[GROOVY-10006] @CompileStatic fails to unify types

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.6
• Fix Version/s: 4.0.0-alpha-3, 2.5.19, 3.0.13
• Component/s: Static compilation, Static Type Checker
• Assignee: Eric Milles
• Reporter: Konstantin Nisht
• Created: 31/Mar/21 16:18
• Updated: 12/Sep/22 22:43
• Resolved: 11/Apr/21 15:47

Description

@CompileStatic
class A {
    static <U> void foo(U a, U b) {}

    static void main(String[] args) {
        foo(1, "")
    }
}

The following code fails to compile with error

Groovyc: [Static type checking] - Cannot call <U> A#foo(U, U) with arguments [int, java.lang.String]

U should be inferred to LUB(Integer, String), hence the call should be successful.

Issue Links

• is related to: GROOVY-5692 TypeChecked not checking generics placeholder types across arguments when a method has multiple arguments