share/bison/glr.cc

   1                                                                     -*- C -*-
   2
   3 # C++ GLR skeleton for Bison
   4 # Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation,
   5 # Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20
  21 # This skeleton produces a C++ class that encapsulates a C glr parser.
  22 # This is in order to reduce the maintenance burden.  The glr.c
  23 # skeleton is clean and pure enough so that there are no real
  24 # problems.  The C++ interface is the same as that of lalr1.cc.  In
  25 # fact, glr.c can replace yacc.c without the user noticing any
  26 # difference, and similarly for glr.cc replacing lalr1.cc.
  27 #
  28 # The passing of parse-params
  29 #
  30 #   The additional arguments are stored as members of the parser
  31 #   object, yyparser.  The C routines need to carry yyparser
  32 #   throughout the C parser; that easy: just let yyparser become an
  33 #   additional parse-param.  But because the C++ skeleton needs to
  34 #   know the "real" original parse-param, we save them
  35 #   (b4_parse_param_orig).  Note that b4_parse_param is overquoted
  36 #   (and c.m4 strips one level of quotes).  This is a PITA, and
  37 #   explains why there are so many levels of quotes.
  38 #
  39 # The locations
  40 #
  41 #   We use location.cc just like lalr1.cc, but because glr.c stores
  42 #   the locations in a (C++) union, the position and location classes
  43 #   must not have a constructor.  Therefore, contrary to lalr1.cc, we
  44 #   must not define "b4_location_constructors".  As a consequence the
  45 #   user must initialize the first positions (in particular the
  46 #   filename member).
  47
  48 # We require a pure interface using locations.
  49 m4_define([b4_locations_flag], [1])
  50 m4_define([b4_pure_flag],      [1])
  51
  52 # The header is mandatory.
  53 b4_defines_if([],
  54               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
  55
  56 m4_include(b4_pkgdatadir/[c++.m4])
  57 m4_include(b4_pkgdatadir/[location.cc])
  58
  59 m4_define([b4_parser_class_name],
  60           [b4_percent_define_get([[parser_class_name]])])
  61
  62 # Save the parse parameters.
  63 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  64
  65
  66 # b4_yy_symbol_print_generate
  67 # ---------------------------
  68 # Bypass the default implementation to generate the "yy_symbol_print"
  69 # and "yy_symbol_value_print" functions.
  70 m4_define([b4_yy_symbol_print_generate],
  71 [[
  72 /*--------------------.
  73 | Print this symbol.  |
  74 `--------------------*/
  75
  76 ]b4_c_ansi_function_def([yy_symbol_print],
  77     [static void],
  78     [[FILE *],               []],
  79     [[int yytype],           [yytype]],
  80     [[const b4_namespace_ref::b4_parser_class_name::semantic_type *yyvaluep],
  81                              [yyvaluep]],
  82     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
  83                              [yylocationp]],
  84     b4_parse_param)[
  85 {
  86 ]b4_parse_param_use[]dnl
  87 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  88 }
  89 ]])
  90
  91
  92 # Declare yyerror.
  93 m4_append([b4_post_prologue],
  94 [b4_syncline([@oline@], [@ofile@])
  95
  96 b4_c_ansi_function_decl([yyerror],
  97     [static void],
  98     [[b4_namespace_ref::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
  99     b4_parse_param,
 100     [[const char* msg], [msg]])])
 101
 102
 103 # Define yyerror.
 104 m4_append([b4_epilogue],
 105 [b4_syncline([@oline@], [@ofile@])[
 106 /*------------------.
 107 | Report an error.  |
 108 `------------------*/
 109
 110 ]b4_c_ansi_function_def([yyerror],
 111     [static void],
 112     [[b4_namespace_ref::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
 113     b4_parse_param,
 114     [[const char* msg], [msg]])[
 115 {
 116 ]b4_parse_param_use[]dnl
 117 [  yyparser.error (*yylocationp, msg);
 118 }
 119
 120
 121 ]b4_namespace_open[
 122 ]dnl In this section, the parse param are the original parse_params.
 123 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 124 [  /// Build a parser object.
 125   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 126     :])[
 127 #if YYDEBUG
 128     ]m4_ifset([b4_parse_param], [  ], [ :])[yydebug_ (false),
 129       yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 130 #endif]b4_parse_param_cons[
 131   {
 132   }
 133
 134   ]b4_parser_class_name::~b4_parser_class_name[ ()
 135   {
 136   }
 137
 138   int
 139   ]b4_parser_class_name[::parse ()
 140   {
 141     return ::yyparse (*this]b4_user_args[);
 142   }
 143
 144 #if YYDEBUG
 145   /*--------------------.
 146   | Print this symbol.  |
 147   `--------------------*/
 148
 149   inline void
 150   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 151                            const semantic_type* yyvaluep, const location_type* yylocationp)
 152   {
 153     /* Pacify ``unused variable'' warnings.  */
 154     YYUSE (yyvaluep);
 155     YYUSE (yylocationp);
 156     switch (yytype)
 157       {
 158   ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
 159 [        default:
 160           break;
 161       }
 162   }
 163
 164
 165   void
 166   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 167                            const semantic_type* yyvaluep, const location_type* yylocationp)
 168   {
 169     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 170                << ' ' << yytname[yytype] << " ("
 171                << *yylocationp << ": ";
 172     yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
 173     *yycdebug_ << ')';
 174   }
 175
 176   std::ostream&
 177   ]b4_parser_class_name[::debug_stream () const
 178   {
 179     return *yycdebug_;
 180   }
 181
 182   void
 183   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 184   {
 185     yycdebug_ = &o;
 186   }
 187
 188
 189   ]b4_parser_class_name[::debug_level_type
 190   ]b4_parser_class_name[::debug_level () const
 191   {
 192     return yydebug_;
 193   }
 194
 195   void
 196   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 197   {
 198     yydebug_ = l;
 199   }
 200
 201 #endif
 202 ]m4_popdef([b4_parse_param])dnl
 203 b4_namespace_close[
 204
 205 ]])
 206
 207
 208 # Let glr.c believe that the user arguments include the parser itself.
 209 m4_ifset([b4_parse_param],
 210 [m4_pushdef([b4_parse_param],
 211             m4_dquote([[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]],]
 212 m4_defn([b4_parse_param])))],
 213 [m4_pushdef([b4_parse_param],
 214             [[[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]]]])
 215 ])
 216 m4_include(b4_pkgdatadir/[glr.c])
 217 m4_popdef([b4_parse_param])
 218
 219 m4_divert_push(0)
 220 @output(b4_spec_defines_file@)
 221 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 222   [2002, 2003, 2004, 2005, 2006])[
 223
 224 /* C++ GLR parser skeleton written by Akim Demaille.  */
 225
 226 #ifndef PARSER_HEADER_H
 227 # define PARSER_HEADER_H
 228
 229 ]b4_percent_code_get([[requires]])[
 230
 231 #include <string>
 232 #include <iostream>
 233
 234 /* Using locations.  */
 235 #define YYLSP_NEEDED ]b4_locations_flag[
 236
 237 ]b4_namespace_open[
 238   class position;
 239   class location;
 240 ]b4_namespace_close[
 241
 242 #include "location.hh"
 243
 244 /* Enabling traces.  */
 245 #ifndef YYDEBUG
 246 # define YYDEBUG ]b4_debug_flag[
 247 #endif
 248
 249 /* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
 250    If N is 0, then set CURRENT to the empty location which ends
 251    the previous symbol: RHS[0] (always defined).  */
 252
 253 #ifndef YYLLOC_DEFAULT
 254 # define YYLLOC_DEFAULT(Current, Rhs, N)                                \
 255     do                                                                  \
 256       if (N)                                                            \
 257         {                                                               \
 258           (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
 259           (Current).end    = YYRHSLOC (Rhs, N).end;                     \
 260         }                                                               \
 261       else                                                              \
 262         {                                                               \
 263           (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
 264         }                                                               \
 265     while (/*CONSTCOND*/ 0)
 266 #endif
 267
 268 ]b4_namespace_open[
 269   /// A Bison parser.
 270   class ]b4_parser_class_name[
 271   {
 272   public:
 273     /// Symbol semantic values.
 274 #ifndef YYSTYPE
 275 ]m4_ifdef([b4_stype],
 276 [    union semantic_type
 277     {
 278 b4_user_stype
 279     };],
 280 [m4_if(b4_tag_seen_flag, 0,
 281 [[    typedef int semantic_type;]],
 282 [[    typedef YYSTYPE semantic_type;]])])[
 283 #else
 284     typedef YYSTYPE semantic_type;
 285 #endif
 286     /// Symbol locations.
 287     typedef ]b4_percent_define_get([[location_type]])[ location_type;
 288     /// Tokens.
 289     struct token
 290     {
 291       ]b4_token_enums(b4_tokens)[
 292     };
 293     /// Token type.
 294     typedef token::yytokentype token_type;
 295
 296     /// Build a parser object.
 297     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 298     virtual ~]b4_parser_class_name[ ();
 299
 300     /// Parse.
 301     /// \returns  0 iff parsing succeeded.
 302     virtual int parse ();
 303
 304     /// The current debugging stream.
 305     std::ostream& debug_stream () const;
 306     /// Set the current debugging stream.
 307     void set_debug_stream (std::ostream &);
 308
 309     /// Type for debugging levels.
 310     typedef int debug_level_type;
 311     /// The current debugging level.
 312     debug_level_type debug_level () const;
 313     /// Set the current debugging level.
 314     void set_debug_level (debug_level_type l);
 315
 316   private:
 317
 318   public:
 319     /// Report a syntax error.
 320     /// \param loc    where the syntax error is found.
 321     /// \param msg    a description of the syntax error.
 322     virtual void error (const location_type& loc, const std::string& msg);
 323   private:
 324
 325 #if YYDEBUG
 326   public:
 327     /// \brief Report a symbol value on the debug stream.
 328     /// \param yytype       The token type.
 329     /// \param yyvaluep     Its semantic value.
 330     /// \param yylocationp  Its location.
 331     virtual void yy_symbol_value_print_ (int yytype,
 332                                          const semantic_type* yyvaluep,
 333                                          const location_type* yylocationp);
 334     /// \brief Report a symbol on the debug stream.
 335     /// \param yytype       The token type.
 336     /// \param yyvaluep     Its semantic value.
 337     /// \param yylocationp  Its location.
 338     virtual void yy_symbol_print_ (int yytype,
 339                                    const semantic_type* yyvaluep,
 340                                    const location_type* yylocationp);
 341   private:
 342     /* Debugging.  */
 343     int yydebug_;
 344     std::ostream* yycdebug_;
 345 #endif
 346
 347
 348     /// \brief Reclaim the memory associated to a symbol.
 349     /// \param yymsg        Why this token is reclaimed.
 350     /// \param yytype       The symbol type.
 351     /// \param yyvaluep     Its semantic value.
 352     /// \param yylocationp  Its location.
 353     inline void yydestruct_ (const char* yymsg,
 354                              int yytype,
 355                              semantic_type* yyvaluep,
 356                              location_type* yylocationp);
 357
 358 ]b4_parse_param_vars[
 359   };
 360
 361 ]dnl Redirections for glr.c.
 362 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 363 [b4_token_defines(b4_tokens)])
 364 [
 365 #ifndef YYSTYPE
 366 # define YYSTYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 367 #endif
 368 #ifndef YYLTYPE
 369 # define YYLTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 370 #endif
 371
 372 ]b4_namespace_close[
 373
 374 ]b4_percent_code_get([[provides]])[]dnl
 375
 376 [#endif /* ! defined PARSER_HEADER_H */]
 377 m4_divert_pop(0)