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 # We require a pure interface.
  47 m4_define([b4_pure_flag],      [1])
  48
  49 m4_include(b4_pkgdatadir/[c++.m4])
  50 b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
  51                 [m4_include(b4_pkgdatadir/[location.cc])])])
  52
  53 m4_define([b4_parser_class_name],
  54           [b4_percent_define_get([[parser_class_name]])])
  55
  56 # Save the parse parameters.
  57 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  58
  59
  60 # b4_yy_symbol_print_define
  61 # -------------------------
  62 # Bypass the default implementation to generate the "yy_symbol_print"
  63 # and "yy_symbol_value_print" functions.
  64 m4_define([b4_yy_symbol_print_define],
  65 [[
  66 /*--------------------.
  67 | Print this symbol.  |
  68 `--------------------*/
  69
  70 ]b4_function_define([yy_symbol_print],
  71     [static void],
  72     [[FILE *],      []],
  73     [[int yytype],  [yytype]],
  74     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  75                     [yyvaluep]][]dnl
  76 b4_locations_if([,
  77     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  78                     [yylocationp]]]),
  79     b4_parse_param)[
  80 {
  81 ]b4_parse_param_use[]dnl
  82 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  83 }
  84 ]])
  85
  86
  87 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
  88 # and declaration of yyerror.
  89 m4_append([b4_post_prologue],
  90 [b4_syncline([@oline@], [@ofile@])[
  91 ]b4_yylloc_default_define[
  92 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
  93 ]b4_function_declare([yyerror],
  94     [static void],b4_locations_if([
  95     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  96                         [yylocationp]],])
  97     b4_parse_param,
  98     [[const char* msg], [msg]])])
  99
 100
 101 # Hijack the epilogue to define implementations (yyerror, parser member
 102 # functions etc.).
 103 m4_append([b4_epilogue],
 104 [b4_syncline([@oline@], [@ofile@])[
 105 /*------------------.
 106 | Report an error.  |
 107 `------------------*/
 108
 109 ]b4_function_define([yyerror],
 110     [static void],b4_locations_if([
 111     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 112                         [yylocationp]],])
 113     b4_parse_param,
 114     [[const char* msg], [msg]])[
 115 {
 116 ]b4_parse_param_use[]dnl
 117 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 118 }
 119
 120
 121 ]b4_namespace_open[
 122 ]dnl In this section, the parse params 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 ]b4_api_PREFIX[DEBUG
 128     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 129 #endif]b4_parse_param_cons[
 130   {
 131   }
 132
 133   ]b4_parser_class_name::~b4_parser_class_name[ ()
 134   {
 135   }
 136
 137   int
 138   ]b4_parser_class_name[::parse ()
 139   {
 140     return ::yyparse (*this]b4_user_args[);
 141   }
 142
 143 #if ]b4_api_PREFIX[DEBUG
 144   /*--------------------.
 145   | Print this symbol.  |
 146   `--------------------*/
 147
 148   inline void
 149   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 150                            const semantic_type* yyvaluep]b4_locations_if([[,
 151                            const location_type* yylocationp]])[)
 152   {]b4_locations_if([[
 153     YYUSE (yylocationp);]])[
 154     YYUSE (yyvaluep);
 155     std::ostream& yyoutput = debug_stream ();
 156     std::ostream& yyo = yyoutput;
 157     YYUSE (yyo);
 158     switch (yytype)
 159       {
 160 ]b4_symbol_foreach([b4_symbol_printer])dnl
 161 [        default:
 162           break;
 163       }
 164   }
 165
 166
 167   void
 168   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 169                            const semantic_type* yyvaluep]b4_locations_if([[,
 170                            const location_type* yylocationp]])[)
 171   {
 172     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 173                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 174                << *yylocationp << ": "]])[;
 175     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 176     *yycdebug_ << ')';
 177   }
 178
 179   std::ostream&
 180   ]b4_parser_class_name[::debug_stream () const
 181   {
 182     return *yycdebug_;
 183   }
 184
 185   void
 186   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 187   {
 188     yycdebug_ = &o;
 189   }
 190
 191
 192   ]b4_parser_class_name[::debug_level_type
 193   ]b4_parser_class_name[::debug_level () const
 194   {
 195     return yydebug;
 196   }
 197
 198   void
 199   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 200   {
 201     // Actually, it is yydebug which is really used.
 202     yydebug = l;
 203   }
 204
 205 #endif
 206 ]m4_popdef([b4_parse_param])dnl
 207 b4_namespace_close
 208 ])
 209
 210 # b4_shared_declarations
 211 # ----------------------
 212 # Declaration that might either go into the header (if --defines)
 213 # or open coded in the parser body.
 214 m4_define([b4_shared_declarations],
 215 [dnl In this section, the parse params are the original parse_params.
 216 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 217 b4_percent_code_get([[requires]])[
 218
 219 #include <stdexcept>
 220 #include <string>
 221 #include <iostream>]b4_defines_if([
 222 b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
 223                                          [[#include "location.hh"]])])])[
 224
 225 ]b4_YYDEBUG_define[
 226
 227 ]b4_namespace_open[
 228 ]b4_defines_if([],
 229 [b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
 230                                           [b4_position_define
 231 b4_location_define])])])[
 232
 233   /// A Bison parser.
 234   class ]b4_parser_class_name[
 235   {
 236   public:
 237 ]b4_public_types_declare[
 238
 239     /// Build a parser object.
 240     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 241     virtual ~]b4_parser_class_name[ ();
 242
 243     /// Parse.
 244     /// \returns  0 iff parsing succeeded.
 245     virtual int parse ();
 246
 247     /// The current debugging stream.
 248     std::ostream& debug_stream () const;
 249     /// Set the current debugging stream.
 250     void set_debug_stream (std::ostream &);
 251
 252     /// Type for debugging levels.
 253     typedef int debug_level_type;
 254     /// The current debugging level.
 255     debug_level_type debug_level () const;
 256     /// Set the current debugging level.
 257     void set_debug_level (debug_level_type l);
 258
 259   public:
 260     /// Report a syntax error.]b4_locations_if([[
 261     /// \param loc    where the syntax error is found.]])[
 262     /// \param msg    a description of the syntax error.
 263     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 264
 265 # if ]b4_api_PREFIX[DEBUG
 266   public:
 267     /// \brief Report a symbol value on the debug stream.
 268     /// \param yytype       The token type.
 269     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 270     /// \param yylocationp  Its location.]])[
 271     virtual void yy_symbol_value_print_ (int yytype,
 272                                          const semantic_type* yyvaluep]b4_locations_if([[,
 273                                          const location_type* yylocationp]])[);
 274     /// \brief Report a symbol on the debug stream.
 275     /// \param yytype       The token type.
 276     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 277     /// \param yylocationp  Its location.]])[
 278     virtual void yy_symbol_print_ (int yytype,
 279                                    const semantic_type* yyvaluep]b4_locations_if([[,
 280                                    const location_type* yylocationp]])[);
 281   private:
 282     /* Debugging.  */
 283     std::ostream* yycdebug_;
 284 #endif
 285
 286 ]b4_parse_param_vars[
 287   };
 288
 289 ]dnl Redirections for glr.c.
 290 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 291 [b4_token_defines])
 292 [
 293 #ifndef ]b4_api_PREFIX[STYPE
 294 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 295 #endif
 296 #ifndef ]b4_api_PREFIX[LTYPE
 297 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 298 #endif
 299
 300 ]b4_namespace_close[
 301 ]b4_percent_code_get([[provides]])[
 302 ]m4_popdef([b4_parse_param])dnl
 303 ])
 304
 305 b4_defines_if(
 306 [m4_changecom()dnl
 307 m4_divert_push(0)dnl
 308 @output(b4_spec_defines_file@)@
 309 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 310              [2002-2012])[
 311
 312 /* C++ GLR parser skeleton written by Akim Demaille.  */
 313
 314 ]b4_cpp_guard_open([b4_spec_defines_file])[
 315 ]b4_shared_declarations[
 316 ]b4_cpp_guard_close([b4_spec_defines_file])[
 317 ]m4_divert_pop(0)
 318 m4_changecom[#])])
 319
 320 # Let glr.c (and b4_shared_declarations) believe that the user
 321 # arguments include the parser itself.
 322 m4_ifset([b4_parse_param],
 323 [m4_pushdef([b4_parse_param],
 324             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
 325 m4_defn([b4_parse_param]))],
 326 [m4_pushdef([b4_parse_param],
 327             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
 328 ])
 329 m4_include(b4_pkgdatadir/[glr.c])
 330 m4_popdef([b4_parse_param])