[SR-12903] References to @objc optional funcs do not get indexed

[swift-ci]

Previous ID	SR-12903
Radar	None
Original Reporter	rockbruno (JIRA User)
Type	Bug

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug
Assignee	None
Priority	Medium

md5: 673dbd66810d405d1790652da9602332

Issue Description:

import Foundation

@objc protocol Foo {
    @objc optional func bar()
}

class Sample {

    weak var delegate: Foo?

    func doSomething() {
        delegate?.bar()
    }
}

In this snippet, `bar` from `delegate?.bar()` will not get indexed. This only happens if the declaration is `optional`. It works with just `objc`.

Here's how the AST of this looks like:

(optional_evaluation_expr implicit type='<null>'
(call_expr type='<null>' arg_labels=
(unresolved_dot_expr type='<null>' field 'bar' function_ref=single
(bind_optional_expr type='<null>' depth=0
(unresolved_dot_expr type='<null>' field 'delegate' function_ref=unapplied
(declref_expr implicit type='<null>' decl=blabla.(file).Sample.doSomething().self@/Users/rochab/Desktop/blabla.swift:11:10 function_ref=unapplied))))

Looks like it hasn't got resolved.

[swift-ci]

Comment by Bruno Rocha (JIRA)

@nathawes Have you got any tips on where to start debugging for this? I tried seeing where the indexing trace differs from a plain objc property from an optional one but haven't got much luck.

[nathawes]

I think `delegate?.bar()` needs to be `delegate?.bar?()` for it to be resolved.

[swift-ci]

Comment by Bruno Rocha (JIRA)

Ah crap, that's true, sorry for the bad example. The indexing part is still true though

1:8 | module/C | Foundation | c:@m@Foundation | Ref | rel: 0
3:16 | protocol/Swift | Foo | c:@m@swift_ide_test@objc(pl)Foo | Def | rel: 0
4:25 | instance-method/Swift | bar() | c:@m@swift_ide_test@objc(pl)Foo(im)bar | Def,Dyn,RelChild | rel: 1
RelChild | protocol/Swift | Foo | c:@m@swift_ide_test@objc(pl)Foo
7:7 | class/Swift | Sample | s:14swift_ide_test6SampleC | Def | rel: 0
9:14 | instance-property/Swift | delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvp | Def,RelChild | rel: 1
RelChild | class/Swift | Sample | s:14swift_ide_test6SampleC
9:14 | instance-method/acc-get/Swift | getter:delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvg | Def,Dyn,Impl,RelChild,RelAcc | rel: 1
RelChild,RelAcc | instance-property/Swift | delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvp
9:14 | instance-method/acc-set/Swift | setter:delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvs | Def,Dyn,Impl,RelChild,RelAcc | rel: 1
RelChild,RelAcc | instance-property/Swift | delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvp
9:24 | protocol/Swift | Foo | c:@m@swift_ide_test@objc(pl)Foo | Ref | rel: 0
11:10 | instance-method/Swift | doSomething() | s:14swift_ide_test6SampleC11doSomethingyyF | Def,Dyn,RelChild | rel: 1
RelChild | class/Swift | Sample | s:14swift_ide_test6SampleC
12:9 | instance-property/Swift | delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvp | Ref,Read,RelCont | rel: 1
RelCont | instance-method/Swift | doSomething() | s:14swift_ide_test6SampleC11doSomethingyyF
12:9 | instance-method/acc-get/Swift | getter:delegate | s:14swift_ide_test6SampleC8delegateAA3Foo_pSgvg | Ref,Call,Dyn,Impl,RelRec,RelCall,RelCont | rel: 2
RelCall,RelCont | instance-method/Swift | doSomething() | s:14swift_ide_test6SampleC11doSomethingyyF
RelRec | class/Swift | Sample | s:14swift_ide_test6SampleC
7:7 | constructor/Swift | init() | s:14swift_ide_test6SampleCACycfc | Def,Impl,RelChild | rel: 1
RelChild | class/Swift | Sample | s:14swift_ide_test6SampleC

..but it should be easier to debug with the correct example now

(correct AST for reference

(dynamic_member_ref_expr type='(() -> ())?' location=/Users/rochab/Desktop/blabla.swift:12:19 range=[/Users/rochab/Desktop/blabla.swift:12:9 - line:12:19] decl=blabla.(file).Foo.bar()@/Users/rochab/Desktop/blabla.swift:4:25 [with (substitution_map generic_signature=<Self where Self : Foo> (substitution Self -> Foo))]

)

[swift-ci]

Comment by Bruno Rocha (JIRA)

Found it. SourceEntityWalker doesn't have a case for DynamicMemberRefExpr

[nathawes]

Nice! Thanks for looking into this :-)

[swift-ci]

Comment by Bruno Rocha (JIRA)

#32087