We can encounter these when the compiler modifies an inlinable
function to break apart a struct and the struct uses a private
type for one of its fields. It's questionable whether we /should/
handle this, but meanwhile this /is/ a non-intrusive fix that
preserves the performance of non-resilient libraries.
(That is, it appears this worked in Swift 4.0, though perhaps
not all of the same optimizations kicked in.)
https://bugs.swift.org/browse/SR-6874
Also remove the decl from the known decls and remove a
bunch of code referencing that decl as well as a bunch of other
random things including deserialization support.
This includes removing some specialized diagnostics code that
matched the identifier ImplicitlyUnwrappedOptional, and tweaking
diagnostics for various modes and various issues.
Fixes most of rdar://problem/37121121, among other things.
This has three principal advantages:
- It gives some additional type-safety when working
with known accessors.
- It makes it significantly easier to test whether a declaration
is an accessor and encourages the use of a common idiom.
- It saves a small amount of memory in both FuncDecl and its
serialized form.
The deserialization of the type witnesses for a normal protocol conformance
is crucial to the usability of said conformance. Deserializing the
value witnesses first can fail if they somehow rely on the type
witnesses (e.g., through a recursive conformance).
As a stop-gap, deserialize and record type witnesses *first*, then
deserialize value witnesses afterward. A longer-term solution would
make deserialization of the normal protocol conformance far more
lazy.
Fixes SR-6522 / rdar://problem/35830641, a merge-modules crasher in a
nontrivial project.
We would miscompile in mixed-language-version projects when a Swift class was compiled for one language version, while using Objective-C-imported types that are only available to that version, and then imported into a Swift module with a different language version that wasn't able to see all of the properties because of incompatible imported types. This manifested in a number of ways:
- We assumed we could re-derive the constant field offsets of the class's ivars from the layout, which is wrong if properties are missing, causing accesses to final properties or subclass properties to go to the wrong offsets.
- We assumed we could re-derive the instance size and alignment of a class instance in total, causing code to allocate the wrong amount of memory.
- We neglected to account for the space that stored properties take up in the field offset vector of the class object, causing us to load vtable entries for following subclass methods from the wrong offsets.
Eventually, resilience should reduce our exposure to these kinds of problems. As an incremental step in the right direction, when we look at a class from another module in IRGen, treat it as always variably-sized, so we don't try to hardcode offsets, size, or alignment of its instances. When we import a class, and we're unable to import a stored property, leave behind a new kind of MissingMemberDecl that records the number of field offset vector slots it will take up, so that we lay out subclass objects and compute vtable offsets correctly. Fixes rdar://problem/35330067.
A side effect of this is that the RemoteAST library is no longer able to provide fixed field offsets for class ivars. This doesn't appear to impact the lldb test suite, and they will ultimately need to use more abstract access patterns to get ivar offsets from resilient classes (if they aren't already), so I just removed the RemoteAST test cases that tested for class field offsets for now.
We could handle a typealias itself disappearing, but not if the
typealias was okay but the underlying type wasn't. This came up in
real Swift 3/4 mix-and-match code.
rdar://problem/34940079
Rather than storing contextual types in the type witnesses and associated
conformances of NormalProtocolConformance, store only interface types.
@huonw did most of the work here, and @DougGregor patched things up to
complete the change.
If we can't resolve a cross-reference unambiguously, we're supposed to
produce an llvm::Error and let the calling code handle it. However, if
we couldn't even resolve the /type/ of the cross-reference, we would
just crash. Follow the supported error path in that case too -- in
many cases the error can just propagate upwards to something that can
handle it.
rdar://problem/34821187, plus an extra test case from
rdar://problem/35157494. (The latter will be fixed better later, but
meanwhile let's not regress on the crashing part.)
For now these are underscored attributes, i.e. compiler internal attributes:
@_optimize(speed)
@_optimize(size)
@_optimize(none)
Those attributes override the command-line specified optimization mode for a specific function.
The @_optimize(none) attribute is equivalent to the already existing @_semantics("optimize.sil.never") attribute
Rather than inlining generic signatures in a half dozen places throughout
the serialization format, serialize (uniqued) generic signatures with their
own GenericSignatureID. Update various layouts (generic function types,
SIL function types, generic environments, extension cross-references) to
use GenericSignatureID.
Shaves ~187k off the size of Swift.swiftmodule.
When a particular nominal type or extension thereof declares conformance
to a protocol, check whether that type or extension contains any members
that *nearly* match a defaulted requirement (i.e., a requirement that
is satisfied by something in a protocol extension), but didn’t match
for some reason and weren’t used to satisfy any other requirement of
that protocol. It’s intended to catch subtle mistakes where a default
gets picked instead of the intended member.
This is a generalization of the code we’ve had for @objc optional
requirements for a long time.
Fixes rdar://problem/24714887.
Otherwise, a protocol conformance where the witness was a dynamic
property in another module would trigger an assertion while building
the materializeForSet witness, or miscompile and fail at runtime
if asserts are off.
Support for @noescape SILFunctionTypes.
These are the underlying SIL changes necessary to implement the new
closure capture ABI.
Note: This includes a change to function name mangling that
primarily affects reabstraction thunks.
The new ABI will allow stack allocation of non-escaping closures as a
simple optimization.
The new ABI, and the stack allocation optimization, also require
closure context to be @guaranteed. That will be implemented as the
next step.
Many SIL passes pattern match partial_apply sequences. These all
needed to be fixed to handle the convert_function that SILGen now
emits. The conversion is now needed whenever a function declaration,
which has an escaping type, is passed into a @NoEscape argument.
In addition to supporting new SIL patterns, some optimizations like
inlining and SIL combine are now stronger which could perturb some
benchmark results.
These underlying SIL changes should be merged now to avoid conflicting
with other work. Minor benchmark discrepancies can be investigated as part of
the stack-allocation work.
* Add a noescape attribute to SILFunctionType.
And set this attribute correctly when lowering formal function types to SILFunctionTypes based on @escaping.
This will allow stack allocation of closures, and unblock a related ABI change.
* Flip the polarity on @noescape on SILFunctionType and clarify that
we don't default it.
* Emit withoutActuallyEscaping using a convert_function instruction.
It might be better to use a specialized instruction here, but I'll leave that up to Andy.
Andy: And I'll leave that to Arnold who is implementing SIL support for guaranteed ownership of thick function types.
* Fix SILGen and SIL Parsing.
* Fix the LoadableByAddress pass.
* Fix ClosureSpecializer.
* Fix performance inliner constant propagation.
* Fix the PartialApplyCombiner.
* Adjust SILFunctionType for thunks.
* Add mangling for @noescape/@escaping.
* Fix test cases for @noescape attribute, mangling, convert_function, etc.
* Fix exclusivity test cases.
* Fix AccessEnforcement.
* Fix SILCombine of convert_function -> apply.
* Fix ObjC bridging thunks.
* Various MandatoryInlining fixes.
* Fix SILCombine optimizeApplyOfConvertFunction.
* Fix more test cases after merging (again).
* Fix ClosureSpecializer. Hande convert_function cloning.
Be conservative when combining convert_function. Most of our code doesn't know
how to deal with function type mismatches yet.
* Fix MandatoryInlining.
Be conservative with function conversion. The inliner does not yet know how to
cast arguments or convert between throwing forms.
* Fix PartialApplyCombiner.
Now that the GenericSignatureBuilder is no longer sensitive to the input
module, stop uniquing the canonical GSBs based on that module. The main
win here is when deserializing a generic environment: we would end up
creating a canonical GSB in the module we deserialized and another
canonical GSB in the module in which it is used.
When an associated type declaration “overrides” (restates) an associated
type from a protocol it inherits, note that it overrides that declaration.
SourceKit now reports overrides of associated types.
Previously we stored this inside each default argument
initializer context. This was overkill, because it is
the same for all default arguments in a single function,
and also insufficient, because initializer contexts are
not serialized and thus not available in SILGen when
the function is in a different module.
Instead store it directly inside the function and
serialize it.
NFC for now, since SILGen isn't using this yet.
The base mutability of storage is part of the signature, so be sure
to compute that during validation. Also, serialize it as part of
the storage declaration, and fix some places that synthesize
declarations to set it correctly.
The “inherited” types of an associated type are only needed to
type-check an associated type in the context of its protocol.
Once that is complete, the requirement signature of the protocol
is the “truth”, and we no longer rely on the “inherited” types.
Stop serializing them.
"Accessibility" has a different meaning for app developers, so we've
already deliberately excised it from our diagnostics in favor of terms
like "access control" and "access level". Do the same in the compiler
now that we aren't constantly pulling things into the release branch.
Rename AccessibilityAttr to AccessControlAttr and
SetterAccessibilityAttr to SetterAccessAttr, then track down the last
few uses of "accessibility" that don't have to do with
NSAccessibility. (I left the SourceKit XPC API alone because that's
supposed to be more stable.)
"Accessibility" has a different meaning for app developers, so we've
already deliberately excised it from our diagnostics in favor of terms
like "access control" and "access level". Do the same in the compiler
now that we aren't constantly pulling things into the release branch.
This commit changes the 'Accessibility' enum to be named 'AccessLevel'.
