[PATCH] D155809: [NFC] [Clang] Fix strict weak ordering in ItaniumVTableBuilder

Mon Jul 24 06:04:20 PDT 2023

aaron.ballman added a comment.

In D155809#4527199 <https://reviews.llvm.org/D155809#4527199>, @danlark wrote:

> In D155809#4521494 <https://reviews.llvm.org/D155809#4521494>, @rsmith wrote:
>
>> This looks correct to me, but it's still a little subtle. Perhaps it'd be clearer to map the method to an integer (0 for copy assignment, 1 for move assignment, 2 for destructor, 3 for equality comparison), and then order them by that integer? That'd be more obviously a strict weak order.
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> In D155809#4520765 <https://reviews.llvm.org/D155809#4520765>, @shafik wrote:
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>> I am not sure about this change but I think we at least need a test and this does not seem non-functional if it prevents a crash.
>
> This is NFC as it only prevents further assert to fire when stable_sort compares the element with itself

Richard's suggestion makes sense to me as a clarifying change to the code. I also agree with Shafik -- if this prevents an assertion from firing in practice, then it's a functional change that should come with tests. Or are you saying the assertion isn't happening in practice and this is a defensive change?

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  https://reviews.llvm.org/D155809/new/

https://reviews.llvm.org/D155809