1/* Copyright (C) 1992-2018 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library 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
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#ifndef _SYS_CDEFS_H
19#define _SYS_CDEFS_H 1
20
21/* We are almost always included from features.h. */
22#ifndef _FEATURES_H
23# include <features.h>
24#endif
25
26/* The GNU libc does not support any K&R compilers or the traditional mode
27 of ISO C compilers anymore. Check for some of the combinations not
28 anymore supported. */
29#if defined __GNUC__ && !defined __STDC__
30# error "You need a ISO C conforming compiler to use the glibc headers"
31#endif
32
33/* Some user header file might have defined this before. */
34#undef __P
35#undef __PMT
36
37#ifdef __GNUC__
38
39/* All functions, except those with callbacks or those that
40 synchronize memory, are leaf functions. */
41# if __GNUC_PREREQ (4, 6) && !defined _LIBC
42# define __LEAF , __leaf__
43# define __LEAF_ATTR __attribute__ ((__leaf__))
44# else
45# define __LEAF
46# define __LEAF_ATTR
47# endif
48
49/* GCC can always grok prototypes. For C++ programs we add throw()
50 to help it optimize the function calls. But this works only with
51 gcc 2.8.x and egcs. For gcc 3.2 and up we even mark C functions
52 as non-throwing using a function attribute since programs can use
53 the -fexceptions options for C code as well. */
54# if !defined __cplusplus && __GNUC_PREREQ (3, 3)
55# define __THROW __attribute__ ((__nothrow__ __LEAF))
56# define __THROWNL __attribute__ ((__nothrow__))
57# define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
58# define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
59# else
60# if defined __cplusplus && __GNUC_PREREQ (2,8)
61# define __THROW throw ()
62# define __THROWNL throw ()
63# define __NTH(fct) __LEAF_ATTR fct throw ()
64# define __NTHNL(fct) fct throw ()
65# else
66# define __THROW
67# define __THROWNL
68# define __NTH(fct) fct
69# define __NTHNL(fct) fct
70# endif
71# endif
72
73#else /* Not GCC. */
74
75# define __inline /* No inline functions. */
76
77# define __THROW
78# define __THROWNL
79# define __NTH(fct) fct
80
81#endif /* GCC. */
82
83/* Compilers that are not clang may object to
84 #if defined __clang__ && __has_extension(...)
85 even though they do not need to evaluate the right-hand side of the &&. */
86#if defined __clang__ && defined __has_extension
87# define __glibc_clang_has_extension(ext) __has_extension (ext)
88#else
89# define __glibc_clang_has_extension(ext) 0
90#endif
91
92/* These two macros are not used in glibc anymore. They are kept here
93 only because some other projects expect the macros to be defined. */
94#define __P(args) args
95#define __PMT(args) args
96
97/* For these things, GCC behaves the ANSI way normally,
98 and the non-ANSI way under -traditional. */
99
100#define __CONCAT(x,y) x ## y
101#define __STRING(x) #x
102
103/* This is not a typedef so `const __ptr_t' does the right thing. */
104#define __ptr_t void *
105
106
107/* C++ needs to know that types and declarations are C, not C++. */
108#ifdef __cplusplus
109# define __BEGIN_DECLS extern "C" {
110# define __END_DECLS }
111#else
112# define __BEGIN_DECLS
113# define __END_DECLS
114#endif
115
116
117/* Fortify support. */
118#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
119#define __bos0(ptr) __builtin_object_size (ptr, 0)
120
121#if __GNUC_PREREQ (4,3)
122# define __warndecl(name, msg) \
123 extern void name (void) __attribute__((__warning__ (msg)))
124# define __warnattr(msg) __attribute__((__warning__ (msg)))
125# define __errordecl(name, msg) \
126 extern void name (void) __attribute__((__error__ (msg)))
127#else
128# define __warndecl(name, msg) extern void name (void)
129# define __warnattr(msg)
130# define __errordecl(name, msg) extern void name (void)
131#endif
132
133/* Support for flexible arrays.
134 Headers that should use flexible arrays only if they're "real"
135 (e.g. only if they won't affect sizeof()) should test
136 #if __glibc_c99_flexarr_available. */
137#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
138# define __flexarr []
139# define __glibc_c99_flexarr_available 1
140#elif __GNUC_PREREQ (2,97)
141/* GCC 2.97 supports C99 flexible array members as an extension,
142 even when in C89 mode or compiling C++ (any version). */
143# define __flexarr []
144# define __glibc_c99_flexarr_available 1
145#elif defined __GNUC__
146/* Pre-2.97 GCC did not support C99 flexible arrays but did have
147 an equivalent extension with slightly different notation. */
148# define __flexarr [0]
149# define __glibc_c99_flexarr_available 1
150#else
151/* Some other non-C99 compiler. Approximate with [1]. */
152# define __flexarr [1]
153# define __glibc_c99_flexarr_available 0
154#endif
155
156
157/* __asm__ ("xyz") is used throughout the headers to rename functions
158 at the assembly language level. This is wrapped by the __REDIRECT
159 macro, in order to support compilers that can do this some other
160 way. When compilers don't support asm-names at all, we have to do
161 preprocessor tricks instead (which don't have exactly the right
162 semantics, but it's the best we can do).
163
164 Example:
165 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
166
167#if defined __GNUC__ && __GNUC__ >= 2
168
169# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
170# ifdef __cplusplus
171# define __REDIRECT_NTH(name, proto, alias) \
172 name proto __THROW __asm__ (__ASMNAME (#alias))
173# define __REDIRECT_NTHNL(name, proto, alias) \
174 name proto __THROWNL __asm__ (__ASMNAME (#alias))
175# else
176# define __REDIRECT_NTH(name, proto, alias) \
177 name proto __asm__ (__ASMNAME (#alias)) __THROW
178# define __REDIRECT_NTHNL(name, proto, alias) \
179 name proto __asm__ (__ASMNAME (#alias)) __THROWNL
180# endif
181# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
182# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
183
184/*
185#elif __SOME_OTHER_COMPILER__
186
187# define __REDIRECT(name, proto, alias) name proto; \
188 _Pragma("let " #name " = " #alias)
189*/
190#endif
191
192/* GCC has various useful declarations that can be made with the
193 `__attribute__' syntax. All of the ways we use this do fine if
194 they are omitted for compilers that don't understand it. */
195#if !defined __GNUC__ || __GNUC__ < 2
196# define __attribute__(xyz) /* Ignore */
197#endif
198
199/* At some point during the gcc 2.96 development the `malloc' attribute
200 for functions was introduced. We don't want to use it unconditionally
201 (although this would be possible) since it generates warnings. */
202#if __GNUC_PREREQ (2,96)
203# define __attribute_malloc__ __attribute__ ((__malloc__))
204#else
205# define __attribute_malloc__ /* Ignore */
206#endif
207
208/* Tell the compiler which arguments to an allocation function
209 indicate the size of the allocation. */
210#if __GNUC_PREREQ (4, 3)
211# define __attribute_alloc_size__(params) \
212 __attribute__ ((__alloc_size__ params))
213#else
214# define __attribute_alloc_size__(params) /* Ignore. */
215#endif
216
217/* At some point during the gcc 2.96 development the `pure' attribute
218 for functions was introduced. We don't want to use it unconditionally
219 (although this would be possible) since it generates warnings. */
220#if __GNUC_PREREQ (2,96)
221# define __attribute_pure__ __attribute__ ((__pure__))
222#else
223# define __attribute_pure__ /* Ignore */
224#endif
225
226/* This declaration tells the compiler that the value is constant. */
227#if __GNUC_PREREQ (2,5)
228# define __attribute_const__ __attribute__ ((__const__))
229#else
230# define __attribute_const__ /* Ignore */
231#endif
232
233/* At some point during the gcc 3.1 development the `used' attribute
234 for functions was introduced. We don't want to use it unconditionally
235 (although this would be possible) since it generates warnings. */
236#if __GNUC_PREREQ (3,1)
237# define __attribute_used__ __attribute__ ((__used__))
238# define __attribute_noinline__ __attribute__ ((__noinline__))
239#else
240# define __attribute_used__ __attribute__ ((__unused__))
241# define __attribute_noinline__ /* Ignore */
242#endif
243
244/* Since version 3.2, gcc allows marking deprecated functions. */
245#if __GNUC_PREREQ (3,2)
246# define __attribute_deprecated__ __attribute__ ((__deprecated__))
247#else
248# define __attribute_deprecated__ /* Ignore */
249#endif
250
251/* Since version 4.5, gcc also allows one to specify the message printed
252 when a deprecated function is used. clang claims to be gcc 4.2, but
253 may also support this feature. */
254#if __GNUC_PREREQ (4,5) || \
255 __glibc_clang_has_extension (__attribute_deprecated_with_message__)
256# define __attribute_deprecated_msg__(msg) \
257 __attribute__ ((__deprecated__ (msg)))
258#else
259# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
260#endif
261
262/* At some point during the gcc 2.8 development the `format_arg' attribute
263 for functions was introduced. We don't want to use it unconditionally
264 (although this would be possible) since it generates warnings.
265 If several `format_arg' attributes are given for the same function, in
266 gcc-3.0 and older, all but the last one are ignored. In newer gccs,
267 all designated arguments are considered. */
268#if __GNUC_PREREQ (2,8)
269# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
270#else
271# define __attribute_format_arg__(x) /* Ignore */
272#endif
273
274/* At some point during the gcc 2.97 development the `strfmon' format
275 attribute for functions was introduced. We don't want to use it
276 unconditionally (although this would be possible) since it
277 generates warnings. */
278#if __GNUC_PREREQ (2,97)
279# define __attribute_format_strfmon__(a,b) \
280 __attribute__ ((__format__ (__strfmon__, a, b)))
281#else
282# define __attribute_format_strfmon__(a,b) /* Ignore */
283#endif
284
285/* The nonull function attribute allows to mark pointer parameters which
286 must not be NULL. */
287#if __GNUC_PREREQ (3,3)
288# define __nonnull(params) __attribute__ ((__nonnull__ params))
289#else
290# define __nonnull(params)
291#endif
292
293/* If fortification mode, we warn about unused results of certain
294 function calls which can lead to problems. */
295#if __GNUC_PREREQ (3,4)
296# define __attribute_warn_unused_result__ \
297 __attribute__ ((__warn_unused_result__))
298# if __USE_FORTIFY_LEVEL > 0
299# define __wur __attribute_warn_unused_result__
300# endif
301#else
302# define __attribute_warn_unused_result__ /* empty */
303#endif
304#ifndef __wur
305# define __wur /* Ignore */
306#endif
307
308/* Forces a function to be always inlined. */
309#if __GNUC_PREREQ (3,2)
310/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
311 it conflicts with this definition. Therefore undefine it first to
312 allow either header to be included first. */
313# undef __always_inline
314# define __always_inline __inline __attribute__ ((__always_inline__))
315#else
316# undef __always_inline
317# define __always_inline __inline
318#endif
319
320/* Associate error messages with the source location of the call site rather
321 than with the source location inside the function. */
322#if __GNUC_PREREQ (4,3)
323# define __attribute_artificial__ __attribute__ ((__artificial__))
324#else
325# define __attribute_artificial__ /* Ignore */
326#endif
327
328/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
329 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
330 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
331 older than 4.3 may define these macros and still not guarantee GNU inlining
332 semantics.
333
334 clang++ identifies itself as gcc-4.2, but has support for GNU inlining
335 semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
336 __GNUC_GNU_INLINE__ macro definitions. */
337#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
338 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
339 || defined __GNUC_GNU_INLINE__)))
340# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
341# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
342# define __extern_always_inline \
343 extern __always_inline __attribute__ ((__gnu_inline__))
344# else
345# define __extern_inline extern __inline
346# define __extern_always_inline extern __always_inline
347# endif
348#endif
349
350#ifdef __extern_always_inline
351# define __fortify_function __extern_always_inline __attribute_artificial__
352#endif
353
354/* GCC 4.3 and above allow passing all anonymous arguments of an
355 __extern_always_inline function to some other vararg function. */
356#if __GNUC_PREREQ (4,3)
357# define __va_arg_pack() __builtin_va_arg_pack ()
358# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
359#endif
360
361/* It is possible to compile containing GCC extensions even if GCC is
362 run in pedantic mode if the uses are carefully marked using the
363 `__extension__' keyword. But this is not generally available before
364 version 2.8. */
365#if !__GNUC_PREREQ (2,8)
366# define __extension__ /* Ignore */
367#endif
368
369/* __restrict is known in EGCS 1.2 and above. */
370#if !__GNUC_PREREQ (2,92)
371# define __restrict /* Ignore */
372#endif
373
374/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
375 array_name[restrict]
376 GCC 3.1 supports this. */
377#if __GNUC_PREREQ (3,1) && !defined __GNUG__
378# define __restrict_arr __restrict
379#else
380# ifdef __GNUC__
381# define __restrict_arr /* Not supported in old GCC. */
382# else
383# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
384# define __restrict_arr restrict
385# else
386/* Some other non-C99 compiler. */
387# define __restrict_arr /* Not supported. */
388# endif
389# endif
390#endif
391
392#if __GNUC__ >= 3
393# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
394# define __glibc_likely(cond) __builtin_expect ((cond), 1)
395#else
396# define __glibc_unlikely(cond) (cond)
397# define __glibc_likely(cond) (cond)
398#endif
399
400#if (!defined _Noreturn \
401 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
402 && !__GNUC_PREREQ (4,7))
403# if __GNUC_PREREQ (2,8)
404# define _Noreturn __attribute__ ((__noreturn__))
405# else
406# define _Noreturn
407# endif
408#endif
409
410#if __GNUC_PREREQ (8, 0)
411/* Describes a char array whose address can safely be passed as the first
412 argument to strncpy and strncat, as the char array is not necessarily
413 a NUL-terminated string. */
414# define __attribute_nonstring__ __attribute__ ((__nonstring__))
415#else
416# define __attribute_nonstring__
417#endif
418
419#if (!defined _Static_assert && !defined __cplusplus \
420 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
421 && (!__GNUC_PREREQ (4, 6) || defined __STRICT_ANSI__))
422# define _Static_assert(expr, diagnostic) \
423 extern int (*__Static_assert_function (void)) \
424 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
425#endif
426
427#include <bits/wordsize.h>
428#include <bits/long-double.h>
429
430#if defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
431# define __LDBL_COMPAT 1
432# ifdef __REDIRECT
433# define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
434# define __LDBL_REDIR(name, proto) \
435 __LDBL_REDIR1 (name, proto, __nldbl_##name)
436# define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
437# define __LDBL_REDIR_NTH(name, proto) \
438 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
439# define __LDBL_REDIR1_DECL(name, alias) \
440 extern __typeof (name) name __asm (__ASMNAME (#alias));
441# define __LDBL_REDIR_DECL(name) \
442 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
443# define __REDIRECT_LDBL(name, proto, alias) \
444 __LDBL_REDIR1 (name, proto, __nldbl_##alias)
445# define __REDIRECT_NTH_LDBL(name, proto, alias) \
446 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
447# endif
448#endif
449#if !defined __LDBL_COMPAT || !defined __REDIRECT
450# define __LDBL_REDIR1(name, proto, alias) name proto
451# define __LDBL_REDIR(name, proto) name proto
452# define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
453# define __LDBL_REDIR_NTH(name, proto) name proto __THROW
454# define __LDBL_REDIR_DECL(name)
455# ifdef __REDIRECT
456# define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
457# define __REDIRECT_NTH_LDBL(name, proto, alias) \
458 __REDIRECT_NTH (name, proto, alias)
459# endif
460#endif
461
462/* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
463 intended for use in preprocessor macros.
464
465 Note: MESSAGE must be a _single_ string; concatenation of string
466 literals is not supported. */
467#if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
468# define __glibc_macro_warning1(message) _Pragma (#message)
469# define __glibc_macro_warning(message) \
470 __glibc_macro_warning1 (GCC warning message)
471#else
472# define __glibc_macro_warning(msg)
473#endif
474
475/* Generic selection (ISO C11) is a C-only feature, available in GCC
476 since version 4.9. Previous versions do not provide generic
477 selection, even though they might set __STDC_VERSION__ to 201112L,
478 when in -std=c11 mode. Thus, we must check for !defined __GNUC__
479 when testing __STDC_VERSION__ for generic selection support.
480 On the other hand, Clang also defines __GNUC__, so a clang-specific
481 check is required to enable the use of generic selection. */
482#if !defined __cplusplus \
483 && (__GNUC_PREREQ (4, 9) \
484 || __glibc_clang_has_extension (c_generic_selections) \
485 || (!defined __GNUC__ && defined __STDC_VERSION__ \
486 && __STDC_VERSION__ >= 201112L))
487# define __HAVE_GENERIC_SELECTION 1
488#else
489# define __HAVE_GENERIC_SELECTION 0
490#endif
491
492#endif /* sys/cdefs.h */
493