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 # Hijack the initial action to initialize the locations.
  87 ]b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
  88 [m4_define([b4_initial_action],
  89 [yylloc.initialize ();]m4_ifdef([b4_initial_action], [
  90 m4_defn([b4_initial_action])]))])])[
  91
  92 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
  93 # and declaration of yyerror.
  94 ]m4_append([b4_post_prologue],
  95 [b4_syncline([@oline@], [@ofile@])[
  96 ]b4_yylloc_default_define[
  97 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
  98 ]b4_function_declare([yyerror],
  99     [static void],b4_locations_if([
 100     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 101                         [yylocationp]],])
 102     b4_parse_param,
 103     [[const char* msg], [msg]])])
 104
 105
 106 # Hijack the epilogue to define implementations (yyerror, parser member
 107 # functions etc.).
 108 m4_append([b4_epilogue],
 109 [b4_syncline([@oline@], [@ofile@])[
 110 /*------------------.
 111 | Report an error.  |
 112 `------------------*/
 113
 114 ]b4_function_define([yyerror],
 115     [static void],b4_locations_if([
 116     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 117                         [yylocationp]],])
 118     b4_parse_param,
 119     [[const char* msg], [msg]])[
 120 {
 121 ]b4_parse_param_use[]dnl
 122 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 123 }
 124
 125
 126 ]b4_namespace_open[
 127 ]dnl In this section, the parse params are the original parse_params.
 128 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 129 [  /// Build a parser object.
 130   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 131     :])[
 132 #if ]b4_api_PREFIX[DEBUG
 133     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 134 #endif]b4_parse_param_cons[
 135   {
 136   }
 137
 138   ]b4_parser_class_name::~b4_parser_class_name[ ()
 139   {
 140   }
 141
 142   int
 143   ]b4_parser_class_name[::parse ()
 144   {
 145     return ::yyparse (*this]b4_user_args[);
 146   }
 147
 148 #if ]b4_api_PREFIX[DEBUG
 149   /*--------------------.
 150   | Print this symbol.  |
 151   `--------------------*/
 152
 153   inline void
 154   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 155                            const semantic_type* yyvaluep]b4_locations_if([[,
 156                            const location_type* yylocationp]])[)
 157   {]b4_locations_if([[
 158     YYUSE (yylocationp);]])[
 159     YYUSE (yyvaluep);
 160     std::ostream& yyoutput = debug_stream ();
 161     std::ostream& yyo = yyoutput;
 162     YYUSE (yyo);
 163     switch (yytype)
 164       {
 165 ]b4_symbol_foreach([b4_symbol_printer])dnl
 166 [        default:
 167           break;
 168       }
 169   }
 170
 171
 172   void
 173   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 174                            const semantic_type* yyvaluep]b4_locations_if([[,
 175                            const location_type* yylocationp]])[)
 176   {
 177     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 178                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 179                << *yylocationp << ": "]])[;
 180     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 181     *yycdebug_ << ')';
 182   }
 183
 184   std::ostream&
 185   ]b4_parser_class_name[::debug_stream () const
 186   {
 187     return *yycdebug_;
 188   }
 189
 190   void
 191   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 192   {
 193     yycdebug_ = &o;
 194   }
 195
 196
 197   ]b4_parser_class_name[::debug_level_type
 198   ]b4_parser_class_name[::debug_level () const
 199   {
 200     return yydebug;
 201   }
 202
 203   void
 204   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 205   {
 206     // Actually, it is yydebug which is really used.
 207     yydebug = l;
 208   }
 209
 210 #endif
 211 ]m4_popdef([b4_parse_param])dnl
 212 b4_namespace_close
 213 ])
 214
 215 # b4_shared_declarations
 216 # ----------------------
 217 # Declaration that might either go into the header (if --defines)
 218 # or open coded in the parser body.
 219 m4_define([b4_shared_declarations],
 220 [dnl In this section, the parse params are the original parse_params.
 221 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 222 b4_percent_code_get([[requires]])[
 223
 224 #include <stdexcept>
 225 #include <string>
 226 #include <iostream>]b4_defines_if([
 227 b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
 228                                          [[#include "location.hh"]])])])[
 229
 230 ]b4_YYDEBUG_define[
 231
 232 ]b4_namespace_open[
 233 ]b4_defines_if([],
 234 [b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
 235                                           [b4_position_define
 236 b4_location_define])])])[
 237
 238   /// A Bison parser.
 239   class ]b4_parser_class_name[
 240   {
 241   public:
 242 ]b4_public_types_declare[
 243
 244     /// Build a parser object.
 245     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 246     virtual ~]b4_parser_class_name[ ();
 247
 248     /// Parse.
 249     /// \returns  0 iff parsing succeeded.
 250     virtual int parse ();
 251
 252     /// The current debugging stream.
 253     std::ostream& debug_stream () const;
 254     /// Set the current debugging stream.
 255     void set_debug_stream (std::ostream &);
 256
 257     /// Type for debugging levels.
 258     typedef int debug_level_type;
 259     /// The current debugging level.
 260     debug_level_type debug_level () const;
 261     /// Set the current debugging level.
 262     void set_debug_level (debug_level_type l);
 263
 264   public:
 265     /// Report a syntax error.]b4_locations_if([[
 266     /// \param loc    where the syntax error is found.]])[
 267     /// \param msg    a description of the syntax error.
 268     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 269
 270 # if ]b4_api_PREFIX[DEBUG
 271   public:
 272     /// \brief Report a symbol value on the debug stream.
 273     /// \param yytype       The token type.
 274     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 275     /// \param yylocationp  Its location.]])[
 276     virtual void yy_symbol_value_print_ (int yytype,
 277                                          const semantic_type* yyvaluep]b4_locations_if([[,
 278                                          const location_type* yylocationp]])[);
 279     /// \brief Report a symbol on the debug stream.
 280     /// \param yytype       The token type.
 281     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 282     /// \param yylocationp  Its location.]])[
 283     virtual void yy_symbol_print_ (int yytype,
 284                                    const semantic_type* yyvaluep]b4_locations_if([[,
 285                                    const location_type* yylocationp]])[);
 286   private:
 287     /* Debugging.  */
 288     std::ostream* yycdebug_;
 289 #endif
 290
 291 ]b4_parse_param_vars[
 292   };
 293
 294 ]dnl Redirections for glr.c.
 295 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 296 [b4_token_defines])
 297 [
 298 #ifndef ]b4_api_PREFIX[STYPE
 299 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 300 #endif
 301 #ifndef ]b4_api_PREFIX[LTYPE
 302 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 303 #endif
 304
 305 ]b4_namespace_close[
 306 ]b4_percent_code_get([[provides]])[
 307 ]m4_popdef([b4_parse_param])dnl
 308 ])
 309
 310 b4_defines_if(
 311 [m4_changecom()dnl
 312 m4_divert_push(0)dnl
 313 @output(b4_spec_defines_file@)@
 314 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 315              [2002-2012])[
 316
 317 /* C++ GLR parser skeleton written by Akim Demaille.  */
 318
 319 ]b4_cpp_guard_open([b4_spec_defines_file])[
 320 ]b4_shared_declarations[
 321 ]b4_cpp_guard_close([b4_spec_defines_file])[
 322 ]b4_output_end()])
 323
 324 # Let glr.c (and b4_shared_declarations) believe that the user
 325 # arguments include the parser itself.
 326 m4_ifset([b4_parse_param],
 327 [m4_pushdef([b4_parse_param],
 328             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
 329 m4_defn([b4_parse_param]))],
 330 [m4_pushdef([b4_parse_param],
 331             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
 332 ])
 333 m4_include(b4_pkgdatadir/[glr.c])
 334 m4_popdef([b4_parse_param])