api/head/v8config_8h_source.html

// Copyright 2013 the V8 project authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.


#ifndef V8CONFIG_H_

#define V8CONFIG_H_


// gcc 10 defines __cplusplus to "an unspecified value strictly larger than

// 201703L" for its experimental -std=gnu++2a config.

// TODO(leszeks): Change to `__cplusplus <= 202002L` once we only support

// compilers with full C++20 support.

#if __cplusplus <= 201703L

#error "C++20 or later required."

#endif


#ifdef V8_GN_HEADER

#if !__has_include("v8-gn.h")

#error Missing v8-gn.h. The configuration for v8 is missing from the include \

path. Add it with -I<path> to the command line

#endif

#include "v8-gn.h"  // NOLINT(build/include_directory)

#endif


#include <memory>

// clang-format off


// Platform headers for feature detection below.

#if defined(__ANDROID__)

# include <sys/cdefs.h>

#elif defined(__APPLE__)

# include <TargetConditionals.h>

#elif defined(__linux__)

# include <features.h>

#elif defined(__MVS__)

# include "zos-base.h"

#endif


// This macro allows to test for the version of the GNU C library (or

// a compatible C library that masquerades as glibc). It evaluates to

// 0 if libc is not GNU libc or compatible.

// Use like:

//  #if V8_GLIBC_PREREQ(2, 3)

//   ...

//  #endif

#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)

# define V8_GLIBC_PREREQ(major, minor)                                    \

    ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))

#else

# define V8_GLIBC_PREREQ(major, minor) 0

#endif


// This macro allows to test for the version of the GNU C++ compiler.

// Note that this also applies to compilers that masquerade as GCC,

// for example clang and the Intel C++ compiler for Linux.

// Use like:

//  #if V8_GNUC_PREREQ(4, 3, 1)

//   ...

//  #endif

#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)

# define V8_GNUC_PREREQ(major, minor, patchlevel)                         \

    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \

     ((major) * 10000 + (minor) * 100 + (patchlevel)))

#elif defined(__GNUC__) && defined(__GNUC_MINOR__)

# define V8_GNUC_PREREQ(major, minor, patchlevel)      \

    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \

     ((major) * 10000 + (minor) * 100 + (patchlevel)))

#else

# define V8_GNUC_PREREQ(major, minor, patchlevel) 0

#endif


// -----------------------------------------------------------------------------

// Operating system detection (host)

//

//  V8_OS_ANDROID       - Android

//  V8_OS_BSD           - BSDish (macOS, Net/Free/Open/DragonFlyBSD)

//  V8_OS_CYGWIN        - Cygwin

//  V8_OS_DRAGONFLYBSD  - DragonFlyBSD

//  V8_OS_FREEBSD       - FreeBSD

//  V8_OS_FUCHSIA       - Fuchsia

//  V8_OS_LINUX         - Linux (Android, ChromeOS, Linux, ...)

//  V8_OS_DARWIN        - Darwin (macOS, iOS)

//  V8_OS_MACOS         - macOS

//  V8_OS_IOS           - iOS

//  V8_OS_TVOS          - tvOS (also sets V8_OS_IOS)

//  V8_OS_NETBSD        - NetBSD

//  V8_OS_OPENBSD       - OpenBSD

//  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)

//  V8_OS_QNX           - QNX Neutrino

//  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris

//  V8_OS_STARBOARD     - Starboard (platform abstraction for Cobalt)

//  V8_OS_AIX           - AIX

//  V8_OS_WIN           - Microsoft Windows

//  V8_OS_ZOS           - z/OS


#if defined(__ANDROID__)

# define V8_OS_ANDROID 1

# define V8_OS_LINUX 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "android"


#elif defined(__APPLE__)

# define V8_OS_POSIX 1

# define V8_OS_BSD 1

# define V8_OS_DARWIN 1

# if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE

#  define V8_OS_IOS 1

#  define V8_OS_STRING "ios"

#  if defined(TARGET_OS_TV) && TARGET_OS_TV

#   define V8_OS_TVOS 1

#  endif

# else

#  define V8_OS_MACOS 1

#  define V8_OS_STRING "macos"

# endif  // defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE


#elif defined(__CYGWIN__)

# define V8_OS_CYGWIN 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "cygwin"


#elif defined(__linux__)

# define V8_OS_LINUX 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "linux"


#elif defined(__sun)

# define V8_OS_POSIX 1

# define V8_OS_SOLARIS 1

# define V8_OS_STRING "sun"


#elif defined(STARBOARD)

# define V8_OS_STARBOARD 1

# define V8_OS_STRING "starboard"


#elif defined(_AIX)

# define V8_OS_POSIX 1

# define V8_OS_AIX 1

# define V8_OS_STRING "aix"


#elif defined(__FreeBSD__)

# define V8_OS_BSD 1

# define V8_OS_FREEBSD 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "freebsd"


#elif defined(__Fuchsia__)

# define V8_OS_FUCHSIA 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "fuchsia"


#elif defined(__DragonFly__)

# define V8_OS_BSD 1

# define V8_OS_DRAGONFLYBSD 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "dragonflybsd"


#elif defined(__NetBSD__)

# define V8_OS_BSD 1

# define V8_OS_NETBSD 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "netbsd"


#elif defined(__OpenBSD__)

# define V8_OS_BSD 1

# define V8_OS_OPENBSD 1

# define V8_OS_POSIX 1

# define V8_OS_STRING "openbsd"


#elif defined(__QNXNTO__)

# define V8_OS_POSIX 1

# define V8_OS_QNX 1

# define V8_OS_STRING "qnx"


#elif defined(_WIN32)

# define V8_OS_WIN 1

# define V8_OS_STRING "windows"


#elif defined(__MVS__)

# define V8_OS_POSIX 1

# define V8_OS_ZOS 1

# define V8_OS_STRING "zos"

#endif


// -----------------------------------------------------------------------------

// Operating system detection (target)

//

//  V8_TARGET_OS_ANDROID

//  V8_TARGET_OS_FUCHSIA

//  V8_TARGET_OS_IOS

//  V8_TARGET_OS_TVOS (also sets V8_TARGET_OS_IOS)

//  V8_TARGET_OS_LINUX

//  V8_TARGET_OS_MACOS

//  V8_TARGET_OS_WIN

//  V8_TARGET_OS_CHROMEOS

//

// If not set explicitly, these fall back to corresponding V8_OS_ values.


#ifdef V8_HAVE_TARGET_OS


// The target OS is provided, just check that at least one known value is set.

# if !defined(V8_TARGET_OS_ANDROID) \

  && !defined(V8_TARGET_OS_FUCHSIA) \

  && !defined(V8_TARGET_OS_IOS) \

  && !defined(V8_TARGET_OS_TVOS) \

  && !defined(V8_TARGET_OS_LINUX) \

  && !defined(V8_TARGET_OS_MACOS) \

  && !defined(V8_TARGET_OS_WIN) \

  && !defined(V8_TARGET_OS_CHROMEOS)

#  error No known target OS defined.

# endif


#else  // V8_HAVE_TARGET_OS


# if defined(V8_TARGET_OS_ANDROID) \

  || defined(V8_TARGET_OS_FUCHSIA) \

  || defined(V8_TARGET_OS_IOS) \

  || defined(V8_TARGET_OS_TVOS) \

  || defined(V8_TARGET_OS_LINUX) \

  || defined(V8_TARGET_OS_MACOS) \

  || defined(V8_TARGET_OS_WIN) \

  || defined(V8_TARGET_OS_CHROMEOS)

#  error A target OS is defined but V8_HAVE_TARGET_OS is unset.

# endif


// Fall back to the detected host OS.

#ifdef V8_OS_ANDROID

# define V8_TARGET_OS_ANDROID

#endif


#ifdef V8_OS_FUCHSIA

# define V8_TARGET_OS_FUCHSIA

#endif


#ifdef V8_OS_IOS

# define V8_TARGET_OS_IOS

#endif


#ifdef V8_OS_TVOS

# define V8_TARGET_OS_TVOS

#endif


#ifdef V8_OS_LINUX

# define V8_TARGET_OS_LINUX

#endif


#ifdef V8_OS_MACOS

# define V8_TARGET_OS_MACOS

#endif


#ifdef V8_OS_WIN

# define V8_TARGET_OS_WIN

#endif


#endif  // V8_HAVE_TARGET_OS


#if defined(V8_TARGET_OS_ANDROID)

# define V8_TARGET_OS_STRING "android"

#elif defined(V8_TARGET_OS_FUCHSIA)

# define V8_TARGET_OS_STRING "fuchsia"

#elif defined(V8_TARGET_OS_IOS)

# define V8_TARGET_OS_STRING "ios"

#elif defined(V8_TARGET_OS_LINUX)

# define V8_TARGET_OS_STRING "linux"

#elif defined(V8_TARGET_OS_MACOS)

# define V8_TARGET_OS_STRING "macos"

#elif defined(V8_TARGET_OS_WINDOWS)

# define V8_TARGET_OS_STRING "windows"

#else

# define V8_TARGET_OS_STRING "unknown"

#endif


// -----------------------------------------------------------------------------

// C library detection

//

//  V8_LIBC_MSVCRT  - MSVC libc

//  V8_LIBC_BIONIC  - Bionic libc

//  V8_LIBC_BSD     - BSD libc derivate

//  V8_LIBC_GLIBC   - GNU C library

//  V8_LIBC_UCLIBC  - uClibc

//

// Note that testing for libc must be done using #if not #ifdef. For example,

// to test for the GNU C library, use:

//  #if V8_LIBC_GLIBC

//   ...

//  #endif


#if defined (_MSC_VER)

# define V8_LIBC_MSVCRT 1

#elif defined(__BIONIC__)

# define V8_LIBC_BIONIC 1

# define V8_LIBC_BSD 1

#elif defined(__UCLIBC__)

// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.

# define V8_LIBC_UCLIBC 1

#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)

# define V8_LIBC_GLIBC 1

#else

# define V8_LIBC_BSD V8_OS_BSD

#endif


// -----------------------------------------------------------------------------

// Compiler detection

//

//  V8_CC_GNU     - GCC, or clang in gcc mode

//  V8_CC_INTEL   - Intel C++

//  V8_CC_MINGW   - Minimalist GNU for Windows

//  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)

//  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)

//  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode

//

// C++11 feature detection

//

// Compiler-specific feature detection

//

//  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))

//                                        supported

//  V8_HAS_ATTRIBUTE_CONSTINIT          - __attribute__((require_constant_

//                                                       initialization))

//                                        supported

//  V8_HAS_ATTRIBUTE_NONNULL            - __attribute__((nonnull)) supported

//  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported

//  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported

//  V8_HAS_ATTRIBUTE_USED               - __attribute__((used)) supported

//  V8_HAS_ATTRIBUTE_RETAIN             - __attribute__((retain)) supported

//  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported

//  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))

//                                        supported

//  V8_HAS_CPP_ATTRIBUTE_NODISCARD      - [[nodiscard]] supported

//  V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS

//                                      - [[no_unique_address]] supported

//  V8_HAS_CPP_ATTRIBUTE_LIFETIME_BOUND - [[clang::lifetimebound]] supported

//  V8_HAS_BUILTIN_ADD_OVERFLOW         - __builtin_add_overflow() supported

//  V8_HAS_BUILTIN_BIT_CAST             - __builtin_bit_cast() supported

//  V8_HAS_BUILTIN_BSWAP16              - __builtin_bswap16() supported

//  V8_HAS_BUILTIN_BSWAP32              - __builtin_bswap32() supported

//  V8_HAS_BUILTIN_BSWAP64              - __builtin_bswap64() supported

//  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported

//  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported

//  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported

//  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported

//  V8_HAS_BUILTIN_MUL_OVERFLOW         - __builtin_mul_overflow() supported

//  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported

//  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported

//  V8_HAS_BUILTIN_SMUL_OVERFLOW        - __builtin_smul_overflow() supported

//  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported

//  V8_HAS_BUILTIN_SUB_OVERFLOW         - __builtin_sub_overflow() supported

//  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_overflow() supported

//  V8_HAS_COMPUTED_GOTO                - computed goto/labels as values

//                                        supported

//  V8_HAS_DECLSPEC_NOINLINE            - __declspec(noinline) supported

//  V8_HAS_DECLSPEC_SELECTANY           - __declspec(selectany) supported

//  V8_HAS___FORCEINLINE                - __forceinline supported

//

// Note that testing for compilers and/or features must be done using #if

// not #ifdef. For example, to test for Intel C++ Compiler, use:

//  #if V8_CC_INTEL

//   ...

//  #endif


#if defined(__has_cpp_attribute)

#define V8_HAS_CPP_ATTRIBUTE(FEATURE) __has_cpp_attribute(FEATURE)

#else

#define V8_HAS_CPP_ATTRIBUTE(FEATURE) 0

#endif


#if defined(__clang__)


#if defined(__GNUC__)  // Clang in gcc mode.

# define V8_CC_GNU 1

#endif


# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))

# define V8_HAS_ATTRIBUTE_CONSTINIT \

    (__has_attribute(require_constant_initialization))

# define V8_HAS_ATTRIBUTE_CONST (__has_attribute(const))

# define V8_HAS_ATTRIBUTE_NONNULL (__has_attribute(nonnull))

# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))

# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))

# define V8_HAS_ATTRIBUTE_USED (__has_attribute(used))

# define V8_HAS_ATTRIBUTE_RETAIN (__has_attribute(retain))

# define V8_HAS_ATTRIBUTE_OPTNONE (__has_attribute(optnone))

// Support for the "preserve_most" attribute is limited:

// - 32-bit platforms do not implement it,

// - component builds fail because _dl_runtime_resolve clobbers registers,

// - we see crashes on arm64 on Windows (https://crbug.com/1409934), which can

//   hopefully be fixed in the future.

// Additionally, the initial implementation in clang <= 16 overwrote the return

// register(s) in the epilogue of a preserve_most function, so we only use

// preserve_most in clang >= 17 (see https://reviews.llvm.org/D143425).

#if (defined(_M_X64) || defined(__x86_64__)            /* x64 (everywhere) */  \

     || ((defined(__AARCH64EL__) || defined(_M_ARM64)) /* arm64, but ... */    \

         && !defined(_WIN32)))                         /* not on windows */    \

     && !defined(COMPONENT_BUILD)                      /* no component build */\

     && __clang_major__ >= 17                          /* clang >= 17 */

# define V8_HAS_ATTRIBUTE_PRESERVE_MOST (__has_attribute(preserve_most))

#endif

# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))

# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \

    (__has_attribute(warn_unused_result))

# define V8_HAS_ATTRIBUTE_WEAK (__has_attribute(weak))


# define V8_HAS_CPP_ATTRIBUTE_NODISCARD (V8_HAS_CPP_ATTRIBUTE(nodiscard))

#if defined(V8_CC_MSVC)

# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS       \

    (V8_HAS_CPP_ATTRIBUTE(msvc::no_unique_address) || \

     V8_HAS_CPP_ATTRIBUTE(no_unique_address))

#else

# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \

    (V8_HAS_CPP_ATTRIBUTE(no_unique_address))

#endif

# define V8_HAS_CPP_ATTRIBUTE_LIFETIME_BOUND (V8_HAS_CPP_ATTRIBUTE(clang::lifetimebound))


# define V8_HAS_BUILTIN_ADD_OVERFLOW (__has_builtin(__builtin_add_overflow))

# define V8_HAS_BUILTIN_ASSUME (__has_builtin(__builtin_assume))

# define V8_HAS_BUILTIN_ASSUME_ALIGNED (__has_builtin(__builtin_assume_aligned))

# define V8_HAS_BUILTIN_BIT_CAST (__has_builtin(__builtin_bit_cast))

# define V8_HAS_BUILTIN_BSWAP16 (__has_builtin(__builtin_bswap16))

# define V8_HAS_BUILTIN_BSWAP32 (__has_builtin(__builtin_bswap32))

# define V8_HAS_BUILTIN_BSWAP64 (__has_builtin(__builtin_bswap64))

# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))

# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))

# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))

# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))

# define V8_HAS_BUILTIN_MUL_OVERFLOW (__has_builtin(__builtin_mul_overflow))

# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))

# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))

# define V8_HAS_BUILTIN_SMUL_OVERFLOW (__has_builtin(__builtin_smul_overflow))

# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))

# define V8_HAS_BUILTIN_SUB_OVERFLOW (__has_builtin(__builtin_sub_overflow))

# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))

# define V8_HAS_BUILTIN_UNREACHABLE (__has_builtin(__builtin_unreachable))


// Clang has no __has_feature for computed gotos.

// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html

# define V8_HAS_COMPUTED_GOTO 1


#elif defined(__GNUC__)


# define V8_CC_GNU 1

# if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0

#  define V8_CC_INTEL 1

# endif

# if defined(__MINGW32__)

#  define V8_CC_MINGW32 1

# endif

# if defined(__MINGW64__)

#  define V8_CC_MINGW64 1

# endif

# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)


// FYI: __has_builtin is only available with GCC 10 and later, so explicitly

// check GCC version numbers to enable features. TODO(leszeks): Merge feature

// enabling for GCC 10 and later into the Clang section above, and leave this

// section for GCC 9 and earlier.


// always_inline is available in gcc 4.0 but not very reliable until 4.4.

// Works around "sorry, unimplemented: inlining failed" build errors with

// older compilers.

# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE 1

# define V8_HAS_ATTRIBUTE_NOINLINE 1

# define V8_HAS_ATTRIBUTE_UNUSED 1

# define V8_HAS_ATTRIBUTE_VISIBILITY 1

# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT (!V8_CC_INTEL)

# define V8_HAS_ATTRIBUTE_WEAK 1


// [[nodiscard]] does not work together with with

// __attribute__((visibility(""))) on GCC 7.4 which is why there is no define

// for V8_HAS_CPP_ATTRIBUTE_NODISCARD. See https://crbug.com/v8/11707.


# define V8_HAS_BUILTIN_ASSUME_ALIGNED 1

# if __GNUC__ >= 11

#  define V8_HAS_BUILTIN_BIT_CAST 1

# endif

# define V8_HAS_BUILTIN_CLZ 1

# define V8_HAS_BUILTIN_CTZ 1

# define V8_HAS_BUILTIN_EXPECT 1

# define V8_HAS_BUILTIN_FRAME_ADDRESS 1

# define V8_HAS_BUILTIN_POPCOUNT 1

# define V8_HAS_BUILTIN_UNREACHABLE 1


// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html

#define V8_HAS_COMPUTED_GOTO 1


#endif


#if defined(_MSC_VER)

# define V8_CC_MSVC 1


# define V8_HAS_DECLSPEC_NOINLINE 1

# define V8_HAS_DECLSPEC_SELECTANY 1


# define V8_HAS___FORCEINLINE 1


#endif


// -----------------------------------------------------------------------------

// Helper macros


// A macro used to make better inlining. Don't bother for debug builds.

// Use like:

//   V8_INLINE int GetZero() { return 0; }

#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE

# define V8_INLINE inline __attribute__((always_inline))

#elif !defined(DEBUG) && V8_HAS___FORCEINLINE

# define V8_INLINE __forceinline

#else

# define V8_INLINE inline

#endif


// A macro to force better inlining of calls in a statement. Don't bother for

// debug builds.

// Use like:

//   V8_INLINE_STATEMENT foo = bar(); // Will force inlining the bar() call.

#if !defined(DEBUG) && defined(__clang__) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE

# define V8_INLINE_STATEMENT [[clang::always_inline]]

#else

# define V8_INLINE_STATEMENT

#endif


#if V8_HAS_BUILTIN_ASSUME

#ifdef DEBUG

// In debug mode, check assumptions in addition to adding annotations.

// This helps GCC (and maybe other compilers) figure out that certain

// situations are unreachable.

# define V8_ASSUME(condition)    \

  do {                           \

    DCHECK(condition);           \

    __builtin_assume(condition); \

  } while (false)

#else  // DEBUG

# define V8_ASSUME __builtin_assume

#endif  // DEBUG

#elif V8_HAS_BUILTIN_UNREACHABLE

# define V8_ASSUME(condition)                  \

  do {                                         \

    DCHECK(condition);                         \

    if (!(condition)) __builtin_unreachable(); \

  } while (false)

#else

# define V8_ASSUME USE

#endif


// Prefer c++20 std::assume_aligned. Don't use it on MSVC though, because it's

// not happy with our large 4GB alignment values.

#if __cplusplus >= 202002L && defined(__cpp_lib_assume_aligned) && !V8_CC_MSVC

# define V8_ASSUME_ALIGNED(ptr, alignment) \

  std::assume_aligned<(alignment)>(ptr)

#elif V8_HAS_BUILTIN_ASSUME_ALIGNED

# define V8_ASSUME_ALIGNED(ptr, alignment) \

  __builtin_assume_aligned((ptr), (alignment))

#else

# define V8_ASSUME_ALIGNED(ptr, alignment) (ptr)

#endif


// A macro to mark functions whose values don't change (e.g. across calls)

// and thereby compiler is free to hoist and fold multiple calls together.

// Use like:

//   V8_CONST int foo() { ... }

#if V8_HAS_ATTRIBUTE_CONST

# define V8_CONST __attribute__((const))

#else

# define V8_CONST

#endif


// A macro to mark a declaration as requiring constant initialization.

// Use like:

//   int* foo V8_CONSTINIT;

#if V8_HAS_ATTRIBUTE_CONSTINIT

# define V8_CONSTINIT __attribute__((require_constant_initialization))

#else

# define V8_CONSTINIT

#endif


// A macro to mark specific arguments as non-null.

// Use like:

//   int add(int* x, int y, int* z) V8_NONNULL(1, 3) { return *x + y + *z; }

#if V8_HAS_ATTRIBUTE_NONNULL

# define V8_NONNULL(...) __attribute__((nonnull(__VA_ARGS__)))

#else

# define V8_NONNULL(...) /* NOT SUPPORTED */

#endif


// A macro used to tell the compiler to never inline a particular function.

// Use like:

//   V8_NOINLINE int GetMinusOne() { return -1; }

#if V8_HAS_ATTRIBUTE_NOINLINE

# define V8_NOINLINE __attribute__((noinline))

#elif V8_HAS_DECLSPEC_NOINLINE

# define V8_NOINLINE __declspec(noinline)

#else

# define V8_NOINLINE /* NOT SUPPORTED */

#endif


// A macro used to change the calling conventions to preserve all registers (no

// caller-saved registers). Use this for cold functions called from hot

// functions.

// Use like:

//   V8_NOINLINE V8_PRESERVE_MOST void UnlikelyMethod();

#if V8_HAS_ATTRIBUTE_PRESERVE_MOST

# define V8_PRESERVE_MOST __attribute__((preserve_most))

#else

# define V8_PRESERVE_MOST /* NOT SUPPORTED */

#endif


// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.

#if defined(V8_DEPRECATION_WARNINGS)

# define V8_DEPRECATED(message) [[deprecated(message)]]

#else

# define V8_DEPRECATED(message)

#endif


// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.

#if defined(V8_IMMINENT_DEPRECATION_WARNINGS)

# define V8_DEPRECATE_SOON(message) [[deprecated(message)]]

#else

# define V8_DEPRECATE_SOON(message)

#endif


#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) || \

    defined(V8_DEPRECATION_WARNINGS)

#if defined(V8_CC_MSVC)

# define START_ALLOW_USE_DEPRECATED() \

    __pragma(warning(push))           \

    __pragma(warning(disable : 4996))

# define END_ALLOW_USE_DEPRECATED() __pragma(warning(pop))

#else  // !defined(V8_CC_MSVC)

# define START_ALLOW_USE_DEPRECATED()                               \

    _Pragma("GCC diagnostic push")                                  \

    _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")

#define END_ALLOW_USE_DEPRECATED() _Pragma("GCC diagnostic pop")

#endif  // !defined(V8_CC_MSVC)

#else  // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||

       // defined(V8_DEPRECATION_WARNINGS))

#define START_ALLOW_USE_DEPRECATED()

#define END_ALLOW_USE_DEPRECATED()

#endif  // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||

        // defined(V8_DEPRECATION_WARNINGS))

#define ALLOW_COPY_AND_MOVE_WITH_DEPRECATED_FIELDS(ClassName) \

  START_ALLOW_USE_DEPRECATED()                                \

  ClassName(const ClassName&) = default;                      \

  ClassName(ClassName&&) = default;                           \

  ClassName& operator=(const ClassName&) = default;           \

  ClassName& operator=(ClassName&&) = default;                \

  END_ALLOW_USE_DEPRECATED()


#if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 6)

# define V8_ENUM_DEPRECATED(message)

# define V8_ENUM_DEPRECATE_SOON(message)

#else

# define V8_ENUM_DEPRECATED(message) V8_DEPRECATED(message)

# define V8_ENUM_DEPRECATE_SOON(message) V8_DEPRECATE_SOON(message)

#endif


// A macro to provide the compiler with branch prediction information.

#if V8_HAS_BUILTIN_EXPECT

# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))

# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))

#else

# define V8_UNLIKELY(condition) (condition)

# define V8_LIKELY(condition) (condition)

#endif


// Annotate a function indicating the caller must examine the return value.

// Use like:

//   int foo() V8_WARN_UNUSED_RESULT;

#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT

#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))

#else

#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */

#endif


// Annotate functions/variables as weak to allow overriding the symbol.

#if V8_HAS_ATTRIBUTE_WEAK

#define V8_WEAK __attribute__((weak))

#else

#define V8_WEAK /* NOT SUPPORTED */

#endif


// Annotate a class or constructor indicating the caller must assign the

// constructed instances.

// Apply to the whole class like:

//   class V8_NODISCARD Foo() { ... };

// or apply to just one constructor like:

//   V8_NODISCARD Foo() { ... };

// [[nodiscard]] comes in C++17 but supported in clang with -std >= c++11.

#if V8_HAS_CPP_ATTRIBUTE_NODISCARD

#define V8_NODISCARD [[nodiscard]]

#else

#define V8_NODISCARD /* NOT SUPPORTED */

#endif


// The no_unique_address attribute allows tail padding in a non-static data

// member to overlap other members of the enclosing class (and in the special

// case when the type is empty, permits it to fully overlap other members). The

// field is laid out as if a base class were encountered at the corresponding

// point within the class (except that it does not share a vptr with the

// enclosing object).

//

// Apply to a data member like:

//

//   class Foo {

//    V8_NO_UNIQUE_ADDRESS Bar bar_;

//   };

//

// [[no_unique_address]] comes in C++20 but supported in clang with

// -std >= c++11.

#if V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS

#if defined(V8_CC_MSVC) && V8_HAS_CPP_ATTRIBUTE(msvc::no_unique_address)

// Unfortunately MSVC ignores [[no_unique_address]] (see

// https://devblogs.microsoft.com/cppblog/msvc-cpp20-and-the-std-cpp20-switch/#msvc-extensions-and-abi),

// and clang-cl matches it for ABI compatibility reasons. We need to prefer

// [[msvc::no_unique_address]] when available if we actually want any effect.

#define V8_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]

#else

#define V8_NO_UNIQUE_ADDRESS [[no_unique_address]]

#endif

#else

#define V8_NO_UNIQUE_ADDRESS /* NOT SUPPORTED */

#endif


// Annotates a pointer or reference parameter or return value for a member

// function as having lifetime intertwined with the instance on which the

// function is called. For parameters, the function is assumed to store the

// value into the called-on object, so if the referred-to object is later

// destroyed, the called-on object is also considered to be dangling. For return

// values, the value is assumed to point into the called-on object, so if that

// object is destroyed, the returned value is also considered to be dangling.

// Useful to diagnose some cases of lifetime errors.

//

// See also:

//   https://clang.llvm.org/docs/AttributeReference.html#lifetimebound

//

// Usage:

// ```

//   struct S {

//      S(int* p V8_LIFETIME_BOUND);

//      int* Get() V8_LIFETIME_BOUND;

//   };

//   S Func1() {

//     int i = 0;

//     // The following return will not compile; diagnosed as returning address

//     // of a stack object.

//     return S(&i);

//   }

//   int* Func2(int* p) {

//     // The following return will not compile; diagnosed as returning address

//     // of a local temporary.

//     return S(p).Get();

//   }

#if V8_HAS_CPP_ATTRIBUTE_LIFETIME_BOUND

#define V8_LIFETIME_BOUND [[clang::lifetimebound]]

#else

#define V8_LIFETIME_BOUND /* NOT SUPPORTED */

#endif


// Marks a type as being eligible for the "trivial" ABI despite having a

// non-trivial destructor or copy/move constructor. Such types can be relocated

// after construction by simply copying their memory, which makes them eligible

// to be passed in registers. The canonical example is std::unique_ptr.

//

// Use with caution; this has some subtle effects on constructor/destructor

// ordering and will be very incorrect if the type relies on its address

// remaining constant. When used as a function argument (by value), the value

// may be constructed in the caller's stack frame, passed in a register, and

// then used and destructed in the callee's stack frame. A similar thing can

// occur when values are returned.

//

// TRIVIAL_ABI is not needed for types which have a trivial destructor and

// copy/move constructors, since those are automatically trivial by the ABI

// spec.

//

// It is also not likely to be effective on types too large to be passed in one

// or two registers on typical target ABIs.

//

// See also:

//   https://clang.llvm.org/docs/AttributeReference.html#trivial-abi

//   https://libcxx.llvm.org/docs/DesignDocs/UniquePtrTrivialAbi.html

#if defined(__clang__) && defined(__has_attribute)

#if __has_attribute(trivial_abi)

#define V8_TRIVIAL_ABI [[clang::trivial_abi]]

#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 1

#endif // __has_attribute(trivial_abi)

#endif // defined(__clang__) && defined(__has_attribute)

#if !defined(V8_TRIVIAL_ABI)

#define V8_TRIVIAL_ABI

#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 0

#endif


// Helper macro to define no_sanitize attributes only with clang.

#if defined(__clang__) && defined(__has_attribute)

#if __has_attribute(no_sanitize)

#define V8_CLANG_NO_SANITIZE(what) __attribute__((no_sanitize(what)))

#endif

#endif

#if !defined(V8_CLANG_NO_SANITIZE)

#define V8_CLANG_NO_SANITIZE(what)

#endif


// Exposing private symbols requires exposing public symbols too.

#ifdef BUILDING_V8_SHARED_PRIVATE

#define BUILDING_V8_SHARED

#endif


#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)

#error Inconsistent build configuration: To build the V8 shared library \

set BUILDING_V8_SHARED, to include its headers for linking against the \

V8 shared library set USING_V8_SHARED.

#endif


#ifdef V8_OS_WIN


// Setup for Windows DLL export/import. When building the V8 DLL the

// BUILDING_V8_SHARED needs to be defined. When building a program which uses

// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8

// static library or building a program which uses the V8 static library neither

// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.

#ifdef BUILDING_V8_SHARED

# define V8_EXPORT __declspec(dllexport)

#elif USING_V8_SHARED

# define V8_EXPORT __declspec(dllimport)

#else

# define V8_EXPORT

#endif  // BUILDING_V8_SHARED


#else  // V8_OS_WIN


// Setup for Linux shared library export.

#if (V8_HAS_ATTRIBUTE_VISIBILITY && \

     (defined(BUILDING_V8_SHARED) || USING_V8_SHARED))

# define V8_EXPORT __attribute__((visibility("default")))

#else

# define V8_EXPORT

# endif  // V8_HAS_ATTRIBUTE_VISIBILITY && ...


#endif  // V8_OS_WIN


// clang-format on


// Processor architecture detection.  For more info on what's defined, see:

//   http://msdn.microsoft.com/en-us/library/b0084kay.aspx

//   http://www.agner.org/optimize/calling_conventions.pdf

//   or with gcc, run: "echo | gcc -E -dM -"

// The V8_HOST_ARCH_* macros correspond to the architecture on which V8, as a

// virtual machine and compiler, runs. Don't confuse this with the architecture

// on which V8 is built.

#if defined(_M_X64) || defined(__x86_64__)

#define V8_HOST_ARCH_X64 1

#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4  // Check for x32.

#define V8_HOST_ARCH_32_BIT 1

#else

#define V8_HOST_ARCH_64_BIT 1

#endif

#elif defined(_M_IX86) || defined(__i386__)

#define V8_HOST_ARCH_IA32 1

#define V8_HOST_ARCH_32_BIT 1

#elif defined(__AARCH64EL__) || defined(_M_ARM64)

#define V8_HOST_ARCH_ARM64 1

#define V8_HOST_ARCH_64_BIT 1

#elif defined(__ARMEL__)

#define V8_HOST_ARCH_ARM 1

#define V8_HOST_ARCH_32_BIT 1

#elif defined(__mips64)

#define V8_HOST_ARCH_MIPS64 1

#define V8_HOST_ARCH_64_BIT 1

#elif defined(__loongarch_lp64)

#define V8_HOST_ARCH_LOONG64 1

#define V8_HOST_ARCH_64_BIT 1

#elif defined(__PPC64__) || defined(_ARCH_PPC64)

#define V8_HOST_ARCH_PPC64 1

#define V8_HOST_ARCH_64_BIT 1

#elif defined(__s390x__)

#define V8_HOST_ARCH_S390X 1

#define V8_HOST_ARCH_64_BIT 1

#elif defined(__riscv) || defined(__riscv__)

#if __riscv_xlen == 64

#define V8_HOST_ARCH_RISCV64 1

#define V8_HOST_ARCH_64_BIT 1

#elif __riscv_xlen == 32

#define V8_HOST_ARCH_RISCV32 1

#define V8_HOST_ARCH_32_BIT 1

#else

#error "Cannot detect Riscv's bitwidth"

#endif

#else

#error "Host architecture was not detected as supported by v8"

#endif


// Target architecture detection. This corresponds to the architecture for which

// V8's JIT will generate code (the last stage of the canadian cross-compiler).

// The macros may be set externally. If not, detect in the same way as the host

// architecture, that is, target the native environment as presented by the

// compiler.

#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && \

    !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 &&                    \

    !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390X &&                     \

    !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64 &&                 \

    !V8_TARGET_ARCH_RISCV32

#if defined(_M_X64) || defined(__x86_64__)

#define V8_TARGET_ARCH_X64 1

#elif defined(_M_IX86) || defined(__i386__)

#define V8_TARGET_ARCH_IA32 1

#elif defined(__AARCH64EL__) || defined(_M_ARM64)

#define V8_TARGET_ARCH_ARM64 1

#elif defined(__ARMEL__)

#define V8_TARGET_ARCH_ARM 1

#elif defined(__mips64)

#define V8_TARGET_ARCH_MIPS64 1

#elif defined(__loongarch_lp64)

#define V8_TARGET_ARCH_LOONG64 1

#elif defined(_ARCH_PPC64)

#define V8_TARGET_ARCH_PPC64 1

#elif defined(__s390x__)

#define V8_TARGET_ARCH_S390X 1

#elif defined(__riscv) || defined(__riscv__)

#if __riscv_xlen == 64

#define V8_TARGET_ARCH_RISCV64 1

#elif __riscv_xlen == 32

#define V8_TARGET_ARCH_RISCV32 1

#endif

#else

#error Target architecture was not detected as supported by v8

#endif

#endif


// Determine architecture pointer size.

#if V8_TARGET_ARCH_IA32

#define V8_TARGET_ARCH_32_BIT 1

#elif V8_TARGET_ARCH_X64

#if !V8_TARGET_ARCH_32_BIT && !V8_TARGET_ARCH_64_BIT

#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4  // Check for x32.

#define V8_TARGET_ARCH_32_BIT 1

#else

#define V8_TARGET_ARCH_64_BIT 1

#endif

#endif

#elif V8_TARGET_ARCH_ARM

#define V8_TARGET_ARCH_32_BIT 1

#elif V8_TARGET_ARCH_ARM64

#define V8_TARGET_ARCH_64_BIT 1

#elif V8_TARGET_ARCH_MIPS64

#define V8_TARGET_ARCH_64_BIT 1

#elif V8_TARGET_ARCH_LOONG64

#define V8_TARGET_ARCH_64_BIT 1

#elif V8_TARGET_ARCH_PPC64

#define V8_TARGET_ARCH_64_BIT 1

#elif V8_TARGET_ARCH_S390X

#define V8_TARGET_ARCH_64_BIT 1

#elif V8_TARGET_ARCH_RISCV64

#define V8_TARGET_ARCH_64_BIT 1

#elif V8_TARGET_ARCH_RISCV32

#define V8_TARGET_ARCH_32_BIT 1

#else

#error Unknown target architecture pointer size

#endif


// Check for supported combinations of host and target architectures.

#if V8_TARGET_ARCH_IA32 && !V8_HOST_ARCH_IA32

#error Target architecture ia32 is only supported on ia32 host

#endif

#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT && \

     !((V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64) && V8_HOST_ARCH_64_BIT))

#error Target architecture x64 is only supported on x64 and arm64 host

#endif

#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT && \

     !(V8_HOST_ARCH_X64 && V8_HOST_ARCH_32_BIT))

#error Target architecture x32 is only supported on x64 host with x32 support

#endif

#if (V8_TARGET_ARCH_ARM && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_ARM))

#error Target architecture arm is only supported on arm and ia32 host

#endif

#if (V8_TARGET_ARCH_ARM64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64))

#error Target architecture arm64 is only supported on arm64 and x64 host

#endif

#if (V8_TARGET_ARCH_MIPS64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_MIPS64))

#error Target architecture mips64 is only supported on mips64 and x64 host

#endif

#if (V8_TARGET_ARCH_RISCV64 && \

     !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64 || V8_HOST_ARCH_RISCV64))

#error Target architecture riscv64 is only supported on riscv64, x64, and \

arm64 host

#endif

#if (V8_TARGET_ARCH_RISCV32 && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_RISCV32))

#error Target architecture riscv32 is only supported on riscv32 and ia32 host

#endif

#if (V8_TARGET_ARCH_LOONG64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_LOONG64))

#error Target architecture loong64 is only supported on loong64 and x64 host

#endif


// Determine architecture endianness.

#if V8_TARGET_ARCH_IA32

#define V8_TARGET_LITTLE_ENDIAN 1

#elif V8_TARGET_ARCH_X64

#define V8_TARGET_LITTLE_ENDIAN 1

#elif V8_TARGET_ARCH_ARM

#define V8_TARGET_LITTLE_ENDIAN 1

#elif V8_TARGET_ARCH_ARM64

#define V8_TARGET_LITTLE_ENDIAN 1

#elif V8_TARGET_ARCH_LOONG64

#define V8_TARGET_LITTLE_ENDIAN 1

#elif V8_TARGET_ARCH_MIPS64

#if defined(__MIPSEB__) || defined(V8_TARGET_ARCH_MIPS64_BE)

#define V8_TARGET_BIG_ENDIAN 1

#else

#define V8_TARGET_LITTLE_ENDIAN 1

#endif

#elif V8_TARGET_ARCH_PPC64

#if V8_OS_AIX

#define V8_TARGET_BIG_ENDIAN 1

#else

#define V8_TARGET_LITTLE_ENDIAN 1

#endif

#elif V8_TARGET_ARCH_S390X

#if V8_TARGET_ARCH_S390X_LE_SIM

#define V8_TARGET_LITTLE_ENDIAN 1

#else

#define V8_TARGET_BIG_ENDIAN 1

#endif

#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64

#define V8_TARGET_LITTLE_ENDIAN 1

#elif defined(__BYTE_ORDER__)

#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

#define V8_TARGET_BIG_ENDIAN 1

#else

#define V8_TARGET_LITTLE_ENDIAN 1

#endif

#else

#error Unknown target architecture endianness

#endif


#undef V8_HAS_CPP_ATTRIBUTE


#if !defined(V8_STATIC_ROOTS)

#define V8_STATIC_ROOTS_BOOL false

#else

#define V8_STATIC_ROOTS_BOOL true

#endif

#ifdef V8_TARGET_BIG_ENDIAN

#define V8_TARGET_BIG_ENDIAN_BOOL true

#else

#define V8_TARGET_BIG_ENDIAN_BOOL false

#endif


#endif  // V8CONFIG_H_