libc: `MSVC_DEBUG_INFORMATION_FORMAT` value 'Embedded' not known for this ASM compiler.

[petrhosek]

In #119806 we're seeing the following error:

CMake Error in D:/a/llvm-project/llvm-project/libc/fuzzing/__support/CMakeLists.txt:
  MSVC_DEBUG_INFORMATION_FORMAT value 'Embedded' not known for this ASM
  compiler.

This is due to -DCMAKE_MSVC_DEBUG_INFORMATION_FORMAT=Embedded being set in

llvm-project/.github/workflows/libc-overlay-tests.yml

Lines 76 to 91 in 8c681a9

	# Use MinSizeRel to reduce the size of the build.
	# Notice that CMP0141=NEW and MSVC_DEBUG_INFORMATION_FORMAT=Embedded are required
	# by the sccache tool.
	- name: Configure CMake
	run: >
	cmake -B ${{ steps.strings.outputs.build-output-dir }}
	-DCMAKE_CXX_COMPILER=${{ matrix.compiler.cpp_compiler }}
	-DCMAKE_C_COMPILER=${{ matrix.compiler.c_compiler }}
	-DCMAKE_BUILD_TYPE=MinSizeRel
	-DCMAKE_C_COMPILER_LAUNCHER=sccache
	-DCMAKE_CXX_COMPILER_LAUNCHER=sccache
	-DCMAKE_POLICY_DEFAULT_CMP0141=NEW
	-DCMAKE_MSVC_DEBUG_INFORMATION_FORMAT=Embedded
	-DLLVM_ENABLE_RUNTIMES=libc
	-G Ninja
	-S ${{ github.workspace }}/runtimes

[llvmbot]

@llvm/issue-subscribers-libc

Author: Petr Hosek (petrhosek)

In #119806 we're seeing the following error: ``` CMake Error in D:/a/llvm-project/llvm-project/libc/fuzzing/__support/CMakeLists.txt: MSVC_DEBUG_INFORMATION_FORMAT value 'Embedded' not known for this ASM compiler. ``` This is due to `-DCMAKE_MSVC_DEBUG_INFORMATION_FORMAT=Embedded` being set in https://github.com/llvm/llvm-project/blob/8c681a929b8684f5a4ad2ebd4e3e4f20036a9595/.github/workflows/libc-overlay-tests.yml#L76-L91

[SchrodingerZhu]

I see you have workaround the issue by setting the property separately for specific target. I think that would be the best solution for now.

[michaelrj-google]

I'm not sure why we have any MSVC settings, since we don't currently support building with MSVC.

[SchrodingerZhu]

We do support windows after @Lancern's prior work. And we have CI running to check the windows build.

[michaelrj-google]

We support building on windows, but at least in the past that's been building with clang on windows. I had assumed that was still what we were planning to support.