[GROOVY-9340] Lambda using variable expression parameter produces generics error for self type

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-rc-2
• Fix Version/s: 3.0.0-rc-3
• Assignee: Eric Milles
• Reporter: Eric Milles
• Created: 15/Dec/19 18:35
• Updated: 27/Jan/20 00:44
• Resolved: 20/Dec/19 10:10

Description

Consider the following:

@groovy.transform.CompileStatic
class C {
  void m() {
    java.util.function.Consumer<C> consumer = c -> null
    consumer.accept(this)
  }
}

The lambda expression produces a compiler error:

A transform used a generics containing ClassNode C for the method public void doCall(C c)  { ... } directly. You are not supposed to do this. Please create a new ClassNode referring to the old ClassNode and use the new ClassNode instead of the old one. Otherwise the compiler will create wrong descriptors and a potential NullPointerException in TypeResolver in the OpenJDK. If this is not your own doing, please report this bug to the writer of the transform.
     @ line 4, column 60.
       .function.Consumer<C> consumer = c -> null
                                     ^

    1 error
        at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:287)
        at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1091)
        at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:633)
        at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:612)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:589)
        at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:367)
        at groovy.lang.GroovyClassLoader.lambda$parseClass$2(GroovyClassLoader.java:310)
        ...

Issue Links

• links to: GitHub Pull Request #1126