data/glr.cc

   1                                                                     -*- C -*-
   2
   3 # C++ GLR skeleton for Bison
   4
   5 # Copyright (C) 2002-2012 Free Software Foundation, 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 b4_percent_define_ifdef([[location_type]], [],
  58                         [m4_include(b4_pkgdatadir/[location.cc])])
  59
  60 m4_define([b4_parser_class_name],
  61           [b4_percent_define_get([[parser_class_name]])])
  62
  63 # Save the parse parameters.
  64 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  65
  66
  67 # b4_yy_symbol_print_generate
  68 # ---------------------------
  69 # Bypass the default implementation to generate the "yy_symbol_print"
  70 # and "yy_symbol_value_print" functions.
  71 m4_define([b4_yy_symbol_print_generate],
  72 [[
  73 /*--------------------.
  74 | Print this symbol.  |
  75 `--------------------*/
  76
  77 ]b4_c_ansi_function_def([yy_symbol_print],
  78     [static void],
  79     [[FILE *],               []],
  80     [[int yytype],           [yytype]],
  81     [[const b4_namespace_ref::b4_parser_class_name::semantic_type *yyvaluep],
  82                              [yyvaluep]],
  83     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
  84                              [yylocationp]],
  85     b4_parse_param)[
  86 {
  87 ]b4_parse_param_use[]dnl
  88 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  89 }
  90 ]])
  91
  92
  93 # Declare yyerror.
  94 m4_append([b4_post_prologue],
  95 [b4_syncline([@oline@], [@ofile@])
  96
  97 b4_c_ansi_function_decl([yyerror],
  98     [static void],
  99     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
 100                         [yylocationp]],
 101     b4_parse_param,
 102     [[const char* msg], [msg]])])
 103
 104
 105 # Define yyerror.
 106 m4_append([b4_epilogue],
 107 [b4_syncline([@oline@], [@ofile@])[
 108 /*------------------.
 109 | Report an error.  |
 110 `------------------*/
 111
 112 ]b4_c_ansi_function_def([yyerror],
 113     [static void],
 114     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
 115                         [yylocationp]],
 116     b4_parse_param,
 117     [[const char* msg], [msg]])[
 118 {
 119 ]b4_parse_param_use[]dnl
 120 [  yyparser.error (*yylocationp, msg);
 121 }
 122
 123
 124 ]b4_namespace_open[
 125 ]dnl In this section, the parse param are the original parse_params.
 126 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 127 [  /// Build a parser object.
 128   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 129     :])[
 130 #if YYDEBUG
 131     ]m4_ifset([b4_parse_param], [  ], [ :])[yydebug_ (false),
 132       yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 133 #endif]b4_parse_param_cons[
 134   {
 135   }
 136
 137   ]b4_parser_class_name::~b4_parser_class_name[ ()
 138   {
 139   }
 140
 141   int
 142   ]b4_parser_class_name[::parse ()
 143   {
 144     return ::yyparse (*this]b4_user_args[);
 145   }
 146
 147 #if YYDEBUG
 148   /*--------------------.
 149   | Print this symbol.  |
 150   `--------------------*/
 151
 152   inline void
 153   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 154                            const semantic_type* yyvaluep,
 155                            const location_type* yylocationp)
 156   {
 157     YYUSE (yylocationp);
 158     YYUSE (yyvaluep);
 159     std::ostream& yyoutput = debug_stream ();
 160     std::ostream& yyo = yyoutput;
 161     YYUSE (yyo);
 162     switch (yytype)
 163       {
 164   ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
 165 [        default:
 166           break;
 167       }
 168   }
 169
 170
 171   void
 172   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 173                            const semantic_type* yyvaluep,
 174                            const location_type* yylocationp)
 175   {
 176     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 177                << ' ' << yytname[yytype] << " ("
 178                << *yylocationp << ": ";
 179     yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
 180     *yycdebug_ << ')';
 181   }
 182
 183   std::ostream&
 184   ]b4_parser_class_name[::debug_stream () const
 185   {
 186     return *yycdebug_;
 187   }
 188
 189   void
 190   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 191   {
 192     yycdebug_ = &o;
 193   }
 194
 195
 196   ]b4_parser_class_name[::debug_level_type
 197   ]b4_parser_class_name[::debug_level () const
 198   {
 199     return yydebug_;
 200   }
 201
 202   void
 203   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 204   {
 205     yydebug_ = l;
 206   }
 207
 208 #endif
 209 ]m4_popdef([b4_parse_param])dnl
 210 b4_namespace_close[
 211
 212 ]])
 213
 214
 215 # Let glr.c believe that the user arguments include the parser itself.
 216 m4_ifset([b4_parse_param],
 217 [m4_pushdef([b4_parse_param],
 218             m4_dquote([[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]],]
 219 m4_defn([b4_parse_param])))],
 220 [m4_pushdef([b4_parse_param],
 221             [[[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]]]])
 222 ])
 223 m4_include(b4_pkgdatadir/[glr.c])
 224 m4_popdef([b4_parse_param])
 225
 226 m4_divert_push(0)
 227 @output(b4_spec_defines_file@)@
 228 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 229              [2002-2006, 2009-2012])[
 230
 231 /* C++ GLR parser skeleton written by Akim Demaille.  */
 232
 233 ]b4_cpp_guard_open([b4_spec_defines_file])[
 234
 235 ]b4_percent_code_get([[requires]])[
 236
 237 #include <string>
 238 #include <iostream>
 239 ]b4_percent_define_ifdef([[location_type]], [],
 240                          [[#include "location.hh"]])[
 241
 242 /* Using locations.  */
 243 #define YYLSP_NEEDED ]b4_locations_flag[
 244
 245 /* Enabling traces.  */
 246 #ifndef YYDEBUG
 247 # define YYDEBUG ]b4_debug_flag[
 248 #endif
 249
 250 /* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
 251    If N is 0, then set CURRENT to the empty location which ends
 252    the previous symbol: RHS[0] (always defined).  */
 253
 254 #ifndef YYLLOC_DEFAULT
 255 # define YYLLOC_DEFAULT(Current, Rhs, N)                                \
 256     do                                                                  \
 257       if (N)                                                            \
 258         {                                                               \
 259           (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
 260           (Current).end    = YYRHSLOC (Rhs, N).end;                     \
 261         }                                                               \
 262       else                                                              \
 263         {                                                               \
 264           (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
 265         }                                                               \
 266     while (/*CONSTCOND*/ 0)
 267 #endif
 268
 269 ]b4_namespace_open[
 270   /// A Bison parser.
 271   class ]b4_parser_class_name[
 272   {
 273   public:
 274     /// Symbol semantic values.
 275 #ifndef YYSTYPE
 276 ]m4_ifdef([b4_stype],
 277 [    union semantic_type
 278     {
 279 b4_user_stype
 280     };],
 281 [m4_if(b4_tag_seen_flag, 0,
 282 [[    typedef int semantic_type;]],
 283 [[    typedef YYSTYPE semantic_type;]])])[
 284 #else
 285     typedef YYSTYPE semantic_type;
 286 #endif
 287     /// Symbol locations.
 288     typedef ]b4_percent_define_get([[location_type]],
 289                                    [[location]])[ 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 ]b4_parse_param_vars[
 350   };
 351
 352 ]dnl Redirections for glr.c.
 353 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 354 [b4_token_defines(b4_tokens)])
 355 [
 356 #ifndef YYSTYPE
 357 # define YYSTYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 358 #endif
 359 #ifndef YYLTYPE
 360 # define YYLTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 361 #endif
 362
 363 ]b4_namespace_close[
 364 ]b4_percent_code_get([[provides]])[
 365 ]b4_cpp_guard_close([b4_spec_defines_file])[
 366 ]m4_divert_pop(0)