data/glr.cc

   1 # C++ GLR skeleton for Bison
   2
   3 # Copyright (C) 2002-2012 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 <http://www.gnu.org/licenses/>.
  17
  18
  19 # This skeleton produces a C++ class that encapsulates a C glr parser.
  20 # This is in order to reduce the maintenance burden.  The glr.c
  21 # skeleton is clean and pure enough so that there are no real
  22 # problems.  The C++ interface is the same as that of lalr1.cc.  In
  23 # fact, glr.c can replace yacc.c without the user noticing any
  24 # difference, and similarly for glr.cc replacing lalr1.cc.
  25 #
  26 # The passing of parse-params
  27 #
  28 #   The additional arguments are stored as members of the parser
  29 #   object, yyparser.  The C routines need to carry yyparser
  30 #   throughout the C parser; that's easy: make yyparser an
  31 #   additional parse-param.  But because the C++ skeleton needs to
  32 #   know the "real" original parse-param, we save them
  33 #   (b4_parse_param_orig).  Note that b4_parse_param is overquoted
  34 #   (and c.m4 strips one level of quotes).  This is a PITA, and
  35 #   explains why there are so many levels of quotes.
  36 #
  37 # The locations
  38 #
  39 #   We use location.cc just like lalr1.cc, but because glr.c stores
  40 #   the locations in a union, the position and location classes
  41 #   must not have a constructor.  Therefore, contrary to lalr1.cc, we
  42 #   must not define "b4_location_constructors".  As a consequence the
  43 #   user must initialize the first positions (in particular the
  44 #   filename member).
  45
  46 b4_token_ctor_if([b4_variant_if([],
  47   [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
  48                [cannot use '%s' without '%s'],
  49                [%define api.token.constructor],
  50                [%define api.value.type variant]))])])
  51
  52 # We require a pure interface.
  53 m4_define([b4_pure_flag],      [1])
  54
  55 m4_include(b4_pkgdatadir/[c++.m4])
  56 b4_bison_locations_if([m4_include(b4_pkgdatadir/[location.cc])])
  57
  58 m4_define([b4_parser_class_name],
  59           [b4_percent_define_get([[parser_class_name]])])
  60
  61 # Save the parse parameters.
  62 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  63
  64 # b4_parse_param_wrap
  65 # -------------------
  66 # New ones.
  67 m4_ifset([b4_parse_param],
  68 [m4_define([b4_parse_param_wrap],
  69            [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
  70 m4_defn([b4_parse_param]))],
  71 [m4_define([b4_parse_param_wrap],
  72            [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
  73 ])
  74
  75
  76 # b4_yy_symbol_print_define
  77 # -------------------------
  78 # Bypass the default implementation to generate the "yy_symbol_print"
  79 # and "yy_symbol_value_print" functions.
  80 m4_define([b4_yy_symbol_print_define],
  81 [[
  82 /*--------------------.
  83 | Print this symbol.  |
  84 `--------------------*/
  85
  86 ]b4_function_define([yy_symbol_print],
  87     [static void],
  88     [[FILE *],      []],
  89     [[int yytype],  [yytype]],
  90     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  91                     [yyvaluep]][]dnl
  92 b4_locations_if([,
  93     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  94                     [yylocationp]]]),
  95     b4_parse_param)[
  96 {
  97 ]b4_parse_param_use[]dnl
  98 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  99 }
 100 ]])[
 101
 102 # Hijack the initial action to initialize the locations.
 103 ]b4_bison_locations_if([m4_define([b4_initial_action],
 104 [yylloc.initialize ();]m4_ifdef([b4_initial_action], [
 105 m4_defn([b4_initial_action])]))])[
 106
 107 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
 108 # and declaration of yyerror.
 109 ]m4_append([b4_post_prologue],
 110 [b4_syncline([@oline@], [@ofile@])[
 111 ]b4_yylloc_default_define[
 112 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
 113 ]b4_function_declare([yyerror],
 114     [static void],b4_locations_if([
 115     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 116                         [yylocationp]],])
 117     b4_parse_param,
 118     [[const char* msg], [msg]])])
 119
 120
 121 #undef yynerrs
 122 #undef yychar
 123 #undef yylval]b4_locations_if([
 124 #undef yylloc])
 125
 126 m4_if(b4_prefix, [yy], [],
 127 [[/* Substitute the variable and function names.  */
 128 #define yyparse ]b4_prefix[parse
 129 #define yylex   ]b4_prefix[lex
 130 #define yyerror ]b4_prefix[error
 131 #define yydebug ]b4_prefix[debug
 132 ]]b4_pure_if([], [[
 133 #define yylval  ]b4_prefix[lval
 134 #define yychar  ]b4_prefix[char
 135 #define yynerrs ]b4_prefix[nerrs]b4_locations_if([[
 136 #define yylloc  ]b4_prefix[lloc]])]))
 137
 138 # Hijack the epilogue to define implementations (yyerror, parser member
 139 # functions etc.).
 140 m4_append([b4_epilogue],
 141 [b4_syncline([@oline@], [@ofile@])[
 142
 143 /*------------------.
 144 | Report an error.  |
 145 `------------------*/
 146
 147 ]b4_function_define([yyerror],
 148     [static void],b4_locations_if([
 149     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 150                         [yylocationp]],])
 151     b4_parse_param,
 152     [[const char* msg], [msg]])[
 153 {
 154 ]b4_parse_param_use[]dnl
 155 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 156 }
 157
 158
 159 ]b4_namespace_open[
 160 ]dnl In this section, the parse params are the original parse_params.
 161 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 162 [  /// Build a parser object.
 163   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 164     :])[
 165 #if ]b4_api_PREFIX[DEBUG
 166     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 167 #endif]b4_parse_param_cons[
 168   {
 169   }
 170
 171   ]b4_parser_class_name::~b4_parser_class_name[ ()
 172   {
 173   }
 174
 175   int
 176   ]b4_parser_class_name[::parse ()
 177   {
 178     return ::yyparse (*this]b4_user_args[);
 179   }
 180
 181 #if ]b4_api_PREFIX[DEBUG
 182   /*--------------------.
 183   | Print this symbol.  |
 184   `--------------------*/
 185
 186   inline void
 187   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 188                            const semantic_type* yyvaluep]b4_locations_if([[,
 189                            const location_type* yylocationp]])[)
 190   {]b4_locations_if([[
 191     YYUSE (yylocationp);]])[
 192     YYUSE (yyvaluep);
 193     std::ostream& yyoutput = debug_stream ();
 194     std::ostream& yyo = yyoutput;
 195     YYUSE (yyo);
 196     switch (yytype)
 197       {
 198 ]b4_symbol_foreach([b4_symbol_printer])dnl
 199 [        default:
 200           break;
 201       }
 202   }
 203
 204
 205   void
 206   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 207                            const semantic_type* yyvaluep]b4_locations_if([[,
 208                            const location_type* yylocationp]])[)
 209   {
 210     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 211                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 212                << *yylocationp << ": "]])[;
 213     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 214     *yycdebug_ << ')';
 215   }
 216
 217   std::ostream&
 218   ]b4_parser_class_name[::debug_stream () const
 219   {
 220     return *yycdebug_;
 221   }
 222
 223   void
 224   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 225   {
 226     yycdebug_ = &o;
 227   }
 228
 229
 230   ]b4_parser_class_name[::debug_level_type
 231   ]b4_parser_class_name[::debug_level () const
 232   {
 233     return yydebug;
 234   }
 235
 236   void
 237   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 238   {
 239     // Actually, it is yydebug which is really used.
 240     yydebug = l;
 241   }
 242
 243 #endif
 244 ]m4_popdef([b4_parse_param])dnl
 245 b4_namespace_close
 246 ])
 247
 248 # b4_shared_declarations
 249 # ----------------------
 250 # Declaration that might either go into the header (if --defines)
 251 # or open coded in the parser body.
 252 m4_define([b4_shared_declarations],
 253 [m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 254 b4_percent_code_get([[requires]])[
 255
 256 #include <stdexcept>
 257 #include <string>
 258 #include <iostream>]b4_defines_if([
 259 b4_bison_locations_if([[#include "location.hh"]])])[
 260
 261 ]b4_YYDEBUG_define[
 262
 263 ]b4_namespace_open[
 264 ]b4_defines_if([],
 265 [b4_bison_locations_if([b4_position_define
 266 b4_location_define])])[
 267
 268   /// A Bison parser.
 269   class ]b4_parser_class_name[
 270   {
 271   public:
 272 ]b4_public_types_declare[
 273
 274     /// Build a parser object.
 275     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 276     virtual ~]b4_parser_class_name[ ();
 277
 278     /// Parse.
 279     /// \returns  0 iff parsing succeeded.
 280     virtual int parse ();
 281
 282     /// The current debugging stream.
 283     std::ostream& debug_stream () const;
 284     /// Set the current debugging stream.
 285     void set_debug_stream (std::ostream &);
 286
 287     /// Type for debugging levels.
 288     typedef int debug_level_type;
 289     /// The current debugging level.
 290     debug_level_type debug_level () const;
 291     /// Set the current debugging level.
 292     void set_debug_level (debug_level_type l);
 293
 294   public:
 295     /// Report a syntax error.]b4_locations_if([[
 296     /// \param loc    where the syntax error is found.]])[
 297     /// \param msg    a description of the syntax error.
 298     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 299
 300 # if ]b4_api_PREFIX[DEBUG
 301   public:
 302     /// \brief Report a symbol value on the debug stream.
 303     /// \param yytype       The token type.
 304     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 305     /// \param yylocationp  Its location.]])[
 306     virtual void yy_symbol_value_print_ (int yytype,
 307                                          const semantic_type* yyvaluep]b4_locations_if([[,
 308                                          const location_type* yylocationp]])[);
 309     /// \brief Report a symbol on the debug stream.
 310     /// \param yytype       The token type.
 311     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 312     /// \param yylocationp  Its location.]])[
 313     virtual void yy_symbol_print_ (int yytype,
 314                                    const semantic_type* yyvaluep]b4_locations_if([[,
 315                                    const location_type* yylocationp]])[);
 316   private:
 317     // Debugging.
 318     std::ostream* yycdebug_;
 319 #endif
 320
 321 ]b4_parse_param_vars[
 322   };
 323
 324 ]dnl Redirections for glr.c.
 325 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 326 [b4_token_defines])
 327 [
 328 #ifndef ]b4_api_PREFIX[STYPE
 329 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 330 #endif
 331 #ifndef ]b4_api_PREFIX[LTYPE
 332 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 333 #endif
 334
 335 ]b4_namespace_close[
 336 ]b4_percent_code_get([[provides]])[
 337 ]m4_popdef([b4_parse_param])dnl
 338 ])
 339
 340 b4_defines_if(
 341 [b4_output_begin([b4_spec_defines_file])
 342 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 343              [2002-2012])[
 344
 345 // C++ GLR parser skeleton written by Akim Demaille.
 346
 347 ]b4_cpp_guard_open([b4_spec_defines_file])[
 348 ]b4_shared_declarations[
 349 ]b4_cpp_guard_close([b4_spec_defines_file])[
 350 ]b4_output_end()])
 351
 352 # Let glr.c (and b4_shared_declarations) believe that the user
 353 # arguments include the parser itself.
 354 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_wrap]))
 355 m4_include(b4_pkgdatadir/[glr.c])
 356 m4_popdef([b4_parse_param])