[GROOVY-6616] @CompileStatic Reference to constructor is ambiguous

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.2
• Fix Version/s: 2.3.1
• Component/s: Static compilation
• Assignee: Unassigned
• Reporter: Kenneth Gendron
• Created: 09/Mar/14 19:32
• Updated: 01/Jun/14 18:03
• Resolved: 16/May/14 15:49

Description

Groovy does not properly distinguish between overloaded methods when it is attempting to find the appropriate method to call when using @CompileStatic.

Example:

MethodOverload.java

package test;

public class MethodOverload {
    
    public MethodOverload(String s, short[] arr) {}
    public MethodOverload(String s, int... arr) {}
    public MethodOverload(short[] arr) {} /* Causes confusion within Groovy */
    
    private static final String clz = "@groovy.transform.CompileStatic\n" + 
            "public class Clz {\n" + 
            "public void run() {\n" + 
            "println(new test.MethodOverload('d',1))\n" + 
            "}\n" + 
            "}";

    public static void main(String[] args) throws Exception {
        Class clazz = new groovy.lang.GroovyClassLoader().parseClass(clz);
        clazz.getMethod("run").invoke(clazz.newInstance());
    }
    
}

Running the above will throw the following:

Exception in thread "main" org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
script1394410025829744485975.groovy: 4: [Static type checking] - Reference to method is ambiguous. Cannot choose between [void test.MethodOverload#<init>(short[]), void test.MethodOverload#<init>(java.lang.String, int[])]
@ line 4, column 9.
println(new test.MethodOverload("d",1))

Groovy is mistakenly choosing (short[]) as one of the method candidates.