[all-commits] [llvm/llvm-project] 0d2143: [C++20] [Modules] Warn if we found #include <filen...

[Chuanqi Xu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0d2143611425081bb9db5bb6ee57aaddfd1eda53
      https://github.com/llvm/llvm-project/commit/0d2143611425081bb9db5bb6ee57aaddfd1eda53
  Author: Chuanqi Xu <yedeng.yd at linux.alibaba.com>
  Date:   2023-11-02 (Thu, 02 Nov 2023)

  Changed paths:
    M clang/include/clang/Basic/DiagnosticLexKinds.td
    M clang/lib/Lex/PPDirectives.cpp
    A clang/test/Preprocessor/include-in-module-purview.cppm

  Log Message:
  -----------
  [C++20] [Modules] Warn if we found #include <filename> in module purview (#69555)

Close https://github.com/llvm/llvm-project/issues/68615.

It is generally wrong to include <filename> in the module purview.
Although there are cases to include files in the module purview,
generally these use cases should include files by quotes instead of by
angles. Here we think the files got included by angles are the system
headers.

This is consistency with MSVC too:
https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warnings-by-compiler-version?view=msvc-170#warnings-introduced-in-visual-studio-2022-version-170-compiler-version-1930