[SR-11679] Incorrect fixit suggestion for init in CFType extension

[nicklockwood]

Previous ID	SR-11679
Radar	None
Original Reporter	@nicklockwood
Type	Bug
Status	Resolved
Resolution	Done

Attachment: Download

Additional Detail from JIRA

Votes	1
Component/s	Compiler
Labels	Bug, DiagnosticsQoI, StarterBug
Assignee	alagos (JIRA)
Priority	Medium

md5: 12d2b7a4d3ba982058d48bdb58177541

Issue Description:

Adding initializers to CFTypes via an extension is apparently not supported, but the compiler suggests this can be fixed by adding the `convenience` keyword (which doesn't work).

[belkadan]

This error message comes from diag::designated_init_in_extension in TypeCheckDecl.cpp; we can have it emit a different message if the class is a CF type. The way to test for CF types is shown just above in the same method in order to emit the second diagnostic, diag::cfclass_convenience_init.

[swift-ci]

Comment by Alberto Lagos (JIRA)

Hi @belkadan, it ok if I take this ticket and try to fix it? I believe that it will be a good way to start contributing to swift.

[belkadan]

Yep, welcome! Please ask me or @CodaFi if you have questions.

[swift-ci]

Comment by Alberto Lagos (JIRA)

@belkadan Like you said, above where diag::designated_init_in_extension is emitted, I can determine if the Decl is of type CF:

classDecl->getForeignClassKind() == ClassDecl::ForeignKind::CFType

My solution basically implies duplication of code, is that ok?.

Another question is, where I find the test related to the TypeCheckDecl? (more concrete ```InitKindRequest```).

Thanks!

cc CodaFi (JIRA User)

[belkadan]

I think it's okay to duplicate that check. You shouldn't have to duplicate much more, right? You'd emit the alternative diagnostic instead?

As for where to put the test case, I don't know offhand, but I'd search the test/ directory for the existing messages emitted by diag::designated_init_in_extension and diag::cfclass_convenience_init.

[swift-ci]

Comment by Alberto Lagos (JIRA)

I just submit a PR #28015

Let me know anything.

Thanks @belkadan for your help!