allow a more standard way to pass experimental features
from build systems. Also moved other flags relevant to
diagnostics from Frontend options to Lang options.
Ref: rdar://124648653
language feature, and suppress it for `Clock.measure`.
This allows the _Concurrency swiftinterface file to continue building with
compilers that do not support `OptionalIsolatedParameters`. The feature
suppression drops the `isolated` keyword and replaces `#isolation` with
`nil`.
Allow `@_implements` to be expressed in an extension of the protocol in
which the associated type is defined. Use this to uncomment an
intended use of `@_implements` in `Sequence` that could be used to
replace a longstanding hack for associated type inference.
Since this change means that the standard library module interface
won't be accepted by older compilers, introduce a suppressible feature
ssociatedTypeImplements` that covers the use of `@_implements` on type
declarations. This will hide the `@_implements` attribute from older
compilers.
If an extension isn't imported either directly or via a transitive
(`@_exported`) import, its members should not be visible to name
lookup. Implement this behavior behind the experimental flag
ExtensionImportVisibility.
This allows us to remove their explicit `UNINTERESTING_FEATURE` entries for
them FeatureSet.cpp. All of these features have been present in the compiler
since at least Swift 5.8.
NFC.
Our standard conception of suppressible features assumes we should
always suppress the feature if the compiler doesn't support it.
This presumes that there's no harm in suppressing the feature, and
that's a fine assumption for features that are just adding information
or suppressing new diagnostics. Features that are semantically
relevant, maybe even ABI-breaking, are not a good fit for this,
and so instead of reprinting the decl with the feature suppressed,
we just have to hide the decl entirely. The missing middle here
is that it's sometimes useful to be able to adopt a type change
to an existing declaration, and we'd like older compilers to be
able to use the older version of the declaration. Making a type
change this way is, of course, only really acceptable for
@_alwaysEmitIntoClient declarations; but those represent quite a
few declarations that we'd like to be able to refine the types of.
Rather than trying to come up with heuristics based on
@_alwaysEmitIntoClient or other sources of information, this design
just requires the declaration to opt in with a new attribute,
@_allowFeatureSuppress. When a declaration opts in to suppression
for a conditionally-suppressible feature, the printer uses the
suppression serially-print-with-downgraded-options approach;
otherwise it uses the print-only-if-feature-is-available approach.
To maintain source compatibility, SE-0352 does not open existentials
with "self-conforming" type, such as `any Error` or existentials based
on `@objc` protocols. The proposal specified that this behavior would
change in Swift 6. Implement that behavior change, which can be
enabled prior to Swift 6 with the upcoming feature
`ImplicitOpenExistentials` (as documented in SE-0362).
Fixes#70873 / rdar://120902975.
Suppressing this feature doesn't disable the use of new syntax in the
normal way. Instead, it introduces `@rethrows` on the
AsyncIteratorProtocol and AsyncSequence protocols, so that older
compilers can still use the async sequences generated by newer
compilers and standard libraries.
Fixes the rest of rdar://123782658
The name of the `TaskExecutor` protocol was recently changed to remove
underscores after the feature was accepted in Swift Evolution. An implication
of that rename is that the `buildOrdinaryTaskExecutorRef` builtin changed
the type that it expected as the argument. However, the original change
landed in the standard library which as since produced swiftinterfaces
that contain the following inlinable code:
```
@inlinable public init<E>(ordinary executor: __shared E) where E : _Concurrency._TaskExecutor {
#if $BuiltinBuildTaskExecutor
self.executor = Builtin.buildOrdinaryTaskExecutorRef(executor)
#else
fatalError("Swift compiler is incompatible with this SDK version")
#endif
}
```
When a compiler containing the protocol rename attempts to type check the
above inlinable code, it crashes because the builtin is expecting an argument
conforming to `TaskExecutor`, which doesn't exist in this version of the
standard library. The issue is that the current compiler still supports
the `$BuiltinBuildTaskExecutor` feature guard, but the builtin supported
has since changed.
To resolve this issue, we need to stop supporting the `$BuiltinBuildTaskExecutor`
feature guard and introduce a new one that is only supported by compiler versions
that contain the rename. This approach relies on nothing having adopted the
API, otherwise we would need to stage in the rename as a parallel set of APIs,
and only remove the old APIs once nothing is relying on the old _Concurrency
swiftinterfaces.
Test shadowed variable of same type
Fully type check caller side macro expansion
Skip macro default arg caller side expr at decl primary
Test macro expand more complex expressions
Set synthesized expression as implicit
Add test case for with argument, not compiling currently
Test with swiftinterface
Always use the string representation of the default argument
Now works across module boundary
Check works for multiple files
Make default argument expression work in single file
Use expected-error
Disallow expression macro as default argument
Using as a sub expression in default argument still allowed as expression macros behave the same as built-in magic literals
Even if the final pattern ends up consuming the value, the match itself
must be nondestructive, because any match condition could fail and cause
us to have to go back to the original aggregate. For copyable values,
we can always copy our way out of consuming operations, but we don't
have that luxury for noncopyable types, so the entire match operation
has to be done as a borrow.
For address-only enums, this requires codifying part of our tag layout
algorithm in SIL, namely that an address-only enum will never use
spare bits or other overlapping storage for the enum tag. This allows
us to assume that `unchecked_take_enum_data_addr` is safely non-side-
effecting and match an address-only noncopyable enum as a borrow.
I put TODOs to remove defensive copies from various parts of our
copyable enum codegen, as well as to have the instruction report
its memory behavior as `None` when the projection is nondestructive,
but this disturbs SILGen for existing code in ways SIL passes aren't
yet ready for, so I'll leave those as is for now.
This patch is enough to get simple examples of noncopyable enum switches
to SILGen correctly. Additional work is necessary to stage in the binding
step of the pattern match; for a consuming switch, we'll need to end
the borrow(s) and then reproject the matched components so we can
consume them moving them into the owned bindings. The move-only checker
also needs to be updated because it currently always tries to convert
a switch into a consuming operation.
