[GROOVY-7880] Diamond Operator for own class causes NullPointerException if Static Compilation is enabled

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.3, 2.4.7
• Fix Version/s: 2.4.8
• Component/s: Compiler, Static compilation, Static Type Checker

Environment

Test Machine 1: ArchLinux x64,
openjdk version "1.8.0_92"
OpenJDK Runtime Environment (build 1.8.0_92-b14)
OpenJDK 64-Bit Server VM (build 25.92-b14, mixed mode)

Test Machine 2: MacOSX 10.11.3
Oracle Java Version: 1.8.0_05

• Assignee: Paul King
• Reporter: Roman Leuprecht
• Created: 05/Jul/16 16:23
• Updated: 01/Feb/17 23:18
• Resolved: 11/Aug/16 09:08

Description

When the diamond operator is used to instantiate a generic and the generic is specialized on the class the method is in, static compilation fails with a Nullpointer Exception. Dynamic compilation works, also replacing the diamond operator with the exact type or using "raw" typing.

The following code reproduces the bug on both machines(listed in Environment):

import groovy.transform.CompileStatic

@CompileStatic
class BugTest {
    private class CompilerKiller<T> {
        private T t
        public CompilerKiller(T t){
            this.t = t
        }
    }

    public void "This causes a NPE"(){
        CompilerKiller<BugTest> sample = new CompilerKiller<>(this)
    }

    public void "This causes a NPE as well"(){
        CompilerKiller<BugTest> sample = new CompilerKiller<>(new BugTest())
    }

    public void "This does work"(){
        CompilerKiller<BugTest> sample = new CompilerKiller<BugTest>(this)
    }

    public void "This works as well"(){
        CompilerKiller<BugTest> sample = new CompilerKiller(this)
    }
}

Issue Links

• links to: GitHub Pull Request #382