Enchant: enchant-2.6.5/lib/c++defs.h Source File

Enchant Generic spell checking library

c++defs.h
1 /* C++ compatible function declaration macros.
2 Copyright (C) 2010-2023 Free Software Foundation, Inc.
3
4 This program is free software: you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as published
6 by the Free Software Foundation; either version 2 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 GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 #ifndef _GL_CXXDEFS_H
18 #define _GL_CXXDEFS_H
19
20 /* Begin/end the GNULIB_NAMESPACE namespace. */
21 #if defined __cplusplus && defined GNULIB_NAMESPACE
22 # define _GL_BEGIN_NAMESPACE namespace GNULIB_NAMESPACE {
23 # define _GL_END_NAMESPACE }
24 #else
25 # define _GL_BEGIN_NAMESPACE
26 # define _GL_END_NAMESPACE
27 #endif
28
29 /* The three most frequent use cases of these macros are:
30
31 * For providing a substitute for a function that is missing on some
32 platforms, but is declared and works fine on the platforms on which
33 it exists:
34
35 #if @GNULIB_FOO@
36 # if !@HAVE_FOO@
37 _GL_FUNCDECL_SYS (foo, ...);
38 # endif
39 _GL_CXXALIAS_SYS (foo, ...);
40 _GL_CXXALIASWARN (foo);
41 #elif defined GNULIB_POSIXCHECK
42 ...
43 #endif
44
45 * For providing a replacement for a function that exists on all platforms,
46 but is broken/insufficient and needs to be replaced on some platforms:
47
48 #if @GNULIB_FOO@
49 # if @REPLACE_FOO@
50 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
51 # undef foo
52 # define foo rpl_foo
53 # endif
54 _GL_FUNCDECL_RPL (foo, ...);
55 _GL_CXXALIAS_RPL (foo, ...);
56 # else
57 _GL_CXXALIAS_SYS (foo, ...);
58 # endif
59 _GL_CXXALIASWARN (foo);
60 #elif defined GNULIB_POSIXCHECK
61 ...
62 #endif
63
64 * For providing a replacement for a function that exists on some platforms
65 but is broken/insufficient and needs to be replaced on some of them and
66 is additionally either missing or undeclared on some other platforms:
67
68 #if @GNULIB_FOO@
69 # if @REPLACE_FOO@
70 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
71 # undef foo
72 # define foo rpl_foo
73 # endif
74 _GL_FUNCDECL_RPL (foo, ...);
75 _GL_CXXALIAS_RPL (foo, ...);
76 # else
77 # if !@HAVE_FOO@ or if !@HAVE_DECL_FOO@
78 _GL_FUNCDECL_SYS (foo, ...);
79 # endif
80 _GL_CXXALIAS_SYS (foo, ...);
81 # endif
82 _GL_CXXALIASWARN (foo);
83 #elif defined GNULIB_POSIXCHECK
84 ...
85 #endif
86 */
87
88 /* _GL_EXTERN_C declaration;
89 performs the declaration with C linkage. */
90 #if defined __cplusplus
91 # define _GL_EXTERN_C extern "C"
92 #else
93 # define _GL_EXTERN_C extern
94 #endif
95
96 /* _GL_FUNCDECL_RPL (func, rettype, parameters_and_attributes);
97 declares a replacement function, named rpl_func, with the given prototype,
98 consisting of return type, parameters, and attributes.
99 Example:
100 _GL_FUNCDECL_RPL (open, int, (const char *filename, int flags, ...)
101 _GL_ARG_NONNULL ((1)));
102
103 Note: Attributes, such as _GL_ATTRIBUTE_DEPRECATED, are supported in front
104 of a _GL_FUNCDECL_RPL invocation only in C mode, not in C++ mode. (That's
105 because
106 [[...]] extern "C" <declaration>;
107 is invalid syntax in C++.)
108 */
109 #define _GL_FUNCDECL_RPL(func,rettype,parameters_and_attributes) \
110 _GL_FUNCDECL_RPL_1 (rpl_##func, rettype, parameters_and_attributes)
111 #define _GL_FUNCDECL_RPL_1(rpl_func,rettype,parameters_and_attributes) \
112 _GL_EXTERN_C rettype rpl_func parameters_and_attributes
113
114 /* _GL_FUNCDECL_SYS (func, rettype, parameters_and_attributes);
115 declares the system function, named func, with the given prototype,
116 consisting of return type, parameters, and attributes.
117 Example:
118 _GL_FUNCDECL_SYS (open, int, (const char *filename, int flags, ...)
119 _GL_ARG_NONNULL ((1)));
120 */
121 #define _GL_FUNCDECL_SYS(func,rettype,parameters_and_attributes) \
122 _GL_EXTERN_C rettype func parameters_and_attributes
123
124 /* _GL_CXXALIAS_RPL (func, rettype, parameters);
125 declares a C++ alias called GNULIB_NAMESPACE::func
126 that redirects to rpl_func, if GNULIB_NAMESPACE is defined.
127 Example:
128 _GL_CXXALIAS_RPL (open, int, (const char *filename, int flags, ...));
129
130 Wrapping rpl_func in an object with an inline conversion operator
131 avoids a reference to rpl_func unless GNULIB_NAMESPACE::func is
132 actually used in the program. */
133 #define _GL_CXXALIAS_RPL(func,rettype,parameters) \
134 _GL_CXXALIAS_RPL_1 (func, rpl_##func, rettype, parameters)
135 #if defined __cplusplus && defined GNULIB_NAMESPACE
136 # define _GL_CXXALIAS_RPL_1(func,rpl_func,rettype,parameters) \
137 namespace GNULIB_NAMESPACE \
138 { \
139 static const struct _gl_ ## func ## _wrapper \
140 { \
141 typedef rettype (*type) parameters; \
142 \
143 inline operator type () const \
144 { \
145 return ::rpl_func; \
146 } \
147 } func = {}; \
148 } \
149 _GL_EXTERN_C int _gl_cxxalias_dummy
150 #else
151 # define _GL_CXXALIAS_RPL_1(func,rpl_func,rettype,parameters) \
152 _GL_EXTERN_C int _gl_cxxalias_dummy
153 #endif
154
155 /* _GL_CXXALIAS_MDA (func, rettype, parameters);
156 is to be used when func is a Microsoft deprecated alias, on native Windows.
157 It declares a C++ alias called GNULIB_NAMESPACE::func
158 that redirects to _func, if GNULIB_NAMESPACE is defined.
159 Example:
160 _GL_CXXALIAS_MDA (open, int, (const char *filename, int flags, ...));
161 */
162 #define _GL_CXXALIAS_MDA(func,rettype,parameters) \
163 _GL_CXXALIAS_RPL_1 (func, _##func, rettype, parameters)
164
165 /* _GL_CXXALIAS_RPL_CAST_1 (func, rpl_func, rettype, parameters);
166 is like _GL_CXXALIAS_RPL_1 (func, rpl_func, rettype, parameters);
167 except that the C function rpl_func may have a slightly different
168 declaration. A cast is used to silence the "invalid conversion" error
169 that would otherwise occur. */
170 #if defined __cplusplus && defined GNULIB_NAMESPACE
171 # define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \
172 namespace GNULIB_NAMESPACE \
173 { \
174 static const struct _gl_ ## func ## _wrapper \
175 { \
176 typedef rettype (*type) parameters; \
177 \
178 inline operator type () const \
179 { \
180 return reinterpret_cast<type>(::rpl_func); \
181 } \
182 } func = {}; \
183 } \
184 _GL_EXTERN_C int _gl_cxxalias_dummy
185 #else
186 # define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \
187 _GL_EXTERN_C int _gl_cxxalias_dummy
188 #endif
189
190 /* _GL_CXXALIAS_MDA_CAST (func, rettype, parameters);
191 is like _GL_CXXALIAS_MDA (func, rettype, parameters);
192 except that the C function func may have a slightly different declaration.
193 A cast is used to silence the "invalid conversion" error that would
194 otherwise occur. */
195 #define _GL_CXXALIAS_MDA_CAST(func,rettype,parameters) \
196 _GL_CXXALIAS_RPL_CAST_1 (func, _##func, rettype, parameters)
197
198 /* _GL_CXXALIAS_SYS (func, rettype, parameters);
199 declares a C++ alias called GNULIB_NAMESPACE::func
200 that redirects to the system provided function func, if GNULIB_NAMESPACE
201 is defined.
202 Example:
203 _GL_CXXALIAS_SYS (open, int, (const char *filename, int flags, ...));
204
205 Wrapping func in an object with an inline conversion operator
206 avoids a reference to func unless GNULIB_NAMESPACE::func is
207 actually used in the program. */
208 #if defined __cplusplus && defined GNULIB_NAMESPACE
209 # define _GL_CXXALIAS_SYS(func,rettype,parameters) \
210 namespace GNULIB_NAMESPACE \
211 { \
212 static const struct _gl_ ## func ## _wrapper \
213 { \
214 typedef rettype (*type) parameters; \
215 \
216 inline operator type () const \
217 { \
218 return ::func; \
219 } \
220 } func = {}; \
221 } \
222 _GL_EXTERN_C int _gl_cxxalias_dummy
223 #else
224 # define _GL_CXXALIAS_SYS(func,rettype,parameters) \
225 _GL_EXTERN_C int _gl_cxxalias_dummy
226 #endif
227
228 /* _GL_CXXALIAS_SYS_CAST (func, rettype, parameters);
229 is like _GL_CXXALIAS_SYS (func, rettype, parameters);
230 except that the C function func may have a slightly different declaration.
231 A cast is used to silence the "invalid conversion" error that would
232 otherwise occur. */
233 #if defined __cplusplus && defined GNULIB_NAMESPACE
234 # define _GL_CXXALIAS_SYS_CAST(func,rettype,parameters) \
235 namespace GNULIB_NAMESPACE \
236 { \
237 static const struct _gl_ ## func ## _wrapper \
238 { \
239 typedef rettype (*type) parameters; \
240 \
241 inline operator type () const \
242 { \
243 return reinterpret_cast<type>(::func); \
244 } \
245 } func = {}; \
246 } \
247 _GL_EXTERN_C int _gl_cxxalias_dummy
248 #else
249 # define _GL_CXXALIAS_SYS_CAST(func,rettype,parameters) \
250 _GL_EXTERN_C int _gl_cxxalias_dummy
251 #endif
252
253 /* _GL_CXXALIAS_SYS_CAST2 (func, rettype, parameters, rettype2, parameters2);
254 is like _GL_CXXALIAS_SYS (func, rettype, parameters);
255 except that the C function is picked among a set of overloaded functions,
256 namely the one with rettype2 and parameters2. Two consecutive casts
257 are used to silence the "cannot find a match" and "invalid conversion"
258 errors that would otherwise occur. */
259 #if defined __cplusplus && defined GNULIB_NAMESPACE
260 /* The outer cast must be a reinterpret_cast.
261 The inner cast: When the function is defined as a set of overloaded
262 functions, it works as a static_cast<>, choosing the designated variant.
263 When the function is defined as a single variant, it works as a
264 reinterpret_cast<>. The parenthesized cast syntax works both ways. */
265 # define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \
266 namespace GNULIB_NAMESPACE \
267 { \
268 static const struct _gl_ ## func ## _wrapper \
269 { \
270 typedef rettype (*type) parameters; \
271 \
272 inline operator type () const \
273 { \
274 return reinterpret_cast<type>((rettype2 (*) parameters2)(::func)); \
275 } \
276 } func = {}; \
277 } \
278 _GL_EXTERN_C int _gl_cxxalias_dummy
279 #else
280 # define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \
281 _GL_EXTERN_C int _gl_cxxalias_dummy
282 #endif
283
284 /* _GL_CXXALIASWARN (func);
285 causes a warning to be emitted when ::func is used but not when
286 GNULIB_NAMESPACE::func is used. func must be defined without overloaded
287 variants. */
288 #if defined __cplusplus && defined GNULIB_NAMESPACE
289 # define _GL_CXXALIASWARN(func) \
290 _GL_CXXALIASWARN_1 (func, GNULIB_NAMESPACE)
291 # define _GL_CXXALIASWARN_1(func,namespace) \
292 _GL_CXXALIASWARN_2 (func, namespace)
293 /* To work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43881>,
294 we enable the warning only when not optimizing. */
295 # if !(defined __GNUC__ && !defined __clang__ && __OPTIMIZE__)
296 # define _GL_CXXALIASWARN_2(func,namespace) \
297 _GL_WARN_ON_USE (func, \
298 "The symbol ::" #func " refers to the system function. " \
299 "Use " #namespace "::" #func " instead.")
300 # elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING
301 # define _GL_CXXALIASWARN_2(func,namespace) \
302 extern __typeof__ (func) func
303 # else
304 # define _GL_CXXALIASWARN_2(func,namespace) \
305 _GL_EXTERN_C int _gl_cxxalias_dummy
306 # endif
307 #else
308 # define _GL_CXXALIASWARN(func) \
309 _GL_EXTERN_C int _gl_cxxalias_dummy
310 #endif
311
312 /* _GL_CXXALIASWARN1 (func, rettype, parameters_and_attributes);
313 causes a warning to be emitted when the given overloaded variant of ::func
314 is used but not when GNULIB_NAMESPACE::func is used. */
315 #if defined __cplusplus && defined GNULIB_NAMESPACE
316 # define _GL_CXXALIASWARN1(func,rettype,parameters_and_attributes) \
317 _GL_CXXALIASWARN1_1 (func, rettype, parameters_and_attributes, \
318 GNULIB_NAMESPACE)
319 # define _GL_CXXALIASWARN1_1(func,rettype,parameters_and_attributes,namespace) \
320 _GL_CXXALIASWARN1_2 (func, rettype, parameters_and_attributes, namespace)
321 /* To work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43881>,
322 we enable the warning only when not optimizing. */
323 # if !(defined __GNUC__ && !defined __clang__ && __OPTIMIZE__)
324 # define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \
325 _GL_WARN_ON_USE_CXX (func, rettype, rettype, parameters_and_attributes, \
326 "The symbol ::" #func " refers to the system function. " \
327 "Use " #namespace "::" #func " instead.")
328 # else
329 # define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \
330 _GL_EXTERN_C int _gl_cxxalias_dummy
331 # endif
332 #else
333 # define _GL_CXXALIASWARN1(func,rettype,parameters_and_attributes) \
334 _GL_EXTERN_C int _gl_cxxalias_dummy
335 #endif
336
337 #endif /* _GL_CXXDEFS_H */