* data/glr.c (yy_reduce_print): Change yyrhsVals to yyvsp to remove
compiler errors when using %debug.
Add declaration of yylow when locations in use to avoid compilation
error.
(yyglrReduce): Conditionalize message "Parse ... rejected by rule..."
on whether we are in split mode, for consistency with behavior of
non-GLR parsing.
* data/glr.c: Remove tests for __cplusplus related to definition of
YYSTACKEXPANDABLE.
* doc/bison.texinfo: Rewrite paragraph saying C++ stacks are not
expandable to instead indicate conditions that prevent their expansion
in C++. Reorganize section on GLR semantic values a bit. Remove
discussion of YYLLOC_DEFAULT. Mention restrictions to POD data.
These changes allow users to prefix an action with %? to indicate that it
is a semantic predicate---an expression that is evaluated immediately (not
deferred, even in GLR nondeterministic mode) and causes a syntax error if
false. In GLR parsers, this has the effect of killing one of a set of
split-off parses, just as would an ordinary syntax error.
Changelog:
* NEWS: Describe new semantic-predicate feature.
* data/c.m4 (b4_predicate_case): New definition.
* data/java.m4 (b4_predicate_case): New definition.
* data/glr.c (yyimmediate): Add definition.
(yydoAction): Remove comment, now obsolete.
Do YY_REDUCE_PRINT here.
(yyglrReduce): Alter comment to indicate that semantic values
need not be deferred.
Remove YY_REDUCE_PRINT from here; done in yydoAction.
(yyprocessOneStack): Pass immediate flag.
Delete stacks rejected by predicates in newly split-off parsers.
Change handling of yyerr so that only current stack gets deleted
when semantic predicate fails.
(yyfillin): Don't crash if a semantic value is unresolved (as may
happen in predicate rules).
Copy lr state as well in debugging mode.
Update comment on setting of yysval to include yyloc as well.
(yy_reduce_print): Add yynormal argument. Perform fillin properly.
Report unresolved RHS values.
(yyimmediate): New table.
* src/gram.h (struct rule): Add is_predicate field.
* src/output.c (user_actions_output): Use b4_predicate_case for
predicates.
(prepare_symbols): Output yyimmediate.
* src/scan-gram.l: Add %? token, SC_PREDICATE state.
* src/scan-code.l (code_props_rule_action_init): Add is_predicate
argument.
* src/scan-code.h (struct code_props): Add is_predicate field.
(code_props_rule_action_init): New interface.
* src/parse-gram.y (%?{...}): New token.
(rhs): Add %?{...} rule.
* src/parse-gram.c: Regenerate.
* src/parse-gram.h: Regenerate.
* src/reader.c (grammar_current_rule_action_append): Add
immediate argument.
(grammar_midrule_action): Use new interface for
code_props_rule_action_init.
(grammar_current_rule_action_append): Ditto.
(packgram): Transfer is_predicate value.
* src/reader.h (grammar_current_rule_action_append): New interface.
* doc/bison.texinfo: Document semantic predicates (%?).
* data/glr.c (yylhsNonterm, yyisDefaultedState,yyDefaultAction)
(yygetLRActions,yynewGLRStackItem,yyaddDeferredAction,yyinitStateSet)
(yyinitGLRStack,yyexpandGLRStack,yyupdateSplit,yymarkStackDeleted)
(yyundeleteLastStack,yyglrShift,yyglrShiftDefer,yydoAction,yyglrReduce)
(yyidenticalOptions,yymergeOptionSets,yyresolveStates,yyresolveAction)
(yyresolveLocations,yyresolveValue,yyreducePrint): Update parameter
names in comments and mention all parameters.
(struct yyGLRState): Fix description of yyposn field.
(yyresolveLocations): Correct comment so as not to imply action when
yyn1==0.
(yyresolveAction): Initialize default location properly for empty right-hand
sides.
(yydoAction): Ditto. Add comment explaining apparently dead code.
* tests/glr-regression.at
(Incorrectly initialized location for empty right-hand side in GLR): New test.
fix a small glitch in debugging output.
(yyprocessOneStack, yyrecoverSyntaxError, yyparse): Print newline
after YY_SYMBOL_PRINT where needed.
(struct yyGLRState): Add some comments.
(struct yySemanticOption): Add some comments.
(union yyGLRStackItem): Add comment.
(yymergeOptionSets): Correct this to properly perform the union,
avoiding infinite reported by Michael Rosien.
Update comment.
* tests/glr-regression.at: Add test for GLR merging error reported
by M. Rosien.
(declaration): Replace expected_conflicts with expected_sr_conflicts.
Add %expect-rr rule.
* src/scan-gram.l: Recognize %expect-rr.
* src/conflicts.h (expected_sr_conflicts): Rename from
expected_conflicts.
(expected_rr_conflicts): Declare.
* src/conflicts.c (expected_sr_conflicts): Rename from
expected_conflicts.
(expected_rr_conflicts): Define.
(conflicts_print): Check r/r conflicts against expected_rr_conflicts
for GLR parsers.
Use expected_sr_conflicts in place of expected_conflicts.
Warn if expected_rr_conflicts used in non-GLR parser.
* doc/bison.texinfo: Add documentation for %expect-rr.
(yyrecoverSyntaxError): Correct yyerrState logic. Correct comment.
Allow states with only a default reduction.
Fixes to avoid problem that $-N rules in GLR parsers can cause
buffer overruns, corrupting state.
* src/output.c (prepare_rules): Output max_left_semantic_context.
* src/reader.h (max_left_semantic_context): New
* src/scan-gram.l (max_left_semantic_context): Define.
(handle_action_dollar): Update max_left_semantic_context.
* data/glr.c (YYMAXLEFT): New.
(yydoAction): Increase yyrhsVals size.
(yyresolveAction): Ditto.
Fixes to problems with location handling in GLR parsers reported by
Frank Heckenbach (2003/06/05).
* data/glr.c (YYLTYPE): Make trivial if locations not used.
(YYRHSLOC): Add parentheses, make depend on whether locations used.
(YYLLOC_DEFAULT): Ditto.
(yyuserAction): Use YYLLOC_DEFAULT.
(yydoAction): Remove redundant code.
* tests/cxx-type.at: Exercise location information.
(yylex): Track locations.
(stmtMerge): Return value rather than printing.
tests/glr-regression.at: Add new regression test for the problems
reported by S. Eken with semantic values for embedded rules.
Update copyright notice.
tests/testsuite.at, tests/Makefile.am: Rename glr-regr1.at to
glr-regression.at.
handle negative $ indices or $ indices in embedded rules correctly.
See <http://mail.gnu.org/archive/html/bug-bison/2003-01/msg00076.html>.
(b4_rhs_value): Change to use YYFILL macro.
(b4_rhs_location): Ditto.
(yyfill): New function to copy from stack tree into array
incrementally.
(yyuserAction): Modify to allow incremental move of semantic values
to rhs array when in GLR mode.
Define YYFILL to use in user-defined actions to fill semantic array
as needed.
Remove dummy use of yystack, as there is now a guaranteed use.
(yydoAction): Modify to allow incremental move of semantic values
to rhs array when in GLR mode.
(yyresolveAction): Ditto.
(yyglrShiftDefer): Update comment.
(yyresolveStates): Use X == NULL for pointers, not !X.
(yyglrReduce): Ditto.
(yydoAction): Ditto
the skeleton file name, rather than relying on the -I directory,
to partially alleviate effects of having a skeleton file lying around
in the current directory.
type; it isn't always big enough, since it doesn't necessarily
include non-terminals.
(yytranslate): Expand definition of yy_token_number_type, so that
the latter can be removed.
(yy_token_number_type): Remove, only one use.
* data/bison.c++ (r1_): Parallel change to yyr1 in bison.simple---
don't use TokenNumberType as element type.
* tests/regression.at: Modify expected output to agree with change
to yyr1 and yytranslate.
Paul Hilfinger