Fix issue on specialize 'this_type(interface)' #5970
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| // case in maybeSpecializeGeneric() because we the concrete type of the | ||
| // 'this_type(interface_type)' is not known at that time. So we have to handle this case | ||
| // here. | ||
| if (auto thisType = as<IRThisType>(firstParam->getDataType())) |
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Should we just check for ThisType in the loop above at line 1316?
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| // Replace the first parameter of the function type with the | ||
| // concrete type. | ||
| auto functionType = calleeFunc->getDataType(); |
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firstParamType->replaceUsesWith() is dangerous/incorrect, because there may still be other uses of the type (e.g. outside the function we are processing), and they shouldn't be replaced.
If the intention here is just to create a new IRFuncType and set it to calleeFunc, you can just call fixupFuncType before returning.
| @@ -1328,7 +1328,52 @@ struct SpecializationContext | |||
| // If we never found a parameter or return type worth specializing, we should bail out. | |||
| // | |||
| if (!returnTypeNeedSpecialization && !argumentNeedSpecialization) | |||
| { | |||
| auto firstParam = calleeFunc->getFirstParam(); | |||
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I am not understanding the underlying issue we are trying to fix here.
How can a param type of the callee end up being an ThisType? IIRC ThisType is only used when declaring an interface requirement, and should never appear in any actual methods. I am very confused why the callee here can have its first param type being an IRThisType. They should only just be IRInterfaceType and be handled with the existing code.
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call specialize(base, this_type(interface_type), witness_table) (xxx)
for above IR, maybeSpecializeGeneric() will evaluate specialize, and this will generate a specialized function with this_type(interface_type) as the input parameter.
Let's say the function is named func, then this IR will be
call func(xxx), and the function will be
void func(this_type(interface_type))
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Based on what you said, you mean
call specialize(base, this_type(interface_type), witness_table) (xxx)
this_type(interface_type) should never appear in specialize call?
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I don't know about that.
But if this is the case, then the bug is in more previous stage.
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The PR should also include a regression test for the issue we are fixing. |
Yea, I will add. |
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I did some investigation here, and it appears that the IR for It is something like: The This usually occurs when the front-end produces wrong DeclRef to |
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I drafted an attempt to fix this issue in the front-end here: #5971 It may still not be 100% correct, but this is the direction we should be exploring. |
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It makes sense to me that we should fix the front-end if the |
close issue #5900