Skip to content

[z/OS][libc++] Remove align_val_t dependency in small_buffer.h #114396

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 7 commits into from
Nov 7, 2024
Merged

[z/OS][libc++] Remove align_val_t dependency in small_buffer.h #114396

Changes from 4 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
a83b5ca
Guard to be used only when they are available
zibi2 Oct 31, 2024
ff95378
Add __libcpp_allocate and __libcpp_deallocate in the absense of align…
zibi2 Oct 31, 2024
f05f144
formattig
zibi2 Oct 31, 2024
315a922
Simplify __alloc() and __dealloc() in __utility/small_buffer.h
zibi2 Nov 4, 2024
af06112
Correct previous simplification in __small_buffer::__alloc()
zibi2 Nov 6, 2024
9733748
Correct previous simplification in __small_buffer::__dealloc()
zibi2 Nov 6, 2024
e00d067
Pass the right size to __libcpp_deallocate()
zibi2 Nov 7, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 2 additions & 4 deletions libcxx/include/__utility/small_buffer.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -66,16 +66,14 @@ class __small_buffer {
if constexpr (__fits_in_buffer<_Stored>) {
return std::launder(reinterpret_cast<_Stored*>(__buffer_));
} else {
byte* __allocation = static_cast<byte*>(::operator new[](sizeof(_Stored), align_val_t{alignof(_Stored)}));
std::construct_at(reinterpret_cast<byte**>(__buffer_), __allocation);
return std::launder(reinterpret_cast<_Stored*>(__allocation));
return static_cast<_Stored*>(std::__libcpp_allocate(_BufferSize * sizeof(byte), alignof(_Stored)));
}
}

template <class _Stored>
_LIBCPP_HIDE_FROM_ABI void __dealloc() noexcept {
if constexpr (!__fits_in_buffer<_Stored>)
::operator delete[](*reinterpret_cast<void**>(__buffer_), sizeof(_Stored), align_val_t{alignof(_Stored)});
std::__libcpp_deallocate((void*)__buffer_, _BufferSize * sizeof(byte), alignof(_Stored));
Copy link
Member

@ldionne ldionne Nov 6, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is incorrect, since you're deallocating the buffer itself (which is a member variable), not the pointer contained in the buffer. The previous reinterpret_cast must be kept.

Copy link
Contributor Author

@zibi2 zibi2 Nov 6, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for caching it.

}

template <class _Stored, class... _Args>
Expand Down
Loading