Disassemble SPIR-V via IDxcCompilerX::Disassemble?

[MarijnS95]

Backstory

Running dxc -spirv ... without -Fo for object output, or explicitly requesting a disassembly file with -Fc emits human-readable SPIR-V disassembly. However, it seems this functionality is only available in the dxc executable (and tracing it back to dxclib), but not in libdxcompiler.so.

Confusion/caveats

For one, it seems that CompileWithDebug does not output a debug ppDebugBlob/ppDebugBlobName (despite the _COM_Outptr_opt_/_Outptr_opt_result_z_ annotation stating that Parameter may be null, but in the post-state the pointed-to location can't be null and must be valid), and this data originates from DXC_OUT_PDB which is not in the returned IDxcResult for a SPIR-V compilation unit (SPIR-V doesn't define a separate debug/disassemble-able file/format).

(Then, I'm not sure about this, does Disassemble have enough data when a DXIL object is compiled with -Zi -Qembed_debug or does it require the full PDB here? It seems it cannot disassemble DXC_OUT_OBJECT output regardless of the flags, but may be lacking validation for example)

Goal/request

Since spirv_tools are already used in dxcompiler, would it be possible to move this functionality from dxclib to be reachable via the ::Disassemble APIs (and simply switch on the header magic), allowing dxcompiler to be used for SPIR-V disassembly in a more streamlined manner like DXIL?

[s-perron]

This is not something we will be supporting.