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_


 // 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__ * 100) >=      \

      ((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_AIX           - AIX

 //  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(_AIX)

 #define V8_OS_POSIX 1

 #define V8_OS_AIX 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__)

 // 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

 //

 //  V8_HAS_CXX11_ALIGNAS        - alignas specifier supported

 //  V8_HAS_CXX11_ALIGNOF        - alignof(type) operator supported

 //  V8_HAS_CXX11_STATIC_ASSERT  - static_assert() 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_FRAME_ADDRESS        - __builtin_frame_address() 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_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(__clang__)


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

 # define V8_CC_GNU 1

 #elif defined(_MSC_VER)  // Clang in cl mode.

 # define V8_CC_MSVC 1

 #endif


 // 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_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))

 # 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))


 #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_FRAME_ADDRESS (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))

 # endif


 #elif defined(_MSC_VER)


 # define V8_CC_MSVC 1


 # define V8_HAS___ALIGNOF 1


 # define V8_HAS_DECLSPEC_ALIGN 1

 # define V8_HAS_DECLSPEC_DEPRECATED 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 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 make it easier to see what will be deprecated.

 #define V8_DEPRECATE_SOON(message, declarator) declarator


 // 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


 // 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


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

 // Use like:

 //   int foo() 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


 #endif  // V8CONFIG_H_

v8::AlignOfHelper
Definition: v8config.h:392

v8
Definition: libplatform.h:10