[PATCH] D132136: [clang] Perform implicit lvalue-to-rvalue cast with new interpreter

Wed Aug 31 03:10:37 PDT 2022

tbaeder added a comment.

In D132136#3755724 <https://reviews.llvm.org/D132136#3755724>, @aaron.ballman wrote:

> In D132136#3753290 <https://reviews.llvm.org/D132136#3753290>, @tbaeder wrote:
>
>> In D132136#3751702 <https://reviews.llvm.org/D132136#3751702>, @erichkeane wrote:
>>
>>> Would be great if we had a better test here... is there anything we can do to validate this is happening other than checking for that one note?
>>
>> `EvaluateAsRValue` is called from `Expr::EvaluateAsRValue()`, so I think it would be possible to write a unittest for this. But I think that would be a lot of effort just to test this. There is even `unittests/AST/EvaluateAsRValueTest.cpp` already, but it tests the wrong thing :(
>
> The existing test coverage being wrong seems like all the more reason to add correct test coverage. LValue to RValue conversions are important to get right (lol here's a wonderful demonstration of where we didn't bother to see if we got it right that I accidentally stumbled into when trying to give you a constexpr test case: https://godbolt.org/z/bdxbers3M), especially because they're going to impact which overload gets called when picking between an `&&` and `&` overload.

To be clear, can I land this patch without the unittest? I tried adding this to `EvaluateAsRValueTest.cpp` but I just run into other problems in the new interpreter :) So more unittests would definitely be good.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132136/new/

https://reviews.llvm.org/D132136