[all-commits] [llvm/llvm-project] e38cdc: Disable compiler launcher on external projects and...

[Zero Omega via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e38cdc5933b026cd25cf70c06f690a431c608d63
      https://github.com/llvm/llvm-project/commit/e38cdc5933b026cd25cf70c06f690a431c608d63
  Author: Haowei Wu <haowei at google.com>
  Date:   2023-04-24 (Mon, 24 Apr 2023)

  Changed paths:
    M clang/CMakeLists.txt
    M llvm/cmake/modules/LLVMExternalProjectUtils.cmake

  Log Message:
  -----------
  Disable compiler launcher on external projects and multi stage clang

When using compiler caching program like ccache, there is no point to
use them on external projects or multi-stage clang builds. As these
builds uses fresh from source code toolchain and will pollute the build
cache. If a compiler launcher is still required, a user can explicity
define `CMAKE_C_COMPILER_LAUNCHER` and `CMAKE_CXX_COMPILER_LAUNCHER` in
`CLANG_BOOTSTRAP_PASSTHROUGH` and `LLVM_EXTERNAL_PROJECT_PASSTHROUGH`
flags to enable compiler launcher in these builds.

Differential Revision: https://reviews.llvm.org/D144603