Instead of attaching lookaheads and duplicating the rules being
reduced by a state, attach the lookaheads to the reductions.
* src/state.h (state_t): Remove the `lookaheads',
`lookaheads_rule' member.
(reductions_t): Add a `lookaheads' member.
Use a regular array for the `rules'.
* src/state.c (reductions_new): Initialize the lookaheads member
to 0.
(state_rule_lookaheads_print): Adjust.
* src/state.h, src/state.c (state_reductions_find): New.
* src/conflicts.c (resolve_sr_conflict, set_conflicts)
(count_rr_conflicts): Adjust.
* src/lalr.c (LArule): Remove.
(add_lookback_edge): Adjust.
(state_lookaheads_count): New.
(states_lookaheads_initialize): Merge into...
(initialize_LA): this.
(lalr_free): Adjust.
* src/main.c (main): Don't free nullable and derives too early: it
is used by --verbose.
* src/print.c, src/print_graph.c, src/tables.c: Adjust.

* src/derives.h, src/derives.c (derives): A `rule_t***' instead of
`rule_number_t**'.
(set_derives, free_derives): Rename as...
(derives_compute, derives_free): this.
Adjust all dependencies.
* src/nullable.c (set_nullable, free_nullable): Rename as...
(nullable_compute, nullable_free): these.
(rule_list_t): Store rule_t *, not rule_number_t.
* src/state.c (state_rule_lookaheads_print): Directly compare rule
pointers, instead of their numbers.
* src/main.c (main): Call nullable_free, and derives_free earlier,
as they were lo longer used.

* lib/timevar.c (get_time): Include children time.
* src/lalr.h (LA, LArule): Don't export them: used with the
state_t.
* src/lalr.c (LA, LArule): Static.
* src/lalr.h, src/lalr.c (lalr_free): New.
* src/main.c (main): Call it.
* src/tables.c (pack_vector): Check whether loc is >= to the
table_size, not >.
(pack_tables): Don't free froms, tos, conflict_tos, and pos...
(tables_generate): do it, since that's also it which allocates
them.
Don't free LA and LArule, main does.

Separate parser tables computation and output.
* src/output.c (nvectors, base_t, base, base_ninf, conflict_table)
(conflict_list, conflict_list_cnt, table, check, table_ninf)
(yydefgoto, yydefact, high): Move to...
* src/tables.h, src/tables.c: here.
* src/output.c (vector_number_t, VECTOR_NUMBER_MAX)
(VECTOR_NUMBER_MIN, state_number_to_vector_number)
(symbol_number_to_vector_number, nvectors, BASE_MAX, BASE_MIN)
(froms, tos, conflict_tos, tally, width, action_t, ACTION_MAX)
(ACTION_MIN, actrow, order, nentries, pos, conflrow)
(conflict_list_free, table_size, lowzero, table_grow, conflict_row)
(action_row, save_row, token_actions, save_column, default_goto)
(goto_actions, sort_actions, matching_state, pack_vector)
(table_ninf_remap, pack_table, prepare_actions): Move to...
* src/tables.c: here.
* src/tables.h, src/tables.c(tables_generate, tables_free): New.
* src/output.c (token_actions, output_base, output_conflicts)
(output_check): Merge into...
(prepare_actions): this.
(actions_output): Rename as...
(user_actions_output): this.
* src/main.c (main): Call tables_generate and tables_free.

Steal GCC's --time-report support.
* lib/timevar.c, lib/timevar.h, lib/timevar.def: New,
stolen/adjusted from GCC.
* m4/stage.m4: Remove time related checks.
* m4/timevar.m4: New.
* configure.in: Adjust.
* src/system.h: Adjust to using timevar.h.
* src/getargs.h, src/getargs.c: Support trace_time for
--trace=time.
* src/main.c (stage): Remove.
(main): Replace `stage' invocations with timevar calls.
* src/output.c: Insert pertinent timevar calls.

Let --trace have arguments.
* src/getargs.h (enum trace_e): New.
* src/getargs.c (trace_args, trace_types, trace_argmatch): New.
(long_options, short_options): --trace/-T takes an optional
argument.
Change all the uses of trace_flag to reflect the new flags.
* tests/sets.at (Firsts, Nullable, Broken Closure): Use --trace=sets.
Strengthen `stage' portability.
* m4/stage.m4 (BISON_PREREQ_STAGE): New.
* configure.in: Use it.
Don't check for malloc.h and sys/times.h.
* src/system.h: Include them when appropriate.
* src/main.c (stage): Compile only when mallinfo, struct mallinfo,
times and struct tms are available.

Add HACKING.

In verbose parse error message, don't report `error' as an
expected token.
* tests/actions.at (Printers and Destructors): Adjust.
* tests/calc.at (Calculator $1): Adjust.
* data/yacc.c, data/glr.c, data/lalr1.c: When making the verbose
error message, do not report the parser accepts the error token in
that state.

Normalize conflict related messages.
* src/complain.h, src/complain.c (warn, complain): New.
* src/conflicts.c (conflicts_print): Use them.
(conflict_report_yacc): New, extracted from...
(conflicts_print): here.
* tests/conflicts.at, tests/existing.at: Adjust.

Report rules which are never reduced by the parser: those hidden
by conflicts.
* src/LR0.c (save_reductions): Don't make the final state too
different: save its reduction (accept) instead of having a state
without any action (no shift or goto, no reduce).
Note: the final state is now a ``regular'' state, i.e., the
parsers now contain `reduce 0' as default reduction.
Nevertheless, since they decide to `accept' when yystate =
final_state, they still will not reduce rule 0.
* src/print.c (print_actions, print_reduction): Adjust.
* src/output.c (action_row): Track reduced rules.
(token_actions): Report rules never reduced.
* tests/conflicts.at, tests/regression.at: Adjust.

`stage' was accidently included in a previous patch.
Initiate its autoconfiscation.
* configure.in: Look for malloc.h and sys/times.h.
* src/main.c (stage): Adjust.
Report only when trace_flag.

* src/state.h, src/state.c (transitions_t): Holds state_t*'s, not
state_number_t.
(errs_t): symbol_t*, not symbol_number_t.
(reductions_t): rule_t*, not rule_number_t.
(FOR_EACH_SHIFT): New.
* src/LR0.c, src/conflicts.c, src/lalr.c, src/output.c
* src/print.c, src/print_graph.c: Adjust.

Use $accept and $end, as BYacc and BTYacc do, instead of $axiom and $.
* src/symtab.h, src/symtab.c (eoftoken, axiom): Rename as...
(endtoken, accept): these.
* src/reader.c (reader): Set endtoken's default tag to "$end".
Set undeftoken's tag to "$undefined" instead of "$undefined.".
* doc/bison.texinfo (Table of Symbols): Mention $accept and $end.
Adjust.

* src/reduce.c (reduce_grammar): When the language is empty,
complain about the start symbol, not the axiom.
Use its location.
* tests/reduce.at (Empty Language): New.

* src/reader.h, src/reader.c (gram_error): ... can't get
yycontrol without making too strong assumptions on the parser
itself.
* src/output.c (prepare_tokens): Use the real 0th value of
token_translations instead of `0'.
* src/parse-gram.y (yyerror): Don't rely on yycontrol being
visible here.
* data/yacc.c (yyreport_parse_error): Rename yylocation as yylloc
for the time being: %locations ought to provide it to yyerror.

* src/output.c (prepare_tokens): Go up to ntokens, not ntokens + 1.
* doc/bison.texinfo (Decl Summary): s/$illegal/$undefined./.
* tests/regression.at (Web2c Actions): Adjust.

Stop storing rules from 1 to nrules + 1.
* src/LR0.c, src/closure.c, src/derives.c, src/gram.c, src/lalr.c
* src/nullable.c, src/output.c, src/print.c, src/reader.c
* src/reduce.c: Allocate and free from &rules[0], not &rules[1].
Iterate from 0 to nrules.
Use rule_number_as_item_number and item_number_as_rule_number.
Adjust to `derive' now containing possibly 0.
* src/gram.h (rule_number_as_item_number, item_number_as_rule_number):
Handle the `- 1' part in rule numbers from/to item numbers.
* src/conflicts.c (log_resolution): Fix the message which reversed
shift and reduce.
* src/output.c (action_row): Initialize default_rule to -1.
(token_actions): Adjust.
* tests/sets.at (Nullable, Firsts): Fix the previously bogus
expected output.
* tests/conflicts.at (Resolved SR Conflicts): Likewise.

* data/c.m4 (b4_c_function, b4_c_ansi_args, b4_c_ansi_arg)
(b4_c_knr_arg_names, b4_c_knr_arg_name, b4_c_knr_arg_decls)
(b4_c_knr_arg_decl): New.
* data/yacc.c: Use it to define yysymprint, yydestruct, and
yyreport_parse_error.

* data/yacc.c (yyreport_parse_error): New, extracted from...
(yyparse): here.
(yydestruct, yysymprint): Move above yyparse.
Be K&R compliant.

* data/c.m4 (b4_ints_in, b4_int_type, b4_int_type_for): New,
replace...
(b4_sint_type, b4_uint_type): these.
* data/yacc.c, data/glr.c, data/lalr1.cc: Use b4_int_type_for.
* tests/regression.at (Web2c Actions): Adjust.

* src/gram.h (TIEM_NUMBER_MAX): New.
(item_number_of_rule_number, rule_number_of_item_number): Rename
as...
(rule_number_as_item_number, item_number_as_rule_number): these.
Adjust dependencies.
* src/output.c (vector_number_t, VECTOR_NUMBER_MAX)
(VECTOR_NUMBER_MIN, state_number_to_vector_number)
(symbol_number_to_vector_number): New.
(order): Of vector_number_t* type.
(base_t, BASE_MAX, BASE_MIN): New.
(froms, tos, width, pos, check): Of base_t type.
(action_number_t, ACTION_MIN, ACTION_MAX): New.
(actrow): Of action_number_t type.
(conflrow): Of unsigned int type.
(table_ninf, base_ninf): New.
(GENERATE_MUSCLE_INSERT_TABLE): Also output the `*_min' value.
(muscle_insert_int_table, muscle_insert_base_table)
(muscle_insert_rule_number_table): New.
(prepare_tokens): Output `toknum' as int_table.
(action_row): Returns a rule_number_t.
Use ACTION_MIN, not SHRT_MIN.
(token_actions): yydefact is rule_number_t*.
(table_ninf_remap): New.
(pack_table): Use it for `base' and `table'.
* data/yacc.c, data/glr.c, data/lalr1.cc (YYFLAG): Remove,
replaced with...
(YYPACT_NINF, YYTABLE_NINF): these.
(yypact, yytable): Compute their types instead of hard-coded
`short'.
* tests/regression.at (Web2c Actions): Adjust.

* src/scan-gram.l (id): Can start with an underscore.

* src/assoc.c, src/asssoc.h (assoc_t, assoc_to_string): New.
Adjust all former `associativity' dependencies.
* src/symtab.c (symbol_new): Default associativity is `undef', not
`right'.
(symbol_check_alias_consistence): Adjust.

Fix dates in copyright notice.

* doc/bison.texinfo: Properly set the ``header'' part.
Use @dircategory ``GNU programming tools'' as per Texinfo's
documentation.
Use @copying.

* lib/quotearg.h: Protect against multiple inclusions.
* src/location.h (location_t): Add a `file' member.
(LOCATION_RESET, LOCATION_PRINT): Adjust.
* src/complain.c (warn_at, complain_at, fatal_at): Drop
`error_one_per_line' support.

* src/complain.h, src/complain.c (warn, complain): Remove, unused.
* src/reader.c (lineno): Remove.
Adjust all dependencies.
(get_merge_function): Take a location and use complain_at.
* src/symtab.h, src/symtab.c (symbol_make_alias): Likewise.
* tests/regression.at (Invalid inputs, Mixing %token styles):
Adjust.

* src/parse-gram.y (rules_or_grammar_declaration): Add an error
recovery rule, and forbid extensions when --yacc.
(gram_error): Use complain_at.
* src/reader.c (reader): Exit if there were parse errors.

Regen.

Update.

* tests/synclines.at (AT_SYNCLINES_COMPILE): New.
(AT_TEST_SYNCLINE): Adjust to unusual GCC outputs.
Reported by R Blake <blakers@mac.com>.

* data/yacc.c: Output the copyright notive in the header.

* src/output.c (froms, tos): Are state_number_t.
(save_column): sp, sp1, and sp2 are state_number_t.
(prepare): Rename `final' as `final_state_number', `nnts' as
`nterms_number', `nrules' as `rules_number', `nstates' as
`states_number', and `ntokens' as `tokens_number'.  Remove `nsym',
unused.
* data/yacc.c, data/glr.c, data/lalr1.cc: Adjust.
* data/lalr1.cc (nsym_): Remove, unused.

Regen.

* src/lalr.h, src/lalr.c (goto_number_t): New.
* src/lalr.c (goto_list_t): New.
Propagate them.
* src/nullable.c (rule_list_t): New.
Propagate.
* src/types.h: Remove.

* src/closure.c (print_fderives): Use rule_rhs_print.
* src/derives.c (print_derives): Use rule_rhs_print.
(rule_list_t): New, replaces `shorts'.
(set_derives): Add comments.
* tests/sets.at (Nullable, Firsts): Adjust.

* src/output.c (prepare_actions): Free `tally' and `width'.
(prepare_actions): Allocate and free `order'.
* src/symtab.c (symbols_free): Free `symbols'.
* src/scan-gram.l (scanner_free): Clear Flex's scanners memory.
* src/output.c (m4_invoke): Move to...
* src/scan-skel.l: here.
(<<EOF>>): Close yyout, and free its name.

Fix some memory leaks, and fix a bug: state 0 was examined twice.
* src/LR0.c (new_state): Merge into...
(state_list_append): this.
(new_states): Merge into...
(generate_states): here.
(set_states): Don't ensure a proper `errs' state member here, do it...
* src/conflicts.c (conflicts_solve): here.
* src/state.h, src/state.c: Comment changes.
(state_t): Rename member `shifts' as `transitions'.
Adjust all dependencies.
(errs_new): For consistency, also take the values as argument.
(errs_dup): Remove.
(state_errs_set): New.
(state_reductions_set, state_transitions_set): Assert that no
previous value was assigned.
(state_free): New.
(states_free): Use it.
* src/conflicts.c (resolve_sr_conflict): Don't use an `errs_t' as
temporary storage: use `errs' and `nerrs' as elsewhere.
(set_conflicts): Allocate and free this `errs'.

* lib/libiberty.h: New.
* lib: Update the bitset implementation from upstream.
* src/closure.c, src/lalr.c, src/output.c, src/print_graph.c,
* src/state.c: Use BITSET_FOR_EACH, not BITSET_EXECUTE.
* src/main.c: Adjust bitset stats calls.

Regen.

* src/scan-gram.l (<SC_ESCAPED_CHARACTER>): Convert to unsigned
char, so that negative chars don't collide with $.

(<SC_ESCAPED_CHARACTER>): Convert to unsigned char, so that negative
chars don't collide with $.

Typo.

Regen.

Have the GLR tests be `warning' checked, and fix the warnings.
* data/glr.c (YYFPRINTF): Always define it, not only when YYDEBUG
(yyuserAction, yyreportAmbiguity): `Use' all the arguments.
(yyremoveDeletes): `yyi' and `yyj' are size_t.
Use YYFPRINTF when under if (YYDEBUG) to avoid empty `if' bodies.
(yyaddDeferredAction): static.
(yyglrReduce): yyi, yyk, amd yyposn are size_t.
(yyreportParseError): yyprefix is const.
yytokenp is used only when verbose.
(yy__GNUC__): Replace with __GNUC__.
(yypdumpstack): yyi is size_t.
(yypreference): Un-yy local variables and arguments, to avoid
clashes with `yyr1'.  Anyway, we are not in the user name space.
(yytname_size): be an int, as is compared with ints.
* tests/testsuite.at (AT_COMPILE, AT_PARSER_CHECK): New.
Use them.
* tests/cxx-gram.at: Use quotation to protect $1.
Use AT_COMPILE to enable warnings hunts.
Prototype yylex and yyerror.
`Use' argc.
Include `string.h', not `strings.h'.
Produce and prototype stmtMerge only when used.
yylex takes a location.

We spend a lot of time in quotearg, in particular when --verbose.
* src/symtab.c (symbol_get): Store a quoted version of the key.
(symbol_tag_get, symbol_tag_get_n, symbol_tag_print): Remove.
Adjust all callers.

* src/state.h (reductions_t): Rename member `nreds' as num.
(errs_t): Rename members `nerrs' and `errs' as `num' and `symbols'.
* src/state.c (ERRS_ALLOC, REDUCTIONS_ALLOC): Use the correct types.

* src/state.h, src/state.c (shift_t, SHIFT_SYMBOL, SHIFT_IS_SHIFT)
(SHIFT_IS_GOTO, SHIFT_IS_ERROR, SHIFT_DISABLE, SHIFT_IS_DISABLED)
(shifts_to): Rename as...
(transition_t, TRANSITION_SYMBOL, TRANSITION_IS_TRANSITION)
(TRANSITION_IS_GOTO, TRANSITION_IS_ERROR, TRANSITION_DISABLE)
(TRANSITION_IS_DISABLED, transitions_to): these.

* src/print.c (print_shifts, print_gotos): Merge into...
(print_transitions): this.
(print_transitions, print_errs, print_reductions): Align the
lookaheads columns.
(print_core, print_transitions, print_errs, print_state,
print_grammar): Output empty lines separator before, not after.
(state_default_rule_compute): Rename as...
(state_default_rule): this.
* tests/conflicts.at (Defaulted Conflicted Reduction),
(Unresolved SR Conflicts, Resolved SR Conflicts): Adjust.
* tests/regression.at (Rule Line Numbers, Web2c Report): Adjust.

Display items as we display rules.
* src/gram.h, src/gram.c (rule_lhs_print): New.
* src/gram.c (grammar_rules_partial_print): Use it.
* src/print.c (print_core): Likewise.
* tests/conflicts.at (Defaulted Conflicted Reduction),
(Unresolved SR Conflicts): Adjust.
(Unresolved SR Conflicts): Adjust and rename as...
(Resolved SR Conflicts): this, as was meant.
* tests/regression.at (Web2c Report): Adjust.

* src/print.c (state_default_rule_compute): New, extracted from...
(print_reductions): here.
Pessimize, but clarify the code.
* tests/conflicts.at (Defaulted Conflicted Reduction): New.

* src/output.c (action_row): Let default_rule be always a rule
number.

* src/closure.c (print_firsts, print_fderives, closure):
Use BITSET_EXECUTE.
* src/lalr.c (lookaheads_print): Likewise.
* src/state.c (state_rule_lookaheads_print): Likewise.
* src/print_graph.c (print_core): Likewise.
* src/print.c (print_reductions): Likewise.
* src/output.c (action_row): Likewise.
Use SHIFT_IS_DISABLED, SHIFT_IS_SHIFT and SHIFT_SYMBOL.

* src/print_graph.c: Use report_flag.

* src/lalr.c (traverse, digraph, matrix_print, transpose): Move
to...
* src/relation.h, src/relation.c (traverse, relation_digraph)
(relation_print, relation_transpose): New.

* src/state.h, src/state.c (shifts_to): New.
* src/lalr.c (build_relations): Use it.

* src/gram.h (rule_number_t, RULE_NUMBER_MAX, int_of_rule_number)
(item_number_of_rule_number, rule_number_of_item_number): New.
* src/LR0.c, src/closure.c, src/derives.c, src/derives.h,
* src/gram.c, src/lalr.c, src/nullable.c, src/output.c, src/print.c,
* src/print_graph.c, src/reader.c, src/reduce.c, src/reduce.h:
Propagate their use.
Much remains to be done, in particular wrt `shorts' from types.h.

* src/symtab.c (symbol_new): Initialize the `printer' member.

* src/LR0.c (save_reductions): Remove, replaced by...
* src/state.h, src/state.c (state_reductions_set): New.
(reductions, errs): Rename as...
(reductions_t, errs_t): these.
Adjust all dependencies.

* src/LR0.c (state_list_t, state_list_append): New.
(first_state, last_state): Now symbol_list_t.
(this_state): Remove.
(new_itemsets, append_states, save_reductions): Take a state_t as
argument.
(set_states, generate_states): Adjust.
(save_shifts): Remove, replaced by...
* src/state.h, src/state.c (state_shifts_set): New.
(shifts): Rename as...
(shifts_t): this.
Adjust all dependencies.
* src/state.h (state_t): Remove the `next' member.

* src/vcg.c (quote): Use slot 2, since we often pass symbol tag
escaped in slot 0.

Use hash.h for the state hash table.
* src/LR0.c (STATE_HASH_SIZE, state_hash): Remove.
(allocate_storage): Use state_hash_new.
(free_storage): Use state_hash_free.
(new_state, get_state): Adjust.
* src/lalr.h, src/lalr.c (states): Move to...
* src/states.h (state_t): Remove the `link' member, no longer
used.
* src/states.h, src/states.c: here.
(state_hash_new, state_hash_free, state_hash_lookup)
(state_hash_insert, states_free): New.
* src/states.c (state_table, state_compare, state_hash): New.
* src/output.c (output_actions): Do not free states now, since we
still need to know the final_state number in `prepare', called
afterwards.  Do it...
* src/main.c (main): here: call states_free after `output'.

* src/state.h, src/state.c (state_new): New, extracted from...
* src/LR0.c (new_state): here.
* src/state.h (STATE_ALLOC): Move to...
* src/state.c: here.
* src/LR0.h, src/LR0.c (nstates, final_state): Move to...
* src/state.h, src/state.c: here.

* src/reader.c (gensym): Rename as...
* src/symtab.h, src/symtab.c (dummy_symbol_get): this.
(getsym): Rename as...
(symbol_get): this.

* src/state.h (state_number_t, STATE_NUMBER_MAX): New.
* src/LR0.c, src/LR0.h, src/conflicts.c, src/lalr.c, src/lalr.h,
* src/output.c, src/print.c, src/print_graph.c: Propagate.
* src/LR0.h, src/LR0.h (final_state): Is a state_t*.

Make the test suite pass with warnings checked.
* tests/actions.at (Printers and Destructors): Improve.
Avoid unsigned vs. signed issues.
* tests/calc.at: Don't exercise the scanner here, do it...
* tests/input.at (Torturing the Scanner): here.

* data/glr.c: Correct typo in Emacs-mode directive.  Slightly
  reorganize first lines parallel to yacc.c.

* data/c.m4 (b4_copyright, b4_sint_type, b4_uint_type, b4_token_define)
(b4_token_enum, b4_token_defines): New, factored from...
* data/lalr1.cc, data/yacc.c, glr.c: here.

regen.

* data/yacc.c (yydestruct, yysymprint): Pacify GCC warnings for
unused variables.
* src/output.c (merger_output): static.

* src/reader.h: s/grammer_current_rule_merge_set/grammar_.../.
* src/conflicts.c (conflicts_total_count): `i' is unsigned, to
pacify GCC.
* src/output.c (save_row): Initialize all the variables to pacify GCC.
(merger_output): static.

Fix small formatting glitch.

Initial check-in introducing experimental GLR parsing.  See entry in
ChangeLog dated 2002-06-27 from Paul Hilfinger for details.

Renamed file from bison.glr.

Renaming file to glr.c.

* src/options.h, src/options.c: Remove.
* src/getargs.c (short_options, long_options): New.

Update.

* data/bison.simple, data/bison.c++: Rename as...
* data/yacc.c, data/lalr1.cc: these.
* doc/bison.texinfo (Environment Variables): Remove.

Update.

New file: Tests for GLR parsing.

New file: skeleton for GLR (Generalized LR) parser.

* src/getargs.c (report_argmatch): Initialize strtok().

Update.

Update.

* data/bison.simple (b4_symbol_actions): New, replaces...
(b4_symbol_destructor, b4_symbol_printer): these.
(yysymprint): Be sure to call YYPRINT only for tokens, and using
user token numbers.

* data/bison.simple (yydestructor): Rename as...
(yydestruct): this.

* src/symtab.h, src/symtab.c (symbol_type_set)
(symbol_destructor_set, symbol_precedence_set): The location is
the last argument.
Adjust all callers.

* src/parse-gram.y (YYPRINT, yyprint): Don't mess with the parser
internals.
* src/reader.h, src/reader.c (grammar_current_rule_prec_set):
Takes a location.
* src/symtab.h, src/symtab.c (symbol_class_set)
(symbol_user_token_number_set): Likewise.
Adjust all callers.
Promote complain_at.
* tests/input.at (Type Clashes): Adjust.

* data/bison.simple (YYLEX): Fix the declaration when
%pure-parser.

* data/bison.simple (yysymprint): Don't print the token number,
just its name.
* tests/actions.at (Destructors): Rename as...
(Printers and Destructors): this.
Also exercise %printer.

* data/bison.simple (YYDSYMPRINT): New.
Use it to remove many of the #if YYDEBUG/if (yydebug).

* src/symtab.h, src/symtab.c (symbol_t): printer and
printer_location are new members.
(symbol_printer_set): New.
* src/parse-gram.y (PERCENT_PRINTER): New token.
Handle its associated rule.
* src/scan-gram.l: Adjust.
(handle_destructor_at, handle_destructor_dollar): Rename as...
(handle_symbol_code_at, handle_symbol_code_dollar): these.
* src/output.c (symbol_printers_output): New.
(output_skeleton): Call it.
* data/bison.simple (yysymprint): New.  Cannot be named yyprint
since there are already many grammar files with a user `yyprint'.
Replace the calls to YYPRINT to calls to yysymprint.
* tests/calc.at: Adjust.
* tests/torture.at (AT_DATA_STACK_TORTURE): Remove YYPRINT: it was
taking advantage of parser very internal details (stack size!).

Regen.

* src/scan-gram.l: Complete the scanner with the missing patterns
to pacify Flex.
Use `quote' and `symbol_tag_get' where appropriate.

* tests/actions.at (Destructors): Augment to test locations.
* data/bison.simple (yydestructor): Pass it the current location
if locations are enabled.
Prototype only when __STDC__ or C++.
Change the argument names to move into the yy name space: there is
user code here.

* data/bison.simple (b4_pure_if): New.
Use it instead of #ifdef YYPURE.

* data/bison.simple (m4_location_if): New.
Use it instead of #ifdef YYLSP_NEEDED.

Regen.

Prepare @$ in %destructor, but currently don't bind it in the
skeleton, as %location use is not cleaned up yet.
* src/scan-gram.l (handle_dollar, handle_destructor_at)
(handle_action_at): New.
(handle_at, handle_action_dollar, handle_destructor_dollar): Take
a braced_code_t and a location as additional arguments.
(handle_destructor_dollar): Instead of requiring `b4_eval', just
unquote one when outputting `b4_dollar_dollar'.
Adjust callers.
* data/bison.simple (b4_eval): Remove.
(b4_symbol_destructor): Adjust.
* tests/input.at (Invalid @n): Adjust.

* doc/bison.texinfo: Document ability to have multiple
prologue sections.