[IRGen] Fix crasher in emitPartialApplicationForwarder when the result type is a struct.
#22401
Conversation
…urn type is a tuple that contains a closure. In `emitPartialApplicationForwarder`, when we handle result types that have a type parameter, the lowered result type could be a struct. This happens when we have a function result, for instance: ```swift %0 = function_ref @returns_closure : $@convention(thin) <τ_0_0> (Empty<τ_0_0>) -> (@owned Empty<τ_0_0>, @owned @callee_guaranteed (Empty<τ_0_0>) -> @owned Empty<τ_0_0>) %1 = partial_apply [callee_guaranteed] %0<S>() : $@convention(thin) <τ_0_0> (Empty<τ_0_0>) -> (@owned Empty<τ_0_0>, @owned @callee_guaranteed (Empty<τ_0_0>) -> @owned Empty<τ_0_0>) ``` In this case, we emit code that casts the struct memberwise. Resolves [SR-9709](https://bugs.swift.org/browse/SR-9709).
lib/IRGen/GenFunc.cpp
Outdated
| for (auto i : range(structType->getStructNumElements())) { | ||
| auto desiredEltTy = structType->getElementType(i); | ||
| auto elt = subIGF.Builder.CreateExtractValue(callResult, {i}); | ||
| auto castElt = subIGF.Builder.CreateBitCast(elt, desiredEltTy); |
There was a problem hiding this comment.
Don't you need a recursion here?
Maybe emitCastToSubstSchema() can be used here?
There was a problem hiding this comment.
I don't know enough IRGen. Can any element be a nested struct? I assumed everything has been exploded at this stage.
There was a problem hiding this comment.
Everything is going to be exploded. When we form a direct return value we call getScalarResultType (among other things) which makes this assumption.
There was a problem hiding this comment.
You could use IRGenFunction::coerceValue instead.
// If the result type is dependent on a type parameter we might have to
// cast to the result type - it could be substituted.
if (origConv.getSILResultType().hasTypeParameter()) {
auto ResType = fwd->getReturnType();
if (ResType != callResult->getType())
callResult =
subIGF.coerceValue(callResult, ResType, subIGF.IGM.DataLayout);
}
subIGF.Builder.CreateRet(callResult);
There was a problem hiding this comment.
coerceValue() looks much cleaner, thanks Arnold!
There was a problem hiding this comment.
Done. This is much nicer :)
|
@swift-ci please smoke test |
|
@swift-ci please smoke test and merge |
In
emitPartialApplicationForwarder, when we handle result types that have a type parameter, the lowered result type could be a struct. This happens when we have a function result, for instance:In this case, we emit code that casts the struct memberwise.
Resolves SR-9709.