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.
This is the first patch in a series that will allow new protocol
requirements to be added resiliently, with the runtime filling in
default implementations in witness tables.
First, this adds a new flag to the protocol descriptor indicating
that the protocol is resilient. In this case, there are two
additional fields, MinimumWitnessTableSizeInWords and
DefaultWitnessTableSizeInWords, followed by tail-allocated
default witnesses.
The swift_getGenericWitnessTable() entry point now fills in the
default witnesses from the protocol if the given witness table
template is smaller than the expected witness table size.
This also changes the layout of instantiated witness tables to move
the address point to the end of private data. Previously the private
data came after the requirements, but this meant that adding new
requirements would require sliding the private data at runtime and
accessing it indirectly. It is much simpler to access it from
negative offsets instead.
I updated IRGen to emit the new metadata, but currently all protocols
are flagged as not resilient, and default witnesses are not emitted;
this will come in a subsequent patch once some more plumbing is
in place.
To avoid generating GOT entries for references to protocols defined
in the current module, I had to add some hacks to the existing hack
for this. I'll hopefully clean this up in a principled manner later.
- 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
This comes with a fix for a null pointer dereference in _typeByName()
that would pop with foreign classes that do not have a
NominalTypeDescriptor.
Also, I decided to back out part of the change for now, where the
NominalTypeDescriptor references an accessor function instead of a
pattern, since this broke LLDB, which reaches into the pattern to
get the generic cache.
Soon we will split off the generic cache from the pattern, and at
that time we can change the NominalTypeDescriptor to point at the
cache. But for now, let's avoid needless churn in LLDB by keeping
that part of the setup unchanged.
Change conformance records to reference NominalTypeDescriptors instead of
metadata patterns for resilient or generic types.
For a resilient type, we don't know if the metadata is constant or not,
so we can't directly reference either constant metadata or the metadata
template.
Also, whereas previously NominalTypeDescriptors would point to the
metadata pattern, they now point to the metadata accessor function.
This allows the recently-added logic for instantiating concrete types
by name to continue working.
In turn, swift_initClassMetadata_UniversalStrategy() would reach into
the NominalTypeDescriptor to get the pattern out, so that its bump
allocator could be used to allocate ivar tables. Since the pattern is
no longer available this way, we have to pass it in as a parameter.
In the future, we will split off the read-write metadata cache entry
from the pattern; then swift_initClassMetadata_UniversalStrategy() can
just take a pointer to that, since it doesn't actually need anything
else from the pattern.
Since Clang doesn't guarantee alignment for function pointers, I had
to kill the cute trick that packed the NominalTypeKind into the low
bits of the relative pointer to the pattern; instead the kind is now
stored out of line. We could fix this by packing it with some other
field, or keep it this way in case we add new flags later.
Now that generic metadata is instantiated by calling accessor functions,
this change removes the last remaining place that metadata patterns were
referenced from outside the module they were defined in. Now, the layout
of the metadata pattern and the behavior of swift_getGenericMetadata()
is purely an implementation detail of generic metadata accessors.
This patch allows two previously-XFAIL'd tests to pass.
An individual field record for a nominal type consists of:
- 32-bit general purpose flags,
- 32-bit relative offset to the encoded type reference string, or
32-bit relative offset to the mangled name of the type defined
in another image, and
- 32-bit relative offset to the field name string.
replace ProtocolConformanceTypeKind with TypeMetadataRecordKind
metadata reference does not need to be indirectable
more efficient check for protocol conformances
remove swift_getMangledTypeName(), not needed yet
kill off Remangle.cpp for non-ObjC builds
cleanup
cleanup
cleanup comments
This patch adds powerpc64le Linux support. While the patch also adds
the matching powerpc64 bits, there are endian issues that need to be
sorted out.
The PowerPC LLVM changes for the swift ABI (eg returning three element
non-homogeneous aggregates) are still in the works, but a simple LLVM
fix to allow those aggregates results in swift passing all but 8
test cases.
This commit adds a number of compression routines:
1. A dictionary based compression.
2. Huffman based compression.
3. A compression algorithm for swift names that's based on the other two.
This commit also adds two large autogenerated files: CBCTables.h and HuffTables.h.
These files contain the autogenerated string tables and auto-generated code for
fast compression/decompression. The internal tree data structures are lowered
into code that does the variable length encoding/decoding and searching of
fragments in the codebook. The files were generated by processing the symbols
from several large swift applications (stdlib, unittests, simd, ui app, etc).
The list of the programs is listed as part of the output of the tool in the
header file.
I decided to commit the auto-generated files for two reasons. First, we have a
cyclic dependency problem where we need to analyze the output of the compiler
(swift files) in order to generate the tables. And second, these tables will
become a part of the Swift ABI and should remain constant.
It should be possible to split the code that generates the Trie-based data
structure and auto-generate it as part of the Swift build process.
Reuses the enum metadata layout and builder because most of the logic is
also required for Optional (generic arg and payload). We may want to
optimize this at some point (Optional doesn't have a Parent), but I
don't see much opportunity.
Note that with this approach there will be no change in metadata layout.
Changing the kind still breaks the ABI of course.
Also leaves the MirrorData summary string as "(Enum Value)". We should
consider changing it.
Provide new swift_{alloc,dealloc,project}Box2 entry points that allocate, project, and deallocate typed boxes using runtime-instantiated metadata. Give these a new metadata kind, so that external tools recognize the difference and can interpret the metadata appropriately.
Swift SVN r29714
and use it to update LeaksChecker in a robust way to handle new metadata
kinds.
I also fixed a small typo where the native ErrorType was not included in
the range of non-ObjC isa metadata kinds.
Swift SVN r27718
We have enough flag bits on function types now to warrant stashing an extra word in the metadata key alongside the arguments and results, so add one, and pack the number of arguments, function convention, and 'throws' bit in there. This lets us merge the separate metadata caches for thick/thin/block/C functions into one, saving a bit of runtime memory, and simplifying a bunch of repetitive code in the runtime and IRGen.
This also fixes a subtle bug we had where the runtime getFunctionTypeMetadata function expected the result argument to be passed in the arguments array, but IRGen was passing it as a separate argument, which would have caused function type metadata to fail to be uniqued by result type.
Swift SVN r27651
@objc protocols aren't supported with an ObjC runtime, but we still want values of AnyObject type to be word-sized. Handle this by turning the binary "needsWitnessTable" condition into a "dispatch strategy" enum, so we can recognize the condition "has no methods, so neither swift nor objc dispatch" as distinct from either swift or ObjC protocol representations. Assign this dispatch strategy when we lower AnyObject. Should be NFC for the ObjC-enabled build.
(It would also be beneficial for the ObjC-runtime-enabled version of Swift if AnyObject weren't an @objc protocol; that would mean we could give it a canonical protocol descriptor in the standard library, among other things. There are fairly deep assumptions in Sema that AnyObject is @objc, though, and it's not worth disturbing those assumptions right now.)
Reapplying with updates to the runtime unit tests.
Swift SVN r27341
@objc protocols aren't supported with an ObjC runtime, but we still want values of AnyObject type to be word-sized. Handle this by turning the binary "needsWitnessTable" condition into a "dispatch strategy" enum, so we can recognize the condition "has no methods, so neither swift nor objc dispatch" as distinct from either swift or ObjC protocol representations. Assign this dispatch strategy when we lower AnyObject. Should be NFC for the ObjC-enabled build.
(It would also be beneficial for the ObjC-runtime-enabled version of Swift if AnyObject weren't an @objc protocol; that would mean we could give it a canonical protocol descriptor in the standard library, among other things. There are fairly deep assumptions in Sema that AnyObject is @objc, though, and it's not worth disturbing those assumptions right now.)
Swift SVN r27338
We need to be able to easily recognize ErrorType in the runtime (and AnyObject, which we recognize by strcmp'ing in a few places currently, which is terrible). Carve out a byte in the protocol descriptor and existential type metadata flags where we can store an enumerator to identify interesting protocols and their existential types. While we're here, move the ProtocolDescriptorFlags and ExistentialTypeFlags up to swift/ABI/MetadataValues.h so their layout can be shared easily from IRGen and the runtime. NFC yet (except you're now arbitrarily limited to 16M protocols in a composition instead of 2G, but hopefully nobody will notice).
Swift SVN r26361
Teach IRGen and the runtime about the extra inhabitants
of function pointers, and take advantage of that in
thin and thick function types.
Also add runtime entrypoints for thin function type
metadata.
Swift SVN r24346
IRGen uses a typedef, SpareBitVector, for its principal
purpose of tracking spare bits. Other uses should not
use this typedef, and I've tried to follow that, but I
did this rewrite mostly with sed and may have missed
some fixups.
This should be almost completely NFC. There may be
some subtle changes in spare bits for witness tables
and other off-beat pointer types. I also fixed a bug
where IRGen thought that thin functions were two
pointers wide, but this wouldn't have affected anything
because we never store thin functions anyway, since
they're not a valid AST type.
This commit repplies r24305 with two fixes:
- It fixes the computation of spare bits for unusual
integer types to use the already-agreed-upon type
size instead of recomputing it. This fixes the
i386 stdlib build. Joe and I agreed that we should
also change the size to use the LLVM alloc size
instead of the next power of 2, but this patch
does not do that yet.
- It changes the spare bits in function types back
to the empty set. I'll be changing this in a
follow-up, but it needs to be tied to runtime
changes. This fixes the regression test failures.
Swift SVN r24324
IRGen uses a typedef, SpareBitVector, for its principal
purpose of tracking spare bits. Other uses should not
use this typedef, and I've tried to follow that, but I
did this rewrite mostly with sed and may have missed
some fixups.
This should be almost completely NFC. There may be
some subtle changes in spare bits for witness tables
and other off-beat pointer types. I also fixed a bug
where IRGen thought that thin functions were two
pointers wide, but this wouldn't have affected anything
because we never store thin functions anyway, since
they're not a valid AST type.
Swift SVN r24305
We used to reserve a specific spare bit to say "this is a native
object." Now, we're going to say, "if *any* spare bit is set, this is a
native object." At the cost of having no spare bits to work with in the
non-native case, this allows us to store a number in 1..<4 (actually
0..<4, at some cost in speed for the 0 case) along with any native
object on all platforms.
This half bit advantage is important on 32-bit platforms, we have only
spare 2 bits to work with.
Given that on the 64-bit platforms there are *no* spare bits in the case
where the object is a non-native tagged pointer, we have no guarantee of
being able to store extra information along with an arbitrary non-native
object. Giving up the ability to store bits for *all* non-native
objects (even non-tagged ones) is therefore not much of a sacrifice.
Fixes <rdar://problem/18920415> More useful spare bits in Builtin.BridgeObject
Swift SVN r23345
