DXC: Annotate new struct fields and enums

[MarijnS95]

For #474 (comment).

For DXC_FOURCC it would have been awesome if we could have something like the following, if const methods were supported:

public static const uint DXC_FOURCC(char ch0, char ch1, char ch2, char ch3) => ch0 | (ch1 << 8) | (ch2 << 16) | (ch3 << 24);

[MarijnS95]

Unfortunately both these static const UINT32s don't appear to be parsed by enums.json?

[mikebattista]

Seems more like a ClangSharp limitation than enums.json.

[MarijnS95]

Yeah, either way it's something that I expected to show up, but it didn't. Should I manually declare "members", while leaving "autoPopulate" in place in hopes of getting a compilation conflict when ClangSharp can provide these to us, or is it a fix you can do elsewhere in the tooling?

As this PR shows we used to have manual fields for DXC_CP_ too (now unnecessary), while also relying on autoPopulate without conflicts being generated?

[mikebattista]

Yes you can manually declare the missing members together with autoPopulate. The sets will be merged.

[MarijnS95]

Cool. Fixed it by removing it, because they can be autodetected.

I don't remember the status of this PR: I think I got stuck on the static const UINT32s not being parsed, only #defines? Is there any plan/solution for that?

[MarijnS95]

Seems more like a ClangSharp limitation than enums.json.

@mikebattista Am I right to assume that ClangSharp emits whatever it finds after preprocessing? I'd assume that all the preprocessor directives are flattened out, which is why the ConstantsScraper specifically looks for #define in source files:

win32metadata/sources/MetadataUtils/ConstantsScraper.cs

Lines 32 to 34 in 2e6b619

	private static readonly Regex DefineRegex =
	new Regex(
	@"^\s*#\s*define\s+([_A-Za-z][\dA-Za-z_]+)\s+(.+)");

This is the only code that looks at autoPopulate. Assuming that "actual C constants" are extracted from ClangSharp and written elsewhere (could it be ConstantWriter?), is this where we should insert extra logic to turn static const definitions into grouped enums as well?