v8/include/v8config.h
2014-09-09 14:18:17 +00:00

420 lines
15 KiB
C++

// 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_
// 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>
#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__) >= \
((major) * 10000 + (minor) * 100 + (patchlevel)))
#else
# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
#endif
// -----------------------------------------------------------------------------
// Operating system detection
//
// V8_OS_ANDROID - Android
// V8_OS_BSD - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
// V8_OS_CYGWIN - Cygwin
// V8_OS_DRAGONFLYBSD - DragonFlyBSD
// V8_OS_FREEBSD - FreeBSD
// V8_OS_LINUX - Linux
// V8_OS_MACOSX - Mac OS X
// V8_OS_NACL - Native Client
// 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_WIN - Microsoft Windows
#if defined(__ANDROID__)
# define V8_OS_ANDROID 1
# define V8_OS_LINUX 1
# define V8_OS_POSIX 1
#elif defined(__APPLE__)
# define V8_OS_BSD 1
# define V8_OS_MACOSX 1
# define V8_OS_POSIX 1
#elif defined(__native_client__)
# define V8_OS_NACL 1
# define V8_OS_POSIX 1
#elif defined(__CYGWIN__)
# define V8_OS_CYGWIN 1
# define V8_OS_POSIX 1
#elif defined(__linux__)
# define V8_OS_LINUX 1
# define V8_OS_POSIX 1
#elif defined(__sun)
# define V8_OS_POSIX 1
# define V8_OS_SOLARIS 1
#elif defined(__FreeBSD__)
# define V8_OS_BSD 1
# define V8_OS_FREEBSD 1
# define V8_OS_POSIX 1
#elif defined(__DragonFly__)
# define V8_OS_BSD 1
# define V8_OS_DRAGONFLYBSD 1
# define V8_OS_POSIX 1
#elif defined(__NetBSD__)
# define V8_OS_BSD 1
# define V8_OS_NETBSD 1
# define V8_OS_POSIX 1
#elif defined(__OpenBSD__)
# define V8_OS_BSD 1
# define V8_OS_OPENBSD 1
# define V8_OS_POSIX 1
#elif defined(__QNXNTO__)
# define V8_OS_POSIX 1
# define V8_OS_QNX 1
#elif defined(_WIN32)
# define V8_OS_WIN 1
#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__)
# 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_CLANG - Clang
// V8_CC_GNU - GNU C++
// 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++
//
// C++11 feature detection
//
// V8_HAS_CXX11_ALIGNAS - alignas specifier supported
// V8_HAS_CXX11_ALIGNOF - alignof(type) operator supported
// V8_HAS_CXX11_STATIC_ASSERT - static_assert() supported
// V8_HAS_CXX11_DELETE - deleted functions supported
// V8_HAS_CXX11_FINAL - final marker supported
// V8_HAS_CXX11_OVERRIDE - override marker supported
//
// Compiler-specific feature detection
//
// V8_HAS___ALIGNOF - __alignof(type) operator supported
// V8_HAS___ALIGNOF__ - __alignof__(type) operator supported
// V8_HAS_ATTRIBUTE_ALIGNED - __attribute__((aligned(n))) supported
// V8_HAS_ATTRIBUTE_ALWAYS_INLINE - __attribute__((always_inline))
// supported
// V8_HAS_ATTRIBUTE_DEPRECATED - __attribute__((deprecated)) supported
// V8_HAS_ATTRIBUTE_NOINLINE - __attribute__((noinline)) supported
// V8_HAS_ATTRIBUTE_UNUSED - __attribute__((unused)) supported
// V8_HAS_ATTRIBUTE_VISIBILITY - __attribute__((visibility)) supported
// V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
// 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_POPCOUNT - __builtin_popcount() supported
// V8_HAS_BUILTIN_SADD_OVERFLOW - __builtin_sadd_overflow() supported
// V8_HAS_BUILTIN_SSUB_OVERFLOW - __builtin_ssub_overflow() supported
// V8_HAS_DECLSPEC_ALIGN - __declspec(align(n)) supported
// V8_HAS_DECLSPEC_DEPRECATED - __declspec(deprecated) supported
// V8_HAS_DECLSPEC_NOINLINE - __declspec(noinline) supported
// V8_HAS___FINAL - __final supported in non-C++11 mode
// V8_HAS___FORCEINLINE - __forceinline supported
// V8_HAS_SEALED - MSVC style sealed marker 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(__clang__)
# define V8_CC_CLANG 1
// Clang defines __alignof__ as alias for __alignof
# define V8_HAS___ALIGNOF 1
# define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
# define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
# define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
(__has_attribute(warn_unused_result))
# 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_POPCOUNT (__has_builtin(__builtin_popcount))
# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
# define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
# define V8_HAS_CXX11_STATIC_ASSERT (__has_feature(cxx_static_assert))
# define V8_HAS_CXX11_DELETE (__has_feature(cxx_deleted_functions))
# define V8_HAS_CXX11_FINAL (__has_feature(cxx_override_control))
# define V8_HAS_CXX11_OVERRIDE (__has_feature(cxx_override_control))
#elif defined(__GNUC__)
# define V8_CC_GNU 1
// Intel C++ also masquerades as GCC 3.2.0
# define V8_CC_INTEL (defined(__INTEL_COMPILER))
# define V8_CC_MINGW32 (defined(__MINGW32__))
# define V8_CC_MINGW64 (defined(__MINGW64__))
# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
# define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
// 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 (V8_GNUC_PREREQ(4, 4, 0))
# define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
# define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
# define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
# define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
# define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
(!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
# define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
# define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
# define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
# define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
// g++ requires -std=c++0x or -std=gnu++0x to support C++11 functionality
// without warnings (functionality used by the macros below). These modes
// are detectable by checking whether __GXX_EXPERIMENTAL_CXX0X__ is defined or,
// more standardly, by checking whether __cplusplus has a C++11 or greater
// value. Current versions of g++ do not correctly set __cplusplus, so we check
// both for forward compatibility.
# if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
# define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
# define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
# define V8_HAS_CXX11_STATIC_ASSERT (V8_GNUC_PREREQ(4, 3, 0))
# define V8_HAS_CXX11_DELETE (V8_GNUC_PREREQ(4, 4, 0))
# define V8_HAS_CXX11_OVERRIDE (V8_GNUC_PREREQ(4, 7, 0))
# define V8_HAS_CXX11_FINAL (V8_GNUC_PREREQ(4, 7, 0))
# else
// '__final' is a non-C++11 GCC synonym for 'final', per GCC r176655.
# define V8_HAS___FINAL (V8_GNUC_PREREQ(4, 7, 0))
# endif
#elif defined(_MSC_VER)
# define V8_CC_MSVC 1
# define V8_HAS___ALIGNOF 1
// Override control was added with Visual Studio 2005, but
// Visual Studio 2010 and earlier spell "final" as "sealed".
# define V8_HAS_CXX11_FINAL (_MSC_VER >= 1700)
# define V8_HAS_CXX11_OVERRIDE (_MSC_VER >= 1400)
# define V8_HAS_SEALED (_MSC_VER >= 1400)
# define V8_HAS_DECLSPEC_ALIGN 1
# define V8_HAS_DECLSPEC_DEPRECATED (_MSC_VER >= 1300)
# define V8_HAS_DECLSPEC_NOINLINE 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 used to tell the compiler to never inline a particular function.
// Don't bother for debug builds.
// Use like:
// V8_NOINLINE int GetMinusOne() { return -1; }
#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
# define V8_NOINLINE __attribute__((noinline))
#elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
# define V8_NOINLINE __declspec(noinline)
#else
# define V8_NOINLINE /* NOT SUPPORTED */
#endif
// A macro to mark classes or functions as deprecated.
#if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
# define V8_DEPRECATED(message, declarator) \
declarator __attribute__((deprecated(message)))
#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
# define V8_DEPRECATED(message, declarator) \
declarator __attribute__((deprecated))
#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
# define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
#else
# define V8_DEPRECATED(message, declarator) declarator
#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
// A macro to specify that a method is deleted from the corresponding class.
// Any attempt to use the method will always produce an error at compile time
// when this macro can be implemented (i.e. if the compiler supports C++11).
// If the current compiler does not support C++11, use of the annotated method
// will still cause an error, but the error will most likely occur at link time
// rather than at compile time. As a backstop, method declarations using this
// macro should be private.
// Use like:
// class A {
// private:
// A(const A& other) V8_DELETE;
// A& operator=(const A& other) V8_DELETE;
// };
#if V8_HAS_CXX11_DELETE
# define V8_DELETE = delete
#else
# define V8_DELETE /* NOT SUPPORTED */
#endif
// This macro allows to specify memory alignment for structs, classes, etc.
// Use like:
// class V8_ALIGNED(16) MyClass { ... };
// V8_ALIGNED(32) int array[42];
#if V8_HAS_CXX11_ALIGNAS
# define V8_ALIGNED(n) alignas(n)
#elif V8_HAS_ATTRIBUTE_ALIGNED
# define V8_ALIGNED(n) __attribute__((aligned(n)))
#elif V8_HAS_DECLSPEC_ALIGN
# define V8_ALIGNED(n) __declspec(align(n))
#else
# define V8_ALIGNED(n) /* NOT SUPPORTED */
#endif
// This macro is similar to V8_ALIGNED(), but takes a type instead of size
// in bytes. If the compiler does not supports using the alignment of the
// |type|, it will align according to the |alignment| instead. For example,
// Visual Studio C++ cannot combine __declspec(align) and __alignof. The
// |alignment| must be a literal that is used as a kind of worst-case fallback
// alignment.
// Use like:
// struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
// V8_ALIGNAS(double, 8) int array[100];
#if V8_HAS_CXX11_ALIGNAS
# define V8_ALIGNAS(type, alignment) alignas(type)
#elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
# define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
#else
# define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
#endif
// This macro returns alignment in bytes (an integer power of two) required for
// any instance of the given type, which is either complete type, an array type,
// or a reference type.
// Use like:
// size_t alignment = V8_ALIGNOF(double);
#if V8_HAS_CXX11_ALIGNOF
# define V8_ALIGNOF(type) alignof(type)
#elif V8_HAS___ALIGNOF
# define V8_ALIGNOF(type) __alignof(type)
#elif V8_HAS___ALIGNOF__
# define V8_ALIGNOF(type) __alignof__(type)
#else
// Note that alignment of a type within a struct can be less than the
// alignment of the type stand-alone (because of ancient ABIs), so this
// should only be used as a last resort.
namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
# define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
#endif
#endif // V8CONFIG_H_