aaron.ballman added a comment. In D141472#4106091 <https://reviews.llvm.org/D141472#4106091>, @tbaeder wrote:
>> Member pointers (for functions or for data) are weird in that they're not >> the typical pointer width. They're actually a pointer and between >> one-to-three other fields in a trenchcoat, depending on the circumstances. >> You generally need the function pointer, but you also may need various >> offsets (to this, to the vtable, etc). There's some more information about >> how it's done in MSVC (which is different from Itanium ABI, but we can do >> what we want for the constant expression interpreter): >> https://rants.vastheman.com/2021/09/21/msvc/ >> >> I don't think there's a problem with `FunctionPointer` per se, I'm more >> wondering are you planning to also add a `MemberPointer` type or are you >> planning to reuse `FunctionPointer` to handle function members (and >> presumably something else for data members)? >> >> As for virtual functions in general, the standard has rules: >> http://eel.is/c++draft/expr.const#5.6 and http://eel.is/c++draft/expr.const#7 > > I was thinking that the `dynamicDispatch` in https://godbolt.org/z/rf9Ks77Wo > would be a good reproducer since the actual function to call is only known > when calling `dynamicDispatch()`, but that example already works when doing a > few changes to `classify()` the right types and adding a `if > (BO->isPtrMemOP()) { return visit(RHS); }` to `VisitBinaryOperator()`. That is a reasonable test, but probably not sufficient as nothing is really testing the layout of those objects (the calls return a constant). How about a test like: https://godbolt.org/z/rhhhvxYxf where there are offsets to member variables involved? CHANGES SINCE LAST ACTION https://reviews.llvm.org/D141472/new/ https://reviews.llvm.org/D141472 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
