[PATCH] D144603: Add option to disable compiler launcher on external projects

[Petr Hosek via Phabricator via cfe-commits]

phosek added a comment.

A more generic version might be to have a list of variables to (not) passthrough.

First option is to remove `{C,CXX}_COMPILER_LAUNCHER` from `_BOOTSTRAP_DEFAULT_PASSTHROUGH` and then include it as needed by setting something like `CLANG_BOOTSTRAP_EXTRA_PASSTHROUGH=C_COMPILER_LAUNCHER;CXX_COMPILER_LAUNCHER`.
Second option is to provide a way to filter out variable from passthrough, for example `CLANG_BOOTSTRAP_NO_PASSTHROUGH=C_COMPILER_LAUNCHER;CXX_COMPILER_LAUNCHER`.

I slightly prefer the first option, but it'd be a breaking change, so the second option might be the only feasible one.



================
Comment at: llvm/cmake/modules/LLVMExternalProjectUtils.cmake:305-310
+  set(C_COMPILER_LAUNCHER ${CMAKE_C_COMPILER_LAUNCHER})
+  set(CXX_COMPILER_LAUNCHER ${CMAKE_CXX_COMPILER_LAUNCHER})
+  if (LLVM_DISABLE_COMPILER_LAUNCHER_FOR_EXT_PROJECT)
+    set(C_COMPILER_LAUNCHER "")
+    set(CXX_COMPILER_LAUNCHER "")
+  endif()
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I think it's better to avoid setting these at all if disabled rather than setting them to an empty string. You can just append these to `cmake_args`.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D144603/new/

https://reviews.llvm.org/D144603