[CMake] Set ASM compiler for external projects
authorPetr Hosek <phosek@google.com>
Tue, 28 Jan 2020 03:14:32 +0000 (19:14 -0800)
committerPetr Hosek <phosek@google.com>
Tue, 28 Jan 2020 19:39:21 +0000 (11:39 -0800)
commit56b7f595d2b402ff177ca42214325c8fdea10fb0
tree6c357c79bfa5e2d2d685906494b217abdb45804c
parent04488c485a8875ba4bd6d2d004ac778276ae37e0
[CMake] Set ASM compiler for external projects

This is necessary on Windows, otherwise CMake fails. It's not
conventional on Windows to use cl for assembly (you'd use ml or ml64
instead), but CMake has a separate ASM_MASM mode for that, and clang-cl
works fine for assembly so we'll use that on Windows for consistency.

Differential Revision: https://reviews.llvm.org/D73522
llvm/cmake/modules/LLVMExternalProjectUtils.cmake