data/glr.cc

   1 # C++ GLR skeleton for Bison
   2 # Copyright (C) 2002-2010 Free Software Foundation, Inc.
   3
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 # This skeleton produces a C++ class that encapsulates a C glr parser.
  19 # This is in order to reduce the maintenance burden.  The glr.c
  20 # skeleton is clean and pure enough so that there are no real
  21 # problems.  The C++ interface is the same as that of lalr1.cc.  In
  22 # fact, glr.c can replace yacc.c without the user noticing any
  23 # difference, and similarly for glr.cc replacing lalr1.cc.
  24 #
  25 # The passing of parse-params
  26 #
  27 #   The additional arguments are stored as members of the parser
  28 #   object, yyparser.  The C routines need to carry yyparser
  29 #   throughout the C parser; that's easy: make yyparser an
  30 #   additional parse-param.  But because the C++ skeleton needs to
  31 #   know the "real" original parse-param, we save them
  32 #   (b4_parse_param_orig).  Note that b4_parse_param is overquoted
  33 #   (and c.m4 strips one level of quotes).  This is a PITA, and
  34 #   explains why there are so many levels of quotes.
  35 #
  36 # The locations
  37 #
  38 #   We use location.cc just like lalr1.cc, but because glr.c stores
  39 #   the locations in a union, the position and location classes
  40 #   must not have a constructor.  Therefore, contrary to lalr1.cc, we
  41 #   must not define "b4_location_constructors".  As a consequence the
  42 #   user must initialize the first positions (in particular the
  43 #   filename member).
  44
  45 # We require a pure interface using locations.
  46 m4_define([b4_percent_define(locations)], [])
  47 m4_define([b4_pure_flag],      [1])
  48
  49 # The header is mandatory.
  50 b4_defines_if([],
  51               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
  52
  53 m4_include(b4_pkgdatadir/[c++.m4])
  54 m4_include(b4_pkgdatadir/[location.cc])
  55
  56 m4_define([b4_parser_class_name],
  57           [b4_percent_define_get([[parser_class_name]])])
  58
  59 # Save the parse parameters.
  60 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  61
  62
  63 # b4_yy_symbol_print_generate
  64 # ---------------------------
  65 # Bypass the default implementation to generate the "yy_symbol_print"
  66 # and "yy_symbol_value_print" functions.
  67 m4_define([b4_yy_symbol_print_generate],
  68 [[
  69 /*--------------------.
  70 | Print this symbol.  |
  71 `--------------------*/
  72
  73 ]b4_c_ansi_function_def([yy_symbol_print],
  74     [static void],
  75     [[FILE *],               []],
  76     [[int yytype],           [yytype]],
  77     [[const b4_namespace_ref::b4_parser_class_name::semantic_type *yyvaluep],
  78                              [yyvaluep]],
  79     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
  80                              [yylocationp]],
  81     b4_parse_param)[
  82 {
  83 ]b4_parse_param_use[]dnl
  84 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  85 }
  86 ]])
  87
  88
  89 # Declare yyerror.
  90 m4_append([b4_post_prologue],
  91 [b4_syncline([@oline@], [@ofile@])
  92
  93 b4_c_ansi_function_decl([yyerror],
  94     [static void],
  95     [[b4_namespace_ref::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
  96     b4_parse_param,
  97     [[const char* msg], [msg]])])
  98
  99
 100 # Define yyerror.
 101 m4_append([b4_epilogue],
 102 [b4_syncline([@oline@], [@ofile@])[
 103 /*------------------.
 104 | Report an error.  |
 105 `------------------*/
 106
 107 ]b4_c_ansi_function_def([yyerror],
 108     [static void],
 109     [[b4_namespace_ref::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
 110     b4_parse_param,
 111     [[const char* msg], [msg]])[
 112 {
 113 ]b4_parse_param_use[]dnl
 114 [  yyparser.error (*yylocationp, msg);
 115 }
 116
 117
 118 ]b4_namespace_open[
 119 ]dnl In this section, the parse param are the original parse_params.
 120 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 121 [  /// Build a parser object.
 122   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 123     :])[
 124 #if YYDEBUG
 125     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 126 #endif]b4_parse_param_cons[
 127   {
 128   }
 129
 130   ]b4_parser_class_name::~b4_parser_class_name[ ()
 131   {
 132   }
 133
 134   int
 135   ]b4_parser_class_name[::parse ()
 136   {
 137     return ::yyparse (*this]b4_user_args[);
 138   }
 139
 140 #if YYDEBUG
 141   /*--------------------.
 142   | Print this symbol.  |
 143   `--------------------*/
 144
 145   inline void
 146   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 147                            const semantic_type* yyvaluep, const location_type* yylocationp)
 148   {
 149     /* Pacify ``unused variable'' warnings.  */
 150     YYUSE (yyvaluep);
 151     YYUSE (yylocationp);
 152     switch (yytype)
 153       {
 154 ]b4_symbol_foreach([b4_symbol_printer])dnl
 155 [        default:
 156           break;
 157       }
 158   }
 159
 160
 161   void
 162   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 163                            const semantic_type* yyvaluep, const location_type* yylocationp)
 164   {
 165     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 166                << ' ' << yytname[yytype] << " ("
 167                << *yylocationp << ": ";
 168     yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
 169     *yycdebug_ << ')';
 170   }
 171
 172   std::ostream&
 173   ]b4_parser_class_name[::debug_stream () const
 174   {
 175     return *yycdebug_;
 176   }
 177
 178   void
 179   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 180   {
 181     yycdebug_ = &o;
 182   }
 183
 184
 185   ]b4_parser_class_name[::debug_level_type
 186   ]b4_parser_class_name[::debug_level () const
 187   {
 188     return yydebug;
 189   }
 190
 191   void
 192   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 193   {
 194     yydebug = l;
 195   }
 196
 197 #endif
 198 ]m4_popdef([b4_parse_param])dnl
 199 b4_namespace_close[
 200 ]])
 201
 202
 203 # Let glr.c believe that the user arguments include the parser itself.
 204 m4_ifset([b4_parse_param],
 205 [m4_pushdef([b4_parse_param],
 206             m4_dquote([[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]],]
 207 m4_defn([b4_parse_param])))],
 208 [m4_pushdef([b4_parse_param],
 209             [[[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]]]])
 210 ])
 211 m4_include(b4_pkgdatadir/[glr.c])
 212 m4_popdef([b4_parse_param])
 213
 214 m4_divert_push(0)
 215 @output(b4_spec_defines_file@)@
 216 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 217              [2002-2010])[
 218
 219 /* C++ GLR parser skeleton written by Akim Demaille.  */
 220
 221 #ifndef PARSER_HEADER_H
 222 # define PARSER_HEADER_H
 223
 224 ]b4_percent_code_get([[requires]])[
 225
 226 #include <stdexcept>
 227 #include <string>
 228 #include <iostream>
 229
 230 /* Using locations.  */
 231 #define YYLSP_NEEDED ]b4_locations_if([1], [0])[
 232
 233 ]b4_namespace_open[
 234   class position;
 235   class location;
 236 ]b4_namespace_close[
 237
 238 #include "location.hh"
 239
 240 /* Enabling traces.  */
 241 #ifndef YYDEBUG
 242 # define YYDEBUG ]b4_parse_trace_if([1], [0])[
 243 #endif
 244
 245 /* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
 246    If N is 0, then set CURRENT to the empty location which ends
 247    the previous symbol: RHS[0] (always defined).  */
 248
 249 #ifndef YYLLOC_DEFAULT
 250 # define YYLLOC_DEFAULT(Current, Rhs, N)                                \
 251     do                                                                  \
 252       if (N)                                                            \
 253         {                                                               \
 254           (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
 255           (Current).end    = YYRHSLOC (Rhs, N).end;                     \
 256         }                                                               \
 257       else                                                              \
 258         {                                                               \
 259           (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
 260         }                                                               \
 261     while (/*CONSTCOND*/ 0)
 262 #endif
 263
 264 ]b4_namespace_open[
 265   /// A Bison parser.
 266   class ]b4_parser_class_name[
 267   {
 268   public:
 269 ]b4_public_types_declare[
 270
 271     /// Build a parser object.
 272     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 273     virtual ~]b4_parser_class_name[ ();
 274
 275     /// Parse.
 276     /// \returns  0 iff parsing succeeded.
 277     virtual int parse ();
 278
 279     /// The current debugging stream.
 280     std::ostream& debug_stream () const;
 281     /// Set the current debugging stream.
 282     void set_debug_stream (std::ostream &);
 283
 284     /// Type for debugging levels.
 285     typedef int debug_level_type;
 286     /// The current debugging level.
 287     debug_level_type debug_level () const;
 288     /// Set the current debugging level.
 289     void set_debug_level (debug_level_type l);
 290
 291   public:
 292     /// Report a syntax error.
 293     /// \param loc    where the syntax error is found.
 294     /// \param msg    a description of the syntax error.
 295     virtual void error (const location_type& loc, const std::string& msg);
 296
 297 #if YYDEBUG
 298   public:
 299     /// \brief Report a symbol value on the debug stream.
 300     /// \param yytype       The token type.
 301     /// \param yyvaluep     Its semantic value.
 302     /// \param yylocationp  Its location.
 303     virtual void yy_symbol_value_print_ (int yytype,
 304                                          const semantic_type* yyvaluep,
 305                                          const location_type* yylocationp);
 306     /// \brief Report a symbol on the debug stream.
 307     /// \param yytype       The token type.
 308     /// \param yyvaluep     Its semantic value.
 309     /// \param yylocationp  Its location.
 310     virtual void yy_symbol_print_ (int yytype,
 311                                    const semantic_type* yyvaluep,
 312                                    const location_type* yylocationp);
 313   private:
 314     /* Debugging.  */
 315     std::ostream* yycdebug_;
 316 #endif
 317
 318     /// \brief Reclaim the memory associated to a symbol.
 319     /// \param yymsg        Why this token is reclaimed.
 320     /// \param yytype       The symbol type.
 321     /// \param yyvaluep     Its semantic value.
 322     /// \param yylocationp  Its location.
 323     inline void yydestruct_ (const char* yymsg,
 324                              int yytype,
 325                              semantic_type* yyvaluep,
 326                              location_type* yylocationp);
 327
 328 ]b4_parse_param_vars[
 329   };
 330
 331 ]dnl Redirections for glr.c.
 332 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 333 [b4_token_defines(b4_tokens)])
 334 [
 335 #ifndef YYSTYPE
 336 # define YYSTYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 337 #endif
 338 #ifndef YYLTYPE
 339 # define YYLTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 340 #endif
 341
 342 ]b4_namespace_close[
 343
 344 ]b4_percent_code_get([[provides]])[]dnl
 345
 346 [#endif /* ! defined PARSER_HEADER_H */]
 347 m4_divert_pop(0)