data/glr.cc

   1 m4_divert(-1)                                                       -*- C -*-
   2
   3 # C++ GLR skeleton for Bison
   4 # Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   5
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 # 02110-1301  USA
  20
  21
  22 # This skeleton produces a C++ class that encapsulates a C glr parser.
  23 # This is in order to reduce the maintenance burden.  The glr.c
  24 # skeleton is clean and pure enough so that there are no real
  25 # problems.  The C++ interface is the same as that of lalr1.cc.  In
  26 # fact, glr.c can replace yacc.c without the user noticing any
  27 # difference, and similarly for glr.cc replacing lalr1.cc.
  28 #
  29 # The passing of parse-params
  30 #
  31 #   The additional arguments are stored as members of the parser
  32 #   object, yyparser.  The C routines need to carry yyparser
  33 #   throughout the C parser; that easy: just let yyparser become an
  34 #   additional parse-param.  But because the C++ skeleton needs to
  35 #   know the "real" original parse-param, we save them
  36 #   (b4_parse_param_orig).  Note that b4_parse_param is overquoted
  37 #   (and c.m4 strips one level of quotes).  This is a PITA, and
  38 #   explains why there are so many levels of quotes.
  39 #
  40 # The locations
  41 #
  42 #   We use location.cc just like lalr1.cc, but because glr.c stores
  43 #   the locations in a (C++) union, the position and location classes
  44 #   must not have a constructor.  Therefore, contrary to lalr1.cc, we
  45 #   must not define "b4_location_constructors".  As a consequence the
  46 #   user must initialize the first positions (in particular the
  47 #   filename member).
  48
  49 # We require a pure interface using locations.
  50 m4_define([b4_locations_flag], [1])
  51 m4_define([b4_pure_flag],      [1])
  52
  53 # The header is mandatory.
  54 b4_defines_if([],
  55               [m4_fatal(b4_skeleton[: using %defines is mandatory])])
  56
  57 m4_include(b4_pkgdatadir/[c++.m4])
  58 m4_include(b4_pkgdatadir/[location.cc])
  59
  60
  61 # Save the parse parameters.
  62 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  63
  64
  65 # b4_yy_symbol_print_generate
  66 # ---------------------------
  67 # Bypass the default implementation to generate the "yy_symbol_print"
  68 # and "yy_symbol_value_print" functions.
  69 m4_define([b4_yy_symbol_print_generate],
  70 [[
  71 /*--------------------.
  72 | Print this symbol.  |
  73 `--------------------*/
  74
  75 ]b4_c_ansi_function_def([yy_symbol_print],
  76     [static void],
  77     [[FILE *],               []],
  78     [[int yytype],           [yytype]],
  79     [[const b4_namespace::b4_parser_class_name::semantic_type *yyvaluep],
  80                              [yyvaluep]],
  81     [[const b4_namespace::b4_parser_class_name::location_type *yylocationp],
  82                              [yylocationp]],
  83     b4_parse_param)[
  84 {
  85 ]b4_parse_param_use[]dnl
  86 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  87 }
  88 ]])
  89
  90
  91 # Declare yyerror.
  92 m4_append([b4_post_prologue],
  93 [b4_syncline([@oline@], [@ofile@])
  94
  95 b4_c_ansi_function_decl([yyerror],
  96     [static void],
  97     [[b4_namespace::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
  98     b4_parse_param,
  99     [[const char* msg], [msg]])])
 100
 101
 102 # Define yyerror.
 103 m4_append([b4_epilogue],
 104 [b4_syncline([@oline@], [@ofile@])[
 105 /*------------------.
 106 | Report an error.  |
 107 `------------------*/
 108
 109 ]b4_c_ansi_function_def([yyerror],
 110     [static void],
 111     [[b4_namespace::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
 112     b4_parse_param,
 113     [[const char* msg], [msg]])[
 114 {
 115 ]b4_parse_param_use[]dnl
 116 [  yyparser.error (*yylocationp, msg);
 117 }
 118
 119
 120 namespace ]b4_namespace[
 121 {
 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 [} // namespace ]b4_namespace[
 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::b4_parser_class_name& yyparser], [[yyparser]]],]
 212 m4_defn([b4_parse_param])))],
 213 [m4_pushdef([b4_parse_param],
 214             [[[[b4_namespace::b4_parser_class_name& yyparser], [[yyparser]]]]])
 215 ])
 216 m4_include(b4_pkgdatadir/[glr.c])
 217 m4_popdef([b4_parse_param])
 218
 219 @output b4_spec_defines_file
 220 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 221   [2002, 2003, 2004, 2005, 2006])[
 222
 223 /* C++ GLR parser skeleton written by Akim Demaille.  */
 224
 225 #ifndef PARSER_HEADER_H
 226 # define PARSER_HEADER_H
 227
 228 ]m4_ifdef([b4_requires],
 229 [[/* Copy the %requires blocks.  */
 230 ]b4_user_requires])[
 231
 232 #include <string>
 233 #include <iostream>
 234
 235 /* Using locations.  */
 236 #define YYLSP_NEEDED ]b4_locations_flag[
 237
 238 namespace ]b4_namespace[
 239 {
 240   class position;
 241   class location;
 242 }
 243
 244 #include "location.hh"
 245
 246 /* Enabling traces.  */
 247 #ifndef YYDEBUG
 248 # define YYDEBUG ]b4_debug_flag[
 249 #endif
 250
 251 /* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
 252    If N is 0, then set CURRENT to the empty location which ends
 253    the previous symbol: RHS[0] (always defined).  */
 254
 255 #ifndef YYLLOC_DEFAULT
 256 # define YYLLOC_DEFAULT(Current, Rhs, N)                                \
 257     do                                                                  \
 258       if (N)                                                            \
 259         {                                                               \
 260           (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
 261           (Current).end    = YYRHSLOC (Rhs, N).end;                     \
 262         }                                                               \
 263       else                                                              \
 264         {                                                               \
 265           (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
 266         }                                                               \
 267     while (/*CONSTCOND*/ 0)
 268 #endif
 269
 270 namespace ]b4_namespace[
 271 {
 272   /// A Bison parser.
 273   class ]b4_parser_class_name[
 274   {
 275   public:
 276     /// Symbol semantic values.
 277 #ifndef YYSTYPE
 278 ]m4_ifdef([b4_stype],
 279 [    union semantic_type
 280 b4_user_stype
 281         ;],
 282 [m4_if(b4_tag_seen_flag, 0,
 283 [[    typedef int semantic_type;]],
 284 [[    typedef YYSTYPE semantic_type;]])])[
 285 #else
 286     typedef YYSTYPE semantic_type;
 287 #endif
 288     /// Symbol locations.
 289     typedef ]b4_location_type[ location_type;
 290     /// Tokens.
 291     struct token
 292     {
 293       ]b4_token_enums(b4_tokens)[
 294     };
 295     /// Token type.
 296     typedef token::yytokentype token_type;
 297
 298     /// Build a parser object.
 299     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 300     virtual ~]b4_parser_class_name[ ();
 301
 302     /// Parse.
 303     /// \returns  0 iff parsing succeeded.
 304     virtual int parse ();
 305
 306     /// The current debugging stream.
 307     std::ostream& debug_stream () const;
 308     /// Set the current debugging stream.
 309     void set_debug_stream (std::ostream &);
 310
 311     /// Type for debugging levels.
 312     typedef int debug_level_type;
 313     /// The current debugging level.
 314     debug_level_type debug_level () const;
 315     /// Set the current debugging level.
 316     void set_debug_level (debug_level_type l);
 317
 318   private:
 319
 320   public:
 321     /// Report a syntax error.
 322     /// \param loc    where the syntax error is found.
 323     /// \param msg    a description of the syntax error.
 324     virtual void error (const location_type& loc, const std::string& msg);
 325   private:
 326
 327 #if YYDEBUG
 328   public:
 329     /// \brief Report a symbol value on the debug stream.
 330     /// \param yytype       The token type.
 331     /// \param yyvaluep     Its semantic value.
 332     /// \param yylocationp  Its location.
 333     virtual void yy_symbol_value_print_ (int yytype,
 334                                          const semantic_type* yyvaluep,
 335                                          const location_type* yylocationp);
 336     /// \brief Report a symbol on the debug stream.
 337     /// \param yytype       The token type.
 338     /// \param yyvaluep     Its semantic value.
 339     /// \param yylocationp  Its location.
 340     virtual void yy_symbol_print_ (int yytype,
 341                                    const semantic_type* yyvaluep,
 342                                    const location_type* yylocationp);
 343   private:
 344     /* Debugging.  */
 345     int yydebug_;
 346     std::ostream* yycdebug_;
 347 #endif
 348
 349
 350     /// \brief Reclaim the memory associated to a symbol.
 351     /// \param yymsg        Why this token is reclaimed.
 352     /// \param yytype       The symbol type.
 353     /// \param yyvaluep     Its semantic value.
 354     /// \param yylocationp  Its location.
 355     inline void yydestruct_ (const char* yymsg,
 356                              int yytype,
 357                              semantic_type* yyvaluep,
 358                              location_type* yylocationp);
 359
 360 ]b4_parse_param_vars[
 361   };
 362
 363 ]dnl Redirections for glr.c.
 364 m4_ifset([b4_global_tokens_and_yystype],
 365 [b4_token_defines(b4_tokens)])
 366 [
 367 #ifndef YYSTYPE
 368 # define YYSTYPE ]b4_namespace[::]b4_parser_class_name[::semantic_type
 369 #endif
 370 #ifndef YYLTYPE
 371 # define YYLTYPE ]b4_namespace[::]b4_parser_class_name[::location_type
 372 #endif
 373
 374 }
 375
 376 ]m4_ifdef([b4_provides],
 377 [[/* Copy the %provides blocks.  */
 378 ]b4_user_provides])[]dnl
 379
 380 [#endif /* ! defined PARSER_HEADER_H */]