libsysdecode: Teach mktables to handle enums

[des]

Summary

While here, clean up and simplify the existing code.

MFC after: 1 week

[des]

simpler solution

[des]

hmm, given awk's limited regex syntax I think it would be better to process the exclusion using sed and use awk only to pick out enums.

[des]

less awk, more sed

[jhb]

lib/libsysdecode/mktables

57

Having filter be local so it doesn't get created in the global namespace is still nice.

108

s/TABLE_NAME/TABLE_START/? (Old bug I think)

125

I think the only thing here is that this doesn't permit named enums, only enum {\n... }. That's fine for now I guess, but at some point the regex might have to be relaxed to allow a valid C identifier between enum and the {.

[des]

lib/libsysdecode/mktables

125

yes it does, the ([[:space:]].*)? bit takes care of that, and I added support for a leading typedef after you commented. I don't want to make it more specific than that because technically there could be attributes (e.g. enum_extensibility) between the enum keyword and the identifier.

[des]

rf

[des]

further simplify the original code

[glebius]

Thanks a lot! Didn't review the awk/sed code, since not an expert in it.

[jhb]

lib/libsysdecode/mktables

125

I had misread the regex as only matching whitespace. It is pretty generic as you note, but I agree that it's probably not tenable to be more specific than just requiring at least one space before any other non-space characters.