Open Radar

 
Summary:
In general, it is fine to refer to an enclosing function from the body of a closure that is defined within the function.  For example, the following code compiles without a hitch:

func function() {
    let closure: ()->() = { () -> Void in
        let f = function
        return
    }
}

However, the situation changes when the enclosing function is a local function.  This code yields

func outerfunction() {
    func function() {
        let closure: ()->() = { () -> Void in
            let l = function
            return
        }
    }
}

yields the following error:

Instruction does not dominate all uses!
  %6 = bitcast %SS* %0 to %swift.opaque*, !dbg !82
  %2 = bitcast %swift.opaque* %6 to i8*, !dbg !79
LLVM ERROR: Broken function found, compilation aborted!

Steps to Reproduce:
1. Feed swiftc the following text:

func outerfunction() {
    func function() {
        let closure: ()->() = { () -> Void in
            let l = function
            return
        }
    }
}

2. Witness the error.

Expected Results:
This code should perhaps compile without a hitch given that it works just fine for a non-local function.  Or perhaps not, I don't have the clearest sense of the intended semantics of local functions.  At any rate, this sort of error shouldn't be produced.

Actual Results:
Swift Compiler Error

Instruction does not dominate all uses!
  %6 = bitcast %SS* %0 to %swift.opaque*, !dbg !82
  %2 = bitcast %swift.opaque* %6 to i8*, !dbg !79
LLVM ERROR: Broken function found, compilation aborted!

Version:
6.1.1 (6A2008a)
6.2 Beta (6C86e)


Notes:


Configuration:


Attachments: