Allow any declaration to be marked with `@unsafe`, meaning that it
involves unsafe code. This also extends to C declarations marked with
the `swift_attr("unsafe")` attribute.
Under a separate experimental flag (`DisallowUnsafe`), diagnose any
attempt to use an `@unsafe` declaration or any unsafe language feature
(such as `unowned(unsafe)`, `@unchecked Sendable`). This begins to
define a "safe" mode in Swift that prohibits memory-unsafe constructs.
`@unknown default` in switch statements are required for resilient enums since they
might be modified with new fields in the future and modules defining the enums are
generally not built together with the consuming modules.
However, if the modules are in the same package, they are required to be built together,
thus the requirement for `@unknown default` can be skipped. This PR removes the need for
that, enabling less boilerplate. Note this change only impacts typecheck and not SIL gen.
Resolves rdar://130015149.
This makes sure that Swift respects `-Xcc -stdlib=libc++` flags.
Clang already has existing logic to discover the system-wide libc++ installation on Linux. We rely on that logic here.
Importing a Swift module that was built with a different C++ stdlib is not supported and emits an error.
The Cxx module can be imported when compiling with any C++ stdlib. The synthesized conformances, e.g. to CxxRandomAccessCollection also work. However, CxxStdlib currently cannot be imported when compiling with libc++, since on Linux it refers to symbols from libstdc++ which have different mangled names in libc++.
rdar://118357548 / https://github.com/swiftlang/swift/issues/69825
Upstreams the necessary changes to compile references to `@backDeployed`
declarations correctly when a `macabi` target triple or a `-target-variant` is
specified.
There are a few spots in `ActorIsolationRequest` that produce
`unspecified` isolation with `preconcurrency` bit set and diagnostics
rely on that to make downgrade decisions in Swift 5 mode.
This reverts commit 0097ef68a6.
The computation that determined whether an access to a `let` instance
property within a constructor should be an initialization conflated the
cases of "we don't have a base expression" and "the base expression is
not something that could be `self`", and incorrectly identified rvalue
bases as being "initializable". Make the interface properly separate
out these cases, so we don't turn an lvalue into an rvalue access.
Fixes rdar://128661833.
Add global accessors to symbol list if VarDecl is fragile, i.e.
is non-resilient or its defining module allows non-resilient
access.
Don't set the class decl to hidden if it's in a package resilience
domain; even though its defining module is built resilently, the
class symbol should be visible across modules if they are in the
same package with resilience-bypass optimization. In such case,
treat its SubclassScope to Internal.
Resolves rdar://127321129
