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 using locations.
  47 m4_define([b4_percent_define(locations)], [])
  48 m4_define([b4_pure_flag],      [1])
  49
  50 # The header is mandatory.
  51 b4_defines_if([],
  52               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
  53
  54 m4_include(b4_pkgdatadir/[c++.m4])
  55 b4_percent_define_ifdef([[location_type]], [],
  56                         [m4_include(b4_pkgdatadir/[location.cc])])
  57
  58 m4_define([b4_parser_class_name],
  59           [b4_percent_define_get([[parser_class_name]])])
  60
  61 # Save the parse parameters.
  62 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
  63
  64
  65 # b4_yy_symbol_print_generate
  66 # ---------------------------
  67 # Bypass the default implementation to generate the "yy_symbol_print"
  68 # and "yy_symbol_value_print" functions.
  69 m4_define([b4_yy_symbol_print_generate],
  70 [[
  71 /*--------------------.
  72 | Print this symbol.  |
  73 `--------------------*/
  74
  75 ]b4_c_ansi_function_def([yy_symbol_print],
  76     [static void],
  77     [[FILE *],               []],
  78     [[int yytype],           [yytype]],
  79     [[const b4_namespace_ref::b4_parser_class_name::semantic_type *yyvaluep],
  80                              [yyvaluep]],
  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 # Declare yyerror.
  92 m4_append([b4_post_prologue],
  93 [b4_syncline([@oline@], [@ofile@])
  94
  95 b4_c_ansi_function_decl([yyerror],
  96     [static void],
  97     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
  98                         [yylocationp]],
  99     b4_parse_param,
 100     [[const char* msg], [msg]])])
 101
 102
 103 # Define yyerror.
 104 m4_append([b4_epilogue],
 105 [b4_syncline([@oline@], [@ofile@])[
 106 /*------------------.
 107 | Report an error.  |
 108 `------------------*/
 109
 110 ]b4_c_ansi_function_def([yyerror],
 111     [static void],
 112     [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
 113                         [yylocationp]],
 114     b4_parse_param,
 115     [[const char* msg], [msg]])[
 116 {
 117 ]b4_parse_param_use[]dnl
 118 [  yyparser.error (*yylocationp, msg);
 119 }
 120
 121
 122 ]b4_namespace_open[
 123 ]dnl In this section, the parse param are the original parse_params.
 124 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 125 [  /// Build a parser object.
 126   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 127     :])[
 128 #if YYDEBUG
 129     ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 130 #endif]b4_parse_param_cons[
 131   {
 132   }
 133
 134   ]b4_parser_class_name::~b4_parser_class_name[ ()
 135   {
 136   }
 137
 138   int
 139   ]b4_parser_class_name[::parse ()
 140   {
 141     return ::yyparse (*this]b4_user_args[);
 142   }
 143
 144 #if YYDEBUG
 145   /*--------------------.
 146   | Print this symbol.  |
 147   `--------------------*/
 148
 149   inline void
 150   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
 151                            const semantic_type* yyvaluep,
 152                            const location_type* yylocationp)
 153   {
 154     YYUSE (yylocationp);
 155     YYUSE (yyvaluep);
 156     std::ostream& yyoutput = debug_stream ();
 157     std::ostream& yyo = yyoutput;
 158     YYUSE (yyo);
 159     switch (yytype)
 160       {
 161 ]b4_symbol_foreach([b4_symbol_printer])dnl
 162 [        default:
 163           break;
 164       }
 165   }
 166
 167
 168   void
 169   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
 170                            const semantic_type* yyvaluep,
 171                            const location_type* yylocationp)
 172   {
 173     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
 174                << ' ' << yytname[yytype] << " ("
 175                << *yylocationp << ": ";
 176     yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
 177     *yycdebug_ << ')';
 178   }
 179
 180   std::ostream&
 181   ]b4_parser_class_name[::debug_stream () const
 182   {
 183     return *yycdebug_;
 184   }
 185
 186   void
 187   ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
 188   {
 189     yycdebug_ = &o;
 190   }
 191
 192
 193   ]b4_parser_class_name[::debug_level_type
 194   ]b4_parser_class_name[::debug_level () const
 195   {
 196     return yydebug;
 197   }
 198
 199   void
 200   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
 201   {
 202     yydebug = l;
 203   }
 204
 205 #endif
 206 ]m4_popdef([b4_parse_param])dnl
 207 b4_namespace_close[
 208 ]])
 209
 210
 211 # Let glr.c believe that the user arguments include the parser itself.
 212 m4_ifset([b4_parse_param],
 213 [m4_pushdef([b4_parse_param],
 214             m4_dquote([[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]],]
 215 m4_defn([b4_parse_param])))],
 216 [m4_pushdef([b4_parse_param],
 217             [[[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]]]])
 218 ])
 219 m4_include(b4_pkgdatadir/[glr.c])
 220 m4_popdef([b4_parse_param])
 221
 222 m4_divert_push(0)
 223 @output(b4_spec_defines_file@)@
 224 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
 225              [2002-2012])[
 226
 227 /* C++ GLR parser skeleton written by Akim Demaille.  */
 228
 229 ]b4_cpp_guard_open([b4_spec_defines_file])[
 230
 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 /* Using locations.  */
 240 #define YYLSP_NEEDED ]b4_locations_if([1], [0])[
 241
 242 /* Enabling traces.  */
 243 #ifndef YYDEBUG
 244 # define YYDEBUG ]b4_parse_trace_if([1], [0])[
 245 #endif
 246
 247 /* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
 248    If N is 0, then set CURRENT to the empty location which ends
 249    the previous symbol: RHS[0] (always defined).  */
 250
 251 #ifndef YYLLOC_DEFAULT
 252 # define YYLLOC_DEFAULT(Current, Rhs, N)                                \
 253     do                                                                  \
 254       if (N)                                                            \
 255         {                                                               \
 256           (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
 257           (Current).end    = YYRHSLOC (Rhs, N).end;                     \
 258         }                                                               \
 259       else                                                              \
 260         {                                                               \
 261           (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
 262         }                                                               \
 263     while (/*CONSTCOND*/ 0)
 264 #endif
 265
 266 ]b4_namespace_open[
 267   /// A Bison parser.
 268   class ]b4_parser_class_name[
 269   {
 270   public:
 271 ]b4_public_types_declare[
 272
 273     /// Build a parser object.
 274     ]b4_parser_class_name[ (]b4_parse_param_decl[);
 275     virtual ~]b4_parser_class_name[ ();
 276
 277     /// Parse.
 278     /// \returns  0 iff parsing succeeded.
 279     virtual int parse ();
 280
 281     /// The current debugging stream.
 282     std::ostream& debug_stream () const;
 283     /// Set the current debugging stream.
 284     void set_debug_stream (std::ostream &);
 285
 286     /// Type for debugging levels.
 287     typedef int debug_level_type;
 288     /// The current debugging level.
 289     debug_level_type debug_level () const;
 290     /// Set the current debugging level.
 291     void set_debug_level (debug_level_type l);
 292
 293   public:
 294     /// Report a syntax error.
 295     /// \param loc    where the syntax error is found.
 296     /// \param msg    a description of the syntax error.
 297     virtual void error (const location_type& loc, const std::string& msg);
 298
 299 #if YYDEBUG
 300   public:
 301     /// \brief Report a symbol value on the debug stream.
 302     /// \param yytype       The token type.
 303     /// \param yyvaluep     Its semantic value.
 304     /// \param yylocationp  Its location.
 305     virtual void yy_symbol_value_print_ (int yytype,
 306                                          const semantic_type* yyvaluep,
 307                                          const location_type* yylocationp);
 308     /// \brief Report a symbol on the debug stream.
 309     /// \param yytype       The token type.
 310     /// \param yyvaluep     Its semantic value.
 311     /// \param yylocationp  Its location.
 312     virtual void yy_symbol_print_ (int yytype,
 313                                    const semantic_type* yyvaluep,
 314                                    const location_type* yylocationp);
 315   private:
 316     /* Debugging.  */
 317     std::ostream* yycdebug_;
 318 #endif
 319
 320 ]b4_parse_param_vars[
 321   };
 322
 323 ]dnl Redirections for glr.c.
 324 b4_percent_define_flag_if([[global_tokens_and_yystype]],
 325 [b4_token_defines(b4_tokens)])
 326 [
 327 #ifndef YYSTYPE
 328 # define YYSTYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 329 #endif
 330 #ifndef YYLTYPE
 331 # define YYLTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 332 #endif
 333
 334 ]b4_namespace_close[
 335 ]b4_percent_code_get([[provides]])[
 336 ]b4_cpp_guard_close([b4_spec_defines_file])[
 337 ]m4_divert_pop(0)