Given any heap object, this method dumps:
* The pointer address of the heap object.
* The pointer address of the heap metadata of the object.
* The strong reference count.
* The unowned reference count.
* The weak reference count.
* Whether or not the value is in the deinit state.
* Whether or not the heap object uses swift_retain or objc_retain.
* The address of the object's side table if one exists.
This makes it really easy when debugging quickly to get all of the information
that you could possibly need from a HeapObject.
32-bit has a 7-bit inline unowned refcount, then 31 bits in the side table. Overflowing the inline count in deinit on an object that didn't already have a side table would crash, because the code assumed that creating a side table in deinit was not allowed.
(64-bit has 31 bits inline and in the side table. Overflowing the inline count immediately overflows the side table as well, so there's no change in behavior there.)
rdar://problem/33765960
* Remove RegisterPreservingCC. It was unused.
* Remove DefaultCC from the runtime. The distinction between C_CC and DefaultCC
was unused and inconsistently applied. Separate C_CC and DefaultCC are
still present in the compiler.
* Remove function pointer indirection from runtime functions except those
that are used by Instruments. The remaining Instruments interface is
expected to change later due to function pointer liability.
* Remove swift_rt_ wrappers. Function pointers are an ABI liability that we
don't want, and there are better ways to get nonlazy binding if we need it.
The fully custom wrappers were only needed for RegisterPreservingCC and
for optimizing the Instruments function pointers.
* Check for overflow in incrementWeak().
This mirrors what is currently done for unowned reference counts, where overflowing the side table field produces a fatal error. Without this, the count silently wrapped from 2^31-1 to 0, which then caused breakage when the balancing releases happened (possibly including use-after-free bugs).
* Fix the implementation of RefCounts::getWeakCount().
The previous implementation was only appropriate for heap objects, but not side tables. This resulted in the weak count always returning 0 or 1. This change specializes the implementation for the two different cases and returns the correct count for side tables.
* Test large weak retain counts.
This tests the largest allowed weak retain count, as well as the overflow check when that count is exceeded.
(instead of an unused field that we'd rather not initialize)
constexpr can't be 100% enforced in a template, so instead it gets
silently dropped if the instantiated function doesn't fulfill all the
requirements of being constexpr. In this case, that was a constructor
not explicitly initializing all fields, even the one we marked
unavailable. This meant we were using a non-constexpr constructor to
instantiate a global, which semantically requires static
initialization.
(The actual initialization is still optimized away at the LLVM
level. But the Clang frontend doesn't know that.)
Note that the warning will still fire unless you update your Clang
build; I just today cherry-picked the change that handles unnamed
bitfields correctly.
This is a blanket pass replacing use of `__LP64__` with
`__POINTER_WIDTH__ == 64`. The latter is more expressive and also LLP64
clean. This change is needed to enable support for Windows x86_64 which
is a LLP64 environment.
On 32bit platforms there are 7 bits reserved for the unowned retain count. This
makes overflow a likely scenario. Implement overflow into the side table.
rdar://33495003
HeapObject contains an InlineRefCounts. The Swift shim definition of
InlineRefCounts used uint64_t, which has the correct size but the incorrect
alignment on armv7k. This caused the Swift stdlib and the Swift runtime
to disagree about object layouts.
rdar://31664545
This is a purely mechanical change replacing the attributes with the reserved
spelling. Compilers are to not error when they encounter a reserved spelling
for an attribute which they do not support.
It's to be used by code produced by the ReleaseDevirtualizer.
As the function is only used for non-escaping objects, the deallocating bit is set non-atomically.
The standard library has grown significantly, and we need a new
directory structure that clearly reflects the role of the APIs, and
allows future growth.
See stdlib/{public,internal,private}/README.txt for more information.
Swift SVN r25876
