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_bison_locations_if([m4_include(b4_pkgdatadir/[location.cc])])
  51
  52 m4_define([b4_parser_class_name],
  53           [b4_percent_define_get([[parser_class_name]])])
  54
  55 # Save the parse parameters.
  56 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  57
  58 # b4_parse_param_wrap
  59 # -------------------
  60 # New ones.
  61 m4_ifset([b4_parse_param],
  62 [m4_define([b4_parse_param_wrap],
  63            [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
  64 m4_defn([b4_parse_param]))],
  65 [m4_define([b4_parse_param_wrap],
  66            [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
  67 ])
  68
  69
  70 # b4_yy_symbol_print_define
  71 # -------------------------
  72 # Bypass the default implementation to generate the "yy_symbol_print"
  73 # and "yy_symbol_value_print" functions.
  74 m4_define([b4_yy_symbol_print_define],
  75 [[
  76 /*--------------------.
  77 | Print this symbol.  |
  78 `--------------------*/
  79
  80 ]b4_function_define([yy_symbol_print],
  81     [static void],
  82     [[FILE *],      []],
  83     [[int yytype],  [yytype]],
  84     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  85                     [yyvaluep]][]dnl
  86 b4_locations_if([,
  87     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  88                     [yylocationp]]]),
  89     b4_parse_param)[
  90 {
  91 ]b4_parse_param_use[]dnl
  92 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  93 }
  94 ]])[
  95
  96 # Hijack the initial action to initialize the locations.
  97 ]b4_bison_locations_if([m4_define([b4_initial_action],
  98 [yylloc.initialize ();]m4_ifdef([b4_initial_action], [
  99 m4_defn([b4_initial_action])]))])[
 100
 101 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
 102 # and declaration of yyerror.
 103 ]m4_append([b4_post_prologue],
 104 [b4_syncline([@oline@], [@ofile@])[
 105 ]b4_yylloc_default_define[
 106 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
 107 ]b4_function_declare([yyerror],
 108     [static void],b4_locations_if([
 109     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 110                         [yylocationp]],])
 111     b4_parse_param,
 112     [[const char* msg], [msg]])])
 113
 114
 115 # Hijack the epilogue to define implementations (yyerror, parser member
 116 # functions etc.).
 117 m4_append([b4_epilogue],
 118 [b4_syncline([@oline@], [@ofile@])[
 119 /*------------------.
 120 | Report an error.  |
 121 `------------------*/
 122
 123 ]b4_function_define([yyerror],
 124     [static void],b4_locations_if([
 125     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 126                         [yylocationp]],])
 127     b4_parse_param,
 128     [[const char* msg], [msg]])[
 129 {
 130 ]b4_parse_param_use[]dnl
 131 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 132 }
 133
 134
 135 ]b4_namespace_open[
 136 ]dnl In this section, the parse params are the original parse_params.
 137 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 138 [  /// Build a parser object.
 139   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 140     :])[
 141 #if ]b4_api_PREFIX[DEBUG
 142     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 143 #endif]b4_parse_param_cons[
 144   {
 145   }
 146
 147   ]b4_parser_class_name::~b4_parser_class_name[ ()
 148   {
 149   }
 150
 151   int
 152   ]b4_parser_class_name[::parse ()
 153   {
 154     return ::yyparse (*this]b4_user_args[);
 155   }
 156
 157 #if ]b4_api_PREFIX[DEBUG
 158   /*--------------------.
 159   | Print this symbol.  |
 160   `--------------------*/
 161
 162   inline void
 163   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 164                            const semantic_type* yyvaluep]b4_locations_if([[,
 165                            const location_type* yylocationp]])[)
 166   {]b4_locations_if([[
 167     YYUSE (yylocationp);]])[
 168     YYUSE (yyvaluep);
 169     std::ostream& yyoutput = debug_stream ();
 170     std::ostream& yyo = yyoutput;
 171     YYUSE (yyo);
 172     switch (yytype)
 173       {
 174 ]b4_symbol_foreach([b4_symbol_printer])dnl
 175 [        default:
 176           break;
 177       }
 178   }
 179
 180
 181   void
 182   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 183                            const semantic_type* yyvaluep]b4_locations_if([[,
 184                            const location_type* yylocationp]])[)
 185   {
 186     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 187                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 188                << *yylocationp << ": "]])[;
 189     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 190     *yycdebug_ << ')';
 191   }
 192
 193   std::ostream&
 194   ]b4_parser_class_name[::debug_stream () const
 195   {
 196     return *yycdebug_;
 197   }
 198
 199   void
 200   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 201   {
 202     yycdebug_ = &o;
 203   }
 204
 205
 206   ]b4_parser_class_name[::debug_level_type
 207   ]b4_parser_class_name[::debug_level () const
 208   {
 209     return yydebug;
 210   }
 211
 212   void
 213   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 214   {
 215     // Actually, it is yydebug which is really used.
 216     yydebug = l;
 217   }
 218
 219 #endif
 220 ]m4_popdef([b4_parse_param])dnl
 221 b4_namespace_close
 222 ])
 223
 224 # b4_shared_declarations
 225 # ----------------------
 226 # Declaration that might either go into the header (if --defines)
 227 # or open coded in the parser body.
 228 m4_define([b4_shared_declarations],
 229 [m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 230 b4_percent_code_get([[requires]])[
 231
 232 #include <stdexcept>
 233 #include <string>
 234 #include <iostream>]b4_defines_if([
 235 b4_bison_locations_if([[#include "location.hh"]])])[
 236
 237 ]b4_YYDEBUG_define[
 238
 239 ]b4_namespace_open[
 240 ]b4_defines_if([],
 241 [b4_bison_locations_if([b4_position_define
 242 b4_location_define])])[
 243
 244   /// A Bison parser.
 245   class ]b4_parser_class_name[
 246   {
 247   public:
 248 ]b4_public_types_declare[
 249
 250     /// Build a parser object.
 251     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 252     virtual ~]b4_parser_class_name[ ();
 253
 254     /// Parse.
 255     /// \returns  0 iff parsing succeeded.
 256     virtual int parse ();
 257
 258     /// The current debugging stream.
 259     std::ostream& debug_stream () const;
 260     /// Set the current debugging stream.
 261     void set_debug_stream (std::ostream &);
 262
 263     /// Type for debugging levels.
 264     typedef int debug_level_type;
 265     /// The current debugging level.
 266     debug_level_type debug_level () const;
 267     /// Set the current debugging level.
 268     void set_debug_level (debug_level_type l);
 269
 270   public:
 271     /// Report a syntax error.]b4_locations_if([[
 272     /// \param loc    where the syntax error is found.]])[
 273     /// \param msg    a description of the syntax error.
 274     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 275
 276 # if ]b4_api_PREFIX[DEBUG
 277   public:
 278     /// \brief Report a symbol value on the debug stream.
 279     /// \param yytype       The token type.
 280     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 281     /// \param yylocationp  Its location.]])[
 282     virtual void yy_symbol_value_print_ (int yytype,
 283                                          const semantic_type* yyvaluep]b4_locations_if([[,
 284                                          const location_type* yylocationp]])[);
 285     /// \brief Report a symbol on the debug stream.
 286     /// \param yytype       The token type.
 287     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 288     /// \param yylocationp  Its location.]])[
 289     virtual void yy_symbol_print_ (int yytype,
 290                                    const semantic_type* yyvaluep]b4_locations_if([[,
 291                                    const location_type* yylocationp]])[);
 292   private:
 293     /* Debugging.  */
 294     std::ostream* yycdebug_;
 295 #endif
 296
 297 ]b4_parse_param_vars[
 298   };
 299
 300 ]dnl Redirections for glr.c.
 301 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 302 [b4_token_defines])
 303 [
 304 #ifndef ]b4_api_PREFIX[STYPE
 305 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 306 #endif
 307 #ifndef ]b4_api_PREFIX[LTYPE
 308 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 309 #endif
 310
 311 ]b4_namespace_close[
 312 ]b4_percent_code_get([[provides]])[
 313 ]m4_popdef([b4_parse_param])dnl
 314 ])
 315
 316 b4_defines_if(
 317 [b4_output_begin([b4_spec_defines_file])
 318 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 319              [2002-2012])[
 320
 321 /* C++ GLR parser skeleton written by Akim Demaille.  */
 322
 323 ]b4_cpp_guard_open([b4_spec_defines_file])[
 324 ]b4_shared_declarations[
 325 ]b4_cpp_guard_close([b4_spec_defines_file])[
 326 ]b4_output_end()])
 327
 328 # Let glr.c (and b4_shared_declarations) believe that the user
 329 # arguments include the parser itself.
 330 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_wrap]))
 331 m4_include(b4_pkgdatadir/[glr.c])
 332 m4_popdef([b4_parse_param])