Most of the new inspection logic is in Remote Mirror. New code in swift-inspect calls the new Remote Mirror functions and formats the resulting information for display.
Specific Remote Mirror changes:
* Add a call to check if a given metadata is an actor.
* Add calls to get information about actors and tasks.
* Add a `readObj` call to MemoryReader that combines the read and the cast, greatly simplifying code chasing pointers in the remote process.
* Add a generalized facility to the C shims that can allocate a temporary object that remains valid until at least the next call, which is used to return various temporary arrays from the new calls. Remove the existing `lastString` and `lastChunks` member variables in favor of this new facility.
Swift-inspect changes:
* Add a new dump-concurrency command.
* Add a new `ConcurrencyDumper.swift` file with the implementation. The dumper needs to do some additional work with the results from Remote Mirror to build up the task tree and this keeps it all organized.
* Extend `Inspector` to query the target's threads and fetch each thread's current task.
Concurrency runtime changes:
* Add `_swift_concurrency_debug` variables pointing to the various future adapters. Remote Mirror uses these to provide a better view of a tasks's resume pointer.
rdar://85231338
We remove the existing `swift_reflection_iterateAsyncTaskAllocations` API that attempts to provide all necessary information about a tasks's allocations starting from the task. Instead, we split it into two pieces: `swift_reflection_asyncTaskSlabPointer` to get the first slab for a task, and `+swift_reflection_asyncTaskSlabAllocations` to get the allocations in a slab, and a pointer to the next slab.
We also add a dummy metadata pointer to the beginning of each slab. This allows tools to identify slab allocations on the heap without needing to locate every single async task object. They can then use `swift_reflection_asyncTaskSlabAllocations` on such allocations to find out about the contents.
rdar://82549631
We remove the existing `swift_reflection_iterateAsyncTaskAllocations` API that attempts to provide all necessary information about a tasks's allocations starting from the task. Instead, we split it into two pieces: `swift_reflection_asyncTaskSlabPointer` to get the first slab for a task, and `+swift_reflection_asyncTaskSlabAllocations` to get the allocations in a slab, and a pointer to the next slab.
We also add a dummy metadata pointer to the beginning of each slab. This allows tools to identify slab allocations on the heap without needing to locate every single async task object. They can then use `swift_reflection_asyncTaskSlabAllocations` on such allocations to find out about the contents.
rdar://82549631
We were missing a Status field. The reflect_task test didn't catch this becasue it was reading LastAllocation as FirstSlab, which still worked well enough in that context.
rdar://81427584
Fix the declaration of AsyncTask and add a test for iterateAsyncTaskAllocations. Reflection's declaration of AsyncTask had fallen out of sync with the real thing. The test that was supposed to catch this was never actually committed, oops.
Add a swift_reflection_libraryVersion variable to Remote Mirror to indicate the presence of this fix. In the future, the value can be incremented to signal the presence of other changes that can't otherwise be detected.
rdar://80035307
This will allow the heap tool to work out which binary a dynamically allocated
class comes from, by looking up its nominal type descriptor address and then
seeing which binary contains that.
Fixes rdar://65742351.
Implement a version of projectExistential tailored for LLDB. There are 2
differences when projecting existentials for LLDB:
1 - When it comes to existentials, LLDB stores the address of the error
pointer, which must be dereferenced.
2 - When the existential wraps a class type, LLDB expects the address
returned is the class instance itself and not the address of the
reference.
This patch also adapts the swift reflection test machinery to test
projectExistentialAndUnwrapClass as well. This is done by exposing
the new functionality from swift reflection test. It is tested in
existentials.swift, and ensures that the typeref information is
exactly the same as what is expected from projectExistential,
except the out address.
(cherry picked from commit 55e971e06750c3ba29722d558cc5400298f6bdaf)
This code rearchitects and simplifies the projectEnumValue support by
introducing a new `TypeInfo` subclass for each kind of enum, including trivial,
no-payload, single-payload, and three different classes for multi-payload enums:
* "UnsupportedEnum" that we don't understand. This returns "don't know" answers for all requests in cases where the runtime lacks enough information to accurately handle a particular enum.
* MP Enums that only use a separate tag value. This includes generic enums and other dynamic layouts, as well as enums whose payloads have no spare bits.
* MP Enums that use spare bits, possibly in addition to a separate tag. This logic can only be used, of course, if we can in fact compute a spare bit mask that agrees with the compiler.
The final challenge is to choose one of the above three handlings for every MPE. Currently, we do not have an accurate source of information for the spare bit mask, so we never choose the third option above. We use the second option for dynamic MPE layouts (including generics) and the first for everything else.
TODO: Once we can arrange for the compiler to expose spare bit mask data, we'll be able to use that to drive more MPE cases.
ownsAddress was a simple range check on images, but that won't find Metadatas that get allocated on the heap. If an address isn't found, try reading it as a Metadata and doing a range check on the type context descriptor too.
rdar://problem/60981575
Teach RemoteMirror how to project enum values
This adds two new functions to the SwiftRemoteMirror
facility that support inspecting enum values.
Currently, these support non-payload enums and
single-payload enums, including nested enums and
payloads with struct, tuple, and reference payloads.
In particular, it handles nested `Optional` types.
TODO: Multi-payload enums use different strategies for
encoding the cases that aren't yet supported by this
code.
Note: This relies on information from dataLayoutQuery
to correctly decode invalid pointer values that are used
to encode enums. Existing clients will need to augment
their DLQ functions before using these new APIs.
Resolves rdar://59961527
```
/// Projects the value of an enum.
///
/// Takes the address and typeref for an enum and determines the
/// index of the currently-selected case within the enum.
///
/// Returns true iff the enum case could be successfully determined.
/// In particular, note that this code may fail for valid in-memory data
/// if the compiler is using a strategy we do not yet understand.
SWIFT_REMOTE_MIRROR_LINKAGE
int swift_reflection_projectEnumValue(SwiftReflectionContextRef ContextRef,
swift_addr_t EnumAddress,
swift_typeref_t EnumTypeRef,
uint64_t *CaseIndex);
/// Finds information about a particular enum case.
///
/// Given an enum typeref and index of a case, returns:
/// * Typeref of the associated payload or zero if there is no payload
/// * Name of the case if known.
///
/// The Name points to a freshly-allocated C string on the heap. You
/// are responsible for freeing the string (via `free()`) when you are finished.
SWIFT_REMOTE_MIRROR_LINKAGE
int swift_reflection_getEnumCaseTypeRef(SwiftReflectionContextRef ContextRef,
swift_typeref_t EnumTypeRef,
unsigned CaseIndex,
char **CaseName,
swift_typeref_t *PayloadTypeRef);
```
Co-authored-by: Mike Ash <mikeash@apple.com>
TypeRefBuilder and MetadataReader had nearly identical symbolic reference resolvers,
but diverged because TypeRefBuilder had its own local/remote address management mechanism,
and because TypeRefBuilder tries to resolve opaque types to their underlying types, whereas
other MetadataReader clients want to preserve them as written in source. The first problem
has been addressed by making TypeRefBuilder use `RemoteRef` everywhere, and the second
can be handled with a flag (and might be able to be handled more elegantly with some more
refactoring of general opaque type handling in MetadataReader).
Weak import semantics are not available on PE/COFF. Ensure that we do not mark
the type as having weak import semantics. Otherwise, the dllimport'ed symbol is
marked as `dso_local` which is invalid.
Also have swift-reflection-test check if the symbol exists. This allows swift-reflection-test to work with older Remote Mirror dylibs that don't have it.
rdar://problem/50030805
This symbol is meant to be exposed to users of the SwiftRemoteMirror
library which requires that it is explicitly marked with the appropriate
DLL storage on Windows. This should repair the Windows build.
Recent Swift uses 2 as the is-Swift bit when running on newer versions, and 1 on older versions. Since it's difficult or impossible to know what we'll be running on at build time, make the selection at runtime.
* Change the RemoteMirror API to have extensible data layout callback
* Use DLQ_Get prefix on DataLayoutQueryType enum values
* Simplify MemoryReaderImpl and synthesize minimalDataLayoutQueryFunction
Mark the public interfaces with the appropriate visibility/dll storage.
This fixes an issue with the Windows build which keeps the
SwiftRemoteMirror.dll out of date constantly as no import library is
created. That occurs due to the fact that the library does not export
any interfaces.
Take the opportunity to move the public interfaces to protected
visibility on ELF.
* Remove getPointerSize and getSizeSize functions, replace with a single PointerSize value.
* Remove imageLength parameter from addImage, calculate it internally instead.
* Check remote mirrors libraries' metadata version and reject them if it's too old.
* Shim GetStringLength and GetSymbolAddress for the legacy library since we don't pass the caller's context pointer through directly.
* Actually set the IsLegacy flag in the Library struct.
* Implement ownsObject by tracking each added image's data segment and checking metadata pointers against them. The previous approach didn't work.
