Markus Armbruster <arm...@redhat.com> writes: > Kevin Wolf <kw...@redhat.com> writes: [...] >> Yes, don't use optional objects in the middle of the path of a wildcard >> alias unless there is no semantic difference between empty object and >> absent object. > > Aha! So my spidey-sense wasn't entirely wrong.
Like optional members, union branches get visited only when the input is shaped a certain way. Which makes me wonder: does "don't use optional in the middle" apply to union branches, too? Hmm, I figure it doesn't because * If the union is flat, there is no object: the variant members are the members of the branch struct type. * If the union is simple, there is, but it's always there: 'data'. Hope I'm not speaking in riddles. >> This is documented in the code, but it might actually >> still be missing from qapi-code-gen.txt. > > I can't find it there. Needs fixing, obviously. "there" = qapi-code-gen.txt > I guess checking "path of a wildcard alias crosses optional objects" is > hard (impractical?) for the same reasons checking "alias can't resolve" > is. > > I'd expect "alias can't resolve" to be caused by typos, incomplete > renames, and such. Basic testing should catch at least the typos. Not > ideal, but I guess it'll do, at least for now. > > Relying on testing to catch "crosses optional objects" mistakes feels > iffier to me, because it takes more careful tests. > > Ham-fisted way to make basic tests catch it: *ignore* optional objects > when resolving aliases. Is this a bad idea? [...]
