1 # C++ skeleton for Bison
2 
3 # Copyright (C) 2002-2015, 2018-2021 Free Software Foundation, Inc.
4 
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
9 #
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 # GNU General Public License for more details.
14 #
15 # You should have received a copy of the GNU General Public License
16 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
17 
18 m4_include(b4_skeletonsdir/[c++.m4])
19 
20 # api.value.type=variant is valid.
21 m4_define([b4_value_type_setup_variant])
22 
23 # Check the value of %define parse.lac, where LAC stands for lookahead
24 # correction.
25 b4_percent_define_default([[parse.lac]], [[none]])
26 b4_percent_define_check_values([[[[parse.lac]], [[full]], [[none]]]])
27 b4_define_flag_if([lac])
28 m4_define([b4_lac_flag],
29           [m4_if(b4_percent_define_get([[parse.lac]]),
30                  [none], [[0]], [[1]])])
31 
32 
33 # b4_tname_if(TNAME-NEEDED, TNAME-NOT-NEEDED)
34 # -------------------------------------------
35 m4_define([b4_tname_if],
36 [m4_case(b4_percent_define_get([[parse.error]]),
37          [verbose],         [$1],
38          [b4_token_table_if([$1],
39                             [$2])])])
40 
41 
42 # b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
43 # --------------------------------------------------------------
44 # Declare "parser::yy<TABLE-NAME>_" whose contents is CONTENT.
45 m4_define([b4_integral_parser_table_declare],
46 [m4_ifval([$3], [b4_comment([$3], [    ])
47 ])dnl
48     static const b4_int_type_for([$2]) yy$1_[[]];dnl
49 ])
50 
51 # b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
52 # -------------------------------------------------------------
53 # Define "parser::yy<TABLE-NAME>_" whose contents is CONTENT.
54 m4_define([b4_integral_parser_table_define],
55 [  const b4_int_type_for([$2])
56   b4_parser_class::yy$1_[[]] =
57   {
58   $2
59   };dnl
60 ])
61 
62 
63 # b4_symbol_kind(NUM)
64 # -------------------
65 m4_define([b4_symbol_kind],
66 [symbol_kind::b4_symbol_kind_base($@)])
67 
68 
69 # b4_symbol_value_template(VAL, SYMBOL-NUM, [TYPE])
70 # -------------------------------------------------
71 # Same as b4_symbol_value, but used in a template method.  It makes
72 # a difference when using variants.  Note that b4_value_type_setup_union
73 # overrides b4_symbol_value, so we must override it again.
74 m4_copy([b4_symbol_value], [b4_symbol_value_template])
75 m4_append([b4_value_type_setup_union],
76 [m4_copy_force([b4_symbol_value_union], [b4_symbol_value_template])])
77 
78 # b4_lhs_value(SYMBOL-NUM, [TYPE])
79 # --------------------------------
80 # See README.
81 m4_define([b4_lhs_value],
82 [b4_symbol_value([yylhs.value], [$1], [$2])])
83 
84 
85 # b4_lhs_location()
86 # -----------------
87 # Expansion of @$.
88 m4_define([b4_lhs_location],
89 [yylhs.location])
90 
91 
92 # b4_rhs_data(RULE-LENGTH, POS)
93 # -----------------------------
94 # See README.
95 m4_define([b4_rhs_data],
96 [yystack_@{b4_subtract($@)@}])
97 
98 
99 # b4_rhs_state(RULE-LENGTH, POS)
100 # ------------------------------
101 # The state corresponding to the symbol #POS, where the current
102 # rule has RULE-LENGTH symbols on RHS.
103 m4_define([b4_rhs_state],
104 [b4_rhs_data([$1], [$2]).state])
105 
106 
107 # b4_rhs_value(RULE-LENGTH, POS, SYMBOL-NUM, [TYPE])
108 # --------------------------------------------------
109 # See README.
110 m4_define([_b4_rhs_value],
111 [b4_symbol_value([b4_rhs_data([$1], [$2]).value], [$3], [$4])])
112 
113 m4_define([b4_rhs_value],
114 [b4_percent_define_ifdef([api.value.automove],
115                          [YY_MOVE (_b4_rhs_value($@))],
116                          [_b4_rhs_value($@)])])
117 
118 
119 # b4_rhs_location(RULE-LENGTH, POS)
120 # ---------------------------------
121 # Expansion of @POS, where the current rule has RULE-LENGTH symbols
122 # on RHS.
123 m4_define([b4_rhs_location],
124 [b4_rhs_data([$1], [$2]).location])
125 
126 
127 # b4_symbol_action(SYMBOL-NUM, KIND)
128 # ----------------------------------
129 # Run the action KIND (destructor or printer) for SYMBOL-NUM.
130 # Same as in C, but using references instead of pointers.
131 m4_define([b4_symbol_action],
132 [b4_symbol_if([$1], [has_$2],
133 [m4_pushdef([b4_symbol_value], m4_defn([b4_symbol_value_template]))[]dnl
134 b4_dollar_pushdef([yysym.value],
135                   [$1],
136                   [],
137                   [yysym.location])dnl
138       _b4_symbol_case([$1])[]dnl
139 b4_syncline([b4_symbol([$1], [$2_line])], [b4_symbol([$1], [$2_file])])dnl
140         b4_symbol([$1], [$2])
141 b4_syncline([@oline@], [@ofile@])dnl
142         break;
143 
144 m4_popdef([b4_symbol_value])[]dnl
145 b4_dollar_popdef[]dnl
146 ])])
147 
148 
149 # b4_lex
150 # ------
151 # Call yylex.
152 m4_define([b4_lex],
153 [b4_token_ctor_if(
154 [b4_function_call([yylex],
155                   [symbol_type], m4_ifdef([b4_lex_param], b4_lex_param))],
156 [b4_function_call([yylex], [int],
157                   [b4_api_PREFIX[STYPE*], [&yyla.value]][]dnl
158 b4_locations_if([, [[location*], [&yyla.location]]])dnl
159 m4_ifdef([b4_lex_param], [, ]b4_lex_param))])])
160 
161 
162 m4_pushdef([b4_copyright_years],
163            [2002-2015, 2018-2021])
164 
165 m4_define([b4_parser_class],
166           [b4_percent_define_get([[api.parser.class]])])
167 
168 b4_bison_locations_if([# Backward compatibility.
169    m4_define([b4_location_constructors])
170    m4_include(b4_skeletonsdir/[location.cc])])
171 m4_include(b4_skeletonsdir/[stack.hh])
172 b4_variant_if([m4_include(b4_skeletonsdir/[variant.hh])])
173 
174 
175 # b4_shared_declarations(hh|cc)
176 # -----------------------------
177 # Declaration that might either go into the header (if --defines, $1 = hh)
178 # or in the implementation file.
179 m4_define([b4_shared_declarations],
180 [b4_percent_code_get([[requires]])[
181 ]b4_parse_assert_if([# include <cassert>])[
182 # include <cstdlib> // std::abort
183 # include <iostream>
184 # include <stdexcept>
185 # include <string>
186 # include <vector>
187 
188 ]b4_cxx_portability[
189 ]m4_ifdef([b4_location_include],
190           [[# include ]b4_location_include])[
191 ]b4_variant_if([b4_variant_includes])[
192 
193 ]b4_attribute_define[
194 ]b4_cast_define[
195 ]b4_null_define[
196 
197 ]b4_YYDEBUG_define[
198 
199 ]b4_namespace_open[
200 
201 ]b4_bison_locations_if([m4_ifndef([b4_location_file],
202                                   [b4_location_define])])[
203 
204   /// A Bison parser.
205   class ]b4_parser_class[
206   {
207   public:
208 ]b4_public_types_declare[
209 ]b4_symbol_type_define[
210     /// Build a parser object.
211     ]b4_parser_class[ (]b4_parse_param_decl[);
212     virtual ~]b4_parser_class[ ();
213 
214 #if 201103L <= YY_CPLUSPLUS
215     /// Non copyable.
216     ]b4_parser_class[ (const ]b4_parser_class[&) = delete;
217     /// Non copyable.
218     ]b4_parser_class[& operator= (const ]b4_parser_class[&) = delete;
219 #endif
220 
221     /// Parse.  An alias for parse ().
222     /// \returns  0 iff parsing succeeded.
223     int operator() ();
224 
225     /// Parse.
226     /// \returns  0 iff parsing succeeded.
227     virtual int parse ();
228 
229 #if ]b4_api_PREFIX[DEBUG
230     /// The current debugging stream.
231     std::ostream& debug_stream () const YY_ATTRIBUTE_PURE;
232     /// Set the current debugging stream.
233     void set_debug_stream (std::ostream &);
234 
235     /// Type for debugging levels.
236     typedef int debug_level_type;
237     /// The current debugging level.
238     debug_level_type debug_level () const YY_ATTRIBUTE_PURE;
239     /// Set the current debugging level.
240     void set_debug_level (debug_level_type l);
241 #endif
242 
243     /// Report a syntax error.]b4_locations_if([[
244     /// \param loc    where the syntax error is found.]])[
245     /// \param msg    a description of the syntax error.
246     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
247 
248     /// Report a syntax error.
249     void error (const syntax_error& err);
250 
251 ]b4_parse_error_bmatch(
252 [custom\|detailed],
253 [[    /// The user-facing name of the symbol whose (internal) number is
254     /// YYSYMBOL.  No bounds checking.
255     static const char *symbol_name (symbol_kind_type yysymbol);]],
256 [simple],
257 [[#if ]b4_api_PREFIX[DEBUG || ]b4_token_table_flag[
258     /// The user-facing name of the symbol whose (internal) number is
259     /// YYSYMBOL.  No bounds checking.
260     static const char *symbol_name (symbol_kind_type yysymbol);
261 #endif // #if ]b4_api_PREFIX[DEBUG || ]b4_token_table_flag[
262 ]],
263 [verbose],
264 [[    /// The user-facing name of the symbol whose (internal) number is
265     /// YYSYMBOL.  No bounds checking.
266     static std::string symbol_name (symbol_kind_type yysymbol);]])[
267 
268 ]b4_token_constructor_define[
269 ]b4_parse_error_bmatch([custom\|detailed\|verbose], [[
270     class context
271     {
272     public:
273       context (const ]b4_parser_class[& yyparser, const symbol_type& yyla);
274       const symbol_type& lookahead () const YY_NOEXCEPT { return yyla_; }
275       symbol_kind_type token () const YY_NOEXCEPT { return yyla_.kind (); }]b4_locations_if([[
276       const location_type& location () const YY_NOEXCEPT { return yyla_.location; }
277 ]])[
278       /// Put in YYARG at most YYARGN of the expected tokens, and return the
279       /// number of tokens stored in YYARG.  If YYARG is null, return the
280       /// number of expected tokens (guaranteed to be less than YYNTOKENS).
281       int expected_tokens (symbol_kind_type yyarg[], int yyargn) const;
282 
283     private:
284       const ]b4_parser_class[& yyparser_;
285       const symbol_type& yyla_;
286     };
287 ]])[
288   private:
289 #if YY_CPLUSPLUS < 201103L
290     /// Non copyable.
291     ]b4_parser_class[ (const ]b4_parser_class[&);
292     /// Non copyable.
293     ]b4_parser_class[& operator= (const ]b4_parser_class[&);
294 #endif
295 ]b4_lac_if([[
296     /// Check the lookahead yytoken.
297     /// \returns  true iff the token will be eventually shifted.
298     bool yy_lac_check_ (symbol_kind_type yytoken) const;
299     /// Establish the initial context if no initial context currently exists.
300     /// \returns  true iff the token will be eventually shifted.
301     bool yy_lac_establish_ (symbol_kind_type yytoken);
302     /// Discard any previous initial lookahead context because of event.
303     /// \param event  the event which caused the lookahead to be discarded.
304     ///               Only used for debbuging output.
305     void yy_lac_discard_ (const char* event);]])[
306 
307     /// Stored state numbers (used for stacks).
308     typedef ]b4_int_type(0, m4_eval(b4_states_number - 1))[ state_type;
309 ]b4_parse_error_bmatch(
310       [custom], [[
311     /// Report a syntax error
312     /// \param yyctx     the context in which the error occurred.
313     void report_syntax_error (const context& yyctx) const;]],
314       [detailed\|verbose], [[
315     /// The arguments of the error message.
316     int yy_syntax_error_arguments_ (const context& yyctx,
317                                     symbol_kind_type yyarg[], int yyargn) const;
318 
319     /// Generate an error message.
320     /// \param yyctx     the context in which the error occurred.
321     virtual std::string yysyntax_error_ (const context& yyctx) const;]])[
322     /// Compute post-reduction state.
323     /// \param yystate   the current state
324     /// \param yysym     the nonterminal to push on the stack
325     static state_type yy_lr_goto_state_ (state_type yystate, int yysym);
326 
327     /// Whether the given \c yypact_ value indicates a defaulted state.
328     /// \param yyvalue   the value to check
329     static bool yy_pact_value_is_default_ (int yyvalue);
330 
331     /// Whether the given \c yytable_ value indicates a syntax error.
332     /// \param yyvalue   the value to check
333     static bool yy_table_value_is_error_ (int yyvalue);
334 
335     static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;
336     static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
337 
338     /// Convert a scanner token kind \a t to a symbol kind.
339     /// In theory \a t should be a token_kind_type, but character literals
340     /// are valid, yet not members of the token_type enum.
341     static symbol_kind_type yytranslate_ (int t);
342 
343 ]b4_parse_error_bmatch(
344 [simple],
345 [[#if ]b4_api_PREFIX[DEBUG || ]b4_token_table_flag[
346     /// For a symbol, its name in clear.
347     static const char* const yytname_[];
348 #endif // #if ]b4_api_PREFIX[DEBUG || ]b4_token_table_flag[
349 ]],
350 [verbose],
351 [[    /// Convert the symbol name \a n to a form suitable for a diagnostic.
352     static std::string yytnamerr_ (const char *yystr);
353 
354     /// For a symbol, its name in clear.
355     static const char* const yytname_[];
356 ]])[
357 
358     // Tables.
359 ]b4_parser_tables_declare[
360 
361 #if ]b4_api_PREFIX[DEBUG
362 ]b4_integral_parser_table_declare([rline], [b4_rline],
363      [[YYRLINE[YYN] -- Source line where rule number YYN was defined.]])[
364     /// Report on the debug stream that the rule \a r is going to be reduced.
365     virtual void yy_reduce_print_ (int r) const;
366     /// Print the state stack on the debug stream.
367     virtual void yy_stack_print_ () const;
368 
369     /// Debugging level.
370     int yydebug_;
371     /// Debug stream.
372     std::ostream* yycdebug_;
373 
374     /// \brief Display a symbol kind, value and location.
375     /// \param yyo    The output stream.
376     /// \param yysym  The symbol.
377     template <typename Base>
378     void yy_print_ (std::ostream& yyo, const basic_symbol<Base>& yysym) const;
379 #endif
380 
381     /// \brief Reclaim the memory associated to a symbol.
382     /// \param yymsg     Why this token is reclaimed.
383     ///                  If null, print nothing.
384     /// \param yysym     The symbol.
385     template <typename Base>
386     void yy_destroy_ (const char* yymsg, basic_symbol<Base>& yysym) const;
387 
388   private:
389     /// Type access provider for state based symbols.
390     struct by_state
391     {
392       /// Default constructor.
393       by_state () YY_NOEXCEPT;
394 
395       /// The symbol kind as needed by the constructor.
396       typedef state_type kind_type;
397 
398       /// Constructor.
399       by_state (kind_type s) YY_NOEXCEPT;
400 
401       /// Copy constructor.
402       by_state (const by_state& that) YY_NOEXCEPT;
403 
404       /// Record that this symbol is empty.
405       void clear () YY_NOEXCEPT;
406 
407       /// Steal the symbol kind from \a that.
408       void move (by_state& that);
409 
410       /// The symbol kind (corresponding to \a state).
411       /// \a ]b4_symbol(-2, kind)[ when empty.
412       symbol_kind_type kind () const YY_NOEXCEPT;
413 
414       /// The state number used to denote an empty symbol.
415       /// We use the initial state, as it does not have a value.
416       enum { empty_state = 0 };
417 
418       /// The state.
419       /// \a empty when empty.
420       state_type state;
421     };
422 
423     /// "Internal" symbol: element of the stack.
424     struct stack_symbol_type : basic_symbol<by_state>
425     {
426       /// Superclass.
427       typedef basic_symbol<by_state> super_type;
428       /// Construct an empty symbol.
429       stack_symbol_type ();
430       /// Move or copy construction.
431       stack_symbol_type (YY_RVREF (stack_symbol_type) that);
432       /// Steal the contents from \a sym to build this.
433       stack_symbol_type (state_type s, YY_MOVE_REF (symbol_type) sym);
434 #if YY_CPLUSPLUS < 201103L
435       /// Assignment, needed by push_back by some old implementations.
436       /// Moves the contents of that.
437       stack_symbol_type& operator= (stack_symbol_type& that);
438 
439       /// Assignment, needed by push_back by other implementations.
440       /// Needed by some other old implementations.
441       stack_symbol_type& operator= (const stack_symbol_type& that);
442 #endif
443     };
444 
445 ]b4_stack_define[
446 
447     /// Stack type.
448     typedef stack<stack_symbol_type> stack_type;
449 
450     /// The stack.
451     stack_type yystack_;]b4_lac_if([[
452     /// The stack for LAC.
453     /// Logically, the yy_lac_stack's lifetime is confined to the function
454     /// yy_lac_check_. We just store it as a member of this class to hold
455     /// on to the memory and to avoid frequent reallocations.
456     /// Since yy_lac_check_ is const, this member must be mutable.
457     mutable std::vector<state_type> yylac_stack_;
458     /// Whether an initial LAC context was established.
459     bool yy_lac_established_;
460 ]])[
461 
462     /// Push a new state on the stack.
463     /// \param m    a debug message to display
464     ///             if null, no trace is output.
465     /// \param sym  the symbol
466     /// \warning the contents of \a s.value is stolen.
467     void yypush_ (const char* m, YY_MOVE_REF (stack_symbol_type) sym);
468 
469     /// Push a new look ahead token on the state on the stack.
470     /// \param m    a debug message to display
471     ///             if null, no trace is output.
472     /// \param s    the state
473     /// \param sym  the symbol (for its value and location).
474     /// \warning the contents of \a sym.value is stolen.
475     void yypush_ (const char* m, state_type s, YY_MOVE_REF (symbol_type) sym);
476 
477     /// Pop \a n symbols from the stack.
478     void yypop_ (int n = 1);
479 
480     /// Constants.
481     enum
482     {
483       yylast_ = ]b4_last[,     ///< Last index in yytable_.
484       yynnts_ = ]b4_nterms_number[,  ///< Number of nonterminal symbols.
485       yyfinal_ = ]b4_final_state_number[ ///< Termination state number.
486     };
487 
488 ]b4_parse_param_vars[
489 ]b4_percent_code_get([[yy_bison_internal_hook]])[
490   };
491 
492 ]b4_token_ctor_if([b4_yytranslate_define([$1])[
493 ]b4_public_types_define([$1])])[
494 ]b4_namespace_close[
495 
496 ]b4_percent_code_get([[provides]])[
497 ]])
498 
499 ## -------------- ##
500 ## Output files.  ##
501 ## -------------- ##
502 
503 b4_defines_if(
504 [b4_output_begin([b4_spec_header_file])
505 b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++])
506 [
507 /**
508  ** \file ]b4_spec_mapped_header_file[
509  ** Define the ]b4_namespace_ref[::parser class.
510  */
511 
512 // C++ LALR(1) parser skeleton written by Akim Demaille.
513 
514 ]b4_disclaimer[
515 ]b4_cpp_guard_open([b4_spec_mapped_header_file])[
516 ]b4_shared_declarations(hh)[
517 ]b4_cpp_guard_close([b4_spec_mapped_header_file])[
518 ]b4_output_end[
519 ]])
520 
521 
522 b4_output_begin([b4_parser_file_name])[
523 ]b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++])[
524 ]b4_disclaimer[
525 ]b4_percent_code_get([[top]])[]dnl
526 m4_if(b4_prefix, [yy], [],
527 [
528 // Take the name prefix into account.
529 [#]define yylex   b4_prefix[]lex])[
530 
531 ]b4_user_pre_prologue[
532 
533 ]b4_defines_if([[#include "@basename(]b4_spec_header_file[@)"]],
534                [b4_shared_declarations([cc])])[
535 
536 ]b4_user_post_prologue[
537 ]b4_percent_code_get[
538 
539 #ifndef YY_
540 # if defined YYENABLE_NLS && YYENABLE_NLS
541 #  if ENABLE_NLS
542 #   include <libintl.h> // FIXME: INFRINGES ON USER NAME SPACE.
543 #   define YY_(msgid) dgettext ("bison-runtime", msgid)
544 #  endif
545 # endif
546 # ifndef YY_
547 #  define YY_(msgid) msgid
548 # endif
549 #endif
550 ]b4_has_translations_if([
551 #ifndef N_
552 # define N_(Msgid) Msgid
553 #endif
554 ])[
555 
556 // Whether we are compiled with exception support.
557 #ifndef YY_EXCEPTIONS
558 # if defined __GNUC__ && !defined __EXCEPTIONS
559 #  define YY_EXCEPTIONS 0
560 # else
561 #  define YY_EXCEPTIONS 1
562 # endif
563 #endif
564 
565 ]b4_locations_if([dnl
566 [#define YYRHSLOC(Rhs, K) ((Rhs)[K].location)
567 ]b4_yylloc_default_define])[
568 
569 // Enable debugging if requested.
570 #if ]b4_api_PREFIX[DEBUG
571 
572 // A pseudo ostream that takes yydebug_ into account.
573 # define YYCDEBUG if (yydebug_) (*yycdebug_)
574 
575 # define YY_SYMBOL_PRINT(Title, Symbol)         \
576   do {                                          \
577     if (yydebug_)                               \
578     {                                           \
579       *yycdebug_ << Title << ' ';               \
580       yy_print_ (*yycdebug_, Symbol);           \
581       *yycdebug_ << '\n';                       \
582     }                                           \
583   } while (false)
584 
585 # define YY_REDUCE_PRINT(Rule)          \
586   do {                                  \
587     if (yydebug_)                       \
588       yy_reduce_print_ (Rule);          \
589   } while (false)
590 
591 # define YY_STACK_PRINT()               \
592   do {                                  \
593     if (yydebug_)                       \
594       yy_stack_print_ ();                \
595   } while (false)
596 
597 #else // !]b4_api_PREFIX[DEBUG
598 
599 # define YYCDEBUG if (false) std::cerr
600 # define YY_SYMBOL_PRINT(Title, Symbol)  YY_USE (Symbol)
601 # define YY_REDUCE_PRINT(Rule)           static_cast<void> (0)
602 # define YY_STACK_PRINT()                static_cast<void> (0)
603 
604 #endif // !]b4_api_PREFIX[DEBUG
605 
606 #define yyerrok         (yyerrstatus_ = 0)
607 #define yyclearin       (yyla.clear ())
608 
609 #define YYACCEPT        goto yyacceptlab
610 #define YYABORT         goto yyabortlab
611 #define YYERROR         goto yyerrorlab
612 #define YYRECOVERING()  (!!yyerrstatus_)
613 
614 ]b4_namespace_open[
615   /// Build a parser object.
616   ]b4_parser_class::b4_parser_class[ (]b4_parse_param_decl[)
617 #if ]b4_api_PREFIX[DEBUG
618     : yydebug_ (false),
619       yycdebug_ (&std::cerr)]b4_lac_if([,], [m4_ifset([b4_parse_param], [,])])[
620 #else
621 ]b4_lac_if([    :], [m4_ifset([b4_parse_param], [    :])])[
622 #endif]b4_lac_if([[
623       yy_lac_established_ (false)]m4_ifset([b4_parse_param], [,])])[]b4_parse_param_cons[
624   {}
625 
626   ]b4_parser_class::~b4_parser_class[ ()
627   {}
628 
629   ]b4_parser_class[::syntax_error::~syntax_error () YY_NOEXCEPT YY_NOTHROW
630   {}
631 
632   /*---------------.
633   | symbol kinds.  |
634   `---------------*/
635 
636 ]b4_token_ctor_if([], [b4_public_types_define([cc])])[
637 
638   // by_state.
639   ]b4_parser_class[::by_state::by_state () YY_NOEXCEPT
640     : state (empty_state)
641   {}
642 
643   ]b4_parser_class[::by_state::by_state (const by_state& that) YY_NOEXCEPT
644     : state (that.state)
645   {}
646 
647   void
648   ]b4_parser_class[::by_state::clear () YY_NOEXCEPT
649   {
650     state = empty_state;
651   }
652 
653   void
654   ]b4_parser_class[::by_state::move (by_state& that)
655   {
656     state = that.state;
657     that.clear ();
658   }
659 
660   ]b4_parser_class[::by_state::by_state (state_type s) YY_NOEXCEPT
661     : state (s)
662   {}
663 
664   ]b4_parser_class[::symbol_kind_type
665   ]b4_parser_class[::by_state::kind () const YY_NOEXCEPT
666   {
667     if (state == empty_state)
668       return ]b4_symbol(-2, kind)[;
669     else
670       return YY_CAST (symbol_kind_type, yystos_[+state]);
671   }
672 
673   ]b4_parser_class[::stack_symbol_type::stack_symbol_type ()
674   {}
675 
676   ]b4_parser_class[::stack_symbol_type::stack_symbol_type (YY_RVREF (stack_symbol_type) that)
677     : super_type (YY_MOVE (that.state)]b4_variant_if([], [, YY_MOVE (that.value)])b4_locations_if([, YY_MOVE (that.location)])[)
678   {]b4_variant_if([
679     b4_symbol_variant([that.kind ()],
680                       [value], [YY_MOVE_OR_COPY], [YY_MOVE (that.value)])])[
681 #if 201103L <= YY_CPLUSPLUS
682     // that is emptied.
683     that.state = empty_state;
684 #endif
685   }
686 
687   ]b4_parser_class[::stack_symbol_type::stack_symbol_type (state_type s, YY_MOVE_REF (symbol_type) that)
688     : super_type (s]b4_variant_if([], [, YY_MOVE (that.value)])[]b4_locations_if([, YY_MOVE (that.location)])[)
689   {]b4_variant_if([
690     b4_symbol_variant([that.kind ()],
691                       [value], [move], [YY_MOVE (that.value)])])[
692     // that is emptied.
693     that.kind_ = ]b4_symbol(-2, kind)[;
694   }
695 
696 #if YY_CPLUSPLUS < 201103L
697   ]b4_parser_class[::stack_symbol_type&
698   ]b4_parser_class[::stack_symbol_type::operator= (const stack_symbol_type& that)
699   {
700     state = that.state;
701     ]b4_variant_if([b4_symbol_variant([that.kind ()],
702                                       [value], [copy], [that.value])],
703                    [[value = that.value;]])[]b4_locations_if([
704     location = that.location;])[
705     return *this;
706   }
707 
708   ]b4_parser_class[::stack_symbol_type&
709   ]b4_parser_class[::stack_symbol_type::operator= (stack_symbol_type& that)
710   {
711     state = that.state;
712     ]b4_variant_if([b4_symbol_variant([that.kind ()],
713                                       [value], [move], [that.value])],
714                    [[value = that.value;]])[]b4_locations_if([
715     location = that.location;])[
716     // that is emptied.
717     that.state = empty_state;
718     return *this;
719   }
720 #endif
721 
722   template <typename Base>
723   void
724   ]b4_parser_class[::yy_destroy_ (const char* yymsg, basic_symbol<Base>& yysym) const
725   {
726     if (yymsg)
727       YY_SYMBOL_PRINT (yymsg, yysym);]b4_variant_if([], [
728 
729     // User destructor.
730     b4_symbol_actions([destructor], [yysym.kind ()])])[
731   }
732 
733 #if ]b4_api_PREFIX[DEBUG
734   template <typename Base>
735   void
736   ]b4_parser_class[::yy_print_ (std::ostream& yyo, const basic_symbol<Base>& yysym) const
737   {
738     std::ostream& yyoutput = yyo;
739     YY_USE (yyoutput);
740     if (yysym.empty ())
741       yyo << "empty symbol";
742     else
743       {
744         symbol_kind_type yykind = yysym.kind ();
745         yyo << (yykind < YYNTOKENS ? "token" : "nterm")
746             << ' ' << yysym.name () << " ("]b4_locations_if([
747             << yysym.location << ": "])[;
748         ]b4_symbol_actions([printer])[
749         yyo << ')';
750       }
751   }
752 #endif
753 
754   void
755   ]b4_parser_class[::yypush_ (const char* m, YY_MOVE_REF (stack_symbol_type) sym)
756   {
757     if (m)
758       YY_SYMBOL_PRINT (m, sym);
759     yystack_.push (YY_MOVE (sym));
760   }
761 
762   void
763   ]b4_parser_class[::yypush_ (const char* m, state_type s, YY_MOVE_REF (symbol_type) sym)
764   {
765 #if 201103L <= YY_CPLUSPLUS
766     yypush_ (m, stack_symbol_type (s, std::move (sym)));
767 #else
768     stack_symbol_type ss (s, sym);
769     yypush_ (m, ss);
770 #endif
771   }
772 
773   void
774   ]b4_parser_class[::yypop_ (int n)
775   {
776     yystack_.pop (n);
777   }
778 
779 #if ]b4_api_PREFIX[DEBUG
780   std::ostream&
781   ]b4_parser_class[::debug_stream () const
782   {
783     return *yycdebug_;
784   }
785 
786   void
787   ]b4_parser_class[::set_debug_stream (std::ostream& o)
788   {
789     yycdebug_ = &o;
790   }
791 
792 
793   ]b4_parser_class[::debug_level_type
794   ]b4_parser_class[::debug_level () const
795   {
796     return yydebug_;
797   }
798 
799   void
800   ]b4_parser_class[::set_debug_level (debug_level_type l)
801   {
802     yydebug_ = l;
803   }
804 #endif // ]b4_api_PREFIX[DEBUG
805 
806   ]b4_parser_class[::state_type
807   ]b4_parser_class[::yy_lr_goto_state_ (state_type yystate, int yysym)
808   {
809     int yyr = yypgoto_[yysym - YYNTOKENS] + yystate;
810     if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
811       return yytable_[yyr];
812     else
813       return yydefgoto_[yysym - YYNTOKENS];
814   }
815 
816   bool
817   ]b4_parser_class[::yy_pact_value_is_default_ (int yyvalue)
818   {
819     return yyvalue == yypact_ninf_;
820   }
821 
822   bool
823   ]b4_parser_class[::yy_table_value_is_error_ (int yyvalue)
824   {
825     return yyvalue == yytable_ninf_;
826   }
827 
828   int
829   ]b4_parser_class[::operator() ()
830   {
831     return parse ();
832   }
833 
834   int
835   ]b4_parser_class[::parse ()
836   {
837     int yyn;
838     /// Length of the RHS of the rule being reduced.
839     int yylen = 0;
840 
841     // Error handling.
842     int yynerrs_ = 0;
843     int yyerrstatus_ = 0;
844 
845     /// The lookahead symbol.
846     symbol_type yyla;]b4_locations_if([[
847 
848     /// The locations where the error started and ended.
849     stack_symbol_type yyerror_range[3];]])[
850 
851     /// The return value of parse ().
852     int yyresult;]b4_lac_if([[
853 
854     /// Discard the LAC context in case there still is one left from a
855     /// previous invocation.
856     yy_lac_discard_ ("init");]])[
857 
858 #if YY_EXCEPTIONS
859     try
860 #endif // YY_EXCEPTIONS
861       {
862     YYCDEBUG << "Starting parse\n";
863 
864 ]m4_ifdef([b4_initial_action], [
865 b4_dollar_pushdef([yyla.value], [], [], [yyla.location])dnl
866     b4_user_initial_action
867 b4_dollar_popdef])[]dnl
868 
869   [  /* Initialize the stack.  The initial state will be set in
870        yynewstate, since the latter expects the semantical and the
871        location values to have been already stored, initialize these
872        stacks with a primary value.  */
873     yystack_.clear ();
874     yypush_ (YY_NULLPTR, 0, YY_MOVE (yyla));
875 
876   /*-----------------------------------------------.
877   | yynewstate -- push a new symbol on the stack.  |
878   `-----------------------------------------------*/
879   yynewstate:
880     YYCDEBUG << "Entering state " << int (yystack_[0].state) << '\n';
881     YY_STACK_PRINT ();
882 
883     // Accept?
884     if (yystack_[0].state == yyfinal_)
885       YYACCEPT;
886 
887     goto yybackup;
888 
889 
890   /*-----------.
891   | yybackup.  |
892   `-----------*/
893   yybackup:
894     // Try to take a decision without lookahead.
895     yyn = yypact_[+yystack_[0].state];
896     if (yy_pact_value_is_default_ (yyn))
897       goto yydefault;
898 
899     // Read a lookahead token.
900     if (yyla.empty ())
901       {
902         YYCDEBUG << "Reading a token\n";
903 #if YY_EXCEPTIONS
904         try
905 #endif // YY_EXCEPTIONS
906           {]b4_token_ctor_if([[
907             symbol_type yylookahead (]b4_lex[);
908             yyla.move (yylookahead);]], [[
909             yyla.kind_ = yytranslate_ (]b4_lex[);]])[
910           }
911 #if YY_EXCEPTIONS
912         catch (const syntax_error& yyexc)
913           {
914             YYCDEBUG << "Caught exception: " << yyexc.what() << '\n';
915             error (yyexc);
916             goto yyerrlab1;
917           }
918 #endif // YY_EXCEPTIONS
919       }
920     YY_SYMBOL_PRINT ("Next token is", yyla);
921 
922     if (yyla.kind () == ]b4_symbol(1, kind)[)
923     {
924       // The scanner already issued an error message, process directly
925       // to error recovery.  But do not keep the error token as
926       // lookahead, it is too special and may lead us to an endless
927       // loop in error recovery. */
928       yyla.kind_ = ]b4_symbol(2, kind)[;
929       goto yyerrlab1;
930     }
931 
932     /* If the proper action on seeing token YYLA.TYPE is to reduce or
933        to detect an error, take that action.  */
934     yyn += yyla.kind ();
935     if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.kind ())
936       {]b4_lac_if([[
937         if (!yy_lac_establish_ (yyla.kind ()))
938            goto yyerrlab;]])[
939         goto yydefault;
940       }
941 
942     // Reduce or error.
943     yyn = yytable_[yyn];
944     if (yyn <= 0)
945       {
946         if (yy_table_value_is_error_ (yyn))
947           goto yyerrlab;]b4_lac_if([[
948         if (!yy_lac_establish_ (yyla.kind ()))
949            goto yyerrlab;
950 ]])[
951         yyn = -yyn;
952         goto yyreduce;
953       }
954 
955     // Count tokens shifted since error; after three, turn off error status.
956     if (yyerrstatus_)
957       --yyerrstatus_;
958 
959     // Shift the lookahead token.
960     yypush_ ("Shifting", state_type (yyn), YY_MOVE (yyla));]b4_lac_if([[
961     yy_lac_discard_ ("shift");]])[
962     goto yynewstate;
963 
964 
965   /*-----------------------------------------------------------.
966   | yydefault -- do the default action for the current state.  |
967   `-----------------------------------------------------------*/
968   yydefault:
969     yyn = yydefact_[+yystack_[0].state];
970     if (yyn == 0)
971       goto yyerrlab;
972     goto yyreduce;
973 
974 
975   /*-----------------------------.
976   | yyreduce -- do a reduction.  |
977   `-----------------------------*/
978   yyreduce:
979     yylen = yyr2_[yyn];
980     {
981       stack_symbol_type yylhs;
982       yylhs.state = yy_lr_goto_state_ (yystack_[yylen].state, yyr1_[yyn]);]b4_variant_if([
983       /* Variants are always initialized to an empty instance of the
984          correct type. The default '$$ = $1' action is NOT applied
985          when using variants.  */
986       b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [emplace])], [
987       /* If YYLEN is nonzero, implement the default value of the
988          action: '$$ = $1'.  Otherwise, use the top of the stack.
989 
990          Otherwise, the following line sets YYLHS.VALUE to garbage.
991          This behavior is undocumented and Bison users should not rely
992          upon it.  */
993       if (yylen)
994         yylhs.value = yystack_@{yylen - 1@}.value;
995       else
996         yylhs.value = yystack_@{0@}.value;])[
997 ]b4_locations_if([dnl
998 [
999       // Default location.
1000       {
1001         stack_type::slice range (yystack_, yylen);
1002         YYLLOC_DEFAULT (yylhs.location, range, yylen);
1003         yyerror_range[1].location = yylhs.location;
1004       }]])[
1005 
1006       // Perform the reduction.
1007       YY_REDUCE_PRINT (yyn);
1008 #if YY_EXCEPTIONS
1009       try
1010 #endif // YY_EXCEPTIONS
1011         {
1012           switch (yyn)
1013             {
1014 ]b4_user_actions[
1015             default:
1016               break;
1017             }
1018         }
1019 #if YY_EXCEPTIONS
1020       catch (const syntax_error& yyexc)
1021         {
1022           YYCDEBUG << "Caught exception: " << yyexc.what() << '\n';
1023           error (yyexc);
1024           YYERROR;
1025         }
1026 #endif // YY_EXCEPTIONS
1027       YY_SYMBOL_PRINT ("-> $$ =", yylhs);
1028       yypop_ (yylen);
1029       yylen = 0;
1030 
1031       // Shift the result of the reduction.
1032       yypush_ (YY_NULLPTR, YY_MOVE (yylhs));
1033     }
1034     goto yynewstate;
1035 
1036 
1037   /*--------------------------------------.
1038   | yyerrlab -- here on detecting error.  |
1039   `--------------------------------------*/
1040   yyerrlab:
1041     // If not already recovering from an error, report this error.
1042     if (!yyerrstatus_)
1043       {
1044         ++yynerrs_;]b4_parse_error_case(
1045                   [simple], [[
1046         std::string msg = YY_("syntax error");
1047         error (]b4_join(b4_locations_if([yyla.location]), [[YY_MOVE (msg)]])[);]],
1048                   [custom], [[
1049         context yyctx (*this, yyla);
1050         report_syntax_error (yyctx);]],
1051                   [[
1052         context yyctx (*this, yyla);
1053         std::string msg = yysyntax_error_ (yyctx);
1054         error (]b4_join(b4_locations_if([yyla.location]), [[YY_MOVE (msg)]])[);]])[
1055       }
1056 
1057 ]b4_locations_if([[
1058     yyerror_range[1].location = yyla.location;]])[
1059     if (yyerrstatus_ == 3)
1060       {
1061         /* If just tried and failed to reuse lookahead token after an
1062            error, discard it.  */
1063 
1064         // Return failure if at end of input.
1065         if (yyla.kind () == ]b4_symbol(0, kind)[)
1066           YYABORT;
1067         else if (!yyla.empty ())
1068           {
1069             yy_destroy_ ("Error: discarding", yyla);
1070             yyla.clear ();
1071           }
1072       }
1073 
1074     // Else will try to reuse lookahead token after shifting the error token.
1075     goto yyerrlab1;
1076 
1077 
1078   /*---------------------------------------------------.
1079   | yyerrorlab -- error raised explicitly by YYERROR.  |
1080   `---------------------------------------------------*/
1081   yyerrorlab:
1082     /* Pacify compilers when the user code never invokes YYERROR and
1083        the label yyerrorlab therefore never appears in user code.  */
1084     if (false)
1085       YYERROR;
1086 
1087     /* Do not reclaim the symbols of the rule whose action triggered
1088        this YYERROR.  */
1089     yypop_ (yylen);
1090     yylen = 0;
1091     YY_STACK_PRINT ();
1092     goto yyerrlab1;
1093 
1094 
1095   /*-------------------------------------------------------------.
1096   | yyerrlab1 -- common code for both syntax error and YYERROR.  |
1097   `-------------------------------------------------------------*/
1098   yyerrlab1:
1099     yyerrstatus_ = 3;   // Each real token shifted decrements this.
1100     // Pop stack until we find a state that shifts the error token.
1101     for (;;)
1102       {
1103         yyn = yypact_[+yystack_[0].state];
1104         if (!yy_pact_value_is_default_ (yyn))
1105           {
1106             yyn += ]b4_symbol(1, kind)[;
1107             if (0 <= yyn && yyn <= yylast_
1108                 && yycheck_[yyn] == ]b4_symbol(1, kind)[)
1109               {
1110                 yyn = yytable_[yyn];
1111                 if (0 < yyn)
1112                   break;
1113               }
1114           }
1115 
1116         // Pop the current state because it cannot handle the error token.
1117         if (yystack_.size () == 1)
1118           YYABORT;
1119 ]b4_locations_if([[
1120         yyerror_range[1].location = yystack_[0].location;]])[
1121         yy_destroy_ ("Error: popping", yystack_[0]);
1122         yypop_ ();
1123         YY_STACK_PRINT ();
1124       }
1125     {
1126       stack_symbol_type error_token;
1127 ]b4_locations_if([[
1128       yyerror_range[2].location = yyla.location;
1129       YYLLOC_DEFAULT (error_token.location, yyerror_range, 2);]])[
1130 
1131       // Shift the error token.]b4_lac_if([[
1132       yy_lac_discard_ ("error recovery");]])[
1133       error_token.state = state_type (yyn);
1134       yypush_ ("Shifting", YY_MOVE (error_token));
1135     }
1136     goto yynewstate;
1137 
1138 
1139   /*-------------------------------------.
1140   | yyacceptlab -- YYACCEPT comes here.  |
1141   `-------------------------------------*/
1142   yyacceptlab:
1143     yyresult = 0;
1144     goto yyreturn;
1145 
1146 
1147   /*-----------------------------------.
1148   | yyabortlab -- YYABORT comes here.  |
1149   `-----------------------------------*/
1150   yyabortlab:
1151     yyresult = 1;
1152     goto yyreturn;
1153 
1154 
1155   /*-----------------------------------------------------.
1156   | yyreturn -- parsing is finished, return the result.  |
1157   `-----------------------------------------------------*/
1158   yyreturn:
1159     if (!yyla.empty ())
1160       yy_destroy_ ("Cleanup: discarding lookahead", yyla);
1161 
1162     /* Do not reclaim the symbols of the rule whose action triggered
1163        this YYABORT or YYACCEPT.  */
1164     yypop_ (yylen);
1165     YY_STACK_PRINT ();
1166     while (1 < yystack_.size ())
1167       {
1168         yy_destroy_ ("Cleanup: popping", yystack_[0]);
1169         yypop_ ();
1170       }
1171 
1172     return yyresult;
1173   }
1174 #if YY_EXCEPTIONS
1175     catch (...)
1176       {
1177         YYCDEBUG << "Exception caught: cleaning lookahead and stack\n";
1178         // Do not try to display the values of the reclaimed symbols,
1179         // as their printers might throw an exception.
1180         if (!yyla.empty ())
1181           yy_destroy_ (YY_NULLPTR, yyla);
1182 
1183         while (1 < yystack_.size ())
1184           {
1185             yy_destroy_ (YY_NULLPTR, yystack_[0]);
1186             yypop_ ();
1187           }
1188         throw;
1189       }
1190 #endif // YY_EXCEPTIONS
1191   }
1192 
1193   void
1194   ]b4_parser_class[::error (const syntax_error& yyexc)
1195   {
1196     error (]b4_join(b4_locations_if([yyexc.location]),
1197                     [[yyexc.what ()]])[);
1198   }
1199 
1200 ]b4_parse_error_bmatch([custom\|detailed],
1201 [[  const char *
1202   ]b4_parser_class[::symbol_name (symbol_kind_type yysymbol)
1203   {
1204     static const char *const yy_sname[] =
1205     {
1206     ]b4_symbol_names[
1207     };]b4_has_translations_if([[
1208     /* YYTRANSLATABLE[SYMBOL-NUM] -- Whether YY_SNAME[SYMBOL-NUM] is
1209        internationalizable.  */
1210     static ]b4_int_type_for([b4_translatable])[ yytranslatable[] =
1211     {
1212     ]b4_translatable[
1213     };
1214     return (yysymbol < YYNTOKENS && yytranslatable[yysymbol]
1215             ? _(yy_sname[yysymbol])
1216             : yy_sname[yysymbol]);]], [[
1217     return yy_sname[yysymbol];]])[
1218   }
1219 ]],
1220 [simple],
1221 [[#if ]b4_api_PREFIX[DEBUG || ]b4_token_table_flag[
1222   const char *
1223   ]b4_parser_class[::symbol_name (symbol_kind_type yysymbol)
1224   {
1225     return yytname_[yysymbol];
1226   }
1227 #endif // #if ]b4_api_PREFIX[DEBUG || ]b4_token_table_flag[
1228 ]],
1229 [verbose],
1230 [[  /* Return YYSTR after stripping away unnecessary quotes and
1231      backslashes, so that it's suitable for yyerror.  The heuristic is
1232      that double-quoting is unnecessary unless the string contains an
1233      apostrophe, a comma, or backslash (other than backslash-backslash).
1234      YYSTR is taken from yytname.  */
1235   std::string
1236   ]b4_parser_class[::yytnamerr_ (const char *yystr)
1237   {
1238     if (*yystr == '"')
1239       {
1240         std::string yyr;
1241         char const *yyp = yystr;
1242 
1243         for (;;)
1244           switch (*++yyp)
1245             {
1246             case '\'':
1247             case ',':
1248               goto do_not_strip_quotes;
1249 
1250             case '\\':
1251               if (*++yyp != '\\')
1252                 goto do_not_strip_quotes;
1253               else
1254                 goto append;
1255 
1256             append:
1257             default:
1258               yyr += *yyp;
1259               break;
1260 
1261             case '"':
1262               return yyr;
1263             }
1264       do_not_strip_quotes: ;
1265       }
1266 
1267     return yystr;
1268   }
1269 
1270   std::string
1271   ]b4_parser_class[::symbol_name (symbol_kind_type yysymbol)
1272   {
1273     return yytnamerr_ (yytname_[yysymbol]);
1274   }
1275 ]])[
1276 
1277 ]b4_parse_error_bmatch([custom\|detailed\|verbose], [[
1278   // ]b4_parser_class[::context.
1279   ]b4_parser_class[::context::context (const ]b4_parser_class[& yyparser, const symbol_type& yyla)
1280     : yyparser_ (yyparser)
1281     , yyla_ (yyla)
1282   {}
1283 
1284   int
1285   ]b4_parser_class[::context::expected_tokens (symbol_kind_type yyarg[], int yyargn) const
1286   {
1287     // Actual number of expected tokens
1288     int yycount = 0;
1289 ]b4_lac_if([[
1290 #if ]b4_api_PREFIX[DEBUG
1291     // Execute LAC once. We don't care if it is successful, we
1292     // only do it for the sake of debugging output.
1293     if (!yyparser_.yy_lac_established_)
1294       yyparser_.yy_lac_check_ (yyla_.kind ());
1295 #endif
1296 
1297     for (int yyx = 0; yyx < YYNTOKENS; ++yyx)
1298       {
1299         symbol_kind_type yysym = YY_CAST (symbol_kind_type, yyx);
1300         if (yysym != ]b4_symbol(1, kind)[
1301             && yysym != ]b4_symbol(2, kind)[
1302             && yyparser_.yy_lac_check_ (yysym))
1303           {
1304             if (!yyarg)
1305               ++yycount;
1306             else if (yycount == yyargn)
1307               return 0;
1308             else
1309               yyarg[yycount++] = yysym;
1310           }
1311       }]], [[
1312     int yyn = yypact_[+yyparser_.yystack_[0].state];
1313     if (!yy_pact_value_is_default_ (yyn))
1314       {
1315         /* Start YYX at -YYN if negative to avoid negative indexes in
1316            YYCHECK.  In other words, skip the first -YYN actions for
1317            this state because they are default actions.  */
1318         int yyxbegin = yyn < 0 ? -yyn : 0;
1319         // Stay within bounds of both yycheck and yytname.
1320         int yychecklim = yylast_ - yyn + 1;
1321         int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
1322         for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
1323           if (yycheck_[yyx + yyn] == yyx && yyx != ]b4_symbol(1, kind)[
1324               && !yy_table_value_is_error_ (yytable_[yyx + yyn]))
1325             {
1326               if (!yyarg)
1327                 ++yycount;
1328               else if (yycount == yyargn)
1329                 return 0;
1330               else
1331                 yyarg[yycount++] = YY_CAST (symbol_kind_type, yyx);
1332             }
1333       }
1334 ]])[
1335     if (yyarg && yycount == 0 && 0 < yyargn)
1336       yyarg[0] = ]b4_symbol(-2, kind)[;
1337     return yycount;
1338   }
1339 
1340 ]])b4_lac_if([[
1341   bool
1342   ]b4_parser_class[::yy_lac_check_ (symbol_kind_type yytoken) const
1343   {
1344     // Logically, the yylac_stack's lifetime is confined to this function.
1345     // Clear it, to get rid of potential left-overs from previous call.
1346     yylac_stack_.clear ();
1347     // Reduce until we encounter a shift and thereby accept the token.
1348 #if ]b4_api_PREFIX[DEBUG
1349     YYCDEBUG << "LAC: checking lookahead " << symbol_name (yytoken) << ':';
1350 #endif
1351     std::ptrdiff_t lac_top = 0;
1352     while (true)
1353       {
1354         state_type top_state = (yylac_stack_.empty ()
1355                                 ? yystack_[lac_top].state
1356                                 : yylac_stack_.back ());
1357         int yyrule = yypact_[+top_state];
1358         if (yy_pact_value_is_default_ (yyrule)
1359             || (yyrule += yytoken) < 0 || yylast_ < yyrule
1360             || yycheck_[yyrule] != yytoken)
1361           {
1362             // Use the default action.
1363             yyrule = yydefact_[+top_state];
1364             if (yyrule == 0)
1365               {
1366                 YYCDEBUG << " Err\n";
1367                 return false;
1368               }
1369           }
1370         else
1371           {
1372             // Use the action from yytable.
1373             yyrule = yytable_[yyrule];
1374             if (yy_table_value_is_error_ (yyrule))
1375               {
1376                 YYCDEBUG << " Err\n";
1377                 return false;
1378               }
1379             if (0 < yyrule)
1380               {
1381                 YYCDEBUG << " S" << yyrule << '\n';
1382                 return true;
1383               }
1384             yyrule = -yyrule;
1385           }
1386         // By now we know we have to simulate a reduce.
1387         YYCDEBUG << " R" << yyrule - 1;
1388         // Pop the corresponding number of values from the stack.
1389         {
1390           std::ptrdiff_t yylen = yyr2_[yyrule];
1391           // First pop from the LAC stack as many tokens as possible.
1392           std::ptrdiff_t lac_size = std::ptrdiff_t (yylac_stack_.size ());
1393           if (yylen < lac_size)
1394             {
1395               yylac_stack_.resize (std::size_t (lac_size - yylen));
1396               yylen = 0;
1397             }
1398           else if (lac_size)
1399             {
1400               yylac_stack_.clear ();
1401               yylen -= lac_size;
1402             }
1403           // Only afterwards look at the main stack.
1404           // We simulate popping elements by incrementing lac_top.
1405           lac_top += yylen;
1406         }
1407         // Keep top_state in sync with the updated stack.
1408         top_state = (yylac_stack_.empty ()
1409                      ? yystack_[lac_top].state
1410                      : yylac_stack_.back ());
1411         // Push the resulting state of the reduction.
1412         state_type state = yy_lr_goto_state_ (top_state, yyr1_[yyrule]);
1413         YYCDEBUG << " G" << int (state);
1414         yylac_stack_.push_back (state);
1415       }
1416   }
1417 
1418   // Establish the initial context if no initial context currently exists.
1419   bool
1420   ]b4_parser_class[::yy_lac_establish_ (symbol_kind_type yytoken)
1421   {
1422     /* Establish the initial context for the current lookahead if no initial
1423        context is currently established.
1424 
1425        We define a context as a snapshot of the parser stacks.  We define
1426        the initial context for a lookahead as the context in which the
1427        parser initially examines that lookahead in order to select a
1428        syntactic action.  Thus, if the lookahead eventually proves
1429        syntactically unacceptable (possibly in a later context reached via a
1430        series of reductions), the initial context can be used to determine
1431        the exact set of tokens that would be syntactically acceptable in the
1432        lookahead's place.  Moreover, it is the context after which any
1433        further semantic actions would be erroneous because they would be
1434        determined by a syntactically unacceptable token.
1435 
1436        yy_lac_establish_ should be invoked when a reduction is about to be
1437        performed in an inconsistent state (which, for the purposes of LAC,
1438        includes consistent states that don't know they're consistent because
1439        their default reductions have been disabled).
1440 
1441        For parse.lac=full, the implementation of yy_lac_establish_ is as
1442        follows.  If no initial context is currently established for the
1443        current lookahead, then check if that lookahead can eventually be
1444        shifted if syntactic actions continue from the current context.  */
1445     if (!yy_lac_established_)
1446       {
1447 #if ]b4_api_PREFIX[DEBUG
1448         YYCDEBUG << "LAC: initial context established for "
1449                  << symbol_name (yytoken) << '\n';
1450 #endif
1451         yy_lac_established_ = true;
1452         return yy_lac_check_ (yytoken);
1453       }
1454     return true;
1455   }
1456 
1457   // Discard any previous initial lookahead context.
1458   void
1459   ]b4_parser_class[::yy_lac_discard_ (const char* evt)
1460   {
1461    /* Discard any previous initial lookahead context because of Event,
1462       which may be a lookahead change or an invalidation of the currently
1463       established initial context for the current lookahead.
1464 
1465       The most common example of a lookahead change is a shift.  An example
1466       of both cases is syntax error recovery.  That is, a syntax error
1467       occurs when the lookahead is syntactically erroneous for the
1468       currently established initial context, so error recovery manipulates
1469       the parser stacks to try to find a new initial context in which the
1470       current lookahead is syntactically acceptable.  If it fails to find
1471       such a context, it discards the lookahead.  */
1472     if (yy_lac_established_)
1473       {
1474         YYCDEBUG << "LAC: initial context discarded due to "
1475                  << evt << '\n';
1476         yy_lac_established_ = false;
1477       }
1478   }]])b4_parse_error_bmatch([detailed\|verbose], [[
1479 
1480   int
1481   ]b4_parser_class[::yy_syntax_error_arguments_ (const context& yyctx,
1482                                                  symbol_kind_type yyarg[], int yyargn) const
1483   {
1484     /* There are many possibilities here to consider:
1485        - If this state is a consistent state with a default action, then
1486          the only way this function was invoked is if the default action
1487          is an error action.  In that case, don't check for expected
1488          tokens because there are none.
1489        - The only way there can be no lookahead present (in yyla) is
1490          if this state is a consistent state with a default action.
1491          Thus, detecting the absence of a lookahead is sufficient to
1492          determine that there is no unexpected or expected token to
1493          report.  In that case, just report a simple "syntax error".
1494        - Don't assume there isn't a lookahead just because this state is
1495          a consistent state with a default action.  There might have
1496          been a previous inconsistent state, consistent state with a
1497          non-default action, or user semantic action that manipulated
1498          yyla.  (However, yyla is currently not documented for users.)]b4_lac_if([[
1499          In the first two cases, it might appear that the current syntax
1500          error should have been detected in the previous state when
1501          yy_lac_check was invoked.  However, at that time, there might
1502          have been a different syntax error that discarded a different
1503          initial context during error recovery, leaving behind the
1504          current lookahead.]], [[
1505        - Of course, the expected token list depends on states to have
1506          correct lookahead information, and it depends on the parser not
1507          to perform extra reductions after fetching a lookahead from the
1508          scanner and before detecting a syntax error.  Thus, state merging
1509          (from LALR or IELR) and default reductions corrupt the expected
1510          token list.  However, the list is correct for canonical LR with
1511          one exception: it will still contain any token that will not be
1512          accepted due to an error action in a later state.]])[
1513     */
1514 
1515     if (!yyctx.lookahead ().empty ())
1516       {
1517         if (yyarg)
1518           yyarg[0] = yyctx.token ();
1519         int yyn = yyctx.expected_tokens (yyarg ? yyarg + 1 : yyarg, yyargn - 1);
1520         return yyn + 1;
1521       }
1522     return 0;
1523   }
1524 
1525   // Generate an error message.
1526   std::string
1527   ]b4_parser_class[::yysyntax_error_ (const context& yyctx) const
1528   {
1529     // Its maximum.
1530     enum { YYARGS_MAX = 5 };
1531     // Arguments of yyformat.
1532     symbol_kind_type yyarg[YYARGS_MAX];
1533     int yycount = yy_syntax_error_arguments_ (yyctx, yyarg, YYARGS_MAX);
1534 
1535     char const* yyformat = YY_NULLPTR;
1536     switch (yycount)
1537       {
1538 #define YYCASE_(N, S)                         \
1539         case N:                               \
1540           yyformat = S;                       \
1541         break
1542       default: // Avoid compiler warnings.
1543         YYCASE_ (0, YY_("syntax error"));
1544         YYCASE_ (1, YY_("syntax error, unexpected %s"));
1545         YYCASE_ (2, YY_("syntax error, unexpected %s, expecting %s"));
1546         YYCASE_ (3, YY_("syntax error, unexpected %s, expecting %s or %s"));
1547         YYCASE_ (4, YY_("syntax error, unexpected %s, expecting %s or %s or %s"));
1548         YYCASE_ (5, YY_("syntax error, unexpected %s, expecting %s or %s or %s or %s"));
1549 #undef YYCASE_
1550       }
1551 
1552     std::string yyres;
1553     // Argument number.
1554     std::ptrdiff_t yyi = 0;
1555     for (char const* yyp = yyformat; *yyp; ++yyp)
1556       if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount)
1557         {
1558           yyres += symbol_name (yyarg[yyi++]);
1559           ++yyp;
1560         }
1561       else
1562         yyres += *yyp;
1563     return yyres;
1564   }]])[
1565 
1566 
1567   const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) b4_parser_class::yypact_ninf_ = b4_pact_ninf[;
1568 
1569   const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class::yytable_ninf_ = b4_table_ninf[;
1570 
1571 ]b4_parser_tables_define[
1572 
1573 ]b4_parse_error_bmatch([simple\|verbose],
1574 [[#if ]b4_api_PREFIX[DEBUG]b4_tname_if([[ || 1]])[
1575   // YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
1576   // First, the terminals, then, starting at \a YYNTOKENS, nonterminals.
1577   const char*
1578   const ]b4_parser_class[::yytname_[] =
1579   {
1580   ]b4_tname[
1581   };
1582 #endif
1583 ]])[
1584 
1585 #if ]b4_api_PREFIX[DEBUG][
1586 ]b4_integral_parser_table_define([rline], [b4_rline])[
1587 
1588   void
1589   ]b4_parser_class[::yy_stack_print_ () const
1590   {
1591     *yycdebug_ << "Stack now";
1592     for (stack_type::const_iterator
1593            i = yystack_.begin (),
1594            i_end = yystack_.end ();
1595          i != i_end; ++i)
1596       *yycdebug_ << ' ' << int (i->state);
1597     *yycdebug_ << '\n';
1598   }
1599 
1600   void
1601   ]b4_parser_class[::yy_reduce_print_ (int yyrule) const
1602   {
1603     int yylno = yyrline_[yyrule];
1604     int yynrhs = yyr2_[yyrule];
1605     // Print the symbols being reduced, and their result.
1606     *yycdebug_ << "Reducing stack by rule " << yyrule - 1
1607                << " (line " << yylno << "):\n";
1608     // The symbols being reduced.
1609     for (int yyi = 0; yyi < yynrhs; yyi++)
1610       YY_SYMBOL_PRINT ("   $" << yyi + 1 << " =",
1611                        ]b4_rhs_data(yynrhs, yyi + 1)[);
1612   }
1613 #endif // ]b4_api_PREFIX[DEBUG
1614 
1615 ]b4_token_ctor_if([], [b4_yytranslate_define([cc])])[
1616 ]b4_namespace_close[
1617 ]b4_epilogue[]dnl
1618 b4_output_end
1619 
1620 
1621 m4_popdef([b4_copyright_years])dnl
1622