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.
Tweaked diagnostic to use a string instead of a type. Renamed the
feature in `FeatureAvailability.def` (and added the `TaskExecutor`
feature to 6.2). Also fixed the `swift_getActiveExecutor()`
function to return the main executor only when on the main thread.
rdar://141348916
Added an `-executor-factory` argument to the compiler to let you safely
specify the executors you wish to use (by naming a type that returns
them).
Also added some tests of the new functionality.
rdar://141348916
If the feature is enabled, base the requirement for the underscored
accessors on the availability of the non-underscored accessors. If the
(non-underscored) accessor's was available earlier than the feature,
interpret that to mean that the underscored version was available in
that earlier version, and require the underscored version. The goal is
to ensure that the ABI is preserved, so long as the simplest migration
is done (namely, deleting the underscores from the old accessors).
For modify2, cache the required-ness in the same way that it is cached
for modify.
Not all runtimes can correctly operate with types that use noncopyable
generics. When the generic argument of a type is noncopyable, old
runtimes can't recognize that to correctly check conformances that may
be conditional on those arguments being Copyable, etc.
resolves rdar://126239335
and implement it for @isolated(any) function types.
The existing testing was pretty broken: we were diagnosing all sorts
of things that don't require type metadata (like using a tuple with
an extended existential in a value position in an API signature)
and not diagnosing several things that do (like covariant function
conversions that erase types). There's therefore some risk to this
patch, but I'm not too worried because needing metadata like this is
pretty uncommon, and it's likely that programs won't build correctly
anyway --- it'll just get caught by the linker instead of the compiler.
We need to only generate references to `_swift_exceptionPersonality`
if we're building for a new enough runtime. The previous code was
good on Darwin, but would have resulted in build problems on Linux.
rdar://120952971
