Fix include dxcapi.h

[TLescoatTFX]

Hello, I am currently doing a port of Dawn on vcpkg. During this I had to fix an include of dxcapi.h, the code in tint prefixes that filename... As a result, the compiler cannot find dxcapi.h when provided by vcpkg. Sorry for this 6-characters PR.

Almost unrelated, but still about header inclusion, it seems tint includes private headers from SPIRV-Tools (namely source/opt_ir_context.h), is that really necessary ? If so, is there a way to bring that back to upstream ?

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[dj2]

The path is setup this way so it pulls the header from the third_party/dxc/include/ folder which is the copy of DXC we use with Tint.

The SPIR-V Tools header is required if you're building the SPIR-V Reader as we use the optimizer from SPIR-V Tools. As far as I know, there are no plans on making the optimizer API public. That header does exist in upstream SPIR-V tools already though.

[TLescoatTFX]

The path is setup this way so it pulls the header from the third_party/dxc/include/ folder which is the copy of DXC we use with Tint.

Yes. I also think this should not be necessary, notably if the Dawn copy of DXC is the only copy of DXC in the include paths. Furthermore, dawn native already include this header without the prefix...

The SPIR-V Tools header is required if you're building the SPIR-V Reader as we use the optimizer from SPIR-V Tools. As far as I know, there are no plans on making the optimizer API public. That header does exist in upstream SPIR-V tools already though.

Thanks for the info. There seems to be a public API for the SPIRV-Tools optimizer, but I'm not sure if it covers your needs.

[dj2]

If you have both the Dawn copy and DXC, we want to choose the dawn version over the system header.

Yes, there is an interface to run the optimizer, but that isn't what we use/need.

[dj2]

@amaiorano would be in the best position to comment if changing this include to drop the prefix would work as we need.