Are you able to run clang-cl.exe successfully (including linker) from .bat file that calls VsDevCmd? Without calling 4coder.
Hmm, there seems to be progress here.
call "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\Tools\VsDevCmd.bat" -arch=amd64 -host_arch=amd64 -no_logo
clang-cl.exe: warning: unknown argument ignored in clang-cl: '-PDB:jesse_15885.pdb' [-Wunknown-argument]
clang-cl.exe: error: no such file or directory: '/EXPORT:GameUpdate'
But I don't know how to address these errors, because I don't know what's causing them.
I've tested this further. These warnings do not seem to imply that clang-cl has found link.exe. They are just statements about the arguments. If I try to build a minimal C++ program from this command prompt, configured by VsDevCmd.bat, Clang-cl still cannot find link.exe.
I am making the assumption that Clang-cl is looking
for link.exe. It may not. It may have found it but its output still isn't quite compatible with it. I would have liked more pointed error messages about what it's failing to do, which is ironic when Clang is known for quality error messaging.