aaron.ballman added a comment. > In D119051#3715939 <https://reviews.llvm.org/D119051#3715939>, @aaron.ballman > wrote: > >> In D119051#3714645 <https://reviews.llvm.org/D119051#3714645>, @dblaikie >> wrote: >> >>> >> >> I would have thought use of `__is_pod` would tell us, but I'm not seeing the >> behavior described in the test case when using that: >> https://godbolt.org/z/1vr3MK4KW Oddly, it seems that >> `QualType::isCXX11PODType()` doesn't look at `PlainOldData` at all! What is >> your expectation as to how the type trait should be behaving? > > Oh, yeah, seems @rsmith and I discussed this naming/expectations issue a bit > over here previously: https://reviews.llvm.org/D117616#inline-1132622
Ah, thank you for that! In D119051#3717934 <https://reviews.llvm.org/D119051#3717934>, @dblaikie wrote: > I guess the other way to test for pod-for-purposes-of-ABI is IRgen. Looks > like MSVC isn't observable based on sizeof or alignof on these issues (the > previous godbolt shows MSVC's answer to alignment for the packed and size for > the trailing packing don't change based on any of the variations (pod, > non-pod, pod-with-defaulted-special-members)) - but should be observable > based on the returning ABI. > > Ah, here we go: https://godbolt.org/z/sd88zTjPP > > So MSVC does consider the defaulted special member as still a valid > pod-for-purposes-of-ABI and clang is incorrect/not ABI compatible with this. > So MSVC does want this fix. Yeah this strikes me as the right kind of test to add for testing the ABI (codegen cares more about ABI than Sema, broadly speaking). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D119051/new/ https://reviews.llvm.org/D119051 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
