serenity/AK/Platform.h
Daniel Bertalan 9d4dfc1061 AK: Work around Apple Clang __builtin_subc codegen issue
Apple Clang 14.0.3 (Xcode 14.3) miscompiles this builtin on AArch64,
causing the borrow flag to be set incorrectly. I have added a detailed
writeup on Qemu's issue tracker, where the same issue led to a hang when
emulating x86:

https://gitlab.com/qemu-project/qemu/-/issues/1659#note_1408275831

I don't know of any specific issue caused by this on Lagom, but better
safe than sorry.
2023-06-24 18:31:14 +02:00

219 lines
5.4 KiB
C

/*
* Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2022, Nico Weber <thakis@chromium.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#ifndef USING_AK_GLOBALLY
# define USING_AK_GLOBALLY 1
#endif
#ifdef __x86_64__
# define AK_IS_ARCH_X86_64() 1
#else
# define AK_IS_ARCH_X86_64() 0
#endif
#ifdef __aarch64__
# define AK_IS_ARCH_AARCH64() 1
#else
# define AK_IS_ARCH_AARCH64() 0
#endif
#ifdef __wasm32__
# define AK_IS_ARCH_WASM32() 1
#else
# define AK_IS_ARCH_WASM32() 0
#endif
#if (defined(__SIZEOF_POINTER__) && __SIZEOF_POINTER__ == 8) || defined(_WIN64)
# define AK_ARCH_64_BIT
#else
# define AK_ARCH_32_BIT
#endif
#if defined(__clang__) || defined(__CLION_IDE__) || defined(__CLION_IDE_)
# define AK_COMPILER_CLANG
#elif defined(__GNUC__)
# define AK_COMPILER_GCC
#endif
#if defined(__serenity__)
# define AK_OS_SERENITY
#endif
#if defined(__linux__)
# define AK_OS_LINUX
#endif
#if defined(__APPLE__) && defined(__MACH__)
# define AK_OS_MACOS
# define AK_OS_BSD_GENERIC
#endif
#if defined(__FreeBSD__)
# define AK_OS_BSD_GENERIC
# define AK_OS_FREEBSD
#endif
#if defined(__NetBSD__)
# define AK_OS_BSD_GENERIC
# define AK_OS_NETBSD
#endif
#if defined(__OpenBSD__)
# define AK_OS_BSD_GENERIC
# define AK_OS_OPENBSD
#endif
#if defined(__DragonFly__)
# define AK_OS_BSD_GENERIC
# define AK_OS_DRAGONFLY
#endif
#if defined(__sun)
# define AK_OS_BSD_GENERIC
# define AK_OS_SOLARIS
#endif
#if defined(_WIN32) || defined(_WIN64)
# define AK_OS_WINDOWS
#endif
#if defined(__ANDROID__)
# define STR(x) __STR(x)
# define __STR(x) #x
# if __ANDROID_API__ < 30
# pragma message "Invalid android API " STR(__ANDROID_API__)
# error "Build configuration not tested on configured Android API version"
# endif
# undef STR
# undef __STR
# define AK_OS_ANDROID
#endif
#if defined(__EMSCRIPTEN__)
# define AK_OS_EMSCRIPTEN
#endif
#define ARCH(arch) (AK_IS_ARCH_##arch())
#if ARCH(X86_64)
# define VALIDATE_IS_X86()
#else
# define VALIDATE_IS_X86() static_assert(false, "Trying to include x86 only header on non x86 platform");
#endif
#if ARCH(AARCH64)
# define VALIDATE_IS_AARCH64()
#else
# define VALIDATE_IS_AARCH64() static_assert(false, "Trying to include aarch64 only header on non aarch64 platform");
#endif
#if !defined(AK_COMPILER_CLANG)
# define AK_HAS_CONDITIONALLY_TRIVIAL
#endif
// Apple Clang 14.0.3 (shipped in Xcode 14.3) has a bug that causes __builtin_subc{,l,ll}
// to incorrectly return whether a borrow occurred on AArch64. See our writeup for the Qemu
// issue also caused by it: https://gitlab.com/qemu-project/qemu/-/issues/1659#note_1408275831
#if ARCH(AARCH64) && defined(__apple_build_version__) && __clang_major__ == 14
# define AK_BUILTIN_SUBC_BROKEN
#endif
#ifdef ALWAYS_INLINE
# undef ALWAYS_INLINE
#endif
#define ALWAYS_INLINE __attribute__((always_inline)) inline
#ifdef NEVER_INLINE
# undef NEVER_INLINE
#endif
#define NEVER_INLINE __attribute__((noinline))
#ifdef FLATTEN
# undef FLATTEN
#endif
#define FLATTEN __attribute__((flatten))
#ifdef RETURNS_NONNULL
# undef RETURNS_NONNULL
#endif
#define RETURNS_NONNULL __attribute__((returns_nonnull))
#ifdef NO_SANITIZE_ADDRESS
# undef NO_SANITIZE_ADDRESS
#endif
#define NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
#ifdef NAKED
# undef NAKED
#endif
#if !ARCH(AARCH64) || defined(AK_COMPILER_CLANG)
# define NAKED __attribute__((naked))
#else
// GCC doesn't support __attribute__((naked)) on AArch64. We use NAKED to mark functions
// that are entirely written in inline assembly; having these be inlined would cause
// various problems, such as explicit `ret` instructions accidentally exiting the caller
// function or GCC discarding function arguments as they appear "dead".
# define NAKED NEVER_INLINE
#endif
#ifdef DISALLOW
# undef DISALLOW
#endif
#if defined(AK_COMPILER_CLANG)
# define DISALLOW(message) __attribute__((diagnose_if(1, message, "error")))
#else
# define DISALLOW(message) __attribute__((error(message)))
#endif
// GCC doesn't have __has_feature but clang does
#ifndef __has_feature
# define __has_feature(...) 0
#endif
#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
# define HAS_ADDRESS_SANITIZER
# define ASAN_POISON_MEMORY_REGION(addr, size) __asan_poison_memory_region(addr, size)
# define ASAN_UNPOISON_MEMORY_REGION(addr, size) __asan_unpoison_memory_region(addr, size)
#else
# define ASAN_POISON_MEMORY_REGION(addr, size)
# define ASAN_UNPOISON_MEMORY_REGION(addr, size)
#endif
#ifndef AK_OS_SERENITY
# ifdef AK_OS_WINDOWS
// FIXME: No idea where to get this, but it's 4096 anyway :^)
# define PAGE_SIZE 4096
# else
# include <unistd.h>
# undef PAGE_SIZE
# define PAGE_SIZE sysconf(_SC_PAGESIZE)
# endif
#endif
#if defined(AK_OS_WINDOWS)
# define CLOCK_MONOTONIC_COARSE CLOCK_MONOTONIC
#endif
#if defined(AK_OS_BSD_GENERIC) && !defined(AK_OS_FREEBSD)
# define CLOCK_MONOTONIC_COARSE CLOCK_MONOTONIC
# define CLOCK_REALTIME_COARSE CLOCK_REALTIME
#endif
#ifndef AK_SYSTEM_CACHE_ALIGNMENT_SIZE
# if ARCH(AARCH64) || ARCH(X86_64)
# define AK_SYSTEM_CACHE_ALIGNMENT_SIZE 64
# else
# define AK_SYSTEM_CACHE_ALIGNMENT_SIZE 128
# endif
#endif /* AK_SYSTEM_CACHE_ALIGNMENT_SIZE */
#ifdef AK_CACHE_ALIGNED
# undef AK_CACHE_ALIGNED
#endif
#define AK_CACHE_ALIGNED alignas(AK_SYSTEM_CACHE_ALIGNMENT_SIZE)