# Checking GLR Parsing: Regression Tests -*- Autotest -*-
-# Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003, 2005, 2006 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
#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);
/* Reported by S. Eken */
%{
- #define YYSTYPE char const *
- #define yyfalse 0
- #define yytrue 1
+ #define YYSTYPE char *
#include <ctype.h>
#include <stdio.h>
's' var 't'
{ 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:
{ $$ = $1; }
| var ',' var_list
{
- char *s = (char *) malloc (strlen ($1) + 1 + strlen ($3) + 1);
- strcpy (s, $1);
+ char *s = (char *) realloc ($1, strlen ($1) + 1 + strlen ($3) + 1);
strcat (s, ",");
strcat (s, $3);
+ free ($3);
$$ = s;
}
;
%%
-FILE *yyin = NULL;
+FILE *input = NULL;
int
yylex (void)
{
char buf[50];
char *s;
- switch (fscanf (yyin, " %1[a-z,]", buf)) {
+ switch (fscanf (input, " %1[a-z,]", buf)) {
case 1:
return buf[0];
case EOF:
default:
break;
}
- if (fscanf (yyin, "%49s", buf) != 1)
- abort ();
+ if (fscanf (input, "%49s", buf) != 1)
+ return 0;
if (sizeof buf - 1 <= strlen (buf))
abort ();
s = (char *) malloc (strlen (buf) + 1);
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 ();
}
]])
fprintf(stderr,"error: %s\n",s);
}
-FILE *yyin = NULL;
+FILE *input = NULL;
int P[] = { P1, P2 };
int O[] = { O1, O2 };
int yylex (void)
{
char inp[3];
- if (fscanf (yyin, "%2s", inp) == EOF)
+ if (fscanf (input, "%2s", inp) == EOF)
return 0;
switch (inp[0])
{
}
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_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);
+%}
+
+%%
+
+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' { $$ = make_value ("B", "'a'"); } ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const *input = "a";
+ return *input++;
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+
+static char *
+make_value (char const *parent, char const *child)
+{
+ char const format[] = "%s <- %s";
+ char *value =
+ (char *) malloc (strlen (parent) + strlen (child) + sizeof format);
+ sprintf (value, format, parent, child);
+ return value;
+}
+
+static char *
+merge (YYSTYPE s1, YYSTYPE s2)
+{
+ char const format[] = "merge{ %s and %s }";
+ char *value =
+ (char *) malloc (strlen (s1.ptr) + strlen (s2.ptr) + sizeof format);
+ sprintf (value, format, s1.ptr, s2.ptr);
+ return value;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+]])
+
+AT_CHECK([[bison -o glr-regr4.c glr-regr4.y]], 0, [],
+[glr-regr4.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr4])
+
+AT_CHECK([[./glr-regr4]], 0,
+[[merge{ S <- merge{ A <- A1 <- 'a' and A <- A2 <- 'a' } and S <- B <- 'a' }
+]], [])
+
+AT_CLEANUP
+
+
+## -------------------------------------------------------------------------- ##
+## User destructor for unresolved GLR semantic value. See ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00016.html>. ##
+## -------------------------------------------------------------------------- ##
+
+AT_SETUP([User destructor for unresolved GLR semantic value])
+
+AT_DATA_GRAMMAR([glr-regr5.y],
+[[
+%{
+ #include <stdio.h>
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ enum { MAGIC_VALUE = -1057808125 }; /* originally chosen at random */
+%}
+
+%glr-parser
+%union { int value; }
+%type <value> start
+
+%destructor {
+ if ($$ != 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";
+ return *input++;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_CHECK([[bison -o glr-regr5.c glr-regr5.y]], 0, [],
+[glr-regr5.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr5])
+
+AT_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";
+ return *input++;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_CHECK([[bison -o glr-regr6.c glr-regr6.y]], 0, [],
+[glr-regr6.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr6])
+
+AT_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
+%}
+
+%glr-parser
+%union { int *count; }
+%type <count> 'a'
+
+%destructor {
+ if ((*$$)++)
+ 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.count = (int *) malloc (sizeof (int));
+ if (!yylval.count)
+ {
+ fprintf (stderr, "Test inconclusive.\n");
+ exit (EXIT_FAILURE);
+ }
+ *yylval.count = 0;
+ return 'a';
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_CHECK([[bison -o glr-regr7.c glr-regr7.y]], 0, [],
+[glr-regr7.y: conflicts: 2 reduce/reduce
+])
+AT_COMPILE([glr-regr7])
+
+AT_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(const char *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(const char *msg)
+{
+ fprintf (stderr, "error\n");
+}
+
+static int lexIndex;
+
+int yylex (void)
+{
+ lexIndex += 1;
+ switch (lexIndex)
+ {
+ 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;
+ default:
+ return 0;
+ }
+}
+
+int
+main (void)
+{
+ yyparse();
+ return 0;
+}
+]])
+
+AT_CHECK([[bison -o glr-regr8.c glr-regr8.y]], 0, [],
+[glr-regr8.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr8])
+
+AT_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_CHECK([[bison -o glr-regr9.c glr-regr9.y]], 0, [],
+[glr-regr9.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr9])
+
+AT_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 <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)
+{
+ return 0;
+}
+
+int
+main (void)
+{
+ int index;
+ for (index = 0; index < GARBAGE_SIZE; index+=1)
+ garbage[index] = 108;
+ return yyparse ();
+}
+]])
+
+AT_CHECK([[bison -t -o glr-regr10.c glr-regr10.y]], 0, [],
+[glr-regr10.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr10])
+
+AT_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";
+ return *input++;
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse ();
+ if (destructors != 1)
+ {
+ fprintf (stderr, "Destructor calls: %d\n", destructors);
+ return 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_CHECK([[bison -t -o glr-regr11.c glr-regr11.y]], 0, [],
+[glr-regr11.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr11])
+
+AT_CHECK([[./glr-regr11]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked merged semantic value if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked merged semantic value if user action cuts parse])
+
+AT_DATA_GRAMMAR([glr-regr12.y],
+[[
+%glr-parser
+%union { int dummy; }
+%type <dummy> start
+%destructor { has_value = 0; } start
+
+%{
+# include <stdlib.h>
+ static int merge (YYSTYPE, YYSTYPE);
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int has_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start:
+ %merge<merge> { has_value = 1; USE ($$); }
+ | %merge<merge> { USE ($$); 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)
+{
+ return 0;
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse ();
+ if (has_value)
+ {
+ fprintf (stderr, "Destructor not called.\n");
+ return 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_CHECK([[bison -t -o glr-regr12.c glr-regr12.y]], 0, [],
+[glr-regr12.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr12])
+
+AT_CHECK([[./glr-regr12]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Incorrect lookahead during deterministic GLR. See ##
+## <http://lists.gnu.org/archive/html/help-bison/2005-07/msg00017.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. */
+
+%{
+ #include <stdio.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static void print_look_ahead (char const *);
+ #define USE(value)
+%}
+
+%union { char value; }
+%type <value> 'a' 'b'
+%glr-parser
+%locations
+
+%%
+
+start:
+ defstate_init defstate_shift 'b' {
+ USE ($3);
+ print_look_ahead ("start <- defstate_init defstate_shift 'b'");
+ }
+ ;
+defstate_init:
+ {
+ print_look_ahead ("defstate_init <- empty string");
+ }
+ ;
+defstate_shift:
+ nondefstate defstate_look 'a' {
+ USE ($3);
+ print_look_ahead ("defstate_shift <- nondefstate defstate_look 'a'");
+ }
+ ;
+defstate_look:
+ {
+ print_look_ahead ("defstate_look <- empty string");
+ }
+ ;
+nondefstate:
+ {
+ print_look_ahead ("nondefstate <- empty string");
+ }
+ | 'b' {
+ USE ($1);
+ print_look_ahead ("nondefstate <- 'b'");
+ }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const *input = "ab";
+ static int index = 0;
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = index+1;
+ yylval.value = input[index] + 'A' - 'a';
+ return input[index++];
+}
+
+static void
+print_look_ahead (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_CHECK([[bison -t -o glr-regr13.c glr-regr13.y]], 0, [], [])
+AT_COMPILE([glr-regr13])
+
+AT_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 <stdio.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static void print_look_ahead (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_look_ahead ("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_look_ahead ("merge <- nonconflict1 'a' 'b' nonconflict2");
+ }
+ | conflict defstate_look 'a' nonconflict2 'b' defstate_shift %dprec 2 {
+ USE ($3); USE ($5);
+ print_look_ahead ("merge <- conflict defstate_look 'a' nonconflict2 'b'"
+ " defstate_shift");
+ }
+ ;
+
+nonconflict1:
+ {
+ print_look_ahead ("nonconflict1 <- empty string");
+ }
+ ;
+nonconflict2:
+ {
+ print_look_ahead ("nonconflict2 <- empty string");
+ }
+ | 'a' {
+ USE ($1);
+ print_look_ahead ("nonconflict2 <- 'a'");
+ }
+ ;
+conflict:
+ {
+ print_look_ahead ("conflict <- empty string");
+ }
+ ;
+defstate_look:
+ {
+ print_look_ahead ("defstate_look <- empty string");
+ }
+ ;
+
+/* yychar != YYEMPTY but lookahead need is yyfalse. */
+defstate_shift:
+ {
+ print_look_ahead ("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 int index = 0;
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = index+1;
+ yylval.value = input[index] + 'A' - 'a';
+ return input[index++];
+}
+
+static void
+print_look_ahead (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_CHECK([[bison -t -o glr-regr14.c glr-regr14.y]], 0, [],
+[glr-regr14.y: conflicts: 3 reduce/reduce
+])
+AT_COMPILE([glr-regr14])
+
+AT_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
projects / bison.git / blobdiff