The "superclass as associated type" modeling was put in to
maintain backward compatibility.
We just bumped the version number because of new mangling so
we may as well fix this sillyness too.
Adds the runtime implementation for copy-on-write existentials. This support is
enabled if SWIFT_RUNTIME_ENABLE_COW_EXISTENTIALS is defined. Focus is on
correctness -- not performance yet.
Don't use allocate/deallocate/projectBuffer witnesses for globals in cow
existential mode.
Use SWIFT_RUNTIME_ENABLE_COW_EXISTENTIALS configuration to set the default for
SILOptions.
This includes an IRGen fix to use the right projection in
emitMetatypeOfOpaqueExistential if SWIFT_RUNTIME_ENABLE_COW_EXISTENTIALS is set.
Use unknownRetain instead of native retain in dynamicCastToExistential.
It also uses the new mangling for type names in meta-data (except for top-level non-generic classes).
lldb has now support for new mangled metadata type names.
This reinstates commit 21ba292943.
For this we are linking the new re-mangler instead of the old one into the swift runtime library.
Also we are linking the new de-mangling into the swift runtime library.
It also switches to the new mangling for class names of generic swift classes in the metadata.
Note that for non-generic class we still have to use the old mangling, because the ObjC runtime in the OS depends on it (it de-mangles the class names).
But names of generic classes are not handled by the ObjC runtime anyway, so there should be no problem to change the mangling for those.
The reason for this change is that it avoids linking the old re-mangler into the runtime library.
There were a few problems here with subclasses of Objective-C classes.
Use the InstanceStart field from rodata to correctly lay out instance
variables, and verify the results match with dynamic and static layout.
Better fix for <rdar://problem/27932061>.
The alignment was set to 0, which messed up the record layout
computations. Add an assert to catch this in the future.
Fixes <rdar://problem/29115967>.
The approach here is to split this into two cases:
- If all case payloads have a fixed size, spare bits may be
potentially used to differentiate between cases, and the
remote reflection library does not have enough information to
compute the layout itself.
However, the total size must be fixed, so IRGen just emits a
builtin type descriptor (which I need to rename to 'fixed type
descriptor' since these are also used for imported value types,
and now, certain enums).
- If at least one case has a size that depends on a generic
parameter or is a resilient type, IRGen does not know the size,
but this means fancy tricks with spare bits cannot be used either.
The remote reflection library uses the same approach as the
runtime, basically taking the maximum of the payload size and
alignment, and adding a tag byte.
As with single-payload enums, we produce a new kind of
RecordTypeInfo, this time with a field for every enum case.
All cases start at offset zero (but of course this might change,
if for example we put the enum tag before the address point).
Also, just as with single-payload enums, there is no remote
'project case index' operation on ReflectionContext yet.
So the the main benefit from this change is that we don't entirely
give up when doing layout of class instances containing enums;
however, tools still cannot look inside the enum values themselves,
except in the simplest cases involving optionals.
Notably, the remote reflection library finally understands all
of the standard library's collection types -- Array, Character,
Dictionary, Set, and String.
Attempt to lay out single-payload enums, using knowledge of extra
inhabitants where possible.
- The extra inhabitants of an aggregate are the extra inhabitants of
the first field. If the first field is empty, there are no extra
inhabitants, and subsequent fields do not affect anything.
- Function pointers and metatypes have different extra inhabitants
than Builtin.RawPointer, so have IRGen emit distinct builtin type
descriptors for those.
- Opaque existentials do not have extra inhabitants.
- Weak references do not have extra inhabitants.
Also, fix IRGen to emit more accurate enum reflection metadata in
these two cases:
- We now record whether enum cases are indirect or not. An indirect
case is the same as a payload case with Builtin.NativeObject.
- We now record whether a case is empty or not using the same logic
as the rest of IRGen. Previously, we would incorrectly emit a
payload type for a case with a payload that is an empty struct,
for example.
At this point we don't have a way to get the currently inhabited
enum case from a value. However, this is still an improvement because
we can still reflect other fields of aggregates containing enums,
instead of just giving up.
Finally make some methods on TypeCoverter private, and use 'friend'
to allow them to be accessed from other internal classes, making the
public API simpler.
Previously we would emit both a builtin descriptor and field
descriptor for imported classes, but we only need the latter.
Untangle some code and fix a crash with imported Objective-C
generics in the process.
Fixes <rdar://problem/26498484>.
Part 1: Generic SIL Boxes always have instatiated metadata with kind
HeapGenericLocalVariable, which includes a metadata pointer for the
boxed type.
Part 2, after this, is to provide some kind of outgoing pointer map for
fixed heap boxes, whose metadata may be shared among different but
destructor-compatible types.
rdar://problem/26240419
Without this, offsets of captures in closure contexts may be
incorrect if there is a non-empty necessary bindings structure
at the front.
rdar://problem/26312900
- Lower Objective-C class typerefs as strong references with unknown
reference counting.
- Lower other imported C types as builtin blobs of their known
size, alignment, etc.
In the future, it might be beneficial to track which stored properties
of imported types are pointers, for better conservative scanning of
outgoing pointers to the heap.
rdar://problem/26240258
rdar://problem/26240394
Also add end-to-end tests for this finally, and fix a bug in
the SwiftReflectionTest library where we would give up on an
module completely if it did not have a field metadata section.
This is of course wrong if the module defines closures but
not nominal types.
This adds various MetadataReader methods to support closure layout:
- Reading generic arguments from metadata
- Reading parent metadata
- Reading capture descriptor from heap metadata
To a large extent, this is not currently taken advantage of, because
SILGen always wraps address-only captures in SIL box types.
Tests are in the next patch.
Remote metadata for closure contexts points to a capture descriptor.
We have a local copy of all capture descriptors. Translate the
address by recording the local and remote start address of
reflection metadata.
