Move internal usages of `alignof`/`__alignof` to use `_LIBCPP_ALIGNOF`.
Summary:
Starting in Clang 8.0 and GCC 8.0, `alignof` and `__alignof` return different values in same cases. Specifically `alignof` and `_Alignof` return the minimum alignment for a type, where as `__alignof` returns the preferred alignment. libc++ currently uses `__alignof` but means to use `alignof`. See llvm.org/PR39713
This patch introduces the macro `_LIBCPP_ALIGNOF` so we can control which spelling gets used.
This patch does not introduce any ABI guard to provide the old behavior with newer compilers. However, if we decide that is needed, this patch makes it trivial to implement.
I think we should commit this change immediately, and decide what we want to do about the ABI afterwards.
Reviewers: ldionne, EricWF
Reviewed By: ldionne, EricWF
Subscribers: jyknight, christof, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54814
llvm-svn: 351289
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: d108bf85b09e3f1355fea866d90e3dd2266d67b5
diff --git a/include/memory b/include/memory
index 93f04c6..ce2c357 100644
--- a/include/memory
+++ b/include/memory
@@ -1811,10 +1811,10 @@
if (__n > max_size())
__throw_length_error("allocator<T>::allocate(size_t n)"
" 'n' exceeds maximum supported size");
- return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), __alignof(_Tp)));
+ return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
}
_LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
- {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), __alignof(_Tp));}
+ {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
_LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
{return size_type(~0) / sizeof(_Tp);}
#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
@@ -1912,10 +1912,10 @@
if (__n > max_size())
__throw_length_error("allocator<const T>::allocate(size_t n)"
" 'n' exceeds maximum supported size");
- return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), __alignof(_Tp)));
+ return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
}
_LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
- {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), __alignof(_Tp));}
+ {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
_LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
{return size_type(~0) / sizeof(_Tp);}
#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
@@ -2031,7 +2031,7 @@
while (__n > 0)
{
#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
- if (__is_overaligned_for_new(__alignof(_Tp)))
+ if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
{
std::align_val_t __al =
std::align_val_t(std::alignment_of<_Tp>::value);
@@ -2042,7 +2042,7 @@
__n * sizeof(_Tp), nothrow));
}
#else
- if (__is_overaligned_for_new(__alignof(_Tp)))
+ if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
{
// Since aligned operator new is unavailable, return an empty
// buffer rather than one with invalid alignment.
@@ -2066,7 +2066,7 @@
inline _LIBCPP_INLINE_VISIBILITY
void return_temporary_buffer(_Tp* __p) _NOEXCEPT
{
- _VSTD::__libcpp_deallocate_unsized((void*)__p, __alignof(_Tp));
+ _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
}
#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
@@ -5642,7 +5642,7 @@
struct __temp_value {
typedef allocator_traits<_Alloc> _Traits;
- typename aligned_storage<sizeof(_Tp), alignof(_Tp)>::type __v;
+ typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
_Alloc &__a;
_Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }