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1 # C++ GLR skeleton for Bison
2 # Copyright (C) 2002-2010 Free Software Foundation, Inc.
3
4 # This program is free software: you can redistribute it and/or modify
5 # it under the terms of the GNU General Public License as published by
6 # the Free Software Foundation, either version 3 of the License, or
7 # (at your option) any later version.
8 #
9 # This program is distributed in the hope that it will be useful,
10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 # GNU General Public License for more details.
13 #
14 # You should have received a copy of the GNU General Public License
15 # along with this program. If not, see <http://www.gnu.org/licenses/>.
16
17
18 # This skeleton produces a C++ class that encapsulates a C glr parser.
19 # This is in order to reduce the maintenance burden. The glr.c
20 # skeleton is clean and pure enough so that there are no real
21 # problems. The C++ interface is the same as that of lalr1.cc. In
22 # fact, glr.c can replace yacc.c without the user noticing any
23 # difference, and similarly for glr.cc replacing lalr1.cc.
24 #
25 # The passing of parse-params
26 #
27 # The additional arguments are stored as members of the parser
28 # object, yyparser. The C routines need to carry yyparser
29 # throughout the C parser; that's easy: make yyparser an
30 # additional parse-param. But because the C++ skeleton needs to
31 # know the "real" original parse-param, we save them
32 # (b4_parse_param_orig). Note that b4_parse_param is overquoted
33 # (and c.m4 strips one level of quotes). This is a PITA, and
34 # explains why there are so many levels of quotes.
35 #
36 # The locations
37 #
38 # We use location.cc just like lalr1.cc, but because glr.c stores
39 # the locations in a union, the position and location classes
40 # must not have a constructor. Therefore, contrary to lalr1.cc, we
41 # must not define "b4_location_constructors". As a consequence the
42 # user must initialize the first positions (in particular the
43 # filename member).
44
45 # We require a pure interface using locations.
46 m4_define([b4_percent_define(locations)], [])
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_generate
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_generate],
69 [[
70 /*--------------------.
71 | Print this symbol. |
72 `--------------------*/
73
74 ]b4_c_ansi_function_def([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]],
80 [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
81 [yylocationp]],
82 b4_parse_param)[
83 {
84 ]b4_parse_param_use[]dnl
85 [ yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
86 }
87 ]])
88
89
90 # Declare yyerror.
91 m4_append([b4_post_prologue],
92 [b4_syncline([@oline@], [@ofile@])
93
94 b4_c_ansi_function_decl([yyerror],
95 [static void],
96 [[b4_namespace_ref::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
97 b4_parse_param,
98 [[const char* msg], [msg]])])
99
100
101 # Define yyerror.
102 m4_append([b4_epilogue],
103 [b4_syncline([@oline@], [@ofile@])[
104 /*------------------.
105 | Report an error. |
106 `------------------*/
107
108 ]b4_c_ansi_function_def([yyerror],
109 [static void],
110 [[b4_namespace_ref::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
111 b4_parse_param,
112 [[const char* msg], [msg]])[
113 {
114 ]b4_parse_param_use[]dnl
115 [ yyparser.error (*yylocationp, msg);
116 }
117
118
119 ]b4_namespace_open[
120 ]dnl In this section, the parse param are the original parse_params.
121 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
122 [ /// Build a parser object.
123 ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
124 :])[
125 #if YYDEBUG
126 ]m4_ifset([b4_parse_param], [ ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
127 #endif]b4_parse_param_cons[
128 {
129 }
130
131 ]b4_parser_class_name::~b4_parser_class_name[ ()
132 {
133 }
134
135 int
136 ]b4_parser_class_name[::parse ()
137 {
138 return ::yyparse (*this]b4_user_args[);
139 }
140
141 #if YYDEBUG
142 /*--------------------.
143 | Print this symbol. |
144 `--------------------*/
145
146 inline void
147 ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
148 const semantic_type* yyvaluep, const location_type* yylocationp)
149 {
150 /* Pacify ``unused variable'' warnings. */
151 YYUSE (yyvaluep);
152 YYUSE (yylocationp);
153 switch (yytype)
154 {
155 ]b4_symbol_foreach([b4_symbol_printer])dnl
156 [ default:
157 break;
158 }
159 }
160
161
162 void
163 ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
164 const semantic_type* yyvaluep, const location_type* yylocationp)
165 {
166 *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
167 << ' ' << yytname[yytype] << " ("
168 << *yylocationp << ": ";
169 yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
170 *yycdebug_ << ')';
171 }
172
173 std::ostream&
174 ]b4_parser_class_name[::debug_stream () const
175 {
176 return *yycdebug_;
177 }
178
179 void
180 ]b4_parser_class_name[::set_debug_stream (std::ostream& o)
181 {
182 yycdebug_ = &o;
183 }
184
185
186 ]b4_parser_class_name[::debug_level_type
187 ]b4_parser_class_name[::debug_level () const
188 {
189 return yydebug;
190 }
191
192 void
193 ]b4_parser_class_name[::set_debug_level (debug_level_type l)
194 {
195 yydebug = l;
196 }
197
198 #endif
199 ]m4_popdef([b4_parse_param])dnl
200 b4_namespace_close[
201 ]])
202
203
204 # Let glr.c believe that the user arguments include the parser itself.
205 m4_ifset([b4_parse_param],
206 [m4_pushdef([b4_parse_param],
207 m4_dquote([[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]],]
208 m4_defn([b4_parse_param])))],
209 [m4_pushdef([b4_parse_param],
210 [[[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]]]])
211 ])
212 m4_include(b4_pkgdatadir/[glr.c])
213 m4_popdef([b4_parse_param])
214
215 m4_divert_push(0)
216 @output(b4_spec_defines_file@)@
217 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
218 [2002-2010])[
219
220 /* C++ GLR parser skeleton written by Akim Demaille. */
221
222 #ifndef PARSER_HEADER_H
223 # define PARSER_HEADER_H
224
225 ]b4_percent_code_get([[requires]])[
226
227 #include <stdexcept>
228 #include <string>
229 #include <iostream>
230 ]b4_percent_define_ifdef([[location_type]], [],
231 [[#include "location.hh"]])[
232
233 /* Using locations. */
234 #define YYLSP_NEEDED ]b4_locations_if([1], [0])[
235
236 /* Enabling traces. */
237 #ifndef YYDEBUG
238 # define YYDEBUG ]b4_parse_trace_if([1], [0])[
239 #endif
240
241 /* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
242 If N is 0, then set CURRENT to the empty location which ends
243 the previous symbol: RHS[0] (always defined). */
244
245 #ifndef YYLLOC_DEFAULT
246 # define YYLLOC_DEFAULT(Current, Rhs, N) \
247 do \
248 if (N) \
249 { \
250 (Current).begin = YYRHSLOC (Rhs, 1).begin; \
251 (Current).end = YYRHSLOC (Rhs, N).end; \
252 } \
253 else \
254 { \
255 (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end; \
256 } \
257 while (/*CONSTCOND*/ 0)
258 #endif
259
260 ]b4_namespace_open[
261 /// A Bison parser.
262 class ]b4_parser_class_name[
263 {
264 public:
265 ]b4_public_types_declare[
266
267 /// Build a parser object.
268 ]b4_parser_class_name[ (]b4_parse_param_decl[);
269 virtual ~]b4_parser_class_name[ ();
270
271 /// Parse.
272 /// \returns 0 iff parsing succeeded.
273 virtual int parse ();
274
275 /// The current debugging stream.
276 std::ostream& debug_stream () const;
277 /// Set the current debugging stream.
278 void set_debug_stream (std::ostream &);
279
280 /// Type for debugging levels.
281 typedef int debug_level_type;
282 /// The current debugging level.
283 debug_level_type debug_level () const;
284 /// Set the current debugging level.
285 void set_debug_level (debug_level_type l);
286
287 public:
288 /// Report a syntax error.
289 /// \param loc where the syntax error is found.
290 /// \param msg a description of the syntax error.
291 virtual void error (const location_type& loc, const std::string& msg);
292
293 #if YYDEBUG
294 public:
295 /// \brief Report a symbol value on the debug stream.
296 /// \param yytype The token type.
297 /// \param yyvaluep Its semantic value.
298 /// \param yylocationp Its location.
299 virtual void yy_symbol_value_print_ (int yytype,
300 const semantic_type* yyvaluep,
301 const location_type* yylocationp);
302 /// \brief Report a symbol on the debug stream.
303 /// \param yytype The token type.
304 /// \param yyvaluep Its semantic value.
305 /// \param yylocationp Its location.
306 virtual void yy_symbol_print_ (int yytype,
307 const semantic_type* yyvaluep,
308 const location_type* yylocationp);
309 private:
310 /* Debugging. */
311 std::ostream* yycdebug_;
312 #endif
313
314 /// \brief Reclaim the memory associated to a symbol.
315 /// \param yymsg Why this token is reclaimed.
316 /// \param yytype The symbol type.
317 /// \param yyvaluep Its semantic value.
318 /// \param yylocationp Its location.
319 inline void yydestruct_ (const char* yymsg,
320 int yytype,
321 semantic_type* yyvaluep,
322 location_type* yylocationp);
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 YYSTYPE
332 # define YYSTYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
333 #endif
334 #ifndef YYLTYPE
335 # define YYLTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
336 #endif
337
338 ]b4_namespace_close[
339
340 ]b4_percent_code_get([[provides]])[]dnl
341
342 [#endif /* ! defined PARSER_HEADER_H */]
343 m4_divert_pop(0)