There are warnings (-Wextra) in generated C++ code:
ltlparse.cc: In member function 'ltlyy::parser::symbol_number_type
ltlyy::parser::by_state::type_get() const':
ltlparse.cc:452:33: warning: enumeral and non-enumeral type in
conditional expression
return state == empty_state ? empty_symbol : yystos_[state];
Reported by Alexandre Duret-Lutz.
It turns out that -Wall and -Wextra were disabled because of a stupid
typo.
* configure.ac: Fix the stupid typo.
* data/lalr1.cc, src/AnnotationList.c, src/InadequacyList.c,
* src/ielr.c, src/print.c, src/scan-code.l, src/symlist.c,
* src/symlist.h, src/symtab.c, src/tables.c, tests/actions.at,
* tests/calc.at, tests/cxx-type.at, tests/glr-regression.at,
* tests/named-refs.at, tests/torture.at:
Fix warnings, mostly issues about variables used only with assertions,
which are disabled with -DNDEBUG.
A static analysis tool reports that some callers of symbol_list_n_get
might get NULL and not handle it properly. This is not the case, yet
we can suppress this pattern.
Reported by Mike Sullivan.
<https://lists.gnu.org/archive/html/bug-bison/2013-12/msg00027.html>
* src/symlist.c (symbol_list_n_get): Actually it is never called
to return 0. Enforce this postcondition via aver.
(symbol_list_n_type_name_get): Simplify accordingly. In particular,
discards a (translated) useless error message.
* src/symlist.h: Adjust documentation.
* src/scan-code.l: Style change.
When reporting a duplicate directive on a rule, point to its first
occurrence:
one.y:11.10-15: error: only one %empty allowed per rule
%empty {} %empty
^^^^^^
one.y:11.3-8: previous declaration
%empty {} %empty
^^^^^^
And consistently discard the second one.
* src/complain.h, src/complain.c (duplicate_directive): New.
* src/reader.c: Use it where appropriate.
* src/symlist.h, src/symlist.c (symbol_list): Add a dprec_location member.
* tests/actions.at: Adjust expected output.
Provide a means to explicitly denote empty right-hand sides of rules:
instead of
exp: { ... }
allow
exp: %empty { ... }
Make sure that %empty is properly used.
With help from Joel E. Denny and Gabriel Rassoul.
http://lists.gnu.org/archive/html/bison-patches/2013-01/msg00142.html
* src/reader.h, src/reader.c (grammar_current_rule_empty_set): New.
* src/parse-gram.y (%empty): New token.
Use it.
* src/scan-gram.l (%empty): Scan it.
* src/reader.c (grammar_rule_check): Check that %empty is properly used.
* tests/actions.at (Invalid uses of %empty, Valid uses of %empty): New.
* src/complain.c: Space changes.
* src/reader.c: Comment changes.
Avoid && in assertions.
* src/location.c: Move comments to...
* src/location.h: here.
* src/symlist.h, src/symlist.c: Create a pseudo section for members
that apply to the rule.
In a declaration %token A B, the token A is declared before B, but in %left
A B (or with %precedence or %nonassoc or %right), the token B was declared
before A (tokens were declared in reverse order).
* src/symlist.h, src/symlist.c (symbol_list_append): New.
* src/parse-gram.y: Use it instead of symbol_list_prepend.
* tests/input.at: Adjust expectations.
* origin/maint: (29 commits)
regen
synclines: remove spurious empty line
also support $<foo>$ in the %initial-action
skeletons: b4_dollar_pushdef and popdef to simpify complex definitions
regen
printer/destructor: translate only once
factor the handling of m4 escaping
news: schedule the removal of the ";" hack
style changes in the scanners
regen
support $<tag>$ in printers and destructors
scan-code: factor the handling of the type in $<TYPE>$
muscles: fix another occurrence of unescaped type name
glr.cc: fix the handling of yydebug
gnulib: update
formatting changes
tests: fix an assertion
tests: adjust to GCC 4.8, which displays caret errors
be sure to properly escape type names
obstack_quote: escape and quote for M4
muscles: shuffle responsabilities
muscles: make private functions static
muscles: rename private functions/macros
obstack_escape: escape M4 characters
remove dead macro
maint: style changes
doc: avoid problems with case insensitive file systems
configure: fix botched quoting
news: fix typo.
Conflicts:
NEWS
data/c.m4
data/glr.cc
data/lalr1.cc
examples/rpcalc/local.mk
src/muscle-tab.h
src/output.c
src/parse-gram.c
src/parse-gram.h
src/parse-gram.y
src/scan-code.l
src/symlist.c
src/symlist.h
src/symtab.h
tests/calc.at
Currently "%printer {...} a b c d e f" translates the {...} six times.
Not only is this bad for time and space, it also issues six times the
same warnings.
* src/symlist.h, src/symlist.c (symbol_list_destructor_set)
(symbol_list_printer_set): Take the action as code_props instead of
const char *.
* src/parse-gram.y: Translate these actions here.
* src/scan-code.h: Comment change.
* tests/input.at: Check that warnings are issued only once.
Currently they are treated in separated variables, contrary to other
<TYPE> code_props. This duplicates code (and messages for translators)
uselessly, as demonstrated by the fact that thanks to this patch, now
useless <*> and <> code_props are reported like the others.
* src/parse-gram.y (generic_symlist_item): Treat "<*>" and "<>" as regular
type tags.
* src/symlist.h, src/symlist.c (symbol_list_default_tagged_new)
(symbol_list_default_tagless_new,SYMLIST_DEFAULT_TAGGED)
(SYMLIST_DEFAULT_TAGLESS): Remove.
* src/symtab.h, src/symtab.c (default_tagged_code_props)
(default_tagless_code_props, default_tagged_code_props_set)
(default_tagless_code_props_set): Remove.
(symbol_code_props_get): Default to <*> or <>'s code_props.
* tests/actions.at: Complete expected errors: there are new warnings.
* tests/input.at: Likewise.
(Useless printers or destructors): Extend.
* src/symtab.h (symbol_list): Represent semantic types as structure
'semantic_type'.
* src/symlist.c (symbol_list_type_new): Allocate this structure.
(symbol_list_code_props_set): Set this semantic type's status to used if it
was not declared.
* src/symtab.c (semantic_types_sorted): New.
(semantic_type_new): Set the new semantic type's location appropriately.
(symbol_check_defined): If a symbol has a type, then set this type's status
to "declared".
(semantic_type_check_defined, semantic_type_check_defined_processor): Same
as symbol_check_defined and symbol_check_defined_processor, but for semantic
types.
(symbol_check_defined): Check semantic types usefulness.
* src/symtab.h (semantic_type): New fields 'location' and 'status'.
* src/symtab.h, src/symtab.c (semantic_type_new)
(semantic_type_from_uniqstr, semantic_type_get): Accept a location as a
supplementary argument.
* tests/input.at (Unassociated types used for printer of destructor): New.
* tests/c++.at (AT_CHECK_VARIANTS): Fix an error caught by this commit.
There is too much code duplication between %printer and %destructor.
We used to have two functions for each action: the first one for
destructors, the second one for printers. Factor using a
'code_props_type', and an array of code_props instead of two
members.
* src/symlist.h, src/symlist.c (symbol_list_destructor_set)
(symbol_list_printer_set): Fuse into...
(symbol_list_code_props_set): this.
* src/symtab.h, src/symtab.c (default_tagged_destructor)
(default_tagged_printer): Fuse into...
(default_tagged_code_props): this.
(default_tagless_destructor, default_tagless_printer)
(default_tagless_code_props): Likewise.
(code_props_type_string): new.
(symbol_destructor_set, symbol_destructor_get, semantic_type_destructor_set)
(default_tagged_destructor_set, default_tagless_destructor_set)
(symbol_printer_set, symbol_printer_get, semantic_type_printer_set)
(default_tagged_printer_set, default_tagless_printer_set): Replace by...
(symbol_code_props_set, symbol_code_props_get, semantic_type_code_props_set)
(default_tagged_code_props_set, default_tagless_code_props_set): these.
* src/parse-gram.y (grammar_declaration): Adjust.
* src/output.c (CODE_PROP, grammar_declaration): Ditto.
* src/reader.c (symbol_should_be_used): Ditto.
* doc/bison.texinfo (Mid-Rule Actions): Mention that periods and
dashes make symbol names less convenient for named references.
* src/scan-code.l:
(handle_action_dollar): New arg textlen. All callers changed.
(handle_action_at): Likewise. Also, args are pointers to const.
(ref_tail_fields): Remove; no longer used.
(letter): Now includes '-' and '.', since this is for Bison
identifiers.
(id): Now the simpler traditional defn, since letters now include
'-' and '.'.
(c_letter, c_id): New defns.
(ref): Use c_id for unbracketed IDs.
(<SC_RULE_ACTION>): Simplify, now that the distinction between
Bison and unbracketed IDs are now in the regular expressions.
(VARIANT_BAD_BRACKETING): Remove.
(VARIANT_NOT_VISIBLE_FROM_MIDRULE): Renumber.
(find_prefix_end): Remove, replacing with ....
(identifier_matches): New function.
(variant_add): Use it. Omit EXPLICIT_BRACKETING arg; no longer
needed. CP arg is pointer to constant. All callers changed.
(show_sub_messages): Remove args CP, EXPLICIT_BRACKETING, DOLLAR_OR_AT.
New arg TEXT. All callers changed. Do not worry about showing
trailing context.
(parse_ref): Args CP, RULE, TEXT are now pointers to const. New
arg TEXTLEN. Remove arg DOLLAR_OR_AT. All callers changed.
Simplify code now that the regular expressions capture the
restrictions.
* src/scan-gram.l (letter, id): Adjust to match scan-code.l.
* src/symlist.c (symbol_list_null): Arg is now pointer to const.
* src/symlist.h: Likewise.
* tests/named-refs.at (Misleading references): These are now caught
by the C compiler, not by Bison; that's good enough. Adjust test
to reflect this.
(Many kinds of errors, Unresolved references): Adjust expected
diagnostics to match new behavior. The same errors are caught,
though the diagnostics are not quite as fancy.
($ or @ followed by . or -): Likewise. Also, Make the grammar
unambiguous, so that diagnostics are not complicated by ambiguity
warnings.
* src/named-ref.h: Add comments.
* src/parse-gram.y: Readability and style changes.
* src/reader.c: Factoring: assign_named_ref function.
* src/scan-code.l: Factoring and style changes. Rename
parse_named_ref to parse_ref. Use "c-ctype.h" from gnulib.
Use "unsigned" type for variant index. Improve readablity.
* src/scan-gram.l: Change error messages and add comments.
* src/symlist.h: symbol_list_null: New function decl.
* src/symlist.c: symbol_list_null: Implement here.
* tests/named-refs.at: Adjust for new error messages.
* src/named-ref.h: Add comments.
* src/parse-gram.y: Readability and style changes.
* src/reader.c: Factoring: assign_named_ref function.
* src/scan-code.l: Factoring and style changes. Rename
parse_named_ref to parse_ref. Use "c-ctype.h" from gnulib.
Use "unsigned" type for variant index. Improve readablity.
* src/scan-gram.l: Change error messages and add comments.
* src/symlist.h: symbol_list_null: New function decl.
* src/symlist.c: symbol_list_null: Implement here.
* tests/named-refs.at: Adjust for new error messages.
Discussed in:
http://lists.gnu.org/archive/html/bison-patches/2009-01/msg00000.htmlhttp://lists.gnu.org/archive/html/bison-patches/2009-02/msg00002.htmlhttp://lists.gnu.org/archive/html/bison-patches/2009-03/msg00009.html
* src/parse-gram.y: Add new syntax (named_ref.opt).
* src/reader.c: Store named refs in symbol lists.
* src/reader.h: New argument for symbol_append and
action_append functions.
* src/scan-code.h: Add new field (named_ref) into
code_props data structure. Keeps named ref of midrule
actions.
* src/scan-code.l: Support for named refs in semantic
action code. New function 'parse_named_ref'.
* src/scan-gram.l: Support bracketed id.
* src/symlist.c: Store named refs in symbol lists.
* src/symlist.h: New field in symbol list: named_ref.
* src/named-ref.h: New file, a struct for named_ref.
* src/named-ref.c: New file, named_ref_new function.
* src/Makefile.am: Add two new files.
* tests/testsuite.at: Include new test group:
* tests/named-refs.at: this new file.
Discussed in:
http://lists.gnu.org/archive/html/bison-patches/2009-01/msg00000.htmlhttp://lists.gnu.org/archive/html/bison-patches/2009-02/msg00002.htmlhttp://lists.gnu.org/archive/html/bison-patches/2009-03/msg00009.html
* src/parse-gram.y: Add new syntax (named_ref.opt).
* src/reader.c: Store named refs in symbol lists.
* src/reader.h: New argument for symbol_append and
action_append functions.
* src/scan-code.h: Add new field (named_ref) into
code_props data structure. Keeps named ref of midrule
actions.
* src/scan-code.l: Support for named refs in semantic
action code. New function 'parse_named_ref'.
* src/scan-gram.l: Support bracketed id.
* src/symlist.c: Store named refs in symbol lists.
* src/symlist.h: New field in symbol list: named_ref.
* src/named-ref.h: New file, a struct for named_ref.
* src/named-ref.cp: New file, named_ref_new function.
* src/local.mk: Add two new files.
* tests/testsuite.at: Include new test group:
* tests/named-refs.at: this new file.
* src/parse-gram.y (prologue_declaration, braceless, epilogue.opt):
Update all uses of translate_* functions to use the new code_props
interface and to use gram_scanner_last_string_free and
code_scanner_last_string_free where possible.
(grammar_declaration): symbol_list_destructor_set and
symbol_list_printer_set now perform the translation, so don't do it
here. Use gram_scanner_last_string_free where possible.
* src/scan-code.h, src/scan-code.l (translate_symbol_action,
translate_code): Remove, no longer used.
* src/symlist.h, src/symlist.c (symbol_list_destructor_set,
symbol_list_printer_set): Perform code translation here rather than
depending on the caller to do so.
* src/symlist.h (struct symbol_list): Correct some documentation typos.
* src/scan-gram.h (gram_last_string): Remove declaration.
* src/scan-gram.l (last_string): Declare it static.
destructors, printers, and actions into a code_props structure and
interface. This patch merely implements code_props in scan-code.h and
scan-code.l. Future patches will rewrite other modules to use it.
Discussed starting at
<http://lists.gnu.org/archive/html/bison-patches/2006-11/msg00020.html>.
* src/location.h (EMPTY_LOCATION_INIT): Define so that it's easier to
consistently initialize const structs that have an empty location
field.
* src/location.c (empty_location): Initialize with EMPTY_LOCATION_INIT
to ensure consistency.
* src/scan-code.h (code_props): New structure.
(code_props_none_init, CODE_PROPS_NONE_INIT, code_props_none): New
function, macro, and const global variable for initializing a
code_props with no code.
(code_props_plain_init, code_props_symbol_action_init,
code_props_rule_action_init, code_props_translate_code): The rest of
the new code_props functional interface. Among other things, the init
functions set the code_props kind field so that
code_props_translate_code will know whether to behave like
translate_symbol_action, translate_rule_action, or translate_code.
These old translate functions must remain until all other modules are
updated to use the new code_props interface.
(code_scanner_last_string_free): New function similar to
gram_scanner_last_string_free.
(code_scanner_free): Add documentation.
* src/scan-code.l: Implement the new interface.
(code_lex): Make it static, add a code_props* argument, and remove the
rule argument.
(last_string): New static global similar to the one in scan-gram.l.
(SC_RULE_ACTION): Update to use the code_props* argument to code_lex
instead of rule.
(SC_SYMBOL_ACTION): For $$, set the is_value_used member of the
code_props since Bison may one day use this information for destructors
and printers.
(<*><<EOF>>): Use STRING_FINISH so that last_string is set.
(handle_action_dollar): Use symbol_list_n_get and set used flag
directly since symbol_list_n_used_set is removed.
(translate_action): Add a code_props* argument and remove the rule,
action, and location arguments. Pass the code_props* on to code_lex.
(translate_rule_action, translate_symbol_action, translate_code):
Rewrite as wrappers around the new code_props interface.
* src/symlist.h, src/symlist.c (symbol_list_n_used_set): Remove since
it would eventually need to break the encapsulation of code_props.
destructors, printers, and actions into a code_props structure and
interface.
* src/location.h (EMPTY_LOCATION_INIT): Define so that it's easier to
consistently initialize const structs that have an empty location field.
* src/location.c (empty_location): Initialize with EMPTY_LOCATION_INIT
to ensure consistency.
* src/output.c (symbol_destructors_output, symbol_printers_output):
Replace with...
(symbol_code_props_output): ... this to eliminate duplicate code.
(output_skeleton): Update to use symbol_code_props_output.
* src/parse-gram.y (prologue_declaration, braceless, epilogue.opt):
Update all uses of translate_* functions to use the new code_props
interface and to use gram_scanner_last_string_free and
code_scanner_last_string_free where possible.
(grammar_declaration): symbol_list_destructor_set and
symbol_list_printer_set now perform the translation, so don't do it
here. Use gram_scanner_last_string_free where possible.
* src/reader.c: Update to use code_props interface for destructors and
rule actions.
* src/scan-code.h (code_props): New structure.
(code_props_none_init, CODE_PROPS_NONE_INIT, code_props_none): New
function, macro, and const global variable for initializing a
code_props with no code.
(code_props_plain_init, code_props_symbol_action_init,
code_props_rule_action_init, code_props_translate_code,
code_props_code_get, code_props_location_get,
code_props_is_value_used): The rest of the new code_props interface.
(translate_rule_action, translate_symbol_action, translate_code):
Remove as these are now just special cases within
code_props_translate_code, which is switched on the code_props kind.
(code_scanner_last_string_free): New function similar to
gram_scanner_last_string_free.
* src/scan-code.l: Implement the new interface.
(last_string): New static global similar to the one in scan-gram.l.
(SC_SYMBOL_ACTION): For $$, set the is_value_used member of the
code_props since Bison will one day use this information for
destructors and printers.
(<*><<EOF>>): Use STRING_FINISH so that last_string is set.
(handle_action_dollar): Update to use the code_props interface of rule
actions. Use symbol_list_n_get and set is_value_used directly since
symbol_list_n_used_set is removed.
* src/symlist.h, src/symlist.c (symbol_list): Replace action,
action_location, and used members with a code_props member, and update
all uses.
(symbol_list_n_used_set): Remove since it would need to break the
encapsulation of code_props.
(symbol_list_destructor_set, symbol_list_printer_set): Perform code
translation here rather than depending on the caller to do so.
* src/symtab.h (symbol, semantic_type): Remove destructor_location and
printer_location members and change the type of the destructor and
printer members to code_props.
(symbol_destructor_location_get, symbol_printer_location_get): Remove
unneeded.
(symbol_destructor_set, symbol_destructor_get, symbol_printer_set,
symbol_printer_get, semantic_type_destructor_set,
semantic_type_printer_set, default_tagged_destructor_set,
default_tagless_destructor_set, default_tagged_printer_set,
default_tagless_printer_set): Use code_props in arguments and return
types in place of const char * and location.
* src/symtab.c: Update implementation for interface and struct changes.
(default_tagged_destructor_location,
default_tagless_destructor_location, default_tagged_printer_location,
default_tagless_printer_location): Remove since we...
(default_tagged_destructor, default_tagless_destructor,
default_tagged_printer, default_tagless_printer): ... change the type
of these to code_props.
(SYMBOL_CODE_PRINT): New similar to SYMBOL_ATTR_PRINT but for
code_props members.
(symbol_print): Use SYMBOL_CODE_PRINT.
* src/scan-gram.h (gram_last_string): Remove declaration.
* src/scan-gram.l (last_string): Declare it static.
Discussed starting at
<http://lists.gnu.org/archive/html/bison-patches/2006-09/msg00060.html>.
* NEWS (2.3a+): Mention.
* doc/bison.texinfo (Freeing Discarded Symbols): Document this and the
previous change today related to mid-rules.
(Bison Symbols): Remove %symbol-default and add <*> and <!>.
* src/parser-gram.y (PERCENT_SYMBOL_DEFAULT): Remove.
(TYPE_TAG_ANY): Add as <*>.
(TYPE_TAG_NONE): Add as <!>.
(generic_symlist_item): Remove RHS for %symbol-default and add RHS's
for <*> and <!>.
* src/scan-gram.l (PERCENT_SYMBOL_DEFAULT): Remove.
(TYPE_TAG_ANY, TYPE_TAG_NONE): Add.
* src/symlist.c (symbol_list_default_new): Split into tagged and
tagless versions.
(symbol_list_destructor_set, symbol_list_printer_set): Split
SYMLIST_DEFAULT case into SYMLIST_DEFAULT_TAGGED and
SYMLIST_DEFAULT_TAGLESS.
* src/symlist.h: Update symbol_list_default*_new prototypes.
(symbol_list.content_type): Split enum value SYMLIST_DEFAULT into
SYMLIST_DEFAULT_TAGGED and SYMLIST_DEFAULT_TAGLESS.
* src/symtab.c (default_destructor, default_destructor_location,
default_printer, default_printer_location): Split each into tagged and
tagless versions.
(symbol_destructor_get, symbol_destructor_location_get,
symbol_printer_get, symbol_printer_location_get): Implement tagged
default and tagless default cases.
(default_destructor_set, default_printer_set): Split each into tagged
and tagless versions.
* src/symtab.h: Update prototypes.
* tests/actions.at (Default %printer and %destructor): Rename to...
(Default tagless %printer and %destructor): ... this, and extend.
(Per-type %printer and %destructor): Rename to...
(Default tagged and per-type %printer and %destructor): ... this, and
extend.
(Default %printer and %destructor for user-defined end token): Extend.
(Default %printer and %destructor are not for error or $undefined):
Update.
(Default %printer and %destructor are not for $accept): Update.
(Default %printer and %destructor for mid-rule values): Extend.
* tests/input.at (Default %printer and %destructor redeclared): Extend.
(Unused values with default %destructor): Extend.
%symbol-default instead of an empty symbol list, and start working on
new per-type %destructor/%printer. Discussed at
<http://lists.gnu.org/archive/html/bison-patches/2006-09/msg00007.html>.
* NEWS (2.3+): Add %symbol-default to example.
* bison.texinfo (Freeing Discarded Symbols): Likewise.
(Bison Symbols): Add entry for %symbol-default.
* src/parse-gram.y (PERCENT_SYMBOL_DEFAULT): New token.
(generic_symlist, generic_symlist_item): New nonterminals for creating
a list in which each item is a symbol, semantic type, or
%symbol-default.
(grammar_declaration): Use generic_symlist in %destructor and %printer
declarations instead of symbols.1 or an empty list.
(symbol_declaration, precedence_declaration, symbols.1): Update actions
for changes to symbol_list.
* src/reader.c: Update for changes to symbol_list.
* src/scan-code.l: Likewise.
* src/scan-gram.l: Scan new PERCENT_SYMBOL_DEFAULT token.
* src/symlist.c, src/symlist.h: Extend such that a list node may
represent a semantic type or a %symbol-default in addition to just an
ordinary symbol. Add switched functions for setting %destructor's and
%printer's.
* tests/actions.at, tests/input.at: Add %symbol-default to all default
%destructor/%printer declarations.
declared after the %merge.
* src/reader.c (get_merge_function): Don't set the merger type yet.
(record_merge_function_type): New function for setting the merger type
and checking for clashes.
(grammar_current_rule_merge_set): Set the location of the %merge for
the current rule.
(packgram): Invoke record_merge_function_type for each rule now that
all symbol type declarations have been parsed.
* src/reader.h (merger_list.type_declaration_location): New member
storing the location of the first %merge from which the type for this
merging function was derived.
* src/symlist.h (symbol_list.merger_declaration_location): New member
storing the location of a rule's %merge, if any.
* tests/glr-regression.at (Missed %merge type warnings when LHS type is
declared later): New test to catch the error fixed by the above patch.
declarations appear after the rules. Don't mistake the type of $$ in
a midrule to be that of its parent rule's $$.
* src/reader.c (grammar_current_rule_end): Don't invoke
grammar_rule_check yet since not all symbol declarations may have been
parsed yet.
(grammar_midrule_action): Likewise.
Don't record whether the midrule's $$ has been used yet since actions
haven't been translated yet.
Record the midrule's parent rule and its RHS index within the parent
rule.
(grammar_current_rule_action_append): Don't translate the action yet
since not all symbol declarations may have been parsed yet and, thus,
warnings about types for $$, $n, @$, and @n can't be reported yet.
(packgram): Translate the action and invoke grammar_rule_check now that
all symbol declarations have been parsed.
* src/scan-code.l (handle_action_dollar): Now that this is invoked
after parsing the entire grammar file, the symbol list here in the case
of a midrule is actually the midrule's empty RHS, so reference its
parent rule's RHS where necessary.
On the other hand, now that you can already know it's a midrule, you
aren't forced to think $$ has the same type as its parent rule's $$.
(handle_action_at): In the case of a midrule, reference the parent rule
where necessary.
* src/symlist.c (symbol_list_new): Initialize new midrule-related
members.
(symbol_list_length): Now that this is invoked after all rules have
been parsed, a NULL symbol (rather than a NULL symbol list node)
terminates a rule. symbol_list_print already does this correctly.
* src/symlist.h (symbol_list.midrule_parent_rule,
symbol_list.midrule_parent_rhs_index): New members so that midrules can
remember their relationships with their parents.
* tests/input.at (Type Clashes): Extend to catch the midrule $$ error
fixed by the above patch.
(_AT_UNUSED_VALUES_DECLARATIONS, AT_CHECK_UNUSED_VALUES): New m4 macros
implementing...
(Unused values): ... this old test case and...
(Unused values before symbol declarations): ... this new test case.
This one is the same as `Unused values' except that all symbol
declarations appear after the rules in order to catch the rest of the
errors fixed by the above patch.
* src/symlist.h, src/symlist.c (symbol_list): Add a mid_rule
member.
(symbol_list_new): Adjust.
* src/reader.c (symbol_typed_p): New.
(grammar_rule_check): Use it.
(grammar_midrule_action): Bind a mid-rule LHS to its rule.
Check its rule.
* tests/input.at (AT_CHECK_UNUSED_VALUES): New.
Use it.
* tests/actions.at (Exotic Dollars): Adjust.
