rjmccall added a reviewer: ahatanak. rjmccall added inline comments.
================ Comment at: clang/lib/CodeGen/CGCall.cpp:2198 + // reference to the underlying object. Mark it accordingly. + Attrs.addAttribute(llvm::Attribute::NoAlias); + ---------------- fhahn wrote: > rjmccall wrote: > > This definitely can't be added unconditionally to all types; you need to > > rule out non-trivial C++ class types, as well as types with ObjC weak > > references. > Updated to rule out non trivially-copyable types. > > I am not sure how to best handle types with weak references. I did not manage > to find any helpers that traverse a whole type to check if it contains weak > references. > > I added `clang/test/CodeGenObjC/pass-by-value-noalias.m` and IIUC `noalias` > should not be added for that case. The restriction should not be by triviality but by whether indirectness is forced semantically. That may currently only be available on RecordDecl (as `RecordDecl::getArgPassingRestrictions`), but you could definitely add an accessor to `Type` which checked for a RecordType and otherwise returned that there are no passing constraints. Tagging Akira, who worked on this. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D85473/new/ https://reviews.llvm.org/D85473 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
