[GROOVY-10670] Cannot resolve type in the presence of use-site contravariance

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 4.0.3
• Component/s: Static compilation, Static Type Checker
• Assignee: Eric Milles
• Reporter: Stefanos Chaliasos
• Created: 28/Jun/22 22:05
• Updated: 15/Apr/23 16:24

Description

I have the following Groovy program.

 

class Main {
  static final Bar<? super Short> bar = new Bar<Short>((Short) -94)
  static final short foo = Main.bar.x
}

class Bar<P> {
  public final P x
  public Bar(P x) { 
    this.x = x 
  }
}

 

Actual Behavior

The program does not compile, and I get the following error.

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Main.groovy: 5: [Static type checking] - Cannot assign value of type java.lang.Object to variable of type short
@ line 5, column 28.
static final short foo = Main.bar.x
^
1 error

Expected Behavior

Compile successfully.

Comment

Note that the equivalent Java program is accepted by javac.

Tested against 4.0.3 and master (commit: 2e82c9f5bd6201ed4724b26714275f4cef9df6e8).