Also remove mention of the word “contextual” type from the diagnostic
that rewrites array literals into dictionary literals and scale back
the scope of the diagnostic. This method was catching and
mis-diagnosing too many errors that could better be handled by invalid
conversion diagnostics.
The original hope was we could make these heuristics really good, but
since that is not currently in sight (and may never be), we want to be
able to turn them off. For now, just plumb through an internal flag to
control the behaviour. A future change will customize the behaviour in
SourceKit.
rdar://31113161
Also, give each class hierarchy at least 8 bits for the 'Kind' field.
In practice, no class hierarchy has more than 256 nodes, so this
optimizees code generation to make isa/dyn_cast faster.
Inline bitfields are a common design pattern in LLVM and derived
projects, but the associated boilerplate can be demotivating and
brittle. This new header makes it easier to define and use inline
bitfields in Swift.
This also reorders some fields for better code generation.
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.
If we used the requirement signature to create a protocol requirement
element in a requirement source, there's no need to verify that it's
from the requirement signature (duh).
The Swift class model does not support overriding declarations where either
the overridden declaration or the overriding declaration are in an extension.
However, the Objective-C class model does, so marking the declaration as
@objc (when possible) will work around the limitation.
Customize the "cannot override declaration in extension" diagnostic to
suggest adding @objc to the overridden declaration in cases where
@objc is permitted. Fixes SR-6512 / rdar://problem/35787914.
This presents a regression in diagnostic quality that is definitely
worth it not to lie to SILGen about whether a switch is covered or not.
At the same time, disable SIL’s unreachable diagnostic for ‘default’
clauses which would previously cause a warning to be emitted if the
default was proven to be unreachable. This analysis is incomplete
anyways and can be done by Sema in the future if we desire.
