[PATCH] D91488: Consider reference, pointer, and pointer-to-membber TemplateArguments to be different if they have different types.

[Arthur O'Dwyer via Phabricator via cfe-commits]

Quuxplusone added inline comments.


================
Comment at: clang/lib/AST/ItaniumMangle.cpp:4861
+    // We need correct types when the template-name is unresolved or when it
+    // might be overloaded.
+    if (!ResolvedTemplate)
----------------
And from the PR summary:

> namely mangling such template arguments as being cast to the parameter type in the case where the template name is unresolved or overloaded

This phrasing worries me a little bit. Are you saying that you might mangle the name of `foo<SomeT>` in one way, when there's also a `foo<Some, Other, Args>` in scope, and in a different way, when there's not? That doesn't seem conforming. So I imagine it's more likely that I'm misunderstanding what you mean by "might be overloaded" / "is overloaded". Could you explain for my information, and perhaps also adjust the wording of these code comments to make the explanation less needed?

Specifically, I think it would be non-conforming if the TU

    // https://godbolt.org/z/YjPqMd
    template<char *> void foo();
    char arr[6];
    extern template void foo<arr>();  // #1
    int main() { foo<arr>(); }

could not be linked against the TU

    template<int> int foo();
    template<char *> void foo();  // is this "overloading"?
    extern char arr[6];
    template<> void foo<arr>() {}  // #2

because lines #1 and #2 disagreed about the way to mangle `foo<arr>`. (Again, I'm pretty sure you haven't made them disagree... but I remain unclear on what's meant by "overloading" in this PR, if it's //not// this.)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D91488/new/

https://reviews.llvm.org/D91488