data/glr.cc

   1                                                                     -*- C -*-
   2
   3 # C++ GLR skeleton for Bison
   4
   5 # Copyright (C) 2002-2012 Free Software Foundation, Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20
  21 # This skeleton produces a C++ class that encapsulates a C glr parser.
  22 # This is in order to reduce the maintenance burden.  The glr.c
  23 # skeleton is clean and pure enough so that there are no real
  24 # problems.  The C++ interface is the same as that of lalr1.cc.  In
  25 # fact, glr.c can replace yacc.c without the user noticing any
  26 # difference, and similarly for glr.cc replacing lalr1.cc.
  27 #
  28 # The passing of parse-params
  29 #
  30 #   The additional arguments are stored as members of the parser
  31 #   object, yyparser.  The C routines need to carry yyparser
  32 #   throughout the C parser; that easy: just let yyparser become an
  33 #   additional parse-param.  But because the C++ skeleton needs to
  34 #   know the "real" original parse-param, we save them
  35 #   (b4_parse_param_orig).  Note that b4_parse_param is overquoted
  36 #   (and c.m4 strips one level of quotes).  This is a PITA, and
  37 #   explains why there are so many levels of quotes.
  38 #
  39 # The locations
  40 #
  41 #   We use location.cc just like lalr1.cc, but because glr.c stores
  42 #   the locations in a (C++) union, the position and location classes
  43 #   must not have a constructor.  Therefore, contrary to lalr1.cc, we
  44 #   must not define "b4_location_constructors".  As a consequence the
  45 #   user must initialize the first positions (in particular the
  46 #   filename member).
  47
  48 # We require a pure interface using locations.
  49 m4_define([b4_locations_flag], [1])
  50 m4_define([b4_pure_flag],      [1])
  51
  52 # The header is mandatory.
  53 b4_defines_if([],
  54               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
  55
  56 m4_include(b4_pkgdatadir/[c++.m4])
  57 b4_percent_define_ifdef([[api.location.type]], [],
  58                         [m4_include(b4_pkgdatadir/[location.cc])])
  59
  60 m4_define([b4_parser_class_name],
  61           [b4_percent_define_get([[parser_class_name]])])
  62
  63 # Save the parse parameters.
  64 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  65
  66
  67 # b4_yy_symbol_print_generate
  68 # ---------------------------
  69 # Bypass the default implementation to generate the "yy_symbol_print"
  70 # and "yy_symbol_value_print" functions.
  71 m4_define([b4_yy_symbol_print_generate],
  72 [[
  73 /*--------------------.
  74 | Print this symbol.  |
  75 `--------------------*/
  76
  77 ]b4_c_ansi_function_def([yy_symbol_print],
  78     [static void],
  79     [[FILE *],               []],
  80     [[int yytype],           [yytype]],
  81     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  82                              [yyvaluep]],
  83     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  84                              [yylocationp]],
  85     b4_parse_param)[
  86 {
  87 ]b4_parse_param_use[]dnl
  88 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  89 }
  90 ]])[
  91
  92 # Hijack the initial action to initialize the locations.
  93 ]b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
  94 [m4_define([b4_initial_action],
  95 [yylloc.initialize ();]m4_ifdef([b4_initial_action], [
  96 m4_defn([b4_initial_action])]))])])[
  97
  98 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
  99 # and declaration of yyerror.
 100 ]m4_append([b4_post_prologue],
 101 [b4_syncline([@oline@], [@ofile@])[
 102 ]b4_yylloc_default_define[
 103 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
 104 ]b4_c_ansi_function_decl([yyerror],
 105     [static void],
 106     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 107                         [yylocationp]],
 108     b4_parse_param,
 109     [[const char* msg], [msg]])])
 110
 111
 112 # Hijack the epilogue to define implementations (yyerror, parser member
 113 # functions etc.).
 114 m4_append([b4_epilogue],
 115 [b4_syncline([@oline@], [@ofile@])[
 116 /*------------------.
 117 | Report an error.  |
 118 `------------------*/
 119
 120 ]b4_c_ansi_function_def([yyerror],
 121     [static void],
 122     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 123                         [yylocationp]],
 124     b4_parse_param,
 125     [[const char* msg], [msg]])[
 126 {
 127 ]b4_parse_param_use[]dnl
 128 [  yyparser.error (*yylocationp, msg);
 129 }
 130
 131
 132 ]b4_namespace_open[
 133 ]dnl In this section, the parse param are the original parse_params.
 134 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 135 [  /// Build a parser object.
 136   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 137     :])[
 138 #if ]b4_api_PREFIX[DEBUG
 139     ]m4_ifset([b4_parse_param], [  ], [ :])[
 140       yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 141 #endif]b4_parse_param_cons[
 142   {
 143   }
 144
 145   ]b4_parser_class_name::~b4_parser_class_name[ ()
 146   {
 147   }
 148
 149   int
 150   ]b4_parser_class_name[::parse ()
 151   {
 152     return ::yyparse (*this]b4_user_args[);
 153   }
 154
 155 #if ]b4_api_PREFIX[DEBUG
 156   /*--------------------.
 157   | Print this symbol.  |
 158   `--------------------*/
 159
 160   inline void
 161   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 162                            const semantic_type* yyvaluep,
 163                            const location_type* yylocationp)
 164   {
 165     YYUSE (yylocationp);
 166     YYUSE (yyvaluep);
 167     std::ostream& yyoutput = debug_stream ();
 168     std::ostream& yyo = yyoutput;
 169     YYUSE (yyo);
 170     ]b4_symbol_actions([printers])[
 171   }
 172
 173
 174   void
 175   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 176                            const semantic_type* yyvaluep,
 177                            const location_type* yylocationp)
 178   {
 179     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 180                << ' ' << yytname[yytype] << " ("
 181                << *yylocationp << ": ";
 182     yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
 183     *yycdebug_ << ')';
 184   }
 185
 186   std::ostream&
 187   ]b4_parser_class_name[::debug_stream () const
 188   {
 189     return *yycdebug_;
 190   }
 191
 192   void
 193   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 194   {
 195     yycdebug_ = &o;
 196   }
 197
 198
 199   ]b4_parser_class_name[::debug_level_type
 200   ]b4_parser_class_name[::debug_level () const
 201   {
 202     return yydebug;
 203   }
 204
 205   void
 206   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 207   {
 208     // Actually, it is yydebug which is really used.
 209     yydebug = l;
 210   }
 211
 212 #endif
 213 ]m4_popdef([b4_parse_param])dnl
 214 b4_namespace_close])
 215
 216
 217 # Let glr.c believe that the user arguments include the parser itself.
 218 m4_ifset([b4_parse_param],
 219 [m4_pushdef([b4_parse_param],
 220             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
 221 m4_defn([b4_parse_param]))],
 222 [m4_pushdef([b4_parse_param],
 223             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
 224 ])
 225 m4_include(b4_pkgdatadir/[glr.c])
 226 m4_popdef([b4_parse_param])
 227
 228 b4_output_begin([b4_spec_defines_file])
 229 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 230              [2002-2006, 2009-2012])[
 231
 232 /* C++ GLR parser skeleton written by Akim Demaille.  */
 233
 234 ]b4_cpp_guard_open([b4_spec_defines_file])[
 235
 236 ]b4_percent_code_get([[requires]])[
 237
 238 # include <string>
 239 # include <iostream>
 240 ]b4_percent_define_ifdef([[api.location.type]], [],
 241                          [[# include "location.hh"]])[
 242
 243 ]b4_YYDEBUG_define[
 244
 245 ]b4_namespace_open[
 246   /// A Bison parser.
 247   class ]b4_parser_class_name[
 248   {
 249   public:
 250     /// Symbol semantic values.
 251 # ifndef ]b4_api_PREFIX[STYPE
 252 ]m4_ifdef([b4_stype],
 253 [    union semantic_type
 254     {
 255 b4_user_stype
 256     };],
 257 [m4_if(b4_tag_seen_flag, 0,
 258 [[    typedef int semantic_type;]],
 259 [[    typedef ]b4_api_PREFIX[STYPE semantic_type;]])])[
 260 # else
 261     typedef ]b4_api_PREFIX[STYPE semantic_type;
 262 # endif
 263     /// Symbol locations.
 264     typedef ]b4_percent_define_get([[api.location.type]],
 265                                    [[location]])[ location_type;
 266     /// Tokens.
 267     struct token
 268     {
 269       ]b4_token_enums(b4_tokens)[
 270     };
 271     /// Token type.
 272     typedef token::yytokentype token_type;
 273
 274     /// Build a parser object.
 275     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 276     virtual ~]b4_parser_class_name[ ();
 277
 278     /// Parse.
 279     /// \returns  0 iff parsing succeeded.
 280     virtual int parse ();
 281
 282     /// The current debugging stream.
 283     std::ostream& debug_stream () const;
 284     /// Set the current debugging stream.
 285     void set_debug_stream (std::ostream &);
 286
 287     /// Type for debugging levels.
 288     typedef int debug_level_type;
 289     /// The current debugging level.
 290     debug_level_type debug_level () const;
 291     /// Set the current debugging level.
 292     void set_debug_level (debug_level_type l);
 293
 294   private:
 295
 296   public:
 297     /// Report a syntax error.
 298     /// \param loc    where the syntax error is found.
 299     /// \param msg    a description of the syntax error.
 300     virtual void error (const location_type& loc, const std::string& msg);
 301   private:
 302
 303 # if ]b4_api_PREFIX[DEBUG
 304   public:
 305     /// \brief Report a symbol value on the debug stream.
 306     /// \param yytype       The token type.
 307     /// \param yyvaluep     Its semantic value.
 308     /// \param yylocationp  Its location.
 309     virtual void yy_symbol_value_print_ (int yytype,
 310                                          const semantic_type* yyvaluep,
 311                                          const location_type* yylocationp);
 312     /// \brief Report a symbol on the debug stream.
 313     /// \param yytype       The token type.
 314     /// \param yyvaluep     Its semantic value.
 315     /// \param yylocationp  Its location.
 316     virtual void yy_symbol_print_ (int yytype,
 317                                    const semantic_type* yyvaluep,
 318                                    const location_type* yylocationp);
 319   private:
 320     /* Debugging.  */
 321     std::ostream* yycdebug_;
 322 # endif
 323
 324 ]b4_parse_param_vars[
 325   };
 326
 327 ]dnl Redirections for glr.c.
 328 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 329 [b4_token_defines(b4_tokens)])
 330 [
 331 #ifndef ]b4_api_PREFIX[STYPE
 332 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 333 #endif
 334 #ifndef ]b4_api_PREFIX[LTYPE
 335 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 336 #endif
 337
 338 ]b4_namespace_close[
 339 ]b4_percent_code_get([[provides]])[
 340 ]b4_cpp_guard_close([b4_spec_defines_file])[
 341 ]b4_output_end()