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 b4_token_ctor_if([b4_variant_if([],
  47   [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
  48                [cannot use '%s' without '%s'],
  49                [%define api.token.constructor],
  50                [%define api.value.type variant]))])])
  51
  52 # We require a pure interface.
  53 m4_define([b4_pure_flag],      [1])
  54
  55 m4_include(b4_pkgdatadir/[c++.m4])
  56 b4_bison_locations_if([m4_include(b4_pkgdatadir/[location.cc])])
  57
  58 m4_define([b4_parser_class_name],
  59           [b4_percent_define_get([[parser_class_name]])])
  60
  61 # Save the parse parameters.
  62 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  63
  64 # b4_parse_param_wrap
  65 # -------------------
  66 # New ones.
  67 m4_ifset([b4_parse_param],
  68 [m4_define([b4_parse_param_wrap],
  69            [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
  70 m4_defn([b4_parse_param]))],
  71 [m4_define([b4_parse_param_wrap],
  72            [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
  73 ])
  74
  75
  76 # b4_yy_symbol_print_define
  77 # -------------------------
  78 # Bypass the default implementation to generate the "yy_symbol_print"
  79 # and "yy_symbol_value_print" functions.
  80 m4_define([b4_yy_symbol_print_define],
  81 [[
  82 /*--------------------.
  83 | Print this symbol.  |
  84 `--------------------*/
  85
  86 ]b4_function_define([yy_symbol_print],
  87     [static void],
  88     [[FILE *],      []],
  89     [[int yytype],  [yytype]],
  90     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  91                     [yyvaluep]][]dnl
  92 b4_locations_if([,
  93     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  94                     [yylocationp]]]),
  95     b4_parse_param)[
  96 {
  97 ]b4_parse_param_use[]dnl
  98 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  99 }
 100 ]])[
 101
 102 # Hijack the initial action to initialize the locations.
 103 ]b4_bison_locations_if([m4_define([b4_initial_action],
 104 [yylloc.initialize ();]m4_ifdef([b4_initial_action], [
 105 m4_defn([b4_initial_action])]))])[
 106
 107 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
 108 # and declaration of yyerror.
 109 ]m4_append([b4_post_prologue],
 110 [b4_syncline([@oline@], [@ofile@])[
 111 ]b4_yylloc_default_define[
 112 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
 113 ]b4_function_declare([yyerror],
 114     [static void],b4_locations_if([
 115     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 116                         [yylocationp]],])
 117     b4_parse_param,
 118     [[const char* msg], [msg]])])
 119
 120
 121 # Hijack the epilogue to define implementations (yyerror, parser member
 122 # functions etc.).
 123 m4_append([b4_epilogue],
 124 [b4_syncline([@oline@], [@ofile@])[
 125 /*------------------.
 126 | Report an error.  |
 127 `------------------*/
 128
 129 ]b4_function_define([yyerror],
 130     [static void],b4_locations_if([
 131     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 132                         [yylocationp]],])
 133     b4_parse_param,
 134     [[const char* msg], [msg]])[
 135 {
 136 ]b4_parse_param_use[]dnl
 137 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 138 }
 139
 140
 141 ]b4_namespace_open[
 142 ]dnl In this section, the parse params are the original parse_params.
 143 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 144 [  /// Build a parser object.
 145   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 146     :])[
 147 #if ]b4_api_PREFIX[DEBUG
 148     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 149 #endif]b4_parse_param_cons[
 150   {
 151   }
 152
 153   ]b4_parser_class_name::~b4_parser_class_name[ ()
 154   {
 155   }
 156
 157   int
 158   ]b4_parser_class_name[::parse ()
 159   {
 160     return ::yyparse (*this]b4_user_args[);
 161   }
 162
 163 #if ]b4_api_PREFIX[DEBUG
 164   /*--------------------.
 165   | Print this symbol.  |
 166   `--------------------*/
 167
 168   inline void
 169   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 170                            const semantic_type* yyvaluep]b4_locations_if([[,
 171                            const location_type* yylocationp]])[)
 172   {]b4_locations_if([[
 173     YYUSE (yylocationp);]])[
 174     YYUSE (yyvaluep);
 175     std::ostream& yyoutput = debug_stream ();
 176     std::ostream& yyo = yyoutput;
 177     YYUSE (yyo);
 178     switch (yytype)
 179       {
 180 ]b4_symbol_foreach([b4_symbol_printer])dnl
 181 [        default:
 182           break;
 183       }
 184   }
 185
 186
 187   void
 188   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 189                            const semantic_type* yyvaluep]b4_locations_if([[,
 190                            const location_type* yylocationp]])[)
 191   {
 192     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 193                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 194                << *yylocationp << ": "]])[;
 195     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 196     *yycdebug_ << ')';
 197   }
 198
 199   std::ostream&
 200   ]b4_parser_class_name[::debug_stream () const
 201   {
 202     return *yycdebug_;
 203   }
 204
 205   void
 206   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 207   {
 208     yycdebug_ = &o;
 209   }
 210
 211
 212   ]b4_parser_class_name[::debug_level_type
 213   ]b4_parser_class_name[::debug_level () const
 214   {
 215     return yydebug;
 216   }
 217
 218   void
 219   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 220   {
 221     // Actually, it is yydebug which is really used.
 222     yydebug = l;
 223   }
 224
 225 #endif
 226 ]m4_popdef([b4_parse_param])dnl
 227 b4_namespace_close
 228 ])
 229
 230 # b4_shared_declarations
 231 # ----------------------
 232 # Declaration that might either go into the header (if --defines)
 233 # or open coded in the parser body.
 234 m4_define([b4_shared_declarations],
 235 [m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 236 b4_percent_code_get([[requires]])[
 237
 238 #include <stdexcept>
 239 #include <string>
 240 #include <iostream>]b4_defines_if([
 241 b4_bison_locations_if([[#include "location.hh"]])])[
 242
 243 ]b4_YYDEBUG_define[
 244
 245 ]b4_namespace_open[
 246 ]b4_defines_if([],
 247 [b4_bison_locations_if([b4_position_define
 248 b4_location_define])])[
 249
 250   /// A Bison parser.
 251   class ]b4_parser_class_name[
 252   {
 253   public:
 254 ]b4_public_types_declare[
 255
 256     /// Build a parser object.
 257     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 258     virtual ~]b4_parser_class_name[ ();
 259
 260     /// Parse.
 261     /// \returns  0 iff parsing succeeded.
 262     virtual int parse ();
 263
 264     /// The current debugging stream.
 265     std::ostream& debug_stream () const;
 266     /// Set the current debugging stream.
 267     void set_debug_stream (std::ostream &);
 268
 269     /// Type for debugging levels.
 270     typedef int debug_level_type;
 271     /// The current debugging level.
 272     debug_level_type debug_level () const;
 273     /// Set the current debugging level.
 274     void set_debug_level (debug_level_type l);
 275
 276   public:
 277     /// Report a syntax error.]b4_locations_if([[
 278     /// \param loc    where the syntax error is found.]])[
 279     /// \param msg    a description of the syntax error.
 280     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 281
 282 # if ]b4_api_PREFIX[DEBUG
 283   public:
 284     /// \brief Report a symbol value on the debug stream.
 285     /// \param yytype       The token type.
 286     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 287     /// \param yylocationp  Its location.]])[
 288     virtual void yy_symbol_value_print_ (int yytype,
 289                                          const semantic_type* yyvaluep]b4_locations_if([[,
 290                                          const location_type* yylocationp]])[);
 291     /// \brief Report a symbol on the debug stream.
 292     /// \param yytype       The token type.
 293     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 294     /// \param yylocationp  Its location.]])[
 295     virtual void yy_symbol_print_ (int yytype,
 296                                    const semantic_type* yyvaluep]b4_locations_if([[,
 297                                    const location_type* yylocationp]])[);
 298   private:
 299     // Debugging.
 300     std::ostream* yycdebug_;
 301 #endif
 302
 303 ]b4_parse_param_vars[
 304   };
 305
 306 ]dnl Redirections for glr.c.
 307 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 308 [b4_token_defines])
 309 [
 310 #ifndef ]b4_api_PREFIX[STYPE
 311 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 312 #endif
 313 #ifndef ]b4_api_PREFIX[LTYPE
 314 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 315 #endif
 316
 317 ]b4_namespace_close[
 318 ]b4_percent_code_get([[provides]])[
 319 ]m4_popdef([b4_parse_param])dnl
 320 ])
 321
 322 b4_defines_if(
 323 [b4_output_begin([b4_spec_defines_file])
 324 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 325              [2002-2012])[
 326
 327 // C++ GLR parser skeleton written by Akim Demaille.
 328
 329 ]b4_cpp_guard_open([b4_spec_defines_file])[
 330 ]b4_shared_declarations[
 331 ]b4_cpp_guard_close([b4_spec_defines_file])[
 332 ]b4_output_end()])
 333
 334 # Let glr.c (and b4_shared_declarations) believe that the user
 335 # arguments include the parser itself.
 336 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_wrap]))
 337 m4_include(b4_pkgdatadir/[glr.c])
 338 m4_popdef([b4_parse_param])