[test] silgen test coverage for async thunks of non-async funcs #62984
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In light of SE-338, you'd think all functions converted to be `async` would have hops in their reabstraction thunks. But that's not the case. A non-async function that is not otherwise isolated according to its type, when converted to become an async function, should not have hops in its reabstraction thunk; not even to the generic executor. That was not intuitive for me, so I thought I'd add extra test coverage to ensure we maintain that existing behavior, since we rely on it when non-async functions have their isolation casted away when in an isolated context (only allowed when it's not also Sendable). Thus, when it's called later on, it needs to inherit the executor, as its guaranteed to only be called while on a matching one. For example: ``` @mainactor func caller() async { let f: () -> () = mainActorFn let g: () async -> () = f await g() // g cannot be hopping to a different executor, it must inherit! } ```
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@swift-ci please smoke test and merge |
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In light of SE-338, you'd think all functions converted to be
asyncwould have hops in their reabstraction thunks.But that's not the case. A non-async function that is not otherwise isolated according to its type, when converted to become an async function, should not have hops in its reabstraction thunk; not even to the generic executor.
That was not intuitive for me, so I thought I'd add extra test coverage to ensure we maintain that existing behavior, since we rely on it when non-async functions have their isolation casted away when in an isolated context (only allowed when it's not also Sendable). Thus, when it's called later on, it needs to inherit the executor, as its guaranteed to only be called while on a matching one. For example: