[SR-5626] [SourceKit] Include name range in subscript structure

[marcelofabri]

Previous ID	SR-5626
Radar	None
Original Reporter	@marcelofabri
Type	Improvement
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Source Tooling
Labels	Improvement
Assignee	@nkcsgexi
Priority	Medium

md5: 9175a59a48621f4bbf14108ac4dbcedc

Issue Description:

#11258 added support for source.lang.swift.decl.function.subscript in a structure.

However, key.nameoffset and key.namelength are both 0.

I'm willing to send a PR, but I need some help on how to find the name length (or end). I was able to find the arrow start (but this would make the name length larger than needed).

I also tried using the parameters (similar how it's done in SourceRange AbstractFunctionDecl::getSignatureSourceRange()), but it didn't include the right parentheses for some reason (so the length is shorter than expected).

[marcelofabri]

cc @nkcsgexi

[nkcsgexi]

We merged this. Right?

[marcelofabri]

We merged #11258 but we still don't add name ranges in the structure.

[nkcsgexi]

I'll take it.

[nkcsgexi]

@marcelofabriThe name range for the following code:
```
class C {
subscript(index: Int) -> Int{
get {
return 1
}
}
}
```
is 0 because `index` is an internal name. We don't show internal name for argument in general. Do you actually need them?

[marcelofabri]

There're some use cases that we use the name range:

• searching for generic clauses inside it

• using its end as start to search for an arrow

• using its end to search for the return type

Although index is an internal name, it's still present on key.substructure (even with a name range), so I don't see why we shouldn't add the name range to the subscript structure itself.

[nkcsgexi]

@marcelofabricould we add another key to signify the internal name instead of changing what it means for `key.nameoffset` and `key.namelength`?i.e. they are for external names.
In ParamDecl, getNameLoc() will give us the start position of the internal name. Mind opening a PR for this?

[marcelofabri]

@nkcsgexi Just to be clear that we're talking about the same thing, this is a structure currently for a subscript:

{
  key.kind: source.lang.swift.decl.function.subscript,
  key.accessibility: source.lang.swift.accessibility.internal,
  key.setter_accessibility: source.lang.swift.accessibility.internal,
  key.name: "subscript(_:)",
  key.offset: 16,
  key.length: 36,
  key.nameoffset: 0, 
  key.namelength: 0,
  key.bodyoffset: 42,
  key.bodylength: 9,
  key.substructure: [
    {
      key.kind: source.lang.swift.decl.var.parameter,
      key.name: "i",
      key.offset: 26,
      key.length: 6,
      key.typename: "Int",
      key.nameoffset: 0,
      key.namelength: 0
    }
  ]
}

My original issue was about key.nameoffset and key.namelength on the top level (source.lang.swift.decl.function.subscript), but I think you're talking about the parameter only.

Actually, I event hadn't noticed that, but I guess it's consistent with a function with a unnamed parameter (func foo(_ i: Int)). So I think we should leave the parameter as it is (at least for now). What I expected is that the top level subscript had a name range.

[nkcsgexi]

Thanks for the explanation, @marcelofabri In ASTPrinter.h, there is a utility called "getKeywordLen". Will this help you get the end location of "subscript"?

[marcelofabri]

@nkcsgexi That can help getting the length of "subscript", but all other (function) declarations also include the parameters in name range. Wouldn't that be the preferred behavior?

[nkcsgexi]

#11376