[GROOVY-9346] Closure shared variable type is polluted with previous assignment type

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.5.8
• Component/s: Static Type Checker
• Assignee: Unassigned
• Reporter: Daniil Ovchinnikov
• Created: 19/Dec/19 14:09
• Updated: 19/Dec/19 14:09

Description

class A { def foo() {42} }

@groovy.transform.CompileStatic
def cs() {
    def var  
    var = "hi" // commenting this line fixes the issue 
    var = new A() 
    def c = {
        var = new A()
    }
    c()
    var.foo() // [Static type checking] - A closure shared variable [var] has been assigned with various types and the method [foo()] 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.
}
assert cs() == 42