2014-10-24 Christophe Lyon <christophe.lyon@linaro.org>
[official-gcc.git] / include / ansidecl.h
blob0fb23bba792dbb30d852723b9ac9a5d337e3aedc
1 /* ANSI and traditional C compatability macros
2 Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
3 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2013
4 Free Software Foundation, Inc.
5 This file is part of the GNU C Library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
21 /* ANSI and traditional C compatibility macros
23 ANSI C is assumed if __STDC__ is #defined.
25 Macro ANSI C definition Traditional C definition
26 ----- ---- - ---------- ----------- - ----------
27 PTR `void *' `char *'
28 const not defined `'
29 volatile not defined `'
30 signed not defined `'
32 For ease of writing code which uses GCC extensions but needs to be
33 portable to other compilers, we provide the GCC_VERSION macro that
34 simplifies testing __GNUC__ and __GNUC_MINOR__ together, and various
35 wrappers around __attribute__. Also, __extension__ will be #defined
36 to nothing if it doesn't work. See below. */
38 #ifndef _ANSIDECL_H
39 #define _ANSIDECL_H 1
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
45 /* Every source file includes this file,
46 so they will all get the switch for lint. */
47 /* LINTLIBRARY */
49 /* Using MACRO(x,y) in cpp #if conditionals does not work with some
50 older preprocessors. Thus we can't define something like this:
52 #define HAVE_GCC_VERSION(MAJOR, MINOR) \
53 (__GNUC__ > (MAJOR) || (__GNUC__ == (MAJOR) && __GNUC_MINOR__ >= (MINOR)))
55 and then test "#if HAVE_GCC_VERSION(2,7)".
57 So instead we use the macro below and test it against specific values. */
59 /* This macro simplifies testing whether we are using gcc, and if it
60 is of a particular minimum version. (Both major & minor numbers are
61 significant.) This macro will evaluate to 0 if we are not using
62 gcc at all. */
63 #ifndef GCC_VERSION
64 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
65 #endif /* GCC_VERSION */
67 #if defined (__STDC__) || defined(__cplusplus) || defined (_AIX) || (defined (__mips) && defined (_SYSTYPE_SVR4)) || defined(_WIN32)
68 /* All known AIX compilers implement these things (but don't always
69 define __STDC__). The RISC/OS MIPS compiler defines these things
70 in SVR4 mode, but does not define __STDC__. */
71 /* eraxxon@alumni.rice.edu: The Compaq C++ compiler, unlike many other
72 C++ compilers, does not define __STDC__, though it acts as if this
73 was so. (Verified versions: 5.7, 6.2, 6.3, 6.5) */
75 #define PTR void *
77 #undef const
78 #undef volatile
79 #undef signed
81 /* inline requires special treatment; it's in C99, and GCC >=2.7 supports
82 it too, but it's not in C89. */
83 #undef inline
84 #if __STDC_VERSION__ >= 199901L || defined(__cplusplus) || (defined(__SUNPRO_C) && defined(__C99FEATURES__))
85 /* it's a keyword */
86 #else
87 # if GCC_VERSION >= 2007
88 # define inline __inline__ /* __inline__ prevents -pedantic warnings */
89 # else
90 # define inline /* nothing */
91 # endif
92 #endif
94 #else /* Not ANSI C. */
96 #define PTR char *
98 /* some systems define these in header files for non-ansi mode */
99 #undef const
100 #undef volatile
101 #undef signed
102 #undef inline
103 #define const
104 #define volatile
105 #define signed
106 #define inline
108 #endif /* ANSI C. */
110 /* Define macros for some gcc attributes. This permits us to use the
111 macros freely, and know that they will come into play for the
112 version of gcc in which they are supported. */
114 #if (GCC_VERSION < 2007)
115 # define __attribute__(x)
116 #endif
118 /* Attribute __malloc__ on functions was valid as of gcc 2.96. */
119 #ifndef ATTRIBUTE_MALLOC
120 # if (GCC_VERSION >= 2096)
121 # define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
122 # else
123 # define ATTRIBUTE_MALLOC
124 # endif /* GNUC >= 2.96 */
125 #endif /* ATTRIBUTE_MALLOC */
127 /* Attributes on labels were valid as of gcc 2.93 and g++ 4.5. For
128 g++ an attribute on a label must be followed by a semicolon. */
129 #ifndef ATTRIBUTE_UNUSED_LABEL
130 # ifndef __cplusplus
131 # if GCC_VERSION >= 2093
132 # define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED
133 # else
134 # define ATTRIBUTE_UNUSED_LABEL
135 # endif
136 # else
137 # if GCC_VERSION >= 4005
138 # define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED ;
139 # else
140 # define ATTRIBUTE_UNUSED_LABEL
141 # endif
142 # endif
143 #endif
145 /* Similarly to ARG_UNUSED below. Prior to GCC 3.4, the C++ frontend
146 couldn't parse attributes placed after the identifier name, and now
147 the entire compiler is built with C++. */
148 #ifndef ATTRIBUTE_UNUSED
149 #if GCC_VERSION >= 3004
150 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
151 #else
152 #define ATTRIBUTE_UNUSED
153 #endif
154 #endif /* ATTRIBUTE_UNUSED */
156 /* Before GCC 3.4, the C++ frontend couldn't parse attributes placed after the
157 identifier name. */
158 #if ! defined(__cplusplus) || (GCC_VERSION >= 3004)
159 # define ARG_UNUSED(NAME) NAME ATTRIBUTE_UNUSED
160 #else /* !__cplusplus || GNUC >= 3.4 */
161 # define ARG_UNUSED(NAME) NAME
162 #endif /* !__cplusplus || GNUC >= 3.4 */
164 #ifndef ATTRIBUTE_NORETURN
165 #define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
166 #endif /* ATTRIBUTE_NORETURN */
168 /* Attribute `nonnull' was valid as of gcc 3.3. */
169 #ifndef ATTRIBUTE_NONNULL
170 # if (GCC_VERSION >= 3003)
171 # define ATTRIBUTE_NONNULL(m) __attribute__ ((__nonnull__ (m)))
172 # else
173 # define ATTRIBUTE_NONNULL(m)
174 # endif /* GNUC >= 3.3 */
175 #endif /* ATTRIBUTE_NONNULL */
177 /* Attribute `returns_nonnull' was valid as of gcc 4.9. */
178 #ifndef ATTRIBUTE_RETURNS_NONNULL
179 # if (GCC_VERSION >= 4009)
180 # define ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
181 # else
182 # define ATTRIBUTE_RETURNS_NONNULL
183 # endif /* GNUC >= 4.9 */
184 #endif /* ATTRIBUTE_RETURNS_NONNULL */
186 /* Attribute `pure' was valid as of gcc 3.0. */
187 #ifndef ATTRIBUTE_PURE
188 # if (GCC_VERSION >= 3000)
189 # define ATTRIBUTE_PURE __attribute__ ((__pure__))
190 # else
191 # define ATTRIBUTE_PURE
192 # endif /* GNUC >= 3.0 */
193 #endif /* ATTRIBUTE_PURE */
195 /* Use ATTRIBUTE_PRINTF when the format specifier must not be NULL.
196 This was the case for the `printf' format attribute by itself
197 before GCC 3.3, but as of 3.3 we need to add the `nonnull'
198 attribute to retain this behavior. */
199 #ifndef ATTRIBUTE_PRINTF
200 #define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) ATTRIBUTE_NONNULL(m)
201 #define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2)
202 #define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3)
203 #define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4)
204 #define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5)
205 #define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6)
206 #endif /* ATTRIBUTE_PRINTF */
208 /* Use ATTRIBUTE_FPTR_PRINTF when the format attribute is to be set on
209 a function pointer. Format attributes were allowed on function
210 pointers as of gcc 3.1. */
211 #ifndef ATTRIBUTE_FPTR_PRINTF
212 # if (GCC_VERSION >= 3001)
213 # define ATTRIBUTE_FPTR_PRINTF(m, n) ATTRIBUTE_PRINTF(m, n)
214 # else
215 # define ATTRIBUTE_FPTR_PRINTF(m, n)
216 # endif /* GNUC >= 3.1 */
217 # define ATTRIBUTE_FPTR_PRINTF_1 ATTRIBUTE_FPTR_PRINTF(1, 2)
218 # define ATTRIBUTE_FPTR_PRINTF_2 ATTRIBUTE_FPTR_PRINTF(2, 3)
219 # define ATTRIBUTE_FPTR_PRINTF_3 ATTRIBUTE_FPTR_PRINTF(3, 4)
220 # define ATTRIBUTE_FPTR_PRINTF_4 ATTRIBUTE_FPTR_PRINTF(4, 5)
221 # define ATTRIBUTE_FPTR_PRINTF_5 ATTRIBUTE_FPTR_PRINTF(5, 6)
222 #endif /* ATTRIBUTE_FPTR_PRINTF */
224 /* Use ATTRIBUTE_NULL_PRINTF when the format specifier may be NULL. A
225 NULL format specifier was allowed as of gcc 3.3. */
226 #ifndef ATTRIBUTE_NULL_PRINTF
227 # if (GCC_VERSION >= 3003)
228 # define ATTRIBUTE_NULL_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n)))
229 # else
230 # define ATTRIBUTE_NULL_PRINTF(m, n)
231 # endif /* GNUC >= 3.3 */
232 # define ATTRIBUTE_NULL_PRINTF_1 ATTRIBUTE_NULL_PRINTF(1, 2)
233 # define ATTRIBUTE_NULL_PRINTF_2 ATTRIBUTE_NULL_PRINTF(2, 3)
234 # define ATTRIBUTE_NULL_PRINTF_3 ATTRIBUTE_NULL_PRINTF(3, 4)
235 # define ATTRIBUTE_NULL_PRINTF_4 ATTRIBUTE_NULL_PRINTF(4, 5)
236 # define ATTRIBUTE_NULL_PRINTF_5 ATTRIBUTE_NULL_PRINTF(5, 6)
237 #endif /* ATTRIBUTE_NULL_PRINTF */
239 /* Attribute `sentinel' was valid as of gcc 3.5. */
240 #ifndef ATTRIBUTE_SENTINEL
241 # if (GCC_VERSION >= 3005)
242 # define ATTRIBUTE_SENTINEL __attribute__ ((__sentinel__))
243 # else
244 # define ATTRIBUTE_SENTINEL
245 # endif /* GNUC >= 3.5 */
246 #endif /* ATTRIBUTE_SENTINEL */
249 #ifndef ATTRIBUTE_ALIGNED_ALIGNOF
250 # if (GCC_VERSION >= 3000)
251 # define ATTRIBUTE_ALIGNED_ALIGNOF(m) __attribute__ ((__aligned__ (__alignof__ (m))))
252 # else
253 # define ATTRIBUTE_ALIGNED_ALIGNOF(m)
254 # endif /* GNUC >= 3.0 */
255 #endif /* ATTRIBUTE_ALIGNED_ALIGNOF */
257 /* Useful for structures whose layout must much some binary specification
258 regardless of the alignment and padding qualities of the compiler. */
259 #ifndef ATTRIBUTE_PACKED
260 # define ATTRIBUTE_PACKED __attribute__ ((packed))
261 #endif
263 /* Attribute `hot' and `cold' was valid as of gcc 4.3. */
264 #ifndef ATTRIBUTE_COLD
265 # if (GCC_VERSION >= 4003)
266 # define ATTRIBUTE_COLD __attribute__ ((__cold__))
267 # else
268 # define ATTRIBUTE_COLD
269 # endif /* GNUC >= 4.3 */
270 #endif /* ATTRIBUTE_COLD */
271 #ifndef ATTRIBUTE_HOT
272 # if (GCC_VERSION >= 4003)
273 # define ATTRIBUTE_HOT __attribute__ ((__hot__))
274 # else
275 # define ATTRIBUTE_HOT
276 # endif /* GNUC >= 4.3 */
277 #endif /* ATTRIBUTE_HOT */
279 /* We use __extension__ in some places to suppress -pedantic warnings
280 about GCC extensions. This feature didn't work properly before
281 gcc 2.8. */
282 #if GCC_VERSION < 2008
283 #define __extension__
284 #endif
286 /* This is used to declare a const variable which should be visible
287 outside of the current compilation unit. Use it as
288 EXPORTED_CONST int i = 1;
289 This is because the semantics of const are different in C and C++.
290 "extern const" is permitted in C but it looks strange, and gcc
291 warns about it when -Wc++-compat is not used. */
292 #ifdef __cplusplus
293 #define EXPORTED_CONST extern const
294 #else
295 #define EXPORTED_CONST const
296 #endif
298 /* Be conservative and only use enum bitfields with C++ or GCC.
299 FIXME: provide a complete autoconf test for buggy enum bitfields. */
301 #ifdef __cplusplus
302 #define ENUM_BITFIELD(TYPE) enum TYPE
303 #elif (GCC_VERSION > 2000)
304 #define ENUM_BITFIELD(TYPE) __extension__ enum TYPE
305 #else
306 #define ENUM_BITFIELD(TYPE) unsigned int
307 #endif
309 #ifdef __cplusplus
311 #endif
313 #endif /* ansidecl.h */