Fix finding references to interface methods

[0101]

A more thorough fix for #15371

[psfinaki]

All the debug key store stuff is just for the convenience and not directly related to the bug, right?

[0101]

All the debug key store stuff is just for the convenience and not directly related to the bug, right?

Yes. And it should all be disabled and not adding any overhead - unless you manually enable it for debugging.

[psfinaki]

Out of curiousity, in plain language, how does this fix the bug given that you don't touch editor code here?

IMO this doesn't feel like a very elegant thing, but if this fixes the bug and we don't have a better idea...

[0101]

Out of curiousity, in plain language, how does this fix the bug given that you don't touch editor code here?

IMO this doesn't feel like a very elegant thing, but if this fixes the bug and we don't have a better idea...

Finding references is a feature of Compiler Service, not editor. ItemKeyStore is an optimization to save memory. Instead of saving the symbols as objects we write their representation into memory mapped file as bytes (+ the range). Then when we need to find references the written bytes needs to be exactly the same for all of them. However, the symbols are not always the same (as here - definition of abstract method vs implementation or override). So that needs to be dealt with in this code.

If we want to make it more elegant we probably have to come up with a different system. Might be interesting to see how Roslyn does it.