How to output MSL shader source code

[XAMPPRocky]

Hello I'm working on a tool that uses MoltenVK, however we're running into an issue where the SPIRV we provide is valid, however the MSL that is being generated is not. I'm currently trying to investigate and am having trouble replicating the compiled source code using spirv-cross or MoltenVKShaderConverter. Is there a way to get the MoltenVK library to output the compiled MSL code it's generating and not just warnings?

[eddyb]

There appears to be logging logic in MVKShaderModule::convert:

MoltenVK/MoltenVK/MoltenVK/GPUObjects/MVKShaderModule.mm

Line 276 in 82ab40e

bool shouldLogCode = mvkGetMVKConfiguration()->debugMode;

MoltenVK/MoltenVK/MoltenVK/GPUObjects/MVKShaderModule.mm

Lines 300 to 301 in 82ab40e

	if (wasConverted) {
	if (shouldLogCode) { MVKLogInfo("%s", _spvConverter.getResultLog().c_str()); }

EDIT: and based on this, what you need to do is set the MKV_DEBUG=1 environment variable, I believe:

MoltenVK/MoltenVK/MoltenVK/Utility/MVKEnvironment.cpp

Line 30 in 84c6095

MVK_SET_FROM_ENV_OR_BUILD_BOOL (_mvkConfig.debugMode, MVK_DEBUG);

[billhollings]

This answer to use MVK_DEBUG is correct. @eddyb Thanks for responding!

Documentation on the configuration environment variables and settings can be found in the vk_mvk_moltenvk.h file.