Stdatomic.h was potentially redefining _Atomic, in spite of a
prior definition by <atomic>. This could cause g++ builds that
included <stdatomic.h> with an available <atomic> header to break.
A functional stdatomic.h is a prerequisite for fixing the
following bugs. This is the middle of 3 AOSP updates to
bionics stdatomic.h that are needded to get there.
Bug:16880454
Bug:16513433
Change-Id: I562c7115118c0587d594d4d5b62d25101e47bfd8
(cherry picked from commit 3e4a0099a179d7acee63d78c8fc4c3cc7b0bae42)
We seem to use this stdatomic.h sometimes, and slightly different prebuilts
at other times, making them all difficult to test, and making it unclear
which one we're testing. This generalizes the bionic header so that it
can be used directly as the prebuilt header as well. So long as they
don't diverge again, that should somewhat improve test coverage.
Use the correct builtin for atomic_is_lock_free.
Fix atomic_flag_init.
Turn on atomic tests even with __GLIBC__, since they now appear to pass.
Include uchar.h in stdatomic.h where needed.
Add a basic memory ordering test.
Fix bit-rotted comments in bionic tests makefile.
Prerequisite for fixing b/16880454 and
Bug:16513433
Change-Id: If6a14c1075b379395ba5d93357d56025c0ffab68
(cherry picked from commit 00aaea364501b3b0abe58dae461136159df1e356)
This is an alternate, somewhat simpler, fix that makes it safe to
include both <atomic> and <stdatomic.h> from C++ code in either order.
It means that C code consistently uses one implementation of atomics
and C++ another. We still have to make sure that those two
implementations interoperate correctly at runtime; in particular,
any flavor of atomic object needs to be represented exactly like the
underlying type, with the proper alignment constraint.
Bug:17007799
Change-Id: Iffcfc5220d8fa150f89dd083a121b24d23f268fc
(cherry picked from commit 019d3958118b7dc3ec8444ad2accca50c268b737)
Some platform code is apparently compiled with switches that do
not support char16_t and char32_t. This caused stdatomic.h to fail
to compile. This CL makes stdatomic.h usable in those environments.
(cherry picked from commit 8b002362d996859ebfc8588d6859a9a79203dc27)
Change-Id: Ie5a17f20b8b545c97128d00605b4eabd2a6bfe3e
