This attribute forces programmers to acknowledge every
copy that is required to happen in the body of the
function. Only those copies that make sense according
to Swift's ownership rules should be "required".
The way this is implemented as of now is to flag each
non-explicit copy in a function, coming from SILGen, as
an error through PerformanceDiagnostics.
We allow placeholder types in interface types in certain cases to allow
better recovery since we can suggest the inferred type as a replacement.
When referencing those decls though we need to make sure we record a fix
since we cannot form a valid solution with them.
Contents in namespaces are imported to the bridging header module
`__ObjC`. When macros attached to a decl imported from a namespace are
expanded, they also end up in `__ObjC`. This prevents them from
inheriting imports from the module they originated in. This patch
implements a workaround by adding an alternative constructor to
`ImportResolver` that takes an explicit origin module as input,
overriding which module counts as the "parent" module.
Non-explicit submodules don't need to be explicitly added to the list of
imports to be visible, since their decls are implicitly exported. Skip
these modules even when present in the list of imports. Explicit
submodules are imported *regardless* of whether another module
imports them however.
The imported top-level module inherits the imports of all its
(transitive) submodules. Since multiple submodules can import the same
modules these need to be deduplicated to avoid redundant work.
This flag dumps all imports for each SourceFile after it's gone through
import resolution. It is only intended for testing purposes.
There are other ways to print imports, but they don't correspond 1:1 to
the imports actually resolved, which is a bit problematic when testing
implicit clang module imports.
swift_coroFrameAlloc was introduced in the Swift 6.2 runtime. Give it
the appropriate availability in IRGen, so that it gets weak
availability when needed (per the deployment target). Then, only
create the stub function for calling into swift_coroFrameAlloc or
malloc (when the former isn't available) when we're back-deploying to
a runtime prior to Swift 6.2. This is a small code size/performance
win when allocating coroutine frames on Swift 6.2-or-newer platforms.
This has a side effect of fixing a bug in Embedded Swift, where the
swift_coroFrameAlloc was getting unconditionally set to have weak
external linkage despite behind defined in the same LLVM module
(because it comes from the standard library).
Fixes rdar://149695139 / issue #80947.
When a module has been imported `@preconcurrency` in source, when it is printed
in a `swiftinterface` file it should be printed along with the attribute to
ensure that type checking of the module's public declarations behaves
consistently.
This fix is a little unsatisfying because it adds another a linear scan over
all imports in the source for each printed import. This should be improved, but
it can be done later.
Resolves rdar://136857313.
When emitting diagnostics for the Embedded Swift restrictions outside
of Embedded Swift mode, consider `#if $Embedded` and `#if
hasFeature(Embedded)` configurations. If the code where we would emit
the diagnostic would be disabled in Embedded Swift by one of those
checks, don't emit the diagnostic. This helps code that can compile
either with Embedded or regular Swift stay within the restrictions on
Embedded Swift.
Untyped throws depends on existentials (`any Error`), and is therefore
not available in Embedded Swift. Introduce a diagnostic that diagnoses
any use of untyped throws, suggesting that one use typed throws
instead.
Make this an opt-in diagnostic enabled with `-Wwarning
EmbeddedRestrictions`, whether in Embedded Swift or not, using the
"default ignore" flag on these new warnings. Document this new
diagnostic group, and put the existing Embedded Swift error about
weak/unowned references in it as well.
Part of the general push to have the type checker identify code that
will not compile as Embedded Swift earlier, rdar://133874555.
We still need to solve a branch with a ReturnStmt to avoid leaving
the contextual result type unbound. This isn't currently legal anyway,
so isn't likely to come up often in practice, but make sure we can
still solve.
If a `.swiftinterface` file does not include an explicit `-language-mode`
option (or its predecessor `swift-version`) and needs to be built as a
dependency of a client compilation, then the invocation to build the module
from interface would end up inheriting the language mode that the client code
is built with. This can result in spurious type checking diagnostics or even
mis-compilation. To ensure that a module interface is always built using the
language mode that its source code was originally built with, require an
explicit `-language-mode` option when emitting swiftinterface files.
Resolves rdar://145168219.
