/* Copyright (C) 1992-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* We are almost always included from features.h. */
/* The GNU libc does not support any K&R compilers or the traditional mode
of ISO C compilers anymore. Check for some of the combinations not
#if defined __GNUC__ && !defined __STDC__
# error "You need a ISO C conforming compiler to use the glibc headers"
/* Some user header file might have defined this before. */
/* All functions, except those with callbacks or those that
synchronize memory, are leaf functions. */
# if __GNUC_PREREQ (4, 6) && !defined _LIBC
# define __LEAF , __leaf__
# define __LEAF_ATTR __attribute__ ((__leaf__))
/* GCC can always grok prototypes. For C++ programs we add throw()
to help it optimize the function calls. But this works only with
gcc 2.8.x and egcs. For gcc 3.2 and up we even mark C functions
as non-throwing using a function attribute since programs can use
the -fexceptions options for C code as well. */
# if !defined __cplusplus && __GNUC_PREREQ (3, 3)
# define __THROW __attribute__ ((__nothrow__ __LEAF))
# define __THROWNL __attribute__ ((__nothrow__))
# define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
# define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
# if defined __cplusplus && __GNUC_PREREQ (2,8)
# define __THROW throw ()
# define __THROWNL throw ()
# define __NTH(fct) __LEAF_ATTR fct throw ()
# define __NTHNL(fct) fct throw ()
# define __NTHNL(fct) fct
# if (defined __cplusplus \
|| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
# define __inline /* No inline functions. */
/* Compilers that are not clang may object to
#if defined __clang__ && __has_extension(...)
even though they do not need to evaluate the right-hand side of the &&. */
#if defined __clang__ && defined __has_extension
# define __glibc_clang_has_extension(ext) __has_extension (ext)
# define __glibc_clang_has_extension(ext) 0
/* These two macros are not used in glibc anymore. They are kept here
only because some other projects expect the macros to be defined. */
/* For these things, GCC behaves the ANSI way normally,
and the non-ANSI way under -traditional. */
#define __CONCAT(x,y) x ## y
/* This is not a typedef so `const __ptr_t' does the right thing. */
/* C++ needs to know that types and declarations are C, not C++. */
# define __BEGIN_DECLS extern "C" {
#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
#define __bos0(ptr) __builtin_object_size (ptr, 0)
/* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
|| __GNUC_PREREQ (12, 0))
# define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
# define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
# define __glibc_objsize0(__o) __bos0 (__o)
# define __glibc_objsize(__o) __bos (__o)
#if __USE_FORTIFY_LEVEL > 0
/* Compile time conditions to choose between the regular, _chk and _chk_warn
variants. These conditions should get evaluated to constant and optimized
#define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
#define __glibc_unsigned_or_positive(__l) \
((__typeof (__l)) 0 < (__typeof (__l)) -1 \
|| (__builtin_constant_p (__l) && (__l) > 0))
/* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
condition can be folded to a constant and if it is true, or unknown (-1) */
#define __glibc_safe_or_unknown_len(__l, __s, __osz) \
((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
|| (__glibc_unsigned_or_positive (__l) \
&& __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
&& __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
/* Conversely, we know at compile time that the length is unsafe if the
__L * __S <= __OBJSZ condition can be folded to a constant and if it is
#define __glibc_unsafe_len(__l, __s, __osz) \
(__glibc_unsigned_or_positive (__l) \
&& __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
&& !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
/* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
#define __glibc_fortify(f, __l, __s, __osz, ...) \
(__glibc_safe_or_unknown_len (__l, __s, __osz) \
? __ ## f ## _alias (__VA_ARGS__) \
: (__glibc_unsafe_len (__l, __s, __osz) \
? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
: __ ## f ## _chk (__VA_ARGS__, __osz)))
/* Fortify function f, where object size argument passed to f is the number of
elements and not total size. */
#define __glibc_fortify_n(f, __l, __s, __osz, ...) \
(__glibc_safe_or_unknown_len (__l, __s, __osz) \
? __ ## f ## _alias (__VA_ARGS__) \
: (__glibc_unsafe_len (__l, __s, __osz) \
? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
: __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))
# define __warndecl(name, msg) \
extern void name (void) __attribute__((__warning__ (msg)))
# define __warnattr(msg) __attribute__((__warning__ (msg)))
# define __errordecl(name, msg) \
extern void name (void) __attribute__((__error__ (msg)))
# define __warndecl(name, msg) extern void name (void)
# define __errordecl(name, msg) extern void name (void)
/* Support for flexible arrays.
Headers that should use flexible arrays only if they're "real"
(e.g. only if they won't affect sizeof()) should test
#if __glibc_c99_flexarr_available. */
#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __glibc_c99_flexarr_available 1
#elif __GNUC_PREREQ (2,97)
/* GCC 2.97 supports C99 flexible array members as an extension,
even when in C89 mode or compiling C++ (any version). */
# define __glibc_c99_flexarr_available 1
/* Pre-2.97 GCC did not support C99 flexible arrays but did have
an equivalent extension with slightly different notation. */
# define __glibc_c99_flexarr_available 1
/* Some other non-C99 compiler. Approximate with [1]. */
# define __glibc_c99_flexarr_available 0
/* __asm__ ("xyz") is used throughout the headers to rename functions
at the assembly language level. This is wrapped by the __REDIRECT
macro, in order to support compilers that can do this some other
way. When compilers don't support asm-names at all, we have to do
preprocessor tricks instead (which don't have exactly the right
semantics, but it's the best we can do).
int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
#if defined __GNUC__ && __GNUC__ >= 2
# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
# define __REDIRECT_NTH(name, proto, alias) \
name proto __THROW __asm__ (__ASMNAME (#alias))
# define __REDIRECT_NTHNL(name, proto, alias) \
name proto __THROWNL __asm__ (__ASMNAME (#alias))
# define __REDIRECT_NTH(name, proto, alias) \
name proto __asm__ (__ASMNAME (#alias)) __THROW
# define __REDIRECT_NTHNL(name, proto, alias) \
name proto __asm__ (__ASMNAME (#alias)) __THROWNL
# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
#elif __SOME_OTHER_COMPILER__
# define __REDIRECT(name, proto, alias) name proto; \
_Pragma("let " #name " = " #alias)
/* GCC has various useful declarations that can be made with the
`__attribute__' syntax. All of the ways we use this do fine if
they are omitted for compilers that don't understand it. */
#if !defined __GNUC__ || __GNUC__ < 2
# define __attribute__(xyz) /* Ignore */
/* At some point during the gcc 2.96 development the `malloc' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
# define __attribute_malloc__ __attribute__ ((__malloc__))
# define __attribute_malloc__ /* Ignore */
/* Tell the compiler which arguments to an allocation function
indicate the size of the allocation. */
# define __attribute_alloc_size__(params) \
__attribute__ ((__alloc_size__ params))
# define __attribute_alloc_size__(params) /* Ignore. */
/* At some point during the gcc 2.96 development the `pure' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
# define __attribute_pure__ __attribute__ ((__pure__))
# define __attribute_pure__ /* Ignore */
/* This declaration tells the compiler that the value is constant. */
# define __attribute_const__ __attribute__ ((__const__))
# define __attribute_const__ /* Ignore */
/* At some point during the gcc 3.1 development the `used' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
# define __attribute_used__ __attribute__ ((__used__))
# define __attribute_noinline__ __attribute__ ((__noinline__))
# define __attribute_used__ __attribute__ ((__unused__))
# define __attribute_noinline__ /* Ignore */
/* Since version 3.2, gcc allows marking deprecated functions. */
# define __attribute_deprecated__ __attribute__ ((__deprecated__))
# define __attribute_deprecated__ /* Ignore */
/* Since version 4.5, gcc also allows one to specify the message printed
when a deprecated function is used. clang claims to be gcc 4.2, but
may also support this feature. */
#if __GNUC_PREREQ (4,5) || \
__glibc_clang_has_extension (__attribute_deprecated_with_message__)
# define __attribute_deprecated_msg__(msg) \
__attribute__ ((__deprecated__ (msg)))
# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
/* At some point during the gcc 2.8 development the `format_arg' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings.
If several `format_arg' attributes are given for the same function, in
gcc-3.0 and older, all but the last one are ignored. In newer gccs,
all designated arguments are considered. */
# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
# define __attribute_format_arg__(x) /* Ignore */
/* At some point during the gcc 2.97 development the `strfmon' format
attribute for functions was introduced. We don't want to use it
unconditionally (although this would be possible) since it
# define __attribute_format_strfmon__(a,b) \
__attribute__ ((__format__ (__strfmon__, a, b)))
# define __attribute_format_strfmon__(a,b) /* Ignore */
/* The nonull function attribute allows to mark pointer parameters which
# define __nonnull(params) __attribute__ ((__nonnull__ params))
# define __nonnull(params)
/* If fortification mode, we warn about unused results of certain
function calls which can lead to problems. */
# define __attribute_warn_unused_result__ \
__attribute__ ((__warn_unused_result__))
# if __USE_FORTIFY_LEVEL > 0
# define __wur __attribute_warn_unused_result__
# define __attribute_warn_unused_result__ /* empty */
# define __wur /* Ignore */
/* Forces a function to be always inlined. */
/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
it conflicts with this definition. Therefore undefine it first to
allow either header to be included first. */
# define __always_inline __inline __attribute__ ((__always_inline__))
# define __always_inline __inline
/* Associate error messages with the source location of the call site rather
than with the source location inside the function. */
# define __attribute_artificial__ __attribute__ ((__artificial__))
# define __attribute_artificial__ /* Ignore */
/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
older than 4.3 may define these macros and still not guarantee GNU inlining
clang++ identifies itself as gcc-4.2, but has support for GNU inlining
semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
__GNUC_GNU_INLINE__ macro definitions. */
#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
|| (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
|| defined __GNUC_GNU_INLINE__)))
# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
# define __extern_always_inline \
extern __always_inline __attribute__ ((__gnu_inline__))
# define __extern_inline extern __inline
# define __extern_always_inline extern __always_inline
#ifdef __extern_always_inline
# define __fortify_function __extern_always_inline __attribute_artificial__
/* GCC 4.3 and above allow passing all anonymous arguments of an
__extern_always_inline function to some other vararg function. */
# define __va_arg_pack() __builtin_va_arg_pack ()
# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
/* It is possible to compile containing GCC extensions even if GCC is
run in pedantic mode if the uses are carefully marked using the
`__extension__' keyword. But this is not generally available before
# define __extension__ /* Ignore */
/* __restrict is known in EGCS 1.2 and above. */
#if !__GNUC_PREREQ (2,92)
# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __restrict restrict
# define __restrict /* Ignore */
/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
GCC 3.1 supports this. */
#if __GNUC_PREREQ (3,1) && !defined __GNUG__
# define __restrict_arr __restrict
# define __restrict_arr /* Not supported in old GCC. */
# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __restrict_arr restrict
/* Some other non-C99 compiler. */
# define __restrict_arr /* Not supported. */
# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
# define __glibc_likely(cond) __builtin_expect ((cond), 1)
# define __glibc_unlikely(cond) (cond)
# define __glibc_likely(cond) (cond)
# define __glibc_has_attribute(attr) __has_attribute (attr)
# define __glibc_has_attribute(attr) 0
#if (!defined _Noreturn \
&& (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
# define _Noreturn __attribute__ ((__noreturn__))
/* Describes a char array whose address can safely be passed as the first
argument to strncpy and strncat, as the char array is not necessarily
a NUL-terminated string. */
# define __attribute_nonstring__ __attribute__ ((__nonstring__))
# define __attribute_nonstring__
#if (!defined _Static_assert && !defined __cplusplus \
&& (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
&& (!__GNUC_PREREQ (4, 6) || defined __STRICT_ANSI__))
# define _Static_assert(expr, diagnostic) \
extern int (*__Static_assert_function (void)) \
[!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]