[all-commits] [llvm/llvm-project] 4a7be4: [C++20] [Modules] Remove unmaintained Header Module

[Chuanqi Xu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4a7be42d922af0e2a60e08cbac062f57666c0003
      https://github.com/llvm/llvm-project/commit/4a7be42d922af0e2a60e08cbac062f57666c0003
  Author: Chuanqi Xu <yedeng.yd at linux.alibaba.com>
  Date:   2022-11-18 (Fri, 18 Nov 2022)

  Changed paths:
    M clang/include/clang/Driver/Action.h
    M clang/include/clang/Driver/Options.td
    M clang/include/clang/Frontend/FrontendActions.h
    M clang/include/clang/Frontend/FrontendOptions.h
    M clang/include/clang/Lex/ModuleMap.h
    M clang/lib/Driver/Action.cpp
    M clang/lib/Driver/Driver.cpp
    M clang/lib/Driver/ToolChains/Clang.cpp
    M clang/lib/Frontend/CompilerInvocation.cpp
    M clang/lib/Frontend/FrontendActions.cpp
    M clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
    M clang/lib/Lex/ModuleMap.cpp
    R clang/test/CXX/cpp/cpp.module/Inputs/attrs.h
    R clang/test/CXX/cpp/cpp.module/Inputs/empty.h
    R clang/test/CXX/cpp/cpp.module/p1.cpp
    R clang/test/CXX/cpp/cpp.module/p2.cpp
    M clang/test/CXX/module/module.interface/p2.cpp
    R clang/test/Driver/header-module.cpp
    M clang/test/Driver/modules.cpp
    R clang/test/Misc/serialized-diags-emit-header-module-misconfig.c
    R clang/test/Modules/no-module-map.cpp

  Log Message:
  -----------
  [C++20] [Modules] Remove unmaintained Header Module

Currently there is a -emit-header-module mode, which can combine several
headers together as a module interface. However, this breaks our
assumption (for standard c++ modules) about module interface. The module
interface should come from a module interface unit. And if it is a
header, it should be a header unit. And currently we have no ideas to
combine several headers together.

So I think this mode is an experimental one and it is not maintained and
it is not used. So it will be better to remove them.

Reviewed By: Bigcheese, dblaikie, bruno

Differential Revision: https://reviews.llvm.org/D137609