Fix unlock in two-word version and add missing comment.
Fixes#15Fixes#16
This should fix the hangs in __cxa_guard_acquire() reported on i386 (and
possibly other 32-bit platforms).
Obtained from: https://github.com/libcxxrt/libcxxrt/commit/f2e5509
Fixes: 56aaed388b
MFC after: 2 weeks
This reapplies upstream commit fd484be, as there is a follow-up fix for
the possible hangs in __cxa_guard_acquire() on i386:
Atomics cleanup (#11)
We need to test exception specifiers but they're gone in C++17 so
compile the tests with an older version of the standard.
Rewrite the guard logic to be more idiomatic C++ and more
comprehensible and make sure that atomics are used where necessary.
Obtained from: https://github.com/libcxxrt/libcxxrt/commit/fd484be
Fixes: 56aaed388b
MFC after: 2 weeks
This reverts upstream commit fd484be:
Atomics cleanup (#11)
We need to test exception specifiers but they're gone in C++17 so
compile the tests with an older version of the standard.
Rewrite the guard logic to be more idiomatic C++ and more
comprehensible and make sure that atomics are used where necessary.
It looks like there are some corner cases in the i386 and/or 32-bit
atomics handling, which can make __cxa_guard_acquire() hang in certain
situations.
Reported by: antoine
Obtained from: https://github.com/libcxxrt/libcxxrt/commit/fd484be
Fixes: 56aaed388b
MFC after: 2 weeks
with libc++, which is also C++11. Also change one _Static_assert (which
is really C11) back into static_assert, like upstream.
This should help when compiling libcxxrt with newer versions of gcc,
which refuse to recognize any form of static assertions, if not
compiling for C++11 or higher.
While here, add -nostdinc++ to CFLAGS, to prevent picking up any C++
headers outside the source tree.
MK_LIBCPLUSPLUS=yes to enable). This is a work-in-progress. It works for
me, but is not guaranteed to work for anyone else and may eat your dog.
To build C++ using libc++, add -stdlib=libc++ to your CXX and LD flags.
Bug reports welcome, bug fixes even more welcome...
Approved by: dim (mentor)
