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 # The header is mandatory.
  50 b4_defines_if([],
  51               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
  52
  53 m4_include(b4_pkgdatadir/[c++.m4])
  54 b4_percent_define_ifdef([[location_type]], [],
  55                         [m4_include(b4_pkgdatadir/[location.cc])])
  56
  57 m4_define([b4_parser_class_name],
  58           [b4_percent_define_get([[parser_class_name]])])
  59
  60 # Save the parse parameters.
  61 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  62
  63
  64 # b4_yy_symbol_print_define
  65 # -------------------------
  66 # Bypass the default implementation to generate the "yy_symbol_print"
  67 # and "yy_symbol_value_print" functions.
  68 m4_define([b4_yy_symbol_print_define],
  69 [[
  70 /*--------------------.
  71 | Print this symbol.  |
  72 `--------------------*/
  73
  74 ]b4_function_define([yy_symbol_print],
  75     [static void],
  76     [[FILE *],      []],
  77     [[int yytype],  [yytype]],
  78     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  79                     [yyvaluep]][]dnl
  80 b4_locations_if([,
  81     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  82                     [yylocationp]]]),
  83     b4_parse_param)[
  84 {
  85 ]b4_parse_param_use[]dnl
  86 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  87 }
  88 ]])
  89
  90
  91 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
  92 # and declaration of yyerror.
  93 m4_append([b4_post_prologue],
  94 [b4_syncline([@oline@], [@ofile@])[
  95 ]b4_yylloc_default_define[
  96 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
  97 ]b4_function_declare([yyerror],
  98     [static void],b4_locations_if([
  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 # Hijack the epilogue to define implementations (yyerror, parser member
 106 # functions etc.).
 107 m4_append([b4_epilogue],
 108 [b4_syncline([@oline@], [@ofile@])[
 109 /*------------------.
 110 | Report an error.  |
 111 `------------------*/
 112
 113 ]b4_function_define([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 ]b4_parse_param_use[]dnl
 121 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 122 }
 123
 124
 125 ]b4_namespace_open[
 126 ]dnl In this section, the parse params are the original parse_params.
 127 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 128 [  /// Build a parser object.
 129   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 130     :])[
 131 #if ]b4_api_PREFIX[DEBUG
 132     ]m4_ifset([b4_parse_param], [  ], [ :])[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 ]b4_api_PREFIX[DEBUG
 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]b4_locations_if([[,
 155                            const location_type* yylocationp]])[)
 156   {]b4_locations_if([[
 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 ]b4_symbol_foreach([b4_symbol_printer])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]b4_locations_if([[,
 174                            const location_type* yylocationp]])[)
 175   {
 176     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 177                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 178                << *yylocationp << ": "]])[;
 179     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, 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     // Actually, it is yydebug which is really used.
 206     yydebug = l;
 207   }
 208
 209 #endif
 210 ]m4_popdef([b4_parse_param])dnl
 211 b4_namespace_close])
 212
 213
 214 # Let glr.c believe that the user arguments include the parser itself.
 215 m4_ifset([b4_parse_param],
 216 [m4_pushdef([b4_parse_param],
 217             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
 218 m4_defn([b4_parse_param]))],
 219 [m4_pushdef([b4_parse_param],
 220             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
 221 ])
 222 m4_include(b4_pkgdatadir/[glr.c])
 223 m4_popdef([b4_parse_param])
 224
 225
 226 # b4_shared_declarations
 227 # ----------------------
 228 # Declaration that might either go into the header (if --defines)
 229 # or open coded in the parser body.
 230 m4_define([b4_shared_declarations],
 231 [b4_percent_code_get([[requires]])[
 232
 233 #include <stdexcept>
 234 #include <string>
 235 #include <iostream>
 236 ]b4_percent_define_ifdef([[location_type]], [],
 237                          [[#include "location.hh"]])[
 238
 239 ]b4_YYDEBUG_define[
 240
 241 ]b4_namespace_open[
 242   /// A Bison parser.
 243   class ]b4_parser_class_name[
 244   {
 245   public:
 246 ]b4_public_types_declare[
 247
 248     /// Build a parser object.
 249     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 250     virtual ~]b4_parser_class_name[ ();
 251
 252     /// Parse.
 253     /// \returns  0 iff parsing succeeded.
 254     virtual int parse ();
 255
 256     /// The current debugging stream.
 257     std::ostream& debug_stream () const;
 258     /// Set the current debugging stream.
 259     void set_debug_stream (std::ostream &);
 260
 261     /// Type for debugging levels.
 262     typedef int debug_level_type;
 263     /// The current debugging level.
 264     debug_level_type debug_level () const;
 265     /// Set the current debugging level.
 266     void set_debug_level (debug_level_type l);
 267
 268   public:
 269     /// Report a syntax error.]b4_locations_if([[
 270     /// \param loc    where the syntax error is found.]])[
 271     /// \param msg    a description of the syntax error.
 272     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 273
 274 # if ]b4_api_PREFIX[DEBUG
 275   public:
 276     /// \brief Report a symbol value on the debug stream.
 277     /// \param yytype       The token type.
 278     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 279     /// \param yylocationp  Its location.]])[
 280     virtual void yy_symbol_value_print_ (int yytype,
 281                                          const semantic_type* yyvaluep]b4_locations_if([[,
 282                                          const location_type* yylocationp]])[);
 283     /// \brief Report a symbol on the debug stream.
 284     /// \param yytype       The token type.
 285     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 286     /// \param yylocationp  Its location.]])[
 287     virtual void yy_symbol_print_ (int yytype,
 288                                    const semantic_type* yyvaluep]b4_locations_if([[,
 289                                    const location_type* yylocationp]])[);
 290   private:
 291     /* Debugging.  */
 292     std::ostream* yycdebug_;
 293 #endif
 294
 295 ]b4_parse_param_vars[
 296   };
 297
 298 ]dnl Redirections for glr.c.
 299 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 300 [b4_token_defines])
 301 [
 302 #ifndef ]b4_api_PREFIX[STYPE
 303 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 304 #endif
 305 #ifndef ]b4_api_PREFIX[LTYPE
 306 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 307 #endif
 308
 309 ]b4_namespace_close[
 310 ]b4_percent_code_get([[provides]])[
 311 ]])
 312
 313 m4_divert_push(0)
 314 @output(b4_spec_defines_file@)@
 315 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 316              [2002-2012])[
 317
 318 /* C++ GLR parser skeleton written by Akim Demaille.  */
 319
 320 ]b4_cpp_guard_open([b4_spec_defines_file])[
 321 ]b4_shared_declarations[
 322 ]b4_cpp_guard_close([b4_spec_defines_file])[
 323 ]m4_divert_pop(0)