# Checking GLR Parsing: Regression Tests -*- Autotest -*-
-# Copyright (C) 2002-2003, 2005-2007, 2009-2012 Free Software
+# Copyright (C) 2002-2003, 2005-2007, 2009-2013 Free Software
# Foundation, Inc.
# This program is free software: you can redistribute it and/or modify
AT_BANNER([[GLR Regression Tests]])
-## --------------------------- ##
-## Badly Collapsed GLR States. ##
-## --------------------------- ##
+## ---------------------------- ##
+## Badly Collapsed GLR States. ##
+## ---------------------------- ##
AT_SETUP([Badly Collapsed GLR States])
return 0;
}
+const char *input = YY_NULL;
+
int
-main (void)
+main (int argc, const char* argv[])
{
+ assert (argc == 2);
+ input = argv[1];
return yyparse ();
}
int
yylex (void)
{
- for (;;)
- {
- int ch;
- assert (!feof (stdin));
- ch = getchar ();
- if (ch == EOF)
- return 0;
- else if (ch == 'B' || ch == 'P')
- return ch;
- }
+ return *input++;
}
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr1.c glr-regr1.y]], 0, [],
-[glr-regr1.y: conflicts: 1 shift/reduce
-])
+[[glr-regr1.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
+]])
AT_COMPILE([glr-regr1])
-AT_PARSER_CHECK([[echo BPBPB | ./glr-regr1]], 0,
+AT_PARSER_CHECK([[./glr-regr1 BPBPB]], 0,
[[E -> 'B'
E -> 'B'
E -> E 'P' E
AT_CLEANUP
-## ------------------------------------------------------------ ##
-## Improper handling of embedded actions and $-N in GLR parsers ##
-## ------------------------------------------------------------ ##
+## -------------------------------------------------------------- ##
+## Improper handling of embedded actions and $-N in GLR parsers. ##
+## -------------------------------------------------------------- ##
AT_SETUP([Improper handling of embedded actions and dollar(-N) in GLR parsers])
int
main (int argc, char **argv)
{
+ int res;
input = stdin;
- if (argc == 2 && !(input = fopen (argv[1], "r"))) return 3;
- return yyparse ();
+ if (argc == 2 && !(input = fopen (argv[1], "r")))
+ return 3;
+ res = yyparse ();
+ if (argc == 2 && fclose (input))
+ return 4;
+ return res;
}
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr2a.c glr-regr2a.y]], 0, [],
-[glr-regr2a.y: conflicts: 2 shift/reduce
-])
+[[glr-regr2a.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
+]])
AT_COMPILE([glr-regr2a])
-AT_PARSER_CHECK([[echo s VARIABLE_1 t v x q | ./glr-regr2a]], 0,
+AT_DATA([input1.txt],
+[[s VARIABLE_1 t v x q
+]])
+AT_PARSER_CHECK([[./glr-regr2a input1.txt]], 0,
[[Variable: 'VARIABLE_1'
-]], [])
-AT_PARSER_CHECK([[echo s VARIABLE_1 , ANOTHER_VARIABLE_2 t e | ./glr-regr2a]],
+]])
+
+AT_DATA([input2.txt],
+[[s VARIABLE_1 , ANOTHER_VARIABLE_2 t e
+]])
+AT_PARSER_CHECK([[./glr-regr2a input2.txt]],
0,
[[Varlist: 'VARIABLE_1,ANOTHER_VARIABLE_2'
]])
-AT_PARSER_CHECK([[echo s VARIABLE_3 t v x | ./glr-regr2a]], 0,
+
+AT_DATA([input3.txt],
+[[s VARIABLE_3 t v x
+]])
+AT_PARSER_CHECK([[./glr-regr2a input3.txt]], 0,
[[Variable: 'VARIABLE_3'
-]], [])
+]])
AT_CLEANUP
-## ------------------------------------------------------------ ##
-## Improper merging of GLR delayed action sets ##
-## ------------------------------------------------------------ ##
+## --------------------------------------------- ##
+## Improper merging of GLR delayed action sets. ##
+## --------------------------------------------- ##
AT_SETUP([Improper merging of GLR delayed action sets])
}
int
-main(int argc, char* argv[])
+main (int argc, char* argv[])
{
+ int res;
input = stdin;
- if (argc == 2 && !(input = fopen (argv[1], "r"))) return 3;
- return yyparse ();
+ if (argc == 2 && !(input = fopen (argv[1], "r")))
+ return 3;
+ res = yyparse ();
+ if (argc == 2 && fclose (input))
+ return 4;
+ return res;
}
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr3.c glr-regr3.y]], 0, [],
-[glr-regr3.y: conflicts: 1 shift/reduce, 1 reduce/reduce
-])
+[[glr-regr3.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
+glr-regr3.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr3])
-AT_PARSER_CHECK([[echo p1 t4 o2 p1 p1 t1 o1 t2 p2 o1 t3 p2 p2 | ./glr-regr3]],
+AT_DATA([input.txt],
+[[p1 t4 o2 p1 p1 t1 o1 t2 p2 o1 t3 p2 p2
+]])
+AT_PARSER_CHECK([[./glr-regr3 input.txt]],
0,
[[Result: 1c04
-]], [])
+]])
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Duplicate representation of merged trees. See ##
-## <http://lists.gnu.org/archive/html/help-bison/2005-07/msg00013.html>. ##
-## ------------------------------------------------------------------------- ##
+## ---------------------------------------------------------------------- ##
+## Duplicate representation of merged trees. See ##
+## <http://lists.gnu.org/archive/html/help-bison/2005-07/msg00013.html>. ##
+## ---------------------------------------------------------------------- ##
AT_SETUP([Duplicate representation of merged trees])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr4.c glr-regr4.y]], 0, [],
-[glr-regr4.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr4.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr4])
AT_PARSER_CHECK([[./glr-regr4]], 0,
AT_CLEANUP
-## -------------------------------------------------------------------------- ##
-## User destructor for unresolved GLR semantic value. See ##
-## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00016.html>. ##
-## -------------------------------------------------------------------------- ##
+## ------------------------------------------------------------------------- ##
+## User destructor for unresolved GLR semantic value. See ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00016.html>. ##
+## ------------------------------------------------------------------------- ##
AT_SETUP([User destructor for unresolved GLR semantic value])
%%
]AT_YYLEX_DEFINE(["a"])[
]AT_YYERROR_DEFINE[
-int
-main (void)
-{
- return yyparse () != 1;
-}
+]AT_MAIN_DEFINE[
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr5.c glr-regr5.y]], 0, [],
-[glr-regr5.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr5.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr5])
-AT_PARSER_CHECK([[./glr-regr5]], 0, [],
+AT_PARSER_CHECK([[./glr-regr5]], 1, [],
[syntax is ambiguous
])
AT_CLEANUP
-## -------------------------------------------------------------------------- ##
-## User destructor after an error during a split parse. See ##
-## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00029.html>. ##
-## -------------------------------------------------------------------------- ##
+## ------------------------------------------------------------------------- ##
+## User destructor after an error during a split parse. See ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00029.html>. ##
+## ------------------------------------------------------------------------- ##
AT_SETUP([User destructor after an error during a split parse])
%%
]AT_YYERROR_DEFINE[
]AT_YYLEX_DEFINE(["a"])[
-int
-main (void)
-{
- return yyparse () != 1;
-}
+]AT_MAIN_DEFINE[
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr6.c glr-regr6.y]], 0, [],
-[glr-regr6.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr6.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr6])
-AT_PARSER_CHECK([[./glr-regr6]], 0,
+AT_PARSER_CHECK([[./glr-regr6]], 1,
[Destructor called.
],
[syntax is ambiguous
## ------------------------------------------------------------------------- ##
-## Duplicated user destructor for lookahead. See ##
+## Duplicated user destructor for lookahead. See ##
## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00035.html>. ##
## ------------------------------------------------------------------------- ##
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr7.c glr-regr7.y]], 0, [],
-[glr-regr7.y: conflicts: 2 reduce/reduce
-])
+[[glr-regr7.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr7])
AT_PARSER_CHECK([[./glr-regr7]], 2, [],
## ------------------------------------------------------------------------- ##
## Incorrect default location for empty right-hand sides. Adapted from bug ##
-## report by Claudia Hermann. ##
+## report by Claudia Hermann. ##
## See http://lists.gnu.org/archive/html/bug-bison/2005-10/msg00069.html and ##
## http://lists.gnu.org/archive/html/bug-bison/2005-10/msg00072.html ##
## ------------------------------------------------------------------------- ##
%%
-PortClause : T_PORT InterfaceDeclaration T_PORT
- { printf("%d/%d - %d/%d - %d/%d\n",
- @1.first_column, @1.last_column,
- @2.first_column, @2.last_column,
- @3.first_column, @3.last_column); }
- ;
+PortClause : T_PORT InterfaceDeclaration T_PORT
+ { printf("%d/%d - %d/%d - %d/%d\n",
+ @1.first_column, @1.last_column,
+ @2.first_column, @2.last_column,
+ @3.first_column, @3.last_column); }
+ ;
-InterfaceDeclaration : OptConstantWord %dprec 1
- | OptSignalWord %dprec 2
- ;
+InterfaceDeclaration : OptConstantWord %dprec 1
+ | OptSignalWord %dprec 2
+ ;
-OptConstantWord : /* empty */
- | T_CONSTANT
- ;
+OptConstantWord : /* empty */
+ | T_CONSTANT
+ ;
-OptSignalWord : /* empty */
- { printf("empty: %d/%d\n", @$.first_column, @$.last_column); }
- | T_SIGNAL
- ;
+OptSignalWord : /* empty */
+ { printf("empty: %d/%d\n", @$.first_column, @$.last_column); }
+ | T_SIGNAL
+ ;
%%
}
}
-int
-main (void)
-{
- yyparse();
- return 0;
-}
+]AT_MAIN_DEFINE[
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr8.c glr-regr8.y]], 0, [],
-[glr-regr8.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr8.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr8])
AT_PARSER_CHECK([[./glr-regr8]], 0,
## ------------------------------------------------------------------------- ##
-## No users destructors if stack 0 deleted. See ##
+## No users destructors if stack 0 deleted. See ##
## <http://lists.gnu.org/archive/html/bison-patches/2005-09/msg00109.html>. ##
## ------------------------------------------------------------------------- ##
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr9.c glr-regr9.y]], 0, [],
-[glr-regr9.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr9.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr9])
AT_PARSER_CHECK([[./glr-regr9]], 0, [],
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Corrupted semantic options if user action cuts parse. ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------------ ##
+## Corrupted semantic options if user action cuts parse. ##
+## ------------------------------------------------------ ##
AT_SETUP([Corrupted semantic options if user action cuts parse])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr10.c glr-regr10.y]], 0, [],
-[glr-regr10.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr10.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr10])
AT_PARSER_CHECK([[./glr-regr10]], 0, [], [])
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Undesirable destructors if user action cuts parse. ##
-## ------------------------------------------------------------------------- ##
+## --------------------------------------------------- ##
+## Undesirable destructors if user action cuts parse. ##
+## --------------------------------------------------- ##
AT_SETUP([Undesirable destructors if user action cuts parse])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr11.c glr-regr11.y]], 0, [],
-[glr-regr11.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr11.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr11])
AT_PARSER_CHECK([[./glr-regr11]], 0, [], [])
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Leaked semantic values if user action cuts parse. ##
-## ------------------------------------------------------------------------- ##
+## -------------------------------------------------- ##
+## Leaked semantic values if user action cuts parse. ##
+## -------------------------------------------------- ##
AT_SETUP([Leaked semantic values if user action cuts parse])
int exit_status = yyparse ();
if (parent_rhs_before_value)
{
- fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+ fprintf (stderr, "'parent_rhs_before' destructor not called.\n");
exit_status = 1;
}
if (merged_value)
{
- fprintf (stderr, "`merged' destructor not called.\n");
+ fprintf (stderr, "'merged' destructor not called.\n");
exit_status = 1;
}
if (parent_rhs_after_value)
{
- fprintf (stderr, "`PARENT_RHS_AFTER' destructor not called.\n");
+ fprintf (stderr, "'PARENT_RHS_AFTER' destructor not called.\n");
exit_status = 1;
}
return exit_status;
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr12.c glr-regr12.y]], 0, [],
-[glr-regr12.y: conflicts: 1 shift/reduce, 1 reduce/reduce
-])
+[[glr-regr12.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
+glr-regr12.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr12])
AT_PARSER_CHECK([[./glr-regr12]], 0, [], [])
## ------------------------------------------------------------------------- ##
-## Incorrect lookahead during deterministic GLR. See ##
+## Incorrect lookahead during deterministic GLR. See ##
## <http://lists.gnu.org/archive/html/help-bison/2005-07/msg00017.html> and ##
## <http://lists.gnu.org/archive/html/bison-patches/2006-01/msg00060.html>. ##
## ------------------------------------------------------------------------- ##
{
printf ("'%c', yylval='", yychar);
if (yylval.value > ' ')
- printf ("%c", yylval.value);
+ printf ("%c", yylval.value);
printf ("', yylloc=(%d,%d),(%d,%d)",
- yylloc.first_line, yylloc.first_column,
- yylloc.last_line, yylloc.last_column);
+ yylloc.first_line, yylloc.first_column,
+ yylloc.last_line, yylloc.last_column);
}
printf ("\n");
}
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Incorrect lookahead during nondeterministic GLR. ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------- ##
+## Incorrect lookahead during nondeterministic GLR. ##
+## ------------------------------------------------- ##
AT_SETUP([Incorrect lookahead during nondeterministic GLR])
| conflict defstate_look 'a' nonconflict2 'b' defstate_shift %dprec 2 {
USE ($3); USE ($5);
print_lookahead ("merge <- conflict defstate_look 'a' nonconflict2 'b'"
- " defstate_shift");
+ " defstate_shift");
}
;
USE ($1);
if (yychar != 'd' && yychar != YYEOF)
{
- fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
+ fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
}
}
;
USE ($1);
if (yychar != 'd' && yychar != YYEOF)
{
- fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
+ fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
}
}
;
USE ($1);
if (yychar != 'd' && yychar != YYEOF)
{
- fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
+ fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
}
}
;
{
if (yychar != YYEMPTY)
{
- fprintf (stderr,
- "Found lookahead where shouldn't during stack explosion.\n");
+ fprintf (stderr,
+ "Found lookahead where shouldn't during stack explosion.\n");
}
}
;
{
printf ("'%c', yylval='", yychar);
if (yylval.value > ' ')
- printf ("%c", yylval.value);
+ printf ("%c", yylval.value);
printf ("', yylloc=(%d,%d),(%d,%d)",
- yylloc.first_line, yylloc.first_column,
- yylloc.last_line, yylloc.last_column);
+ yylloc.first_line, yylloc.first_column,
+ yylloc.last_line, yylloc.last_column);
}
printf ("\n");
}
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr14.c glr-regr14.y]], 0, [],
-[glr-regr14.y: conflicts: 3 reduce/reduce
-])
+[[glr-regr14.y: warning: 3 reduce/reduce conflicts [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr14])
AT_PARSER_CHECK([[./glr-regr14]], 0,
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Leaked semantic values when reporting ambiguity. ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------- ##
+## Leaked semantic values when reporting ambiguity. ##
+## ------------------------------------------------- ##
AT_SETUP([Leaked semantic values when reporting ambiguity])
int exit_status = yyparse () != 1;
if (parent_rhs_before_value)
{
- fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+ fprintf (stderr, "'parent_rhs_before' destructor not called.\n");
exit_status = 1;
}
return exit_status;
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr15.c glr-regr15.y]], 0, [],
-[glr-regr15.y: conflicts: 2 reduce/reduce
-])
+[[glr-regr15.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr15])
AT_PARSER_CHECK([[./glr-regr15]], 0, [],
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Leaked lookahead after nondeterministic parse syntax error. ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------------------ ##
+## Leaked lookahead after nondeterministic parse syntax error. ##
+## ------------------------------------------------------------ ##
AT_SETUP([Leaked lookahead after nondeterministic parse syntax error])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr16.c glr-regr16.y]], 0, [],
-[glr-regr16.y: conflicts: 1 reduce/reduce
-])
+[[glr-regr16.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr16])
AT_PARSER_CHECK([[./glr-regr16]], 0, [],
AT_CLEANUP
-## ------------------------------------------------------------------------- ##
-## Uninitialized location when reporting ambiguity. ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------- ##
+## Uninitialized location when reporting ambiguity. ##
+## ------------------------------------------------- ##
AT_SETUP([Uninitialized location when reporting ambiguity])
return input[toknum++];
}
-int
-main (void)
-{
- return yyparse () != 1;
-}
+]AT_MAIN_DEFINE[
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr17.c glr-regr17.y]], 0, [],
-[glr-regr17.y: conflicts: 3 reduce/reduce
-])
+[[glr-regr17.y: warning: 3 reduce/reduce conflicts [-Wconflicts-rr]
+]])
AT_COMPILE([glr-regr17])
-AT_PARSER_CHECK([[./glr-regr17]], 0, [],
+AT_PARSER_CHECK([[./glr-regr17]], 1, [],
[1.1-2.2: syntax is ambiguous
])
AT_CLEANUP
-## -------------------------------------------------------------##
-## Missed %merge type warnings when LHS type is declared later. ##
-## -------------------------------------------------------------##
+## ------------------------------------------------------------- ##
+## Missed %merge type warnings when LHS type is declared later. ##
+## ------------------------------------------------------------- ##
AT_SETUP([Missed %merge type warnings when LHS type is declared later])
%%
]AT_YYERROR_DEFINE[
]AT_YYLEX_DEFINE[
-int
-main (void)
-{
- return yyparse ();
-}
+]AT_MAIN_DEFINE[
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o glr-regr18.c glr-regr18.y]], 1, [],
-[glr-regr18.y:26.18-24: result type clash on merge function 'merge': <type2> != <type1>
-glr-regr18.y:25.18-24: previous declaration
-glr-regr18.y:27.13-19: result type clash on merge function 'merge': <type3> != <type2>
-glr-regr18.y:26.18-24: previous declaration
-])
+[[glr-regr18.y:28.18-24: error: result type clash on merge function 'merge': <type2> != <type1>
+glr-regr18.y:27.18-24: previous declaration
+glr-regr18.y:29.13-19: error: result type clash on merge function 'merge': <type3> != <type2>
+glr-regr18.y:28.18-24: previous declaration
+]])
AT_CLEANUP
AT_SETUP([Ambiguity reports])
-AT_BISON_OPTION_PUSHDEFS
+AT_BISON_OPTION_PUSHDEFS([%debug])
AT_DATA_GRAMMAR([input.y],
[[
%{
%%
]AT_YYLEX_DEFINE(["abc"])[
]AT_YYERROR_DEFINE[
-int
-main (void)
-{
- yydebug = 1;
- return !!yyparse ();
-}
+]AT_MAIN_DEFINE[
]])
AT_BISON_OPTION_POPDEFS
AT_BISON_CHECK([[-o input.c input.y]], 0, [],
-[input.y: conflicts: 1 reduce/reduce
-])
+[[input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
AT_COMPILE([input])
-AT_PARSER_CHECK([[./input]], 1, [],
+AT_PARSER_CHECK([[./input --debug]], 1, [],
[Starting parse
Entering state 0
Reading a token: Next token is token 'a' ()
Reading a token: Next token is token 'b' ()
Shifting token 'b' ()
Entering state 3
-Reducing stack 0 by rule 3 (line 25):
+Reducing stack 0 by rule 3 (line 27):
$1 = token 'b' ()
-> $$ = nterm b ()
Entering state 4
Reading a token: Next token is token 'c' ()
Shifting token 'c' ()
Entering state 6
-Reducing stack 0 by rule 4 (line 26):
+Reducing stack 0 by rule 4 (line 28):
-> $$ = nterm d ()
Entering state 7
Reading a token: Now at end of input.