/* $NetBSD: cdefs.h,v 1.58 2004/12/11 05:59:00 christos Exp $ */ /* * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Berkeley Software Design, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)cdefs.h 8.8 (Berkeley) 1/9/95 */ #ifndef _SYS_CDEFS_H_ #define _SYS_CDEFS_H_ #include #include #define __BIONIC__ 1 /* * Testing against Clang-specific extensions. */ #ifndef __has_extension #define __has_extension __has_feature #endif #ifndef __has_feature #define __has_feature(x) 0 #endif #ifndef __has_include #define __has_include(x) 0 #endif #ifndef __has_builtin #define __has_builtin(x) 0 #endif #ifndef __has_attribute #define __has_attribute(x) 0 #endif #define __strong_alias(alias, sym) \ __asm__(".global " #alias "\n" \ #alias " = " #sym); #if defined(__cplusplus) #define __BEGIN_DECLS extern "C" { #define __END_DECLS } #else #define __BEGIN_DECLS #define __END_DECLS #endif #if defined(__cplusplus) #define __BIONIC_CAST(_k,_t,_v) (_k<_t>(_v)) #else #define __BIONIC_CAST(_k,_t,_v) ((_t) (_v)) #endif #define __BIONIC_ALIGN(__value, __alignment) (((__value) + (__alignment)-1) & ~((__alignment)-1)) /* * The __CONCAT macro is used to concatenate parts of symbol names, e.g. * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. * The __CONCAT macro is a bit tricky -- make sure you don't put spaces * in between its arguments. __CONCAT can also concatenate double-quoted * strings produced by the __STRING macro, but this only works with ANSI C. */ #define ___STRING(x) __STRING(x) #define ___CONCAT(x,y) __CONCAT(x,y) #if defined(__STDC__) || defined(__cplusplus) #define __P(protos) protos /* full-blown ANSI C */ #define __CONCAT(x,y) x ## y #define __STRING(x) #x #if defined(__cplusplus) #define __inline inline /* convert to C++ keyword */ #endif /* !__cplusplus */ #else /* !(__STDC__ || __cplusplus) */ #define __P(protos) () /* traditional C preprocessor */ #define __CONCAT(x,y) x/**/y #define __STRING(x) "x" #endif /* !(__STDC__ || __cplusplus) */ #define __always_inline __attribute__((__always_inline__)) #define __attribute_const__ __attribute__((__const__)) #define __attribute_pure__ __attribute__((__pure__)) #define __dead __attribute__((__noreturn__)) #define __noreturn __attribute__((__noreturn__)) #define __mallocfunc __attribute__((__malloc__)) #define __packed __attribute__((__packed__)) #define __unused __attribute__((__unused__)) #define __used __attribute__((__used__)) #define __printflike(x, y) __attribute__((__format__(printf, x, y))) #define __scanflike(x, y) __attribute__((__format__(scanf, x, y))) /* * GNU C version 2.96 added explicit branch prediction so that * the CPU back-end can hint the processor and also so that * code blocks can be reordered such that the predicted path * sees a more linear flow, thus improving cache behavior, etc. * * The following two macros provide us with a way to use this * compiler feature. Use __predict_true() if you expect the expression * to evaluate to true, and __predict_false() if you expect the * expression to evaluate to false. * * A few notes about usage: * * * Generally, __predict_false() error condition checks (unless * you have some _strong_ reason to do otherwise, in which case * document it), and/or __predict_true() `no-error' condition * checks, assuming you want to optimize for the no-error case. * * * Other than that, if you don't know the likelihood of a test * succeeding from empirical or other `hard' evidence, don't * make predictions. * * * These are meant to be used in places that are run `a lot'. * It is wasteful to make predictions in code that is run * seldomly (e.g. at subsystem initialization time) as the * basic block reordering that this affects can often generate * larger code. */ #define __predict_true(exp) __builtin_expect((exp) != 0, 1) #define __predict_false(exp) __builtin_expect((exp) != 0, 0) #define __wur __attribute__((__warn_unused_result__)) #ifdef __clang__ # define __errorattr(msg) __attribute__((unavailable(msg))) # define __warnattr(msg) __attribute__((deprecated(msg))) # define __warnattr_real(msg) __attribute__((deprecated(msg))) # define __enable_if(cond, msg) __attribute__((enable_if(cond, msg))) # define __clang_error_if(cond, msg) __attribute__((diagnose_if(cond, msg, "error"))) # define __clang_warning_if(cond, msg) __attribute__((diagnose_if(cond, msg, "warning"))) #else # define __errorattr(msg) __attribute__((__error__(msg))) # define __warnattr(msg) __attribute__((__warning__(msg))) # define __warnattr_real __warnattr /* enable_if doesn't exist on other compilers; give an error if it's used. */ /* diagnose_if doesn't exist either, but it's often tagged on non-clang-specific functions */ # define __clang_error_if(cond, msg) # define __clang_warning_if(cond, msg) /* errordecls really don't work as well in clang as they do in GCC. */ # define __errordecl(name, msg) extern void name(void) __errorattr(msg) #endif #if defined(ANDROID_STRICT) /* * For things that are sketchy, but not necessarily an error. FIXME: Enable * this. */ # define __warnattr_strict(msg) /* __warnattr(msg) */ #else # define __warnattr_strict(msg) #endif /* * Some BSD source needs these macros. * Originally they embedded the rcs versions of each source file * in the generated binary. We strip strings during build anyway,. */ #define __IDSTRING(_prefix,_s) /* nothing */ #define __COPYRIGHT(_s) /* nothing */ #define __FBSDID(_s) /* nothing */ #define __RCSID(_s) /* nothing */ #define __SCCSID(_s) /* nothing */ /* * With bionic, you always get all C and POSIX API. * * If you want BSD and/or GNU extensions, _BSD_SOURCE and/or _GNU_SOURCE are * expected to be defined by callers before *any* standard header file is * included. * * In our header files we test against __USE_BSD and __USE_GNU. */ #if defined(_GNU_SOURCE) # define __USE_BSD 1 # define __USE_GNU 1 #endif #if defined(_BSD_SOURCE) # define __USE_BSD 1 #endif /* * _FILE_OFFSET_BITS 64 support. * See https://android.googlesource.com/platform/bionic/+/master/docs/32-bit-abi.md */ #if !defined(__LP64__) && defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS == 64 # define __USE_FILE_OFFSET64 1 /* * Note that __RENAME_IF_FILE_OFFSET64 is only valid if the off_t and off64_t * functions were both added at the same API level because if you use this, * you only have one declaration to attach __INTRODUCED_IN to. */ # define __RENAME_IF_FILE_OFFSET64(func) __RENAME(func) #else # define __RENAME_IF_FILE_OFFSET64(func) #endif /* * For LP32, `long double` == `double`. Historically many `long double` functions were incorrect * on x86, missing on most architectures, and even if they are present and correct, linking to * them just bloats your ELF file by adding extra relocations. The __BIONIC_LP32_USE_LONG_DOUBLE * macro lets us test the headers both ways (and adds an escape valve). * * Note that some functions have their __RENAME_LDBL commented out as a sign that although we could * use __RENAME_LDBL it would actually cause the function to be introduced later because the * `long double` variant appeared before the `double` variant. */ #if defined(__LP64__) || defined(__BIONIC_LP32_USE_LONG_DOUBLE) #define __RENAME_LDBL(rewrite,rewrite_api_level,regular_api_level) __INTRODUCED_IN(regular_api_level) #else #define __RENAME_LDBL(rewrite,rewrite_api_level,regular_api_level) __RENAME(rewrite) __INTRODUCED_IN(rewrite_api_level) #endif /* glibc compatibility. */ #if defined(__LP64__) #define __WORDSIZE 64 #else #define __WORDSIZE 32 #endif /* * When _FORTIFY_SOURCE is defined, automatic bounds checking is * added to commonly used libc functions. If a buffer overrun is * detected, the program is safely aborted. * * https://android-developers.googleblog.com/2017/04/fortify-in-android.html */ #define __BIONIC_FORTIFY_UNKNOWN_SIZE ((size_t) -1) #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 # if defined(__clang__) /* * FORTIFY's _chk functions effectively disable ASAN's stdlib interceptors. * Additionally, the static analyzer/clang-tidy try to pattern match some * standard library functions, and FORTIFY sometimes interferes with this. So, * we turn FORTIFY off in both cases. */ # if !__has_feature(address_sanitizer) && !defined(__clang_analyzer__) # define __BIONIC_FORTIFY 1 # endif # elif defined(__OPTIMIZE__) && __OPTIMIZE__ > 0 # define __BIONIC_FORTIFY 1 # endif #endif #if defined(__BIONIC_FORTIFY) # if _FORTIFY_SOURCE == 2 # define __bos_level 1 # else # define __bos_level 0 # endif # define __bosn(s, n) __builtin_object_size((s), (n)) # define __bos(s) __bosn((s), __bos_level) # define __bos0(s) __bosn((s), 0) # if defined(__clang__) # define __pass_object_size_n(n) __attribute__((pass_object_size(n))) /* * FORTIFY'ed functions all have either enable_if or pass_object_size, which * makes taking their address impossible. Saying (&read)(foo, bar, baz); will * therefore call the unFORTIFYed version of read. */ # define __call_bypassing_fortify(fn) (&fn) /* * Because clang-FORTIFY uses overloads, we can't mark functions as `extern * inline` without making them available externally. */ # define __BIONIC_FORTIFY_INLINE static __inline__ __always_inline /* * We should use __BIONIC_FORTIFY_VARIADIC instead of __BIONIC_FORTIFY_INLINE * for variadic functions because compilers cannot inline them. * The __always_inline attribute is useless, misleading, and could trigger * clang compiler bug to incorrectly inline variadic functions. */ # define __BIONIC_FORTIFY_VARIADIC static __inline__ /* Error functions don't have bodies, so they can just be static. */ # define __BIONIC_ERROR_FUNCTION_VISIBILITY static # else /* * Where they can, GCC and clang-style FORTIFY share implementations. * So, make these nops in GCC. */ # define __pass_object_size_n(n) # define __call_bypassing_fortify(fn) (fn) /* __BIONIC_FORTIFY_NONSTATIC_INLINE is pointless in GCC's FORTIFY */ # define __BIONIC_FORTIFY_INLINE extern __inline__ __always_inline __attribute__((gnu_inline)) __attribute__((__artificial__)) /* __always_inline is probably okay and ignored by gcc in __BIONIC_FORTIFY_VARIADIC */ # define __BIONIC_FORTIFY_VARIADIC __BIONIC_FORTIFY_INLINE # endif #else /* Further increase sharing for some inline functions */ # define __pass_object_size_n(n) #endif #define __pass_object_size __pass_object_size_n(__bos_level) #define __pass_object_size0 __pass_object_size_n(0) #if defined(__BIONIC_FORTIFY) || defined(__BIONIC_DECLARE_FORTIFY_HELPERS) # define __BIONIC_INCLUDE_FORTIFY_HEADERS 1 #endif /* * Used to support clangisms with FORTIFY. Because these change how symbols are * emitted, we need to ensure that bionic itself is built fortified. But lots * of external code (especially stuff using configure) likes to declare * functions directly, and they can't know that the overloadable attribute * exists. This leads to errors like: * * dcigettext.c:151:7: error: redeclaration of 'getcwd' must have the 'overloadable' attribute * char *getcwd (); * ^ * * To avoid this and keep such software building, don't use overloadable if * we're not using fortify. */ #if defined(__clang__) && defined(__BIONIC_FORTIFY) # define __overloadable __attribute__((overloadable)) /* We don't use __RENAME directly because on gcc this could result in unnecessary renames. */ # define __RENAME_CLANG(x) __RENAME(x) #else # define __overloadable # define __RENAME_CLANG(x) #endif /* Used to tag non-static symbols that are private and never exposed by the shared library. */ #define __LIBC_HIDDEN__ __attribute__((visibility("hidden"))) /* * Used to tag symbols that should be hidden for 64-bit, * but visible to preserve binary compatibility for LP32. */ #ifdef __LP64__ #define __LIBC32_LEGACY_PUBLIC__ __attribute__((visibility("hidden"))) #else #define __LIBC32_LEGACY_PUBLIC__ __attribute__((visibility("default"))) #endif /* Used to rename functions so that the compiler emits a call to 'x' rather than the function this was applied to. */ #define __RENAME(x) __asm__(#x) #if __has_builtin(__builtin_umul_overflow) || __GNUC__ >= 5 #if defined(__LP64__) #define __size_mul_overflow(a, b, result) __builtin_umull_overflow(a, b, result) #else #define __size_mul_overflow(a, b, result) __builtin_umul_overflow(a, b, result) #endif #else extern __inline__ __always_inline __attribute__((gnu_inline)) int __size_mul_overflow(__SIZE_TYPE__ a, __SIZE_TYPE__ b, __SIZE_TYPE__ *result) { *result = a * b; static const __SIZE_TYPE__ mul_no_overflow = 1UL << (sizeof(__SIZE_TYPE__) * 4); return (a >= mul_no_overflow || b >= mul_no_overflow) && a > 0 && (__SIZE_TYPE__)-1 / a < b; } #endif #if defined(__clang__) /* * Used when we need to check for overflow when multiplying x and y. This * should only be used where __size_mul_overflow can not work, because it makes * assumptions that __size_mul_overflow doesn't (x and y are positive, ...), * *and* doesn't make use of compiler intrinsics, so it's probably slower than * __size_mul_overflow. */ #define __unsafe_check_mul_overflow(x, y) ((__SIZE_TYPE__)-1 / (x) < (y)) #endif #endif /* !_SYS_CDEFS_H_ */