[javasrc2cpg] fix ext method call full name with same name of a scope var

[xavierpinho]

When dealing with:

• external method calls whose receiver type we can't resolve, and
• if there is a variable in scope with that same name, then

we are resolving to that variable's type, as in:

import org.Client;
import org.Builder;
...
Client foo = new Builder().foo().build(); // build's receiver is org.Client
Client bar = new Builder().somethingElse().build(); // build's receiver is <unresolvedNamespace>

This gets worse: if in the 2nd statement above we had used foo() again instead of somethingElse(), it would resolve again to org.Client.

This patch stinks, though: I'm not a fan of that edge condition. Hopefully we can find something nicer.

[DavidBakerEffendi]

Ideally, our namespace would be org.Builder right? Is it a large effort (or unsound in some cases) to achieve this result based on imports?

[xavierpinho]

Ideally, our namespace would be org.Builder right? Is it a large effort (or unsound in some cases) to achieve this result based on imports?

Not always, would depend on the return type of foo() and somethingElse(). Some libraries would return different types so that the order of operations/methods we can call is coherent.

[johannescoetzee]

This is a good catch! I think this patch is fine to merge to fix it for now. I wonder about matching the NodeWithSimpleName there in general. I originally did it that way to keep the code simple, but I didn't consider all the cases. It might make more sense to only match the specific node types we want to look up (so possibly just identifiers and types, but we'd have to consider all options)

[johannescoetzee]

Ideally, our namespace would be org.Builder right? Is it a large effort (or unsound in some cases) to achieve this result based on imports?

The namespace should already be org.Builder for the foo and somethingElse calls based on the imports. We don't know anything about the return types of those methods though, so can't say anything sensible about the namespace for the build calls.