
+%error-verbose
+
+%%
+
+program: 'x';
+]])
+
+AT_BISON_CHECK([-o input.c input.y])
+AT_COMPILE([input.o], [-c input.c])
+AT_COMPILE([input.o], [-DYYDEBUG -c input.c])
+
+AT_CLEANUP
+
+
+## ----------------- ##
+## YYSTYPE typedef. ##
+## ----------------- ##
-AT_SETUP([Early token definitions])
+AT_SETUP([YYSTYPE typedef])
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+void yyerror (char const *);
+int yylex (void);
+typedef union { char const *val; } YYSTYPE;
+%}
+
+%type <val> program
+
+%%
+
+program: { $$ = ""; };
+]])
+
+AT_BISON_CHECK([-o input.c input.y])
+AT_COMPILE([input.o], [-c input.c])
+
+AT_CLEANUP
+
+
+
+## ------------------------------------- ##
+## Early token definitions with --yacc. ##
+## ------------------------------------- ##
+
+
+AT_SETUP([Early token definitions with --yacc])
# Found in GCJ: they expect the tokens to be defined before the user
# prologue, so that they can use the token definitions in it.
%%
]])
-AT_CHECK([bison -o input.c input.y])
+AT_BISON_CHECK([-y -o input.c input.y])
+AT_COMPILE([input.o], [-c input.c])
+
+AT_CLEANUP
+
+
+
+## ---------------------------------------- ##
+## Early token definitions without --yacc. ##
+## ---------------------------------------- ##
+
+
+AT_SETUP([Early token definitions without --yacc])
+
+# Found in GCJ: they expect the tokens to be defined before the user
+# prologue, so that they can use the token definitions in it.
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+#include <stdio.h>
+void yyerror (const char *s);
+int yylex (void);
+void print_my_token (void);
+%}
+
+%union
+{
+ int val;
+};
+%{
+void
+print_my_token (void)
+{
+ enum yytokentype my_token = MY_TOKEN;
+ printf ("%d\n", my_token);
+}
+%}
+%token MY_TOKEN
+%%
+exp: MY_TOKEN;
+%%
+]])
+
+AT_BISON_CHECK([-o input.c input.y])
AT_COMPILE([input.o], [-c input.c])
AT_CLEANUP
%%
]])
-AT_CHECK([bison -v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y])
AT_CHECK([grep 'tests = {{{{{{{{{{}}}}}}}}}};' input.c], 0, [ignore])
%%
]])
-AT_CHECK([bison -v -o input.c input.y], 0, [],
+AT_BISON_CHECK([-v -o input.c input.y], 0, [],
[[input.y:6.8-14: warning: symbol `"<="' used more than once as a literal string
]])
};
]])
-AT_CHECK([bison -o input.c -v input.y])
+AT_BISON_CHECK([-o input.c -v input.y])
# Check the contents of the report.
AT_CHECK([cat input.output], [],
0 $accept: expr $end
- 1 @1: /* empty */
+ 1 $@1: /* empty */
- 2 expr: 'a' @1 'b'
+ 2 expr: 'a' $@1 'b'
- 3 @2: /* empty */
+ 3 $@2: /* empty */
- 4 expr: @2 'c'
+ 4 expr: $@2 'c'
Terminals, with rules where they appear
on left: 0
expr (7)
on left: 2 4, on right: 0
-@1 (8)
+$@1 (8)
on left: 1, on right: 2
-@2 (9)
+$@2 (9)
on left: 3, on right: 4
'a' shift, and go to state 1
- $default reduce using rule 3 (@2)
+ $default reduce using rule 3 ($@2)
expr go to state 2
- @2 go to state 3
+ $@2 go to state 3
state 1
- 2 expr: 'a' . @1 'b'
+ 2 expr: 'a' . $@1 'b'
- $default reduce using rule 1 (@1)
+ $default reduce using rule 1 ($@1)
- @1 go to state 4
+ $@1 go to state 4
state 2
state 3
- 4 expr: @2 . 'c'
+ 4 expr: $@2 . 'c'
'c' shift, and go to state 6
state 4
- 2 expr: 'a' @1 . 'b'
+ 2 expr: 'a' $@1 . 'b'
'b' shift, and go to state 7
state 6
- 4 expr: @2 'c' .
+ 4 expr: $@2 'c' .
$default reduce using rule 4 (expr)
state 7
- 2 expr: 'a' @1 'b' .
+ 2 expr: 'a' $@1 'b' .
$default reduce using rule 2 (expr)
]])
%%
]])
-AT_CHECK([bison -v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y])
AT_CLEANUP
%{
]])
-AT_CHECK([bison input.y], [1], [],
+AT_BISON_CHECK([input.y], [1], [],
[[input.y:2.1: invalid character: `?'
input.y:3.14: invalid character: `}'
input.y:4.1: invalid character: `%'
input.y:4.2: invalid character: `&'
input.y:5.1-17: invalid directive: `%a-does-not-exist'
-input.y:6.1: invalid character: `%'
-input.y:6.2: invalid character: `-'
+input.y:6.1-2: invalid directive: `%-'
input.y:7.1-8.0: missing `%}' at end of file
+input.y:7.1-8.0: syntax error, unexpected %{...%}
]])
AT_CLEANUP
%union
]])
-AT_CHECK([bison input.y], [1], [],
-[[input.y:3.1: missing `{' in "%destructor {...}"
-input.y:4.1: missing `{' in "%initial-action {...}"
-input.y:4.1: syntax error, unexpected %initial-action {...}, expecting string or identifier
+AT_BISON_CHECK([input.y], [1], [],
+[[input.y:3.1-15: syntax error, unexpected %initial-action, expecting {...}
]])
AT_CLEANUP
# Bison managed, when fed with `%token 'f' "f"' to #define 'f'!
AT_DATA_GRAMMAR([input.y],
[%{
+#include <stdlib.h>
#include <stdio.h>
void yyerror (const char *s);
int yylex (void);
%token B_TOKEN "b"
%token C_TOKEN 'c'
%token 'd' D_TOKEN
-%token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\377\x001\x0000ff??!"
+%token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
+%token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
%%
-exp: "a" "\\\'\?\"\a\b\f\n\r\t\v\001\377\x001\x0000ff??!";
+exp: "a" "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!";
%%
void
yyerror (char const *s)
int
yylex (void)
{
+ static int called;
+ if (called++)
+ abort ();
return SPECIAL;
}
}
]])
-AT_CHECK([bison -o input.c input.y])
+# Checking the warning message guarantees that the trigraph "??!" isn't
+# unnecessarily escaped here even though it would need to be if encoded in a
+# C-string literal. Also notice that unnecessary escaping, such as "\?", from
+# the user specification is eliminated.
+AT_BISON_CHECK([-o input.c input.y], [[0]], [[]],
+[[input.y:22.8-14: warning: symbol SPECIAL redeclared
+input.y:22.8-63: warning: symbol `"\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!"' used more than once as a literal string
+]])
AT_COMPILE([input])
-AT_PARSER_CHECK([./input], 1, [],
-[syntax error, unexpected "\\'?\"\a\b\f\n\r\t\v\001\377\001\377?\?!", expecting a
-])
+
+# Checking the error message here guarantees that yytname, which does contain
+# C-string literals, does have the trigraph escaped correctly. Thus, the
+# symbol name reported by the parser is exactly the same as that reported by
+# Bison itself.
+AT_DATA([experr],
+[[syntax error, unexpected "\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!", expecting a
+]])
+AT_PARSER_CHECK([./input], 1, [], [experr])
AT_CLEANUP
]])
# Pacify font-lock-mode: "
-AT_CHECK([bison -o input.c input.y])
+AT_BISON_CHECK([-o input.c input.y])
AT_COMPILE([input.o], [-c input.c])
AT_CLEANUP
%%
]])
-AT_CHECK([bison -v input.y])
+AT_BISON_CHECK([-v input.y])
AT_CHECK([cat input.output], 0,
[[Grammar
2 CONST_DEC_LIST: CONST_DEC
3 | CONST_DEC_LIST CONST_DEC
- 4 @1: /* empty */
+ 4 $@1: /* empty */
- 5 CONST_DEC: @1 undef_id_tok '=' const_id_tok ';'
+ 5 CONST_DEC: $@1 undef_id_tok '=' const_id_tok ';'
Terminals, with rules where they appear
on left: 2 3, on right: 1 3
CONST_DEC (10)
on left: 5, on right: 2 3
-@1 (11)
+$@1 (11)
on left: 4, on right: 5
0 $accept: . CONST_DEC_PART $end
- $default reduce using rule 4 (@1)
+ $default reduce using rule 4 ($@1)
CONST_DEC_PART go to state 1
CONST_DEC_LIST go to state 2
CONST_DEC go to state 3
- @1 go to state 4
+ $@1 go to state 4
state 1
1 CONST_DEC_PART: CONST_DEC_LIST .
3 CONST_DEC_LIST: CONST_DEC_LIST . CONST_DEC
- undef_id_tok reduce using rule 4 (@1)
+ undef_id_tok reduce using rule 4 ($@1)
$default reduce using rule 1 (CONST_DEC_PART)
CONST_DEC go to state 6
- @1 go to state 4
+ $@1 go to state 4
state 3
state 4
- 5 CONST_DEC: @1 . undef_id_tok '=' const_id_tok ';'
+ 5 CONST_DEC: $@1 . undef_id_tok '=' const_id_tok ';'
undef_id_tok shift, and go to state 7
state 7
- 5 CONST_DEC: @1 undef_id_tok . '=' const_id_tok ';'
+ 5 CONST_DEC: $@1 undef_id_tok . '=' const_id_tok ';'
'=' shift, and go to state 8
state 8
- 5 CONST_DEC: @1 undef_id_tok '=' . const_id_tok ';'
+ 5 CONST_DEC: $@1 undef_id_tok '=' . const_id_tok ';'
const_id_tok shift, and go to state 9
state 9
- 5 CONST_DEC: @1 undef_id_tok '=' const_id_tok . ';'
+ 5 CONST_DEC: $@1 undef_id_tok '=' const_id_tok . ';'
';' shift, and go to state 10
state 10
- 5 CONST_DEC: @1 undef_id_tok '=' const_id_tok ';' .
+ 5 CONST_DEC: $@1 undef_id_tok '=' const_id_tok ';' .
$default reduce using rule 5 (CONST_DEC)
]])
#
# It used to be wrong on yydefact only:
#
-# static const short int yydefact[] =
+# static const yytype_uint8 yydefact[] =
# {
# - 2, 0, 1, 0, 0, 2, 3, 2, 5, 4,
# + 2, 0, 1, 0, 0, 0, 3, 2, 5, 4,
%%
]])
-AT_CHECK([bison -v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y])
-# Check only the tables. We don't use --no-parser, because it is
-# still to be implemented in the experimental branch of Bison.
+# Check only the tables.
[sed -n 's/ *$//;/^static const.*\[\] =/,/^}/p' input.c >tables.c]
AT_CHECK([[cat tables.c]], 0,
-[[static const unsigned char yytranslate[] =
+[[static const yytype_uint8 yytranslate[] =
{
0, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 1, 2, 3, 4,
5, 6
};
-static const unsigned char yyprhs[] =
-{
- 0, 0, 3, 5, 6, 9, 14
-};
-static const yysigned_char yyrhs[] =
-{
- 8, 0, -1, 9, -1, -1, 10, 11, -1, 3,
- 4, 5, 8, -1, 6, 8, -1
-};
-static const unsigned char yyrline[] =
+static const yytype_uint8 yyrline[] =
{
0, 2, 2, 3, 3, 4, 5
};
"$end", "error", "$undefined", "\"if\"", "\"const\"", "\"then\"",
"\"else\"", "$accept", "statement", "struct_stat", "if", "else", 0
};
-static const unsigned short int yytoknum[] =
+static const yytype_uint16 yytoknum[] =
{
0, 256, 257, 258, 259, 260, 261
};
-static const unsigned char yyr1[] =
+static const yytype_int8 yypact[] =
{
- 0, 7, 8, 9, 9, 10, 11
-};
-static const unsigned char yyr2[] =
-{
- 0, 2, 1, 0, 2, 4, 2
+ -2, -1, 4, -8, 0, 2, -8, -2, -8, -2,
+ -8, -8
};
-static const unsigned char yydefact[] =
+static const yytype_uint8 yydefact[] =
{
3, 0, 0, 2, 0, 0, 1, 3, 4, 3,
6, 5
};
-static const yysigned_char yydefgoto[] =
+static const yytype_int8 yypgoto[] =
{
- -1, 2, 3, 4, 8
-};
-static const yysigned_char yypact[] =
-{
- -2, -1, 4, -8, 0, 2, -8, -2, -8, -2,
- -8, -8
+ -8, -7, -8, -8, -8
};
-static const yysigned_char yypgoto[] =
+static const yytype_int8 yydefgoto[] =
{
- -8, -7, -8, -8, -8
+ -1, 2, 3, 4, 8
};
-static const unsigned char yytable[] =
+static const yytype_uint8 yytable[] =
{
10, 1, 11, 5, 6, 0, 7, 9
};
-static const yysigned_char yycheck[] =
+static const yytype_int8 yycheck[] =
{
7, 3, 9, 4, 0, -1, 6, 5
};
-static const unsigned char yystos[] =
+static const yytype_uint8 yystos[] =
{
0, 3, 8, 9, 10, 4, 0, 6, 11, 5,
8, 8
};
+static const yytype_uint8 yyr1[] =
+{
+ 0, 7, 8, 9, 9, 10, 11
+};
+static const yytype_uint8 yyr2[] =
+{
+ 0, 2, 1, 0, 2, 4, 2
+};
]])
AT_CLEANUP
[%{
static int yylex (AT_LALR1_CC_IF([int *], [void]));
AT_LALR1_CC_IF([],
-[#include <stdio.h>
+[#include <stdlib.h>
+#include <stdio.h>
static void yyerror (const char *);])
%}
$1
AT_LALR1_CC_IF(
[/* A C++ error reporting function. */
void
-yy::parser::error (const location&, const std::string& m)
+yy::parser::error (const std::string& m)
{
std::cerr << m << std::endl;
}
yyparse ()
{
yy::parser parser;
- parser.set_debug_level (!!YYDEBUG);
+#if YYDEBUG
+ parser.set_debug_level (YYDEBUG);
+#endif
return parser.parse ();
}
],
static int
yylex (AT_LALR1_CC_IF([int *lval], [void]))
[{
- static int toknum = 0;
- int tokens[] =
+ static int const tokens[] =
{
':', -1
};
+ static size_t toknum;
]AT_LALR1_CC_IF([*lval = 0; /* Pacify GCC. */])[
+ if (! (toknum < sizeof tokens / sizeof *tokens))
+ abort ();
return tokens[toknum++];
}]
[AT_SETUP([Dancer $1])
AT_BISON_OPTION_PUSHDEFS([$1])
_AT_DATA_DANCER_Y([$1])
-AT_CHECK([bison -o dancer.c dancer.y])
-AT_LALR1_CC_IF(
- [AT_CHECK([bison -o dancer.cc dancer.y])
- AT_COMPILE_CXX([dancer])],
- [AT_CHECK([bison -o dancer.c dancer.y])
- AT_COMPILE([dancer])])
+AT_BISON_CHECK([-o dancer.c dancer.y])
+AT_FULL_COMPILE([dancer])
AT_PARSER_CHECK([./dancer], 1, [],
[syntax error, unexpected ':'
])
AT_CHECK_DANCER()
AT_CHECK_DANCER([%glr-parser])
AT_CHECK_DANCER([%skeleton "lalr1.cc"])
+
+
+## ------------------------------------------ ##
+## Diagnostic that expects two alternatives. ##
+## ------------------------------------------ ##
+
+
+# _AT_DATA_EXPECT2_Y(BISON-OPTIONS)
+# --------------------------------
+m4_define([_AT_DATA_EXPECT2_Y],
+[AT_DATA_GRAMMAR([expect2.y],
+[%{
+static int yylex (AT_LALR1_CC_IF([int *], [void]));
+AT_LALR1_CC_IF([],
+[#include <stdio.h>
+#include <stdlib.h>
+static void yyerror (const char *);])
+%}
+$1
+%defines
+%error-verbose
+%token A 1000
+%token B
+
+%%
+program: /* empty */
+ | program e ';'
+ | program error ';';
+
+e: e '+' t | t;
+t: A | B;
+
+%%
+AT_LALR1_CC_IF(
+[/* A C++ error reporting function. */
+void
+yy::parser::error (const std::string& m)
+{
+ std::cerr << m << std::endl;
+}
+
+int
+yyparse ()
+{
+ yy::parser parser;
+ return parser.parse ();
+}
+],
+[static void
+yyerror (const char *s)
+{
+ fprintf (stderr, "%s\n", s);
+}])
+
+static int
+yylex (AT_LALR1_CC_IF([int *lval], [void]))
+[{
+ static int const tokens[] =
+ {
+ 1000, '+', '+', -1
+ };
+ static size_t toknum;
+ ]AT_LALR1_CC_IF([*lval = 0; /* Pacify GCC. */])[
+ if (! (toknum < sizeof tokens / sizeof *tokens))
+ abort ();
+ return tokens[toknum++];
+}]
+
+int
+main (void)
+{
+ return yyparse ();
+}
+])
+])# _AT_DATA_EXPECT2_Y
+
+
+# AT_CHECK_EXPECT2(BISON-OPTIONS)
+# ------------------------------
+# Generate the grammar, compile it, run it.
+m4_define([AT_CHECK_EXPECT2],
+[AT_SETUP([Expecting two tokens $1])
+AT_BISON_OPTION_PUSHDEFS([$1])
+_AT_DATA_EXPECT2_Y([$1])
+AT_BISON_CHECK([-o expect2.c expect2.y])
+AT_FULL_COMPILE([expect2])
+AT_PARSER_CHECK([./expect2], 1, [],
+[syntax error, unexpected '+', expecting A or B
+])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+])
+
+AT_CHECK_EXPECT2()
+AT_CHECK_EXPECT2([%glr-parser])
+AT_CHECK_EXPECT2([%skeleton "lalr1.cc"])
+
+
+
+## --------------------------------------------- ##
+## Braced code in declaration in rules section. ##
+## --------------------------------------------- ##
+
+AT_SETUP([Braced code in declaration in rules section])
+
+# Bison once mistook braced code in a declaration in the rules section to be a
+# rule action.
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+#include <stdio.h>
+static void yyerror (char const *msg);
+static int yylex (void);
+%}
+
+%error-verbose
+
+%%
+
+start:
+ {
+ printf ("Bison would once convert this action to a midrule because of the"
+ " subsequent braced code.\n");
+ }
+ ;
+
+%destructor { fprintf (stderr, "DESTRUCTOR\n"); } 'a';
+%printer { fprintf (yyoutput, "PRINTER"); } 'a';
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ return 'a';
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return !yyparse ();
+}
+]])
+
+AT_BISON_CHECK([-t -o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 0,
+[[Bison would once convert this action to a midrule because of the subsequent braced code.
+]],
+[[Starting parse
+Entering state 0
+Reducing stack by rule 1 (line 20):
+-> $$ = nterm start ()
+Stack now 0
+Entering state 1
+Reading a token: Next token is token 'a' (PRINTER)
+syntax error, unexpected 'a', expecting $end
+Error: popping nterm start ()
+Stack now 0
+Cleanup: discarding lookahead token 'a' (PRINTER)
+DESTRUCTOR
+Stack now 0
+]])
+
+AT_CLEANUP
+
+
+
+## --------------------------------- ##
+## String alias declared after use. ##
+## --------------------------------- ##
+
+AT_SETUP([String alias declared after use])
+
+# Bison once incorrectly asserted that the symbol number for either a token or
+# its alias was the highest symbol number so far at the point of the alias
+# declaration. That was true unless the declaration appeared after their first
+# uses and other tokens appeared in between.
+
+AT_DATA([input.y],
+[[%%
+start: 'a' "A" 'b';
+%token 'a' "A";
+]])
+
+AT_BISON_CHECK([-t -o input.c input.y])
+
+AT_CLEANUP
+
+
+
+## -------------------------------- ##
+## Extra lookahead sets in report. ##
+## -------------------------------- ##
+
+AT_SETUP([[Extra lookahead sets in report]])
+
+# Bison prints each reduction's lookahead set only next to the associated
+# state's one item that (1) is associated with the same rule as the reduction
+# and (2) has its dot at the end of its RHS. Previously, Bison also
+# erroneously printed the lookahead set next to all of the state's other items
+# associated with the same rule. This bug affected only the `.output' file and
+# not the generated parser source code.
+
+AT_DATA([[input.y]],
+[[%%
+start: a | 'a' a 'a' ;
+a: 'a' ;
+]])
+
+AT_BISON_CHECK([[--report=all input.y]])
+AT_CHECK([[sed -n '/^state 1$/,/^state 2$/p' input.output]], [[0]],
+[[state 1
+
+ 2 start: 'a' . a 'a'
+ 3 a: . 'a'
+ 3 | 'a' . [$end]
+
+ 'a' shift, and go to state 4
+
+ $default reduce using rule 3 (a)
+
+ a go to state 5
+
+
+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