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

1 files changed, 20 insertions, 20 deletions

diff --git a/libcxx/include/valarray b/libcxx/include/valarray
index 3188b6af49b..07f38c81150 100644
--- a/libcxx/include/valarray
+++ b/libcxx/include/valarray
@@ -2740,7 +2740,7 @@ __val_expr<_ValExpr>::operator valarray<__val_expr::result_type>() const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<result_type*>(
-                    _VSTD::__libcpp_allocate(__n * sizeof(result_type), __alignof(result_type)));
+                    _VSTD::__libcpp_allocate(__n * sizeof(result_type), _LIBCPP_ALIGNOF(result_type)));
         for (size_t __i = 0; __i != __n; ++__r.__end_, ++__i)
             ::new (__r.__end_) result_type(__expr_[__i]);
     }
@@ -2758,7 +2758,7 @@ valarray<_Tp>::valarray(size_t __n)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-            _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+            _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2793,7 +2793,7 @@ valarray<_Tp>::valarray(const value_type* __p, size_t __n)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-            _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+            _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2819,7 +2819,7 @@ valarray<_Tp>::valarray(const valarray& __v)
     if (__v.size())
     {
         __begin_ = __end_ = static_cast<value_type*>(
-            _VSTD::__libcpp_allocate(__v.size() * sizeof(value_type), __alignof(value_type)));
+            _VSTD::__libcpp_allocate(__v.size() * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2857,7 +2857,7 @@ valarray<_Tp>::valarray(initializer_list<value_type> __il)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-_VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+_VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2887,7 +2887,7 @@ valarray<_Tp>::valarray(const slice_array<value_type>& __sa)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-          _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+          _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2915,7 +2915,7 @@ valarray<_Tp>::valarray(const gslice_array<value_type>& __ga)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2945,7 +2945,7 @@ valarray<_Tp>::valarray(const mask_array<value_type>& __ma)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -2975,7 +2975,7 @@ valarray<_Tp>::valarray(const indirect_array<value_type>& __ia)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {
@@ -3012,7 +3012,7 @@ valarray<_Tp>::__assign_range(const value_type* __f, const value_type* __l)
     {
         __clear(size());
         __begin_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         __end_ = __begin_ + __n;
         _VSTD::uninitialized_copy(__f, __l, __begin_);
     } else {
@@ -3268,7 +3268,7 @@ valarray<_Tp>::operator+() const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
             ::new (__r.__end_) value_type(+*__p);
     }
@@ -3286,7 +3286,7 @@ valarray<_Tp>::operator-() const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
             ::new (__r.__end_) value_type(-*__p);
     }
@@ -3304,7 +3304,7 @@ valarray<_Tp>::operator~() const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
             ::new (__r.__end_) value_type(~*__p);
     }
@@ -3321,7 +3321,7 @@ valarray<_Tp>::operator!() const
     {
         __r.__begin_ =
             __r.__end_ =
-                static_cast<bool*>(_VSTD::__libcpp_allocate(__n * sizeof(bool), __alignof(bool)));
+                static_cast<bool*>(_VSTD::__libcpp_allocate(__n * sizeof(bool), _LIBCPP_ALIGNOF(bool)));
         for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
             ::new (__r.__end_) bool(!*__p);
     }
@@ -3642,7 +3642,7 @@ valarray<_Tp>::shift(int __i) const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         const value_type* __sb;
         value_type* __tb;
         value_type* __te;
@@ -3681,7 +3681,7 @@ valarray<_Tp>::cshift(int __i) const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         __i %= static_cast<int>(__n);
         const value_type* __m = __i >= 0 ? __begin_ + __i : __end_ + __i;
         for (const value_type* __s = __m; __s != __end_; ++__r.__end_, ++__s)
@@ -3703,7 +3703,7 @@ valarray<_Tp>::apply(value_type __f(value_type)) const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
             ::new (__r.__end_) value_type(__f(*__p));
     }
@@ -3721,7 +3721,7 @@ valarray<_Tp>::apply(value_type __f(const value_type&)) const
         __r.__begin_ =
             __r.__end_ =
                 static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
         for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
             ::new (__r.__end_) value_type(__f(*__p));
     }
@@ -3736,7 +3736,7 @@ void valarray<_Tp>::__clear(size_t __capacity)
   {
     while (__end_ != __begin_)
       (--__end_)->~value_type();
-    _VSTD::__libcpp_deallocate(__begin_, __capacity * sizeof(value_type), __alignof(value_type));
+    _VSTD::__libcpp_deallocate(__begin_, __capacity * sizeof(value_type), _LIBCPP_ALIGNOF(value_type));
     __begin_ = __end_ = nullptr;
   }
 }
@@ -3749,7 +3749,7 @@ valarray<_Tp>::resize(size_t __n, value_type __x)
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), __alignof(value_type)));
+           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {