+
+
+## ------------------------------------------------------------------------- ##
+## 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_look_ahead (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_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'");
+ }
+ ;
+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 int i = 0;
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = i + 1;
+ yylval.value = input[i] + 'A' - 'a';
+ return input[i++];
+}
+
+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 -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 i = 0;
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = i + 1;
+ yylval.value = input[i] + 'A' - 'a';
+ return input[i++];
+}
+
+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 -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
+
+
+## ------------------------------------------------------------------------- ##
+## 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)
+{
+ 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_CHECK([[bison -o glr-regr15.c glr-regr15.y]], 0, [],
+[glr-regr15.y: conflicts: 2 reduce/reduce
+])
+AT_COMPILE([glr-regr15])
+
+AT_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";
+ if (*input == 'b')
+ lookahead_value = 1;
+ return *input++;
+}
+
+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_CHECK([[bison -o glr-regr16.c glr-regr16.y]], 0, [],
+[glr-regr16.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr16])
+
+AT_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
+%pure-parser
+%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, "Error at %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 char const *inputp = input;
+ lvalp->dummy = 0;
+ llocp->first_line = llocp->last_line = 2;
+ llocp->first_column = inputp - input + 1;
+ llocp->last_column = llocp->first_column + 1;
+ return *inputp++;
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_CHECK([[bison -o glr-regr17.c glr-regr17.y]], 0, [],
+[glr-regr17.y: conflicts: 3 reduce/reduce
+])
+AT_COMPILE([glr-regr17])
+
+AT_CHECK([[./glr-regr17]], 0, [],
+[Error at 1.1-2.3: syntax is ambiguous.
+])
+
+AT_CLEANUP
projects / bison.git / blobdiff