- Nearly done: TypeRefs and the mangled name decoder.
- Add the swift-reflection-test tool.
The field reflection pipeline is roughly:
- Decode type references
- Substitute generic parameters
- Calculate sizes and offsets
There is currently only one action in the tool, which will test the
*Decode* part of the pipeline: `dump-reflection-section`. This reads
the *swift3_reflect section from an object file and dumps the decoded
type references for all of the stored properties and enum cases in the
file.
- TODO: Write tests with various type arrangements to exercise the
decoder - there are likely some holes in the decoder still since the
AST mangler is quite rich in its kinds.
TODO: The next test mode, `dump-field-types`, will do the following:
1. Launch a swift executable with a canned stopping point
2. Get the address of a heap object instance of interest
3. Dump the fully substituted typerefs of all of the stored properties
or enum case payloads.
That test mode will be more involved since it will attach to another
process and need to read from its address space but will test the
entire out-of-process reflection pipeline in a controlled environment.
We can maybe take this test a step further, with an option or a new
test mode, that prints the entire heap reference graph rooted at that
object of interest, in order to test the ability to detect reference
cycles, for example.
- Implement emission of type references for nominal type field
reflection, using a small custom encoder resulting in packed
structs, not strings. This will let us embed 7-bit encoded
32-bit relative offsets directly in the structure (not yet
hooked in).
- Use the AST Mangler for encoding type references
Archetypes and internal references were complicating this before, so we
can take the opportunity to reuse this machinery and avoid unique code
and new ABI.
Next up: Tests for reading the reflection sections and converting the
demangle tree into a tree of type references.
Todo: For concrete types, serialize the types for associated types of
their conformances to bootstrap the typeref substitution process.
rdar://problem/15617914
