Open Radar

 
Summary:
Nested local functions mustn’t reference themselves, which is terrible, but at least the error is clear. Certain references within closures give a misleading/flat out wrong error, too.


Steps to Reproduce:
1. This code. Compile it.

func f(x: Int?) {
	func g() {
		x.map { _ in
			g
		}
	}
}


Expected Results:
I expected it to bother me about the expression evaluating to an unused closure, or at least to error about the recursive reference.


Actual Results:
./spurious-local-nested-function-error-of-doom.swift:6:4: error: cannot reference a local function with captures from another local function

WAT


Regression:
N/A


Notes:
I found two (count ’em!) sweet crashes trying to reduce this:

1. rdar://19152922
2. rdar://19153007

(Look how small the delta between those numbers is!)

I assume it’s referring to the closure passed to map, but _who knows_! The diagnostic points at the inner reference to g. At least the “local functions cannot reference themselves” error message would point me at the actual problem :\