Anastasia added a comment. In D134445#3920448 <https://reviews.llvm.org/D134445#3920448>, @rjmccall wrote:
> In D134445#3920257 <https://reviews.llvm.org/D134445#3920257>, @Anastasia > wrote: > >> In D134445#3920188 <https://reviews.llvm.org/D134445#3920188>, @rjmccall >> wrote: >> >>> You really can't ask whether a class template pattern is standard layout; >>> it's not meaningful. >> >> Well the templates have to be instantiated with concrete types as kernels >> can't be called from the host code. But if the concrete type is a reference >> or pointer there is no full instantiation apparently as AST dumps in the >> review description show. > > My objection here is to the code that does `CXXRec = > CXXRec->getTemplateInstantiationPattern()`. That is the unsubstituted > template pattern. You then ask if it has standard layout. I do not think > this is the right thing to do. Yes this only works if the type doesn't depend on the template parameter like in the reported test case. But it is not a universal solution. >>> How are pointers and references passed to kernels? Does the pointee get >>> copied or something? If so, you may have a requirement that pointee types >>> be complete, in which case the only problem is probably that you're doing >>> this check too soon, or doing them on declarations rather than on >>> definition/use. >> >> Ok, the kernel function actually already contains the instantiated templates >> since they can't be templated themselves. > > Yes, I understand that. > >> My understanding is that references and pointers to templated types are not >> required to be fully instantiated as they are not ODR-used? > > It's not the ODR, but yes, in standard C++, declaring a parameter of pointer > type does not require the pointee type to be complete, and if the pointee > type is a template type, the compiler is not permitted to immediately try to > instantiate it. Of course, OpenCL `kernel` declarations are not standard C++ > and can use different rules, and I think the fact that OpenCL has this > semantic restriction on pointer arguments to kernels is pretty good license > to do so. There are some places in C++ (e.g. initialization) that do > instantiate templates if a definition is available, and you can request this > by calling `Sema::isCompleteType` instead of `hasDefinition()`. Ok, thanks! I will look into this. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D134445/new/ https://reviews.llvm.org/D134445 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
