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
  59 # b4_yy_symbol_print_define
  60 # -------------------------
  61 # Bypass the default implementation to generate the "yy_symbol_print"
  62 # and "yy_symbol_value_print" functions.
  63 m4_define([b4_yy_symbol_print_define],
  64 [[
  65 /*--------------------.
  66 | Print this symbol.  |
  67 `--------------------*/
  68
  69 ]b4_function_define([yy_symbol_print],
  70     [static void],
  71     [[FILE *],      []],
  72     [[int yytype],  [yytype]],
  73     [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
  74                     [yyvaluep]][]dnl
  75 b4_locations_if([,
  76     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  77                     [yylocationp]]]),
  78     b4_parse_param)[
  79 {
  80 ]b4_parse_param_use[]dnl
  81 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
  82 }
  83 ]])[
  84
  85 # Hijack the initial action to initialize the locations.
  86 ]b4_bison_locations_if([m4_define([b4_initial_action],
  87 [yylloc.initialize ();]m4_ifdef([b4_initial_action], [
  88 m4_defn([b4_initial_action])]))])[
  89
  90 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
  91 # and declaration of yyerror.
  92 ]m4_append([b4_post_prologue],
  93 [b4_syncline([@oline@], [@ofile@])[
  94 ]b4_yylloc_default_define[
  95 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
  96 ]b4_function_declare([yyerror],
  97     [static void],b4_locations_if([
  98     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
  99                         [yylocationp]],])
 100     b4_parse_param,
 101     [[const char* msg], [msg]])])
 102
 103
 104 # Hijack the epilogue to define implementations (yyerror, parser member
 105 # functions etc.).
 106 m4_append([b4_epilogue],
 107 [b4_syncline([@oline@], [@ofile@])[
 108 /*------------------.
 109 | Report an error.  |
 110 `------------------*/
 111
 112 ]b4_function_define([yyerror],
 113     [static void],b4_locations_if([
 114     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 115                         [yylocationp]],])
 116     b4_parse_param,
 117     [[const char* msg], [msg]])[
 118 {
 119 ]b4_parse_param_use[]dnl
 120 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 121 }
 122
 123
 124 ]b4_namespace_open[
 125 ]dnl In this section, the parse params are the original parse_params.
 126 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 127 [  /// Build a parser object.
 128   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 129     :])[
 130 #if ]b4_api_PREFIX[DEBUG
 131     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 132 #endif]b4_parse_param_cons[
 133   {
 134   }
 135
 136   ]b4_parser_class_name::~b4_parser_class_name[ ()
 137   {
 138   }
 139
 140   int
 141   ]b4_parser_class_name[::parse ()
 142   {
 143     return ::yyparse (*this]b4_user_args[);
 144   }
 145
 146 #if ]b4_api_PREFIX[DEBUG
 147   /*--------------------.
 148   | Print this symbol.  |
 149   `--------------------*/
 150
 151   inline void
 152   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 153                            const semantic_type* yyvaluep]b4_locations_if([[,
 154                            const location_type* yylocationp]])[)
 155   {]b4_locations_if([[
 156     YYUSE (yylocationp);]])[
 157     YYUSE (yyvaluep);
 158     std::ostream& yyoutput = debug_stream ();
 159     std::ostream& yyo = yyoutput;
 160     YYUSE (yyo);
 161     switch (yytype)
 162       {
 163 ]b4_symbol_foreach([b4_symbol_printer])dnl
 164 [        default:
 165           break;
 166       }
 167   }
 168
 169
 170   void
 171   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 172                            const semantic_type* yyvaluep]b4_locations_if([[,
 173                            const location_type* yylocationp]])[)
 174   {
 175     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 176                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 177                << *yylocationp << ": "]])[;
 178     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 179     *yycdebug_ << ')';
 180   }
 181
 182   std::ostream&
 183   ]b4_parser_class_name[::debug_stream () const
 184   {
 185     return *yycdebug_;
 186   }
 187
 188   void
 189   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 190   {
 191     yycdebug_ = &o;
 192   }
 193
 194
 195   ]b4_parser_class_name[::debug_level_type
 196   ]b4_parser_class_name[::debug_level () const
 197   {
 198     return yydebug;
 199   }
 200
 201   void
 202   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 203   {
 204     // Actually, it is yydebug which is really used.
 205     yydebug = l;
 206   }
 207
 208 #endif
 209 ]m4_popdef([b4_parse_param])dnl
 210 b4_namespace_close
 211 ])
 212
 213 # b4_shared_declarations
 214 # ----------------------
 215 # Declaration that might either go into the header (if --defines)
 216 # or open coded in the parser body.
 217 m4_define([b4_shared_declarations],
 218 [dnl In this section, the parse params are the original parse_params.
 219 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 220 b4_percent_code_get([[requires]])[
 221
 222 #include <stdexcept>
 223 #include <string>
 224 #include <iostream>]b4_defines_if([
 225 b4_bison_locations_if([[#include "location.hh"]])])[
 226
 227 ]b4_YYDEBUG_define[
 228
 229 ]b4_namespace_open[
 230 ]b4_defines_if([],
 231 [b4_bison_locations_if([b4_position_define
 232 b4_location_define])])[
 233
 234   /// A Bison parser.
 235   class ]b4_parser_class_name[
 236   {
 237   public:
 238 ]b4_public_types_declare[
 239
 240     /// Build a parser object.
 241     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 242     virtual ~]b4_parser_class_name[ ();
 243
 244     /// Parse.
 245     /// \returns  0 iff parsing succeeded.
 246     virtual int parse ();
 247
 248     /// The current debugging stream.
 249     std::ostream& debug_stream () const;
 250     /// Set the current debugging stream.
 251     void set_debug_stream (std::ostream &);
 252
 253     /// Type for debugging levels.
 254     typedef int debug_level_type;
 255     /// The current debugging level.
 256     debug_level_type debug_level () const;
 257     /// Set the current debugging level.
 258     void set_debug_level (debug_level_type l);
 259
 260   public:
 261     /// Report a syntax error.]b4_locations_if([[
 262     /// \param loc    where the syntax error is found.]])[
 263     /// \param msg    a description of the syntax error.
 264     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 265
 266 # if ]b4_api_PREFIX[DEBUG
 267   public:
 268     /// \brief Report a symbol value on the debug stream.
 269     /// \param yytype       The token type.
 270     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 271     /// \param yylocationp  Its location.]])[
 272     virtual void yy_symbol_value_print_ (int yytype,
 273                                          const semantic_type* yyvaluep]b4_locations_if([[,
 274                                          const location_type* yylocationp]])[);
 275     /// \brief Report a symbol on the debug stream.
 276     /// \param yytype       The token type.
 277     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 278     /// \param yylocationp  Its location.]])[
 279     virtual void yy_symbol_print_ (int yytype,
 280                                    const semantic_type* yyvaluep]b4_locations_if([[,
 281                                    const location_type* yylocationp]])[);
 282   private:
 283     /* Debugging.  */
 284     std::ostream* yycdebug_;
 285 #endif
 286
 287 ]b4_parse_param_vars[
 288   };
 289
 290 ]dnl Redirections for glr.c.
 291 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 292 [b4_token_defines])
 293 [
 294 #ifndef ]b4_api_PREFIX[STYPE
 295 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 296 #endif
 297 #ifndef ]b4_api_PREFIX[LTYPE
 298 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 299 #endif
 300
 301 ]b4_namespace_close[
 302 ]b4_percent_code_get([[provides]])[
 303 ]m4_popdef([b4_parse_param])dnl
 304 ])
 305
 306 b4_defines_if(
 307 [m4_changecom()dnl
 308 m4_divert_push(0)dnl
 309 @output(b4_spec_defines_file@)@
 310 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 311              [2002-2012])[
 312
 313 /* C++ GLR parser skeleton written by Akim Demaille.  */
 314
 315 ]b4_cpp_guard_open([b4_spec_defines_file])[
 316 ]b4_shared_declarations[
 317 ]b4_cpp_guard_close([b4_spec_defines_file])[
 318 ]b4_output_end()])
 319
 320 # Let glr.c (and b4_shared_declarations) believe that the user
 321 # arguments include the parser itself.
 322 m4_ifset([b4_parse_param],
 323 [m4_pushdef([b4_parse_param],
 324             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
 325 m4_defn([b4_parse_param]))],
 326 [m4_pushdef([b4_parse_param],
 327             [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
 328 ])
 329 m4_include(b4_pkgdatadir/[glr.c])
 330 m4_popdef([b4_parse_param])