Michael137 added a comment. In D142268#4072358 <https://reviews.llvm.org/D142268#4072358>, @dblaikie wrote:
> So @Michael137 and I talked about this offline, and a few extra details: > > - Generally it's important that types have identical names. Templates try to > do this, but get it wrong in a bunch of ways (& certainly between GCC and > Clang we get it different in a bunch of ways too) which are all > problematic/could cause a debugger to not correctly identify two types in > distinct CUs as being actually the same type. > - That's why we usually use the full name of a template, to ensure it's > identical between instantiations in different CUs > - Because compilers don't all produce character-for-character identical > names, debuggers mostly have to throw away the "<.*>" and recanonicalize from > the `DW_TAG_template_*_parameter`s anyway.. > - But none of that matters, because alias templates aren't strong aliases - > they aren't part of the type system, they're just a name that code can use > - As mentioned, GCC currently only uses the base name, no template parameters > - which isn't super helpful (since you'd then end up with a bunch of > different alias template instantiations all with the same name). > - Clang produces the alias template with the template parameters in the > `DW_AT_name`, but without any `DW_TAG_template_*_parameter` DIEs, which means > we can't apply Simple Template Names here, currently - though might be a nice > thing to do at somepoint. > > But for now, since the name doesn't actually have to be > deconstruct/canonicalize the template parameters - we can just pick whatever > name is nice for the user, really. > > So, I think this is an OK change to make for now - though probably the nicer > thing, long-term, would be to add the template parameter DIEs, and under > `-gsimple-template-names` remove the template parameters from the > `DW_AT_name` (& maybe eventually turn that on by default/migrate to > `-gsimple-template-names`) but for now/when using > non`-gsimple-template-names`, this seems OK, if a bit weird/inconsistent, but > for good reasons because the alias template isn't part of the type system. > (thanks for including the FIXME there) Thanks for the extensive summary! Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D142268/new/ https://reviews.llvm.org/D142268 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
