data/glr.cc

   1 # C++ GLR skeleton for Bison
   2
   3 # Copyright (C) 2002-2015 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 #undef yynerrs
 116 #undef yychar
 117 #undef yylval]b4_locations_if([
 118 #undef yylloc])
 119
 120 m4_if(b4_prefix, [yy], [],
 121 [[/* Substitute the variable and function names.  */
 122 #define yyparse ]b4_prefix[parse
 123 #define yylex   ]b4_prefix[lex
 124 #define yyerror ]b4_prefix[error
 125 #define yydebug ]b4_prefix[debug
 126 ]]b4_pure_if([], [[
 127 #define yylval  ]b4_prefix[lval
 128 #define yychar  ]b4_prefix[char
 129 #define yynerrs ]b4_prefix[nerrs]b4_locations_if([[
 130 #define yylloc  ]b4_prefix[lloc]])]))
 131
 132 # Hijack the epilogue to define implementations (yyerror, parser member
 133 # functions etc.).
 134 m4_append([b4_epilogue],
 135 [b4_syncline([@oline@], [@ofile@])[
 136
 137 /*------------------.
 138 | Report an error.  |
 139 `------------------*/
 140
 141 ]b4_function_define([yyerror],
 142     [static void],b4_locations_if([
 143     [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
 144                         [yylocationp]],])
 145     b4_parse_param,
 146     [[const char* msg], [msg]])[
 147 {
 148 ]b4_parse_param_use[]dnl
 149 [  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 150 }
 151
 152
 153 ]b4_namespace_open[
 154 ]dnl In this section, the parse params are the original parse_params.
 155 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 156 [  /// Build a parser object.
 157   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 158     :])[
 159 #if ]b4_api_PREFIX[DEBUG
 160     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 161 #endif]b4_parse_param_cons[
 162   {
 163   }
 164
 165   ]b4_parser_class_name::~b4_parser_class_name[ ()
 166   {
 167   }
 168
 169   int
 170   ]b4_parser_class_name[::parse ()
 171   {
 172     return ::yyparse (*this]b4_user_args[);
 173   }
 174
 175 #if ]b4_api_PREFIX[DEBUG
 176   /*--------------------.
 177   | Print this symbol.  |
 178   `--------------------*/
 179
 180   inline void
 181   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 182                            const semantic_type* yyvaluep]b4_locations_if([[,
 183                            const location_type* yylocationp]])[)
 184   {]b4_locations_if([[
 185     YYUSE (yylocationp);]])[
 186     YYUSE (yyvaluep);
 187     std::ostream& yyoutput = debug_stream ();
 188     std::ostream& yyo = yyoutput;
 189     YYUSE (yyo);
 190     ]b4_symbol_actions([printer])[
 191   }
 192
 193
 194   void
 195   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 196                            const semantic_type* yyvaluep]b4_locations_if([[,
 197                            const location_type* yylocationp]])[)
 198   {
 199     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 200                << ' ' << yytname[yytype] << " ("]b4_locations_if([[
 201                << *yylocationp << ": "]])[;
 202     yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
 203     *yycdebug_ << ')';
 204   }
 205
 206   std::ostream&
 207   ]b4_parser_class_name[::debug_stream () const
 208   {
 209     return *yycdebug_;
 210   }
 211
 212   void
 213   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 214   {
 215     yycdebug_ = &o;
 216   }
 217
 218
 219   ]b4_parser_class_name[::debug_level_type
 220   ]b4_parser_class_name[::debug_level () const
 221   {
 222     return yydebug;
 223   }
 224
 225   void
 226   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 227   {
 228     // Actually, it is yydebug which is really used.
 229     yydebug = l;
 230   }
 231
 232 #endif
 233 ]m4_popdef([b4_parse_param])dnl
 234 b4_namespace_close
 235 ])
 236
 237 # b4_shared_declarations
 238 # ----------------------
 239 # Declaration that might either go into the header (if --defines)
 240 # or open coded in the parser body.
 241 m4_define([b4_shared_declarations],
 242 [m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 243 b4_percent_code_get([[requires]])[
 244
 245 #include <stdexcept>
 246 #include <string>
 247 #include <iostream>]b4_defines_if([
 248 b4_bison_locations_if([[#include "location.hh"]])])[
 249
 250 ]b4_YYDEBUG_define[
 251
 252 ]b4_namespace_open[
 253 ]b4_defines_if([],
 254 [b4_bison_locations_if([b4_position_define
 255 b4_location_define])])[
 256
 257   /// A Bison parser.
 258   class ]b4_parser_class_name[
 259   {
 260   public:
 261 ]b4_public_types_declare[
 262
 263     /// Build a parser object.
 264     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 265     virtual ~]b4_parser_class_name[ ();
 266
 267     /// Parse.
 268     /// \returns  0 iff parsing succeeded.
 269     virtual int parse ();
 270
 271     /// The current debugging stream.
 272     std::ostream& debug_stream () const;
 273     /// Set the current debugging stream.
 274     void set_debug_stream (std::ostream &);
 275
 276     /// Type for debugging levels.
 277     typedef int debug_level_type;
 278     /// The current debugging level.
 279     debug_level_type debug_level () const;
 280     /// Set the current debugging level.
 281     void set_debug_level (debug_level_type l);
 282
 283   public:
 284     /// Report a syntax error.]b4_locations_if([[
 285     /// \param loc    where the syntax error is found.]])[
 286     /// \param msg    a description of the syntax error.
 287     virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 288
 289 # if ]b4_api_PREFIX[DEBUG
 290   public:
 291     /// \brief Report a symbol value on the debug stream.
 292     /// \param yytype       The token type.
 293     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 294     /// \param yylocationp  Its location.]])[
 295     virtual void yy_symbol_value_print_ (int yytype,
 296                                          const semantic_type* yyvaluep]b4_locations_if([[,
 297                                          const location_type* yylocationp]])[);
 298     /// \brief Report a symbol on the debug stream.
 299     /// \param yytype       The token type.
 300     /// \param yyvaluep     Its semantic value.]b4_locations_if([[
 301     /// \param yylocationp  Its location.]])[
 302     virtual void yy_symbol_print_ (int yytype,
 303                                    const semantic_type* yyvaluep]b4_locations_if([[,
 304                                    const location_type* yylocationp]])[);
 305   private:
 306     // Debugging.
 307     std::ostream* yycdebug_;
 308 #endif
 309
 310 ]b4_parse_param_vars[
 311   };
 312
 313 ]dnl Redirections for glr.c.
 314 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 315 [b4_token_defines])
 316 [
 317 #ifndef ]b4_api_PREFIX[STYPE
 318 # define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 319 #endif
 320 #ifndef ]b4_api_PREFIX[LTYPE
 321 # define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 322 #endif
 323
 324 ]b4_namespace_close[
 325 ]b4_percent_code_get([[provides]])[
 326 ]m4_popdef([b4_parse_param])dnl
 327 ])
 328
 329 b4_defines_if(
 330 [b4_output_begin([b4_spec_defines_file])
 331 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 332              [2002-2015])[
 333
 334 // C++ GLR parser skeleton written by Akim Demaille.
 335
 336 ]b4_cpp_guard_open([b4_spec_defines_file])[
 337 ]b4_shared_declarations[
 338 ]b4_cpp_guard_close([b4_spec_defines_file])[
 339 ]b4_output_end()])
 340
 341 # Let glr.c (and b4_shared_declarations) believe that the user
 342 # arguments include the parser itself.
 343 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_wrap]))
 344 m4_include(b4_pkgdatadir/[glr.c])
 345 m4_popdef([b4_parse_param])