# Checking GLR Parsing: Regression Tests -*- Autotest -*-
-# Copyright (C) 2002, 2003 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) 2002-2003, 2005-2007, 2009-2012 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., 59 Temple Place - Suite 330, Boston, MA
-# 02111-1307, USA.
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
AT_BANNER([[GLR Regression Tests]])
%{
#include <stdio.h>
+#include <stdlib.h>
#define YYSTYPE int
static YYSTYPE exprMerge (YYSTYPE x0, YYSTYPE x1);
int yylex (void);
-int yyerror (char const *msg);
+void yyerror (char const *msg);
%}
return yyparse ();
}
-int
+void
yyerror (char const *msg)
{
fprintf (stderr, "%s\n", msg);
- exit (4);
}
{
for (;;)
{
- int ch = getchar ();
+ int ch;
+ if (feof (stdin))
+ abort ();
+ ch = getchar ();
if (ch == EOF)
- return 0;
+ return 0;
else if (ch == 'B' || ch == 'P')
- return ch;
+ return ch;
}
}
]])
-AT_CHECK([[bison -o glr-regr1.c glr-regr1.y]], 0, [],
+AT_BISON_CHECK([[-o glr-regr1.c glr-regr1.y]], 0, [],
[glr-regr1.y: conflicts: 1 shift/reduce
])
AT_COMPILE([glr-regr1])
-AT_CHECK([[echo BPBPB | ./glr-regr1]], 0,
+AT_PARSER_CHECK([[echo BPBPB | ./glr-regr1]], 0,
[[E -> 'B'
E -> 'B'
E -> E 'P' E
## Improper handling of embedded actions and $-N in GLR parsers ##
## ------------------------------------------------------------ ##
-AT_SETUP([Improper handling of embedded actions and $-N in GLR parsers])
+AT_SETUP([Improper handling of embedded actions and dollar(-N) in GLR parsers])
AT_DATA_GRAMMAR([glr-regr2a.y],
[[/* Regression Test: Improper handling of embedded actions and $-N */
/* Reported by S. Eken */
%{
- #define YYSTYPE char const *
- #define yyfalse 0
- #define yytrue 1
+ #define YYSTYPE char *
#include <ctype.h>
#include <stdio.h>
+ #include <stdlib.h>
#include <string.h>
int yylex (void);
void yyerror (char const *);
command:
's' var 't'
- { printf ("Variable: '%s'\n", $2); }
+ { printf ("Variable: '%s'\n", $2); }
'v' 'x' 'q'
+ { free ($2); }
| 's' var_list 't' 'e'
- { printf ("Varlist: '%s'\n", $2); }
+ { printf ("Varlist: '%s'\n", $2); free ($2); }
| 's' var 't' var_printer 'x'
+ { free ($2); }
;
var:
{ $$ = $1; }
| var ',' var_list
{
- char buffer[50];
- strcpy (buffer, $1);
- strcat (buffer, ",");
- strcat (buffer, $3);
- $$ = strdup (buffer);
- }
+ char *s = (char *) realloc ($1, strlen ($1) + 1 + strlen ($3) + 1);
+ strcat (s, ",");
+ strcat (s, $3);
+ free ($3);
+ $$ = s;
+ }
;
var_printer: 'v'
%%
-FILE *yyin = NULL;
+FILE *input;
int
yylex (void)
-{
+{
char buf[50];
- switch (fscanf (yyin, " %1[a-z,]", buf)) {
+ char *s;
+ if (feof (stdin))
+ abort ();
+ switch (fscanf (input, " %1[a-z,]", buf)) {
case 1:
return buf[0];
case EOF:
default:
break;
}
- fscanf (yyin, "%s", buf);
- yylval = strdup (buf);
+ if (fscanf (input, "%49s", buf) != 1)
+ return 0;
+ if (sizeof buf - 1 <= strlen (buf))
+ abort ();
+ s = (char *) malloc (strlen (buf) + 1);
+ strcpy (s, buf);
+ yylval = s;
return 'V';
}
int
main (int argc, char **argv)
-{
- yyin = stdin;
- if (argc == 2 && !(yyin = fopen (argv[1], "r"))) return 1;
+{
+ input = stdin;
+ if (argc == 2 && !(input = fopen (argv[1], "r"))) return 3;
return yyparse ();
}
]])
-AT_CHECK([[bison -o glr-regr2a.c glr-regr2a.y]], 0, [],
+AT_BISON_CHECK([[-o glr-regr2a.c glr-regr2a.y]], 0, [],
[glr-regr2a.y: conflicts: 2 shift/reduce
])
AT_COMPILE([glr-regr2a])
-AT_CHECK([[echo s VARIABLE_1 t v x q | ./glr-regr2a]], 0,
+AT_PARSER_CHECK([[echo s VARIABLE_1 t v x q | ./glr-regr2a]], 0,
[[Variable: 'VARIABLE_1'
]], [])
-AT_CHECK([[echo s VARIABLE_1 , ANOTHER_VARIABLE_2 t e | ./glr-regr2a]], 0,
+AT_PARSER_CHECK([[echo s VARIABLE_1 , ANOTHER_VARIABLE_2 t e | ./glr-regr2a]],
+0,
[[Varlist: 'VARIABLE_1,ANOTHER_VARIABLE_2'
]])
-AT_CHECK([[echo s VARIABLE_3 t v x | ./glr-regr2a]], 0,
+AT_PARSER_CHECK([[echo s VARIABLE_3 t v x | ./glr-regr2a]], 0,
[[Variable: 'VARIABLE_3'
]], [])
+AT_CLEANUP
+
+## ------------------------------------------------------------ ##
+## Improper merging of GLR delayed action sets ##
+## ------------------------------------------------------------ ##
+
+AT_SETUP([Improper merging of GLR delayed action sets])
+
+AT_DATA_GRAMMAR([glr-regr3.y],
+[[/* Regression Test: Improper merging of GLR delayed action sets. */
+/* Reported by M. Rosien */
+
+%{
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+static int MergeRule (int x0, int x1);
+static void yyerror (char const * s);
+int yylex (void);
+
+#define RULE(x) (1 << (x))
+
+%}
+
+%glr-parser
+
+%token BAD_CHAR
+%token P1 P2 T1 T2 T3 T4 O1 O2
+
+%%
+
+S : P1 T4 O2 NT6 P2 { printf ("Result: %x\n", $4); }
+;
+
+NT1 : P1 T1 O1 T2 P2 { $$ = RULE(2); } %merge<MergeRule>
+;
+
+NT2 : NT1 { $$ = RULE(3); } %merge<MergeRule>
+ | P1 NT1 O1 T3 P2 { $$ = RULE(4); } %merge<MergeRule>
+;
+
+NT3 : T3 { $$ = RULE(5); } %merge<MergeRule>
+ | P1 NT1 O1 T3 P2 { $$ = RULE(6); } %merge<MergeRule>
+;
+
+NT4 : NT3 { $$ = RULE(7); } %merge<MergeRule>
+ | NT2 { $$ = RULE(8); } %merge<MergeRule>
+ | P1 NT2 O1 NT3 P2 { $$ = RULE(9); } %merge<MergeRule>
+;
+
+NT5 : NT4 { $$ = RULE(10); } %merge<MergeRule>
+;
+
+NT6 : P1 NT1 O1 T3 P2 { $$ = RULE(11) | $2; } %merge<MergeRule>
+ | NT5 { $$ = RULE(12) | $1; } %merge<MergeRule>
+;
+
+%%
+
+static int MergeRule (int x0, int x1) {
+ return x0 | x1;
+}
+
+static void yyerror(char const * s) {
+ fprintf(stderr,"error: %s\n",s);
+}
+
+FILE *input = NULL;
+
+int P[] = { P1, P2 };
+int O[] = { O1, O2 };
+int T[] = { T1, T2, T3, T4 };
+
+int yylex (void)
+{
+ char inp[3];
+ if (feof (stdin))
+ abort ();
+ if (fscanf (input, "%2s", inp) == EOF)
+ return 0;
+ switch (inp[0])
+ {
+ case 'p': return P[inp[1] - '1'];
+ case 't': return T[inp[1] - '1'];
+ case 'o': return O[inp[1] - '1'];
+ }
+ return BAD_CHAR;
+}
+
+int main(int argc, char* argv[]) {
+ input = stdin;
+ if (argc == 2 && !(input = fopen (argv[1], "r"))) return 3;
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr3.c glr-regr3.y]], 0, [],
+[glr-regr3.y: conflicts: 1 shift/reduce, 1 reduce/reduce
+])
+AT_COMPILE([glr-regr3])
+
+AT_PARSER_CHECK([[echo p1 t4 o2 p1 p1 t1 o1 t2 p2 o1 t3 p2 p2 | ./glr-regr3]],
+0,
+[[Result: 1c04
+]], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## 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_DATA_GRAMMAR([glr-regr4.y],
+[[
+%union { char *ptr; }
+%type <ptr> S A A1 A2 B
+%glr-parser
+
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <string.h>
+ static char *merge (YYSTYPE, YYSTYPE);
+ static char *make_value (char const *, char const *);
+ static void yyerror (char const *);
+ static int yylex (void);
+ static char *ptrs[100];
+ static char **ptrs_next = ptrs;
+%}
+
+%%
+
+tree: S { printf ("%s\n", $1); } ;
+
+S:
+ A %merge<merge> { $$ = make_value ("S", $1); }
+ | B %merge<merge> { $$ = make_value ("S", $1); }
+ ;
+
+A:
+ A1 %merge<merge> { $$ = make_value ("A", $1); }
+ | A2 %merge<merge> { $$ = make_value ("A", $1); }
+ ;
+
+A1: 'a' { $$ = make_value ("A1", "'a'"); } ;
+A2: 'a' { $$ = make_value ("A2", "'a'"); } ;
+B: 'a' { $$ = make_value ("B", "'a'"); } ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "a";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ int status = yyparse ();
+ while (ptrs_next != ptrs)
+ free (*--ptrs_next);
+ return status;
+}
+
+static char *
+make_value (char const *parent, char const *child)
+{
+ char const format[] = "%s <- %s";
+ char *value = *ptrs_next++ =
+ (char *) malloc (strlen (parent) + strlen (child) + sizeof format);
+ sprintf (value, format, parent, child);
+ return value;
+}
+
+static char *
+merge (YYSTYPE s1, YYSTYPE s2)
+{
+ char const format[] = "merge{ %s and %s }";
+ char *value = *ptrs_next++ =
+ (char *) malloc (strlen (s1.ptr) + strlen (s2.ptr) + sizeof format);
+ sprintf (value, format, s1.ptr, s2.ptr);
+ return value;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr4.c glr-regr4.y]], 0, [],
+[glr-regr4.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr4])
+
+AT_PARSER_CHECK([[./glr-regr4]], 0,
+[[merge{ S <- merge{ A <- A1 <- 'a' and A <- A2 <- 'a' } and S <- B <- 'a' }
+]], [])
+
+AT_CLEANUP
+
+
+## -------------------------------------------------------------------------- ##
+## User destructor for unresolved GLR semantic value. See ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00016.html>. ##
+## -------------------------------------------------------------------------- ##
+
+AT_SETUP([User destructor for unresolved GLR semantic value])
+
+AT_DATA_GRAMMAR([glr-regr5.y],
+[[
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ enum { MAGIC_VALUE = -1057808125 }; /* originally chosen at random */
+%}
+
+%glr-parser
+%union { int value; }
+%type <value> start
+
+%destructor {
+ if ($$ != MAGIC_VALUE)
+ {
+ fprintf (stderr, "Bad destructor call.\n");
+ exit (EXIT_FAILURE);
+ }
+} start
+
+%%
+
+start:
+ 'a' { $$ = MAGIC_VALUE; }
+ | 'a' { $$ = MAGIC_VALUE; }
+ ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "a";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr5.c glr-regr5.y]], 0, [],
+[glr-regr5.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr5])
+
+AT_PARSER_CHECK([[./glr-regr5]], 0, [],
+[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>. ##
+## -------------------------------------------------------------------------- ##
+
+AT_SETUP([User destructor after an error during a split parse])
+
+AT_DATA_GRAMMAR([glr-regr6.y],
+[[
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+%}
+
+%glr-parser
+%union { int value; }
+%type <value> 'a'
+
+%destructor {
+ printf ("Destructor called.\n");
+} 'a'
+
+%%
+
+start: 'a' | 'a' ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "a";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr6.c glr-regr6.y]], 0, [],
+[glr-regr6.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr6])
+
+AT_PARSER_CHECK([[./glr-regr6]], 0,
+[Destructor called.
+],
+[syntax is ambiguous
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Duplicated user destructor for lookahead. See ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00035.html>. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Duplicated user destructor for lookahead])
+
+AT_DATA_GRAMMAR([glr-regr7.y],
+[[
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ #define YYSTACKEXPANDABLE 0
+ typedef struct count_node {
+ int count;
+ struct count_node *prev;
+ } count_node;
+ static count_node *tail;
+%}
+
+%glr-parser
+%union { count_node *node; }
+%type <node> 'a'
+
+%destructor {
+ if ($$->count++)
+ fprintf (stderr, "Destructor called on same value twice.\n");
+} 'a'
+
+%%
+
+start:
+ stack1 start
+ | stack2 start
+ | /* empty */
+ ;
+stack1: 'a' ;
+stack2: 'a' ;
+
+%%
+
+static int
+yylex (void)
+{
+ yylval.node = (count_node*) malloc (sizeof *yylval.node);
+ if (!yylval.node)
+ {
+ fprintf (stderr, "Test inconclusive.\n");
+ exit (EXIT_FAILURE);
+ }
+ yylval.node->count = 0;
+ yylval.node->prev = tail;
+ tail = yylval.node;
+ return 'a';
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ int status = yyparse ();
+ while (tail)
+ {
+ count_node *prev = tail->prev;
+ free (tail);
+ tail = prev;
+ }
+ return status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr7.c glr-regr7.y]], 0, [],
+[glr-regr7.y: conflicts: 2 reduce/reduce
+])
+AT_COMPILE([glr-regr7])
+
+AT_PARSER_CHECK([[./glr-regr7]], 2, [],
+[memory exhausted
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Incorrect default location for empty right-hand sides. Adapted from bug ##
+## 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 ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Incorrectly initialized location for empty right-hand side in GLR])
+
+AT_DATA_GRAMMAR([glr-regr8.y],
+[[
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static void yyerror (char const *msg);
+%}
+
+%token T_CONSTANT
+%token T_PORT
+%token T_SIGNAL
+
+%glr-parser
+
+%%
+
+
+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
+ ;
+
+OptConstantWord : /* empty */
+ | T_CONSTANT
+ ;
+
+OptSignalWord : /* empty */
+ { printf("empty: %d/%d\n", @$.first_column, @$.last_column); }
+ | T_SIGNAL
+ ;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int lexIndex;
+
+int yylex (void)
+{
+ lexIndex += 1;
+ switch (lexIndex)
+ {
+ default:
+ abort ();
+ case 1:
+ yylloc.first_column = 1;
+ yylloc.last_column = 9;
+ return T_PORT;
+ case 2:
+ yylloc.first_column = 13;
+ yylloc.last_column = 17;
+ return T_PORT;
+ case 3:
+ return 0;
+ }
+}
+
+int
+main (void)
+{
+ yyparse();
+ return 0;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr8.c glr-regr8.y]], 0, [],
+[glr-regr8.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr8])
+
+AT_PARSER_CHECK([[./glr-regr8]], 0,
+[empty: 9/9
+1/9 - 9/9 - 13/17
+],
+[])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## No users destructors if stack 0 deleted. See ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-09/msg00109.html>. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([No users destructors if stack 0 deleted])
+
+AT_DATA_GRAMMAR([glr-regr9.y],
+[[
+%{
+# include <stdio.h>
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+# define YYSTACKEXPANDABLE 0
+ static int tokens = 0;
+ static int destructors = 0;
+# define USE(Var)
+%}
+
+%glr-parser
+%union { int dummy; }
+%type <dummy> 'a'
+
+%destructor {
+ destructors += 1;
+} 'a'
+
+%%
+
+start:
+ ambig0 'a' { destructors += 2; USE ($2); }
+ | ambig1 start { destructors += 1; }
+ | ambig2 start { destructors += 1; }
+ ;
+
+ambig0: 'a' ;
+ambig1: 'a' ;
+ambig2: 'a' ;
+
+%%
+
+static int
+yylex (void)
+{
+ tokens += 1;
+ return 'a';
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ int exit_status;
+ exit_status = yyparse ();
+ if (tokens != destructors)
+ {
+ fprintf (stderr, "Tokens = %d, Destructors = %d\n", tokens, destructors);
+ return 1;
+ }
+ return !exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr9.c glr-regr9.y]], 0, [],
+[glr-regr9.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr9])
+
+AT_PARSER_CHECK([[./glr-regr9]], 0, [],
+[memory exhausted
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Corrupted semantic options if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Corrupted semantic options if user action cuts parse])
+
+AT_DATA_GRAMMAR([glr-regr10.y],
+[[
+%{
+# include <stdlib.h>
+# include <stdio.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ #define GARBAGE_SIZE 50
+ static char garbage[GARBAGE_SIZE];
+%}
+
+%glr-parser
+%union { char *ptr; }
+%type <ptr> start
+
+%%
+
+start:
+ %dprec 2 { $$ = garbage; YYACCEPT; }
+ | %dprec 1 { $$ = garbage; YYACCEPT; }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static int called;
+ if (called++)
+ abort ();
+ return 0;
+}
+
+int
+main (void)
+{
+ int i;
+ for (i = 0; i < GARBAGE_SIZE; i+=1)
+ garbage[i] = 108;
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr10.c glr-regr10.y]], 0, [],
+[glr-regr10.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr10])
+
+AT_PARSER_CHECK([[./glr-regr10]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Undesirable destructors if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Undesirable destructors if user action cuts parse])
+
+AT_DATA_GRAMMAR([glr-regr11.y],
+[[
+%{
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int destructors = 0;
+# define USE(val)
+%}
+
+%glr-parser
+%union { int dummy; }
+%type <int> 'a'
+%destructor { destructors += 1; } 'a'
+
+%%
+
+start:
+ 'a' %dprec 2 { USE ($1); destructors += 1; YYACCEPT; }
+ | 'a' %dprec 1 { USE ($1); destructors += 1; YYACCEPT; }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const input[] = "a";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse ();
+ if (destructors != 1)
+ {
+ fprintf (stderr, "Destructor calls: %d\n", destructors);
+ return 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr11.c glr-regr11.y]], 0, [],
+[glr-regr11.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr11])
+
+AT_PARSER_CHECK([[./glr-regr11]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked semantic values if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked semantic values if user action cuts parse])
+
+AT_DATA_GRAMMAR([glr-regr12.y],
+[[
+%glr-parser
+%union { int dummy; }
+%token PARENT_RHS_AFTER
+%type <dummy> parent_rhs_before merged PARENT_RHS_AFTER
+%destructor { parent_rhs_before_value = 0; } parent_rhs_before
+%destructor { merged_value = 0; } merged
+%destructor { parent_rhs_after_value = 0; } PARENT_RHS_AFTER
+
+%{
+# include <stdlib.h>
+ static int merge (YYSTYPE, YYSTYPE);
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int parent_rhs_before_value = 0;
+ static int merged_value = 0;
+ static int parent_rhs_after_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start:
+ alt1 %dprec 1
+ | alt2 %dprec 2
+ ;
+
+alt1:
+ PARENT_RHS_AFTER {
+ USE ($1);
+ parent_rhs_after_value = 0;
+ }
+ ;
+
+alt2:
+ parent_rhs_before merged PARENT_RHS_AFTER {
+ USE (($1, $2, $3));
+ parent_rhs_before_value = 0;
+ merged_value = 0;
+ parent_rhs_after_value = 0;
+ }
+ ;
+
+parent_rhs_before:
+ {
+ USE ($$);
+ parent_rhs_before_value = 1;
+ }
+ ;
+
+merged:
+ %merge<merge> {
+ USE ($$);
+ merged_value = 1;
+ }
+ | cut %merge<merge> {
+ USE ($$);
+ merged_value = 1;
+ }
+ ;
+
+cut: { YYACCEPT; } ;
+
+%%
+
+static int
+merge (YYSTYPE s1, YYSTYPE s2)
+{
+ /* Not invoked. */
+ char dummy = s1.dummy + s2.dummy;
+ return dummy;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static int const input[] = { PARENT_RHS_AFTER, 0 };
+ static size_t toknum;
+ if (! (toknum < sizeof input / sizeof *input))
+ abort ();
+ if (input[toknum] == PARENT_RHS_AFTER)
+ parent_rhs_after_value = 1;
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse ();
+ if (parent_rhs_before_value)
+ {
+ fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+ exit_status = 1;
+ }
+ if (merged_value)
+ {
+ fprintf (stderr, "`merged' destructor not called.\n");
+ exit_status = 1;
+ }
+ if (parent_rhs_after_value)
+ {
+ fprintf (stderr, "`PARENT_RHS_AFTER' destructor not called.\n");
+ exit_status = 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr12.c glr-regr12.y]], 0, [],
+[glr-regr12.y: conflicts: 1 shift/reduce, 1 reduce/reduce
+])
+AT_COMPILE([glr-regr12])
+
+AT_PARSER_CHECK([[./glr-regr12]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## 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>. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Incorrect lookahead during deterministic GLR])
+
+AT_DATA_GRAMMAR([glr-regr13.y],
+[[
+/* Tests:
+ - Defaulted state with initial yychar: yychar == YYEMPTY.
+ - Nondefaulted state: yychar != YYEMPTY.
+ - Defaulted state after lookahead: yychar != YYEMPTY.
+ - Defaulted state after shift: yychar == YYEMPTY.
+ - User action changing the lookahead. */
+
+%{
+ #include <stdio.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static void print_lookahead (char const *);
+ #define USE(value)
+%}
+
+%union { char value; }
+%type <value> 'a' 'b'
+%glr-parser
+%locations
+
+%%
+
+start:
+ defstate_init defstate_shift 'b' change_lookahead 'a' {
+ USE ($3);
+ print_lookahead ("start <- defstate_init defstate_shift 'b'");
+ }
+ ;
+defstate_init:
+ {
+ print_lookahead ("defstate_init <- empty string");
+ }
+ ;
+defstate_shift:
+ nondefstate defstate_look 'a' {
+ USE ($3);
+ print_lookahead ("defstate_shift <- nondefstate defstate_look 'a'");
+ }
+ ;
+defstate_look:
+ {
+ print_lookahead ("defstate_look <- empty string");
+ }
+ ;
+nondefstate:
+ {
+ print_lookahead ("nondefstate <- empty string");
+ }
+ | 'b' {
+ USE ($1);
+ print_lookahead ("nondefstate <- 'b'");
+ }
+ ;
+change_lookahead:
+ {
+ yychar = 'a';
+ }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const input[] = "ab";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = toknum + 1;
+ yylval.value = input[toknum] + 'A' - 'a';
+ return input[toknum++];
+}
+
+static void
+print_lookahead (char const *reduction)
+{
+ printf ("%s:\n yychar=", reduction);
+ if (yychar == YYEMPTY)
+ printf ("YYEMPTY");
+ else if (yychar == YYEOF)
+ printf ("YYEOF");
+ else
+ {
+ printf ("'%c', yylval='", yychar);
+ if (yylval.value > ' ')
+ printf ("%c", yylval.value);
+ printf ("', yylloc=(%d,%d),(%d,%d)",
+ yylloc.first_line, yylloc.first_column,
+ yylloc.last_line, yylloc.last_column);
+ }
+ printf ("\n");
+}
+
+int
+main (void)
+{
+ yychar = '#'; /* Not a token in the grammar. */
+ yylval.value = '!';
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr13.c glr-regr13.y]], 0, [], [])
+AT_COMPILE([glr-regr13])
+
+AT_PARSER_CHECK([[./glr-regr13]], 0,
+[defstate_init <- empty string:
+ yychar=YYEMPTY
+nondefstate <- empty string:
+ yychar='a', yylval='A', yylloc=(1,1),(1,1)
+defstate_look <- empty string:
+ yychar='a', yylval='A', yylloc=(1,1),(1,1)
+defstate_shift <- nondefstate defstate_look 'a':
+ yychar=YYEMPTY
+start <- defstate_init defstate_shift 'b':
+ yychar=YYEMPTY
+], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Incorrect lookahead during nondeterministic GLR. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Incorrect lookahead during nondeterministic GLR])
+
+AT_DATA_GRAMMAR([glr-regr14.y],
+[[
+/* Tests:
+ - Conflicting actions (split-off parse, which copies lookahead need,
+ which is necessarily yytrue) and nonconflicting actions (non-split-off
+ parse) for nondefaulted state: yychar != YYEMPTY.
+ - Merged deferred actions (lookahead need and RHS from different stack
+ than the target state) and nonmerged deferred actions (same stack).
+ - Defaulted state after lookahead: yychar != YYEMPTY.
+ - Defaulted state after shift: yychar == YYEMPTY.
+ - yychar != YYEMPTY but lookahead need is yyfalse (a previous stack has
+ seen the lookahead but current stack has not).
+ - Exceeding stack capacity (stack explosion), and thus reallocating
+ lookahead need array.
+ Note that it does not seem possible to see the initial yychar value during
+ nondeterministic operation since:
+ - In order to preserve the initial yychar, only defaulted states may be
+ entered.
+ - If only defaulted states are entered, there are no conflicts, so
+ nondeterministic operation does not start. */
+
+%union { char value; }
+
+%{
+ #include <stdlib.h>
+ #include <stdio.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static void print_lookahead (char const *);
+ static char merge (union YYSTYPE, union YYSTYPE);
+ #define USE(value)
+%}
+
+%type <value> 'a' 'b' 'c' 'd' stack_explosion
+%glr-parser
+%locations
+
+%%
+
+start:
+ merge 'c' stack_explosion {
+ USE ($2); USE ($3);
+ print_lookahead ("start <- merge 'c' stack_explosion");
+ }
+ ;
+
+/* When merging the 2 deferred actions, the lookahead needs are different. */
+merge:
+ nonconflict1 'a' 'b' nonconflict2 %dprec 1 {
+ USE ($2); USE ($3);
+ print_lookahead ("merge <- nonconflict1 'a' 'b' nonconflict2");
+ }
+ | 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");
+ }
+ ;
+
+nonconflict1:
+ {
+ print_lookahead ("nonconflict1 <- empty string");
+ }
+ ;
+nonconflict2:
+ {
+ print_lookahead ("nonconflict2 <- empty string");
+ }
+ | 'a' {
+ USE ($1);
+ print_lookahead ("nonconflict2 <- 'a'");
+ }
+ ;
+conflict:
+ {
+ print_lookahead ("conflict <- empty string");
+ }
+ ;
+defstate_look:
+ {
+ print_lookahead ("defstate_look <- empty string");
+ }
+ ;
+
+/* yychar != YYEMPTY but lookahead need is yyfalse. */
+defstate_shift:
+ {
+ print_lookahead ("defstate_shift <- empty string");
+ }
+ ;
+
+stack_explosion:
+ { $$ = '\0'; }
+ | alt1 stack_explosion %merge<merge> { $$ = $2; }
+ | alt2 stack_explosion %merge<merge> { $$ = $2; }
+ | alt3 stack_explosion %merge<merge> { $$ = $2; }
+ ;
+alt1:
+ 'd' no_look {
+ USE ($1);
+ if (yychar != 'd' && yychar != YYEOF)
+ {
+ fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
+ }
+ }
+ ;
+alt2:
+ 'd' no_look {
+ USE ($1);
+ if (yychar != 'd' && yychar != YYEOF)
+ {
+ fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
+ }
+ }
+ ;
+alt3:
+ 'd' no_look {
+ USE ($1);
+ if (yychar != 'd' && yychar != YYEOF)
+ {
+ fprintf (stderr, "Incorrect lookahead during stack explosion.\n");
+ }
+ }
+ ;
+no_look:
+ {
+ if (yychar != YYEMPTY)
+ {
+ fprintf (stderr,
+ "Found lookahead where shouldn't during stack explosion.\n");
+ }
+ }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const input[] = "abcdddd";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = toknum + 1;
+ yylval.value = input[toknum] + 'A' - 'a';
+ return input[toknum++];
+}
+
+static void
+print_lookahead (char const *reduction)
+{
+ printf ("%s:\n yychar=", reduction);
+ if (yychar == YYEMPTY)
+ printf ("YYEMPTY");
+ else if (yychar == YYEOF)
+ printf ("YYEOF");
+ else
+ {
+ printf ("'%c', yylval='", yychar);
+ if (yylval.value > ' ')
+ printf ("%c", yylval.value);
+ printf ("', yylloc=(%d,%d),(%d,%d)",
+ yylloc.first_line, yylloc.first_column,
+ yylloc.last_line, yylloc.last_column);
+ }
+ printf ("\n");
+}
+
+static char
+merge (union YYSTYPE s1, union YYSTYPE s2)
+{
+ char dummy = s1.value + s2.value;
+ return dummy;
+}
+
+int
+main (void)
+{
+ yychar = '#'; /* Not a token in the grammar. */
+ yylval.value = '!';
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr14.c glr-regr14.y]], 0, [],
+[glr-regr14.y: conflicts: 3 reduce/reduce
+])
+AT_COMPILE([glr-regr14])
+
+AT_PARSER_CHECK([[./glr-regr14]], 0,
+[conflict <- empty string:
+ yychar='a', yylval='A', yylloc=(1,1),(1,1)
+defstate_look <- empty string:
+ yychar='a', yylval='A', yylloc=(1,1),(1,1)
+nonconflict2 <- empty string:
+ yychar='b', yylval='B', yylloc=(1,2),(1,2)
+defstate_shift <- empty string:
+ yychar=YYEMPTY
+merge <- conflict defstate_look 'a' nonconflict2 'b' defstate_shift:
+ yychar=YYEMPTY
+start <- merge 'c' stack_explosion:
+ yychar=YYEOF
+], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked semantic values when reporting ambiguity. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked semantic values when reporting ambiguity])
+
+AT_DATA_GRAMMAR([glr-regr15.y],
+[[
+%glr-parser
+%destructor { parent_rhs_before_value = 0; } parent_rhs_before
+
+%{
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int parent_rhs_before_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start:
+ alt1 %dprec 1
+ | alt2 %dprec 2
+ ;
+
+/* This stack must be merged into the other stacks *last* (added at the
+ beginning of the semantic options list) so that yyparse will choose to clean
+ it up rather than the tree for which some semantic actions have been
+ performed. Thus, if yyreportAmbiguity longjmp's to yyparse, the values from
+ those other trees are not cleaned up. */
+alt1: ;
+
+alt2:
+ parent_rhs_before ambiguity {
+ USE ($1);
+ parent_rhs_before_value = 0;
+ }
+ ;
+
+parent_rhs_before:
+ {
+ USE ($$);
+ parent_rhs_before_value = 1;
+ }
+ ;
+
+ambiguity: ambiguity1 | ambiguity2 ;
+ambiguity1: ;
+ambiguity2: ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static int called;
+ if (called++)
+ abort ();
+ return 0;
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse () != 1;
+ if (parent_rhs_before_value)
+ {
+ fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+ exit_status = 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr15.c glr-regr15.y]], 0, [],
+[glr-regr15.y: conflicts: 2 reduce/reduce
+])
+AT_COMPILE([glr-regr15])
+
+AT_PARSER_CHECK([[./glr-regr15]], 0, [],
+[syntax is ambiguous
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked lookahead after nondeterministic parse syntax error. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked lookahead after nondeterministic parse syntax error])
+AT_DATA_GRAMMAR([glr-regr16.y],
+[[
+%glr-parser
+%destructor { lookahead_value = 0; } 'b'
+
+%{
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int lookahead_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start: alt1 'a' | alt2 'a' ;
+alt1: ;
+alt2: ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const input[] = "ab";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ if (input[toknum] == 'b')
+ lookahead_value = 1;
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse () != 1;
+ if (lookahead_value)
+ {
+ fprintf (stderr, "Lookahead destructor not called.\n");
+ exit_status = 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr16.c glr-regr16.y]], 0, [],
+[glr-regr16.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr16])
+
+AT_PARSER_CHECK([[./glr-regr16]], 0, [],
+[syntax error
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Uninitialized location when reporting ambiguity. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Uninitialized location when reporting ambiguity])
+AT_DATA_GRAMMAR([glr-regr17.y],
+[[
+%glr-parser
+%locations
+%define api.pure
+%error-verbose
+
+%union { int dummy; }
+
+%{
+ static void yyerror (YYLTYPE *, char const *);
+ static int yylex (YYSTYPE *, YYLTYPE *);
+%}
+
+%initial-action {
+ @$.first_line = 1;
+ @$.first_column = 1;
+ @$.last_line = 1;
+ @$.last_column = 1;
+}
+
+%%
+
+/* Tests the case of an empty RHS that has inherited the location of the
+ previous nonterminal, which is unresolved. That location is reported as the
+ last position of the ambiguity. */
+start: ambig1 empty1 | ambig2 empty2 ;
+
+/* Tests multiple levels of yyresolveLocations recursion. */
+ambig1: sub_ambig1 | sub_ambig2 ;
+ambig2: sub_ambig1 | sub_ambig2 ;
+
+/* Tests the case of a non-empty RHS as well as the case of an empty RHS that
+ has inherited the initial location. The empty RHS's location is reported as
+ the first position in the ambiguity. */
+sub_ambig1: empty1 'a' 'b' ;
+sub_ambig2: empty2 'a' 'b' ;
+empty1: ;
+empty2: ;
+
+%%
+
+static void
+yyerror (YYLTYPE *locp, char const *msg)
+{
+ fprintf (stderr, "%d.%d-%d.%d: %s.\n", locp->first_line,
+ locp->first_column, locp->last_line, locp->last_column, msg);
+}
+
+static int
+yylex (YYSTYPE *lvalp, YYLTYPE *llocp)
+{
+ static char const input[] = "ab";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ lvalp->dummy = 0;
+ llocp->first_line = llocp->last_line = 2;
+ llocp->first_column = toknum + 1;
+ llocp->last_column = llocp->first_column + 1;
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr17.c glr-regr17.y]], 0, [],
+[glr-regr17.y: conflicts: 3 reduce/reduce
+])
+AT_COMPILE([glr-regr17])
+
+AT_PARSER_CHECK([[./glr-regr17]], 0, [],
+[1.1-2.3: syntax is ambiguous.
+])
+
+AT_CLEANUP
+
+
+## -------------------------------------------------------------##
+## Missed %merge type warnings when LHS type is declared later. ##
+## -------------------------------------------------------------##
+
+AT_SETUP([Missed %merge type warnings when LHS type is declared later])
+AT_DATA_GRAMMAR([glr-regr18.y],
+[[%glr-parser
+
+%{
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex ();
+%}
+
+%union {
+ int type1;
+ int type2;
+ int type3;
+}
+
+%%
+
+sym1: sym2 %merge<merge> { $$ = $1; } ;
+sym2: sym3 %merge<merge> { $$ = $1; } ;
+sym3: %merge<merge> { $$ = 0; } ;
+
+%type <type1> sym1;
+%type <type2> sym2;
+%type <type3> sym3;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex ()
+{
+ static int called;
+ if (called++)
+ abort ();
+ return 0;
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+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
+])
+
+AT_CLEANUP
+
+
+## ------------------- ##
+## Ambiguity reports. ##
+## ------------------- ##
+
+AT_SETUP([Ambiguity reports])
+
+AT_DATA_GRAMMAR([input.y],
+[[
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+%}
+
+%debug
+%glr-parser
+
+%%
+start:
+ 'a' b 'c' d
+| 'a' b 'c' d
+;
+b: 'b';
+d: /* nada. */;
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "abc";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return !!yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o input.c input.y]], 0, [],
+[input.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([input])
+
+AT_PARSER_CHECK([[./input]], 1, [],
+[Starting parse
+Entering state 0
+Reading a token: Next token is token 'a' ()
+Shifting token 'a' ()
+Entering state 1
+Reading a token: Next token is token 'b' ()
+Shifting token 'b' ()
+Entering state 3
+Reducing stack 0 by rule 3 (line 25):
+ $1 = token 'b' ()
+-> $$ = nterm b ()
+Entering state 4
+Reading a token: Next token is token 'c' ()
+Shifting token 'c' ()
+Entering state 6
+Reducing stack 0 by rule 4 (line 26):
+-> $$ = nterm d ()
+Entering state 7
+Reading a token: Now at end of input.
+Stack 0 Entering state 7
+Now at end of input.
+Splitting off stack 1 from 0.
+Reduced stack 1 by rule #2; action deferred. Now in state 2.
+Stack 1 Entering state 2
+Now at end of input.
+Reduced stack 0 by rule #1; action deferred. Now in state 2.
+Merging stack 0 into stack 1.
+Stack 1 Entering state 2
+Now at end of input.
+Removing dead stacks.
+Rename stack 1 -> 0.
+On stack 0, shifting token $end ()
+Stack 0 now in state #5
+Ambiguity detected.
+Option 1,
+ start -> <Rule 1, tokens 1 .. 3>
+ 'a' <tokens 1 .. 1>
+ b <tokens 2 .. 2>
+ 'c' <tokens 3 .. 3>
+ d <empty>
+
+Option 2,
+ start -> <Rule 2, tokens 1 .. 3>
+ 'a' <tokens 1 .. 1>
+ b <tokens 2 .. 2>
+ 'c' <tokens 3 .. 3>
+ d <empty>
+
+syntax is ambiguous
+Cleanup: popping token $end ()
+Cleanup: popping unresolved nterm start ()
+Cleanup: popping nterm d ()
+Cleanup: popping token 'c' ()
+Cleanup: popping nterm b ()
+Cleanup: popping token 'a' ()
+])
+
AT_CLEANUP
projects / bison.git / blobdiff