[PATCH] D116983: Clone constructor template parameters when creating deduction guide

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added inline comments.


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Comment at: clang/lib/Sema/SemaTemplate.cpp:2174
+      Args.addOuterTemplateArguments(SubstArgs);
+      Args.addOuterRetainedLevel();
+      NamedDecl *NewParam = transformTemplateParameter(Param, Args);
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aeubanks wrote:
> rsmith wrote:
> > This outer retained level would correspond to the parameters you're building -- we shouldn't add this. Instead, we should have two different `SubstArgs` lists, one for the outer parameters and one for the inner parameters; we should add just the outer parameters here, and add the inner and outer parameters below. (And at the end of each iteration of this loop we should accumulate arguments onto the outer arguments list like we accumulate arguments onto the inner arguments list in the next loop.)
> I think this is what you're referring to? I still don't understand exactly what `Args.addOuterRetainedLevel()` does, and the current draft doesn't fix the modules crash.
I found a few more places that need to be adjusted. Here's where I got to: https://github.com/zygoloid/llvm-project/commit/fffb4b688eb5a91bc2aca673773bc2da018f3dba (this is on top of the earlier version of this patch, though).

There are still some test failures there, so I think some more updates are still needed. We also need to do the same cloning process in `buildSimpleDeductionGuide`, which I think is why the modules unit test is still failing.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D116983/new/

https://reviews.llvm.org/D116983