Skip to content

V
V8
Commit fb190fb6 authored by bmeurer@chromium.org's avatar bmeurer@chromium.org
Browse files
Options

Add V8_ALIGNOF() and use that in lazy-instance.h. 

Also fix the inconsistent attribute naming, and make V8_GNUC_PREREQ() test work for GCC compatible compilers.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/22888008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16311 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent 4db1f475
Hide whitespace changes
Inline Side-by-side
Showing with 56 additions and 25 deletions
include/v8config.h
View file @ fb190fb6
......@@ -86,6 +86,31 @@
#endif
// This macro checks for a required GCC version. It also works with compilers
// that pretend to be GCC, i.e. Clang, ICC or the ARM compiler with the --gnu
// flag.
// Use like this if you want to check for a GCC compatible version:
// #if V8_GNUC_PREREQ(x, y, z)
// ...
// #endif
//
// Use like ths if you want to check for a specific GCC version:
// #if V8_CC_GNU && V8_GNUC_PREREQ(x, y, z)
// ...
// #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
// -----------------------------------------------------------------------------
// Compiler detection
//
......@@ -97,6 +122,7 @@
// C++11 feature detection
//
// V8_HAS_CXX11_ALIGNAS - alignas specifier supported
// V8_HAS_CXX11_ALIGNOF - alignas operator supported
// V8_HAS_CXX11_STATIC_ASSERT - static_assert() supported
// V8_HAS_CXX11_DELETE - deleted functions supported
// V8_HAS_CXX11_FINAL - final marker supported
......@@ -104,7 +130,9 @@
//
// Compiler-specific feature detection
//
// V8_HAS_ATTRIBUTE___ALIGNED__ - __attribute__((__aligned__(n))) supported
// V8_HAS___ALIGNOF - __alignof(t) operator supported
// V8_HAS___ALIGNOF__ - __alignof__(t) 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_VISIBILITY - __attribute__((visibility)) supported
......@@ -117,12 +145,11 @@
#if defined(__clang__)
// Don't treat clang as GCC.
# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
# define V8_CC_CLANG 1
# define V8_HAS_ATTRIBUTE___ALIGNED__ (__has_attribute(__aligned__))
# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(2, 95, 0))
# 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_VISIBILITY (__has_attribute(visibility))
......@@ -137,16 +164,14 @@
#elif defined(__GNUC__)
# define V8_GNUC_PREREQ(major, minor, patchlevel) \
((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >= \
((major) * 10000 + (minor) * 100 + (patchlevel)))
# define V8_CC_GNU 1
# if defined(__MINGW32__)
# define V8_CC_MINGW 1
# endif
# define V8_HAS_ATTRIBUTE___ALIGNED__ (V8_GNUC_PREREQ(2, 95, 0))
# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(2, 95, 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.
......@@ -164,6 +189,7 @@
// 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, 5, 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))
......@@ -175,8 +201,6 @@
#elif defined(_MSC_VER)
# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
# define V8_CC_MSVC 1
// Override control was added with Visual Studio 2005, but
......@@ -188,6 +212,7 @@
# define V8_HAS_DECLSPEC_ALIGN 1
# define V8_HAS_DECLSPEC_DEPRECATED (_MSC_VER >= 1300)
# define V8_HAS___ALIGNOF 1
# define V8_HAS___FORCEINLINE 1
#endif
......@@ -279,12 +304,28 @@
// V8_ALIGNAS(32) int array[42];
#if V8_HAS_CXX11_ALIGNAS
# define V8_ALIGNAS(n) alignas(n)
#elif V8_HAS_ATTRIBUTE___ALIGNED__
# define V8_ALIGNAS(n) __attribute__((__aligned__(n)))
#elif V8_HAS_ATTRIBUTE_ALIGNED
# define V8_ALIGNAS(n) __attribute__((aligned(n)))
#elif V8_HAS_DECLSPEC_ALIGN
# define V8_ALIGNAS(n) __declspec(align(n))
#else
# define V8_ALIGNAS(n) /* NOT SUPPORTED */
#endif
// This macro takes a type and returns the power of 2 byte boundary on which
// the type instances must be allocated.
// Use like:
// size_t alignment = V8_ALIGNOF(double);
// V8_ALIGNAS(V8_ALIGNOF(void*)) int x;
#if V8_HAS_CXX11_ALIGNOF
# define V8_ALIGNOF(t) alignof(t)
#elif V8_HAS___ALIGNOF
# define V8_ALIGNOF(t) __alignof(t)
#elif V8_HAS___ALIGNOF__
# define V8_ALIGNOF(t) __alignof__(t)
#else
namespace v8 { template <typename T> struct AlignOfHelper { char x; T t; }; }
# define V8_ALIGNOF(t) (sizeof(::v8::AlignOfHelper<t>) - sizeof(t))
#endif
#endif // V8CONFIG_H_
src/lazy-instance.h
View file @ fb190fb6
......@@ -111,17 +111,9 @@ struct LeakyInstanceTrait {
// Traits that define how an instance is allocated and accessed.
// TODO(kalmard): __alignof__ is only defined for GCC > 4.2. Fix alignment issue
// on MIPS with other compilers.
#if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 2))
#define LAZY_ALIGN(x) __attribute__((aligned(__alignof__(x))))
#else
#define LAZY_ALIGN(x)
#endif
template <typename T>
struct StaticallyAllocatedInstanceTrait {
typedef char StorageType[sizeof(T)] LAZY_ALIGN(T);
typedef char StorageType[sizeof(T)] V8_ALIGNAS(V8_ALIGNOF(T));
static T* MutableInstance(StorageType* storage) {
return reinterpret_cast<T*>(storage);
......@@ -133,8 +125,6 @@ struct StaticallyAllocatedInstanceTrait {
}
};
#undef LAZY_ALIGN
template <typename T>
struct DynamicallyAllocatedInstanceTrait {
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment