[GROOVY-9345] Closure shared variable type is polluted with unreached assignment type

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Static compilation, Static Type Checker
• Assignee: Unassigned
• Reporter: Daniil Ovchinnikov
• Created: 19/Dec/19 14:04
• Updated: 19/Dec/19 14:04

Description

@groovy.transform.CompileStatic
def cs() {
    def var
    
    var = "hi"
    println var.toUpperCase() // [Static type checking] - A closure shared variable [var] has been assigned with various types and the method [toUpperCase()] does not exist in the lowest upper bound of those types: [java.lang.Object]. In general, this is a bad practice (variable reuse) because the compiler cannot determine safely what is the type of the variable at the moment of the call in a multithreaded context.
    
    def c = {
        var = new Object()
    }
    c()
    var.toString()
}

assert cs() != null