initialization in-place on demand. Initialize parent metadata
references correctly on struct and enum metadata.
Also includes several minor improvements related to relative
pointers that I was using before deciding to simply switch the
parent reference to an absolute reference to get better access
patterns.
Includes a fix since the earlier commit to make enum metadata
writable if they have an unfilled payload size. This didn't show
up on Darwin because "constant" is currently unenforced there in
global data containing relocations.
This patch requires an associated LLDB change which is being
submitted in parallel.
initialization in-place on demand. Initialize parent metadata
references correctly on struct and enum metadata.
Also includes several minor improvements related to relative
pointers that I was using before deciding to simply switch the
parent reference to an absolute reference to get better access
patterns.
This is more amenable to cross-platform remote reflection tests.
Also add a new callback to the memory reader: getSymbolAddress,
which will be used for getting the addresses of nominal type
descriptors for concrete and fixed generic types.
- Read the Parent pointer out of Class/Value metadata and create
typerefs for them.
- Add Parent fields to NominalTypeRef and BoundGenericTypeRef.
- Add TypeRef::getSubstMap(), which creates a new generic argument
map after substitution has taken place on it. This is used to
continue to burrow into nested value types, where generic type
parameters may have a different index.
- Use a DenseMap as that generic argument map.
- Unconditionally key the generic argument map with (Depth, Index)
- Clean up ordering and presentation of Index and Depth. In the rest
of the compiler, Depth comes before Index.
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.
Be more conservative in terms of masking ISAs. This reduces tight coupling with the objc runtime. This commit adds the required calls to IRGen and the runtime, and a test case to make sure IRGen is correct.
Teach swift_deallocPartialClassInstance how to deal with classes that
have pure Objective-C classes in their hierarchy. In such cases, we
need to make sure a few things happen:
1) We deallocate via objc_release rather than
swift_deallocClassInstance.
2) We only attempt to find an execute ivar destroyers for
Swift-defined classes in the hierarchy
3) When we hit the most-derived pure Objective-C class, make sure that we
only execute the dealloc of that class and not any of the subclasses
(which would end up trying to destroy ivars again).
Fixes rdar://problem/25023544.
The size of a protocol's metadata was not a multiple of 8 bytes, so
on 64-bit platforms, the runtime would copy default witnesses from
the wrong address, because IRGen metadata does not add alignment padding,
whereas the in-memory structure does.
Fix this by adding a 32-bit padding field at the end of the protocol
descriptor. Technically this is not necessary on 32-bit, but this keeps
things simpler for now.
The test case for this is a library evolution test exercising resilient
default protocol requirements, but it is not quite ready to go in yet.
Adds a rough sketch of what will be a test harness, currently only supported
on OS X:
- Launch a child process: an executable written in Swift
- Receive the child process's Mach port
- Receive reflection section addresses and the address of a heap instance
of interest
- Perform field type lookup on the instance remotely (TODO)
- Add RuntimeTarget template This will allow for converting between
metadata structures for native host and remote target architectures.
- Create InProcess and External templates for stored pointers
Add a few more types to abstract pointer access in the runtime
structures but keep native in-process pointer access the same as that
with a plain old pointer type.
There is now a notion of a "stored pointer", which is just the raw value
of the pointer, and the actual pointer type, which is used for loads.
Decoupling these allows us to fork the behavior when looking at metadata
in an external process, but keep things the same for the in-process
case.
There are two basic "runtime targets" that you can use to work with
metadata:
InProcess: Defines the pointer to be trivially a T* and stored as a
uintptr_t. A Metadata * is exactly as it was before, but defined via
AbstractMetadata<InProcess>.
External: A template that requires a target to specify its pointer size.
ExternalPointer: An opaque pointer in another address space that can't
(and shouldn't) be indirected with operator* or operator->. The memory
reader will fetch the data explicitly.
"minimal" is defined as the set of requirements that would be
passed to a function with the type's generic signature that
takes the thick metadata of the parent type as its only argument.
In principle, runtime entries could have a hidden visibility, because they are
never called directly from the code produced by IRGen.
But some of the runtime entries are invoked directly from the foundation.
Therefore they should be visible.
We annotate the most popular runtime functions in terms of how often they are invoked from Swift code:
- Many variants of retain/release functions are annotated to use the new calling convention.
But those variants of retain/release functions that may result in calls of objc_retain or objc_release
are not migrated to the new calling convention, because it results in significant performance degradations
when objects of Obj-C derived classes are used.
- Some popular non-reference counting functions like swift_getGenericMetadata or swift_dynamicCast are annotated as well.
The list of these functions is pretty much the same as the the set of functions defined in InstrumentsSupport.h
These are basically the functions that can be intercepted by different tools/profilers/etc.
This new x-macro should be used to define a runtime function that has an internal implementation
inside the runtime library and a global symbol referring to this internal implementation.
An example of such a runtime function is "swift_retain", which has a global symbol "_swift_retain"
referring to its internal implementation "_swift_retain_".
