[all-commits] [llvm/llvm-project] f82df0: [C++20] [Modules] Use CanonicalType for base classes

[Chuanqi Xu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f82df0b285acd8a7115f0bfc55ce44474251c2d1
      https://github.com/llvm/llvm-project/commit/f82df0b285acd8a7115f0bfc55ce44474251c2d1
  Author: Chuanqi Xu <yedeng.yd at linux.alibaba.com>
  Date:   2023-07-11 (Tue, 11 Jul 2023)

  Changed paths:
    M clang/lib/AST/ODRHash.cpp
    A clang/test/Modules/pr63595.cppm

  Log Message:
  -----------
  [C++20] [Modules] Use CanonicalType for base classes

This comes from https://reviews.llvm.org/D153003

By @rsmith, the test case is valid since:

> Per [temp.type]/1.4 (http://eel.is/c++draft/temp.type#1.4),
>
>> Two template-ids are the same if [...] their corresponding template
>> template-arguments refer to the same template.
> so B<A> and B<NS::A> are the same type. The stricter "same sequence of
> tokens" rule doesn't apply here, because using-declarations are not
> definitions.

> we should either (preferably) be including only the syntactic form of
> the base specifier (because local syntax is what the ODR covers), or
> the canonical type (which should be the same for both
> using-declarations).

Here we adopt the second suggested solutions.

Reviewed By: cor3ntin, v.g.vassilev

Differential Revision: https://reviews.llvm.org/D154324