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# if (defined __cplusplus \
76 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
77# define __inline inline
78# else
79# define __inline /* No inline functions. */
80# endif
81
82# define __THROW
83# define __THROWNL
84# define __NTH(fct) fct
85
86#endif /* GCC. */
87
88/* Compilers that are not clang may object to
89 #if defined __clang__ && __has_extension(...)
90 even though they do not need to evaluate the right-hand side of the &&. */
91#if defined __clang__ && defined __has_extension
92# define __glibc_clang_has_extension(ext) __has_extension (ext)
93#else
94# define __glibc_clang_has_extension(ext) 0
95#endif
96
97/* These two macros are not used in glibc anymore. They are kept here
98 only because some other projects expect the macros to be defined. */
99#define __P(args) args
100#define __PMT(args) args
101
102/* For these things, GCC behaves the ANSI way normally,
103 and the non-ANSI way under -traditional. */
104
105#define __CONCAT(x,y) x ## y
106#define __STRING(x) #x
107
108/* This is not a typedef so `const __ptr_t' does the right thing. */
109#define __ptr_t void *
110
111
112/* C++ needs to know that types and declarations are C, not C++. */
113#ifdef __cplusplus
114# define __BEGIN_DECLS extern "C" {
115# define __END_DECLS }
116#else
117# define __BEGIN_DECLS
118# define __END_DECLS
119#endif
120
121
122/* Fortify support. */
123#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
124#define __bos0(ptr) __builtin_object_size (ptr, 0)
125
126#if __GNUC_PREREQ (4,3)
127# define __warndecl(name, msg) \
128 extern void name (void) __attribute__((__warning__ (msg)))
129# define __warnattr(msg) __attribute__((__warning__ (msg)))
130# define __errordecl(name, msg) \
131 extern void name (void) __attribute__((__error__ (msg)))
132#else
133# define __warndecl(name, msg) extern void name (void)
134# define __warnattr(msg)
135# define __errordecl(name, msg) extern void name (void)
136#endif
137
138/* Support for flexible arrays.
139 Headers that should use flexible arrays only if they're "real"
140 (e.g. only if they won't affect sizeof()) should test
141 #if __glibc_c99_flexarr_available. */
142#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
143# define __flexarr []
144# define __glibc_c99_flexarr_available 1
145#elif __GNUC_PREREQ (2,97)
146/* GCC 2.97 supports C99 flexible array members as an extension,
147 even when in C89 mode or compiling C++ (any version). */
148# define __flexarr []
149# define __glibc_c99_flexarr_available 1
150#elif defined __GNUC__
151/* Pre-2.97 GCC did not support C99 flexible arrays but did have
152 an equivalent extension with slightly different notation. */
153# define __flexarr [0]
154# define __glibc_c99_flexarr_available 1
155#else
156/* Some other non-C99 compiler. Approximate with [1]. */
157# define __flexarr [1]
158# define __glibc_c99_flexarr_available 0
159#endif
160
161
162/* __asm__ ("xyz") is used throughout the headers to rename functions
163 at the assembly language level. This is wrapped by the __REDIRECT
164 macro, in order to support compilers that can do this some other
165 way. When compilers don't support asm-names at all, we have to do
166 preprocessor tricks instead (which don't have exactly the right
167 semantics, but it's the best we can do).
168
169 Example:
170 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
171
172#if defined __GNUC__ && __GNUC__ >= 2
173
174# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
175# ifdef __cplusplus
176# define __REDIRECT_NTH(name, proto, alias) \
177 name proto __THROW __asm__ (__ASMNAME (#alias))
178# define __REDIRECT_NTHNL(name, proto, alias) \
179 name proto __THROWNL __asm__ (__ASMNAME (#alias))
180# else
181# define __REDIRECT_NTH(name, proto, alias) \
182 name proto __asm__ (__ASMNAME (#alias)) __THROW
183# define __REDIRECT_NTHNL(name, proto, alias) \
184 name proto __asm__ (__ASMNAME (#alias)) __THROWNL
185# endif
186# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
187# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
188
189/*
190#elif __SOME_OTHER_COMPILER__
191
192# define __REDIRECT(name, proto, alias) name proto; \
193 _Pragma("let " #name " = " #alias)
194*/
195#endif
196
197/* GCC has various useful declarations that can be made with the
198 `__attribute__' syntax. All of the ways we use this do fine if
199 they are omitted for compilers that don't understand it. */
200#if !defined __GNUC__ || __GNUC__ < 2
201# define __attribute__(xyz) /* Ignore */
202#endif
203
204/* At some point during the gcc 2.96 development the `malloc' attribute
205 for functions was introduced. We don't want to use it unconditionally
206 (although this would be possible) since it generates warnings. */
207#if __GNUC_PREREQ (2,96)
208# define __attribute_malloc__ __attribute__ ((__malloc__))
209#else
210# define __attribute_malloc__ /* Ignore */
211#endif
212
213/* Tell the compiler which arguments to an allocation function
214 indicate the size of the allocation. */
215#if __GNUC_PREREQ (4, 3)
216# define __attribute_alloc_size__(params) \
217 __attribute__ ((__alloc_size__ params))
218#else
219# define __attribute_alloc_size__(params) /* Ignore. */
220#endif
221
222/* At some point during the gcc 2.96 development the `pure' attribute
223 for functions was introduced. We don't want to use it unconditionally
224 (although this would be possible) since it generates warnings. */
225#if __GNUC_PREREQ (2,96)
226# define __attribute_pure__ __attribute__ ((__pure__))
227#else
228# define __attribute_pure__ /* Ignore */
229#endif
230
231/* This declaration tells the compiler that the value is constant. */
232#if __GNUC_PREREQ (2,5)
233# define __attribute_const__ __attribute__ ((__const__))
234#else
235# define __attribute_const__ /* Ignore */
236#endif
237
238/* At some point during the gcc 3.1 development the `used' attribute
239 for functions was introduced. We don't want to use it unconditionally
240 (although this would be possible) since it generates warnings. */
241#if __GNUC_PREREQ (3,1)
242# define __attribute_used__ __attribute__ ((__used__))
243# define __attribute_noinline__ __attribute__ ((__noinline__))
244#else
245# define __attribute_used__ __attribute__ ((__unused__))
246# define __attribute_noinline__ /* Ignore */
247#endif
248
249/* Since version 3.2, gcc allows marking deprecated functions. */
250#if __GNUC_PREREQ (3,2)
251# define __attribute_deprecated__ __attribute__ ((__deprecated__))
252#else
253# define __attribute_deprecated__ /* Ignore */
254#endif
255
256/* Since version 4.5, gcc also allows one to specify the message printed
257 when a deprecated function is used. clang claims to be gcc 4.2, but
258 may also support this feature. */
259#if __GNUC_PREREQ (4,5) || \
260 __glibc_clang_has_extension (__attribute_deprecated_with_message__)
261# define __attribute_deprecated_msg__(msg) \
262 __attribute__ ((__deprecated__ (msg)))
263#else
264# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
265#endif
266
267/* At some point during the gcc 2.8 development the `format_arg' attribute
268 for functions was introduced. We don't want to use it unconditionally
269 (although this would be possible) since it generates warnings.
270 If several `format_arg' attributes are given for the same function, in
271 gcc-3.0 and older, all but the last one are ignored. In newer gccs,
272 all designated arguments are considered. */
273#if __GNUC_PREREQ (2,8)
274# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
275#else
276# define __attribute_format_arg__(x) /* Ignore */
277#endif
278
279/* At some point during the gcc 2.97 development the `strfmon' format
280 attribute for functions was introduced. We don't want to use it
281 unconditionally (although this would be possible) since it
282 generates warnings. */
283#if __GNUC_PREREQ (2,97)
284# define __attribute_format_strfmon__(a,b) \
285 __attribute__ ((__format__ (__strfmon__, a, b)))
286#else
287# define __attribute_format_strfmon__(a,b) /* Ignore */
288#endif
289
290/* The nonull function attribute allows to mark pointer parameters which
291 must not be NULL. */
292#if __GNUC_PREREQ (3,3)
293# define __nonnull(params) __attribute__ ((__nonnull__ params))
294#else
295# define __nonnull(params)
296#endif
297
298/* If fortification mode, we warn about unused results of certain
299 function calls which can lead to problems. */
300#if __GNUC_PREREQ (3,4)
301# define __attribute_warn_unused_result__ \
302 __attribute__ ((__warn_unused_result__))
303# if __USE_FORTIFY_LEVEL > 0
304# define __wur __attribute_warn_unused_result__
305# endif
306#else
307# define __attribute_warn_unused_result__ /* empty */
308#endif
309#ifndef __wur
310# define __wur /* Ignore */
311#endif
312
313/* Forces a function to be always inlined. */
314#if __GNUC_PREREQ (3,2)
315/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
316 it conflicts with this definition. Therefore undefine it first to
317 allow either header to be included first. */
318# undef __always_inline
319# define __always_inline __inline __attribute__ ((__always_inline__))
320#else
321# undef __always_inline
322# define __always_inline __inline
323#endif
324
325/* Associate error messages with the source location of the call site rather
326 than with the source location inside the function. */
327#if __GNUC_PREREQ (4,3)
328# define __attribute_artificial__ __attribute__ ((__artificial__))
329#else
330# define __attribute_artificial__ /* Ignore */
331#endif
332
333/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
334 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
335 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
336 older than 4.3 may define these macros and still not guarantee GNU inlining
337 semantics.
338
339 clang++ identifies itself as gcc-4.2, but has support for GNU inlining
340 semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
341 __GNUC_GNU_INLINE__ macro definitions. */
342#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
343 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
344 || defined __GNUC_GNU_INLINE__)))
345# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
346# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
347# define __extern_always_inline \
348 extern __always_inline __attribute__ ((__gnu_inline__))
349# else
350# define __extern_inline extern __inline
351# define __extern_always_inline extern __always_inline
352# endif
353#endif
354
355#ifdef __extern_always_inline
356# define __fortify_function __extern_always_inline __attribute_artificial__
357#endif
358
359/* GCC 4.3 and above allow passing all anonymous arguments of an
360 __extern_always_inline function to some other vararg function. */
361#if __GNUC_PREREQ (4,3)
362# define __va_arg_pack() __builtin_va_arg_pack ()
363# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
364#endif
365
366/* It is possible to compile containing GCC extensions even if GCC is
367 run in pedantic mode if the uses are carefully marked using the
368 `__extension__' keyword. But this is not generally available before
369 version 2.8. */
370#if !__GNUC_PREREQ (2,8)
371# define __extension__ /* Ignore */
372#endif
373
374/* __restrict is known in EGCS 1.2 and above. */
375#if !__GNUC_PREREQ (2,92)
376# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
377# define __restrict restrict
378# else
379# define __restrict /* Ignore */
380# endif
381#endif
382
383/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
384 array_name[restrict]
385 GCC 3.1 supports this. */
386#if __GNUC_PREREQ (3,1) && !defined __GNUG__
387# define __restrict_arr __restrict
388#else
389# ifdef __GNUC__
390# define __restrict_arr /* Not supported in old GCC. */
391# else
392# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
393# define __restrict_arr restrict
394# else
395/* Some other non-C99 compiler. */
396# define __restrict_arr /* Not supported. */
397# endif
398# endif
399#endif
400
401#if __GNUC__ >= 3
402# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
403# define __glibc_likely(cond) __builtin_expect ((cond), 1)
404#else
405# define __glibc_unlikely(cond) (cond)
406# define __glibc_likely(cond) (cond)
407#endif
408
409#ifdef __has_attribute
410# define __glibc_has_attribute(attr) __has_attribute (attr)
411#else
412# define __glibc_has_attribute(attr) 0
413#endif
414
415#if (!defined _Noreturn \
416 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
417 && !__GNUC_PREREQ (4,7))
418# if __GNUC_PREREQ (2,8)
419# define _Noreturn __attribute__ ((__noreturn__))
420# else
421# define _Noreturn
422# endif
423#endif
424
425#if __GNUC_PREREQ (8, 0)
426/* Describes a char array whose address can safely be passed as the first
427 argument to strncpy and strncat, as the char array is not necessarily
428 a NUL-terminated string. */
429# define __attribute_nonstring__ __attribute__ ((__nonstring__))
430#else
431# define __attribute_nonstring__
432#endif
433
434/* Undefine (also defined in libc-symbols.h). */
435#undef __attribute_copy__
436#if __GNUC_PREREQ (9, 0)
437/* Copies attributes from the declaration or type referenced by
438 the argument. */
439# define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
440#else
441# define __attribute_copy__(arg)
442#endif
443
444#if (!defined _Static_assert && !defined __cplusplus \
445 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
446 && (!__GNUC_PREREQ (4, 6) || defined __STRICT_ANSI__))
447# define _Static_assert(expr, diagnostic) \
448 extern int (*__Static_assert_function (void)) \
449 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
450#endif
451
452#include <bits/wordsize.h>
453#include <bits/long-double.h>
454
455#if defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
456# define __LDBL_COMPAT 1
457# ifdef __REDIRECT
458# define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
459# define __LDBL_REDIR(name, proto) \
460 __LDBL_REDIR1 (name, proto, __nldbl_##name)
461# define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
462# define __LDBL_REDIR_NTH(name, proto) \
463 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
464# define __LDBL_REDIR1_DECL(name, alias) \
465 extern __typeof (name) name __asm (__ASMNAME (#alias));
466# define __LDBL_REDIR_DECL(name) \
467 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
468# define __REDIRECT_LDBL(name, proto, alias) \
469 __LDBL_REDIR1 (name, proto, __nldbl_##alias)
470# define __REDIRECT_NTH_LDBL(name, proto, alias) \
471 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
472# endif
473#endif
474#if !defined __LDBL_COMPAT || !defined __REDIRECT
475# define __LDBL_REDIR1(name, proto, alias) name proto
476# define __LDBL_REDIR(name, proto) name proto
477# define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
478# define __LDBL_REDIR_NTH(name, proto) name proto __THROW
479# define __LDBL_REDIR_DECL(name)
480# ifdef __REDIRECT
481# define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
482# define __REDIRECT_NTH_LDBL(name, proto, alias) \
483 __REDIRECT_NTH (name, proto, alias)
484# endif
485#endif
486
487/* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
488 intended for use in preprocessor macros.
489
490 Note: MESSAGE must be a _single_ string; concatenation of string
491 literals is not supported. */
492#if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
493# define __glibc_macro_warning1(message) _Pragma (#message)
494# define __glibc_macro_warning(message) \
495 __glibc_macro_warning1 (GCC warning message)
496#else
497# define __glibc_macro_warning(msg)
498#endif
499
500/* Generic selection (ISO C11) is a C-only feature, available in GCC
501 since version 4.9. Previous versions do not provide generic
502 selection, even though they might set __STDC_VERSION__ to 201112L,
503 when in -std=c11 mode. Thus, we must check for !defined __GNUC__
504 when testing __STDC_VERSION__ for generic selection support.
505 On the other hand, Clang also defines __GNUC__, so a clang-specific
506 check is required to enable the use of generic selection. */
507#if !defined __cplusplus \
508 && (__GNUC_PREREQ (4, 9) \
509 || __glibc_clang_has_extension (c_generic_selections) \
510 || (!defined __GNUC__ && defined __STDC_VERSION__ \
511 && __STDC_VERSION__ >= 201112L))
512# define __HAVE_GENERIC_SELECTION 1
513#else
514# define __HAVE_GENERIC_SELECTION 0
515#endif
516
517#endif /* sys/cdefs.h */
518