[GROOVY-9807] Static compile of dynamically generated code produces different output in a top-level class and a nested class

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 3.0.6
• Fix Version/s: 4.0.0-alpha-3, 2.5.16, 3.0.10
• Component/s: Static compilation
• Environment: openjdk version "1.8.0_242" ; OpenJDK Runtime Environment (build 1.8.0_242-8u242-b08-0ubuntu3~18.04-b08) ; OpenJDK 64-Bit Server VM (build 25.242-b08, mixed mode)
• Assignee: Eric Milles
• Reporter: Lyuben Atanasov
• Created: 04/Nov/20 13:30
• Updated: 01/Feb/22 17:59
• Resolved: 16/Mar/21 13:39

Description

I have encountered an issue when trying to generate code, containing chained method calls, at runtime (without source code) and compiling using CompileStatic.
What I am trying to achieve is produce code similar to:

public StringBuilder test() {
    StringBuilder sb = new StringBuilder().append("testString");
    return sb;
}

I create the appropriate AST nodes, statements, expressions, etc.
Everything works fine if I add a method like the one shown in a top-level class (the class is also dynamically generated at runtime). However, if I try to add the exact same method to a nested class, it seems like the groovy compiler gets somehow confused and, judging by the decompiler output, produces something like:

public StringBuilder test() {
    StringBuilder sb = ((StringBuilder)((Closure)this).getThisObject()).append("testString");
    return sb;
}

Naturally, this does not work.

Here's how I try to generate the method:

ClassNode topLevelClass = ClassHelper.make(
    "com.example.groovycompiler.test.TopLevelClass");
InnerClassNode nestedClass = new InnerClassNode(
    topLevelClass,
    "com.example.groovycompiler.test.TopLevelClass$NestedClass",
    Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC,
    ClassHelper.OBJECT_TYPE);
ClassNode stringBuilderClass = ClassHelper.make(StringBuilder.class);
nestedClass.addMethod(
    "test",
    Opcodes.ACC_PUBLIC,
    stringBuilderClass,
    Parameter.EMPTY_ARRAY,
    ClassNode.EMPTY_ARRAY,
    block(
        declS(
            varX("sb", stringBuilderClass),
            callX(ctorX(stringBuilderClass), "append",
                args(constX("testString")))),
        returnS(
            varX("sb", stringBuilderClass))
    )
);

Perhaps I am missing something, in which case I will be very happy to receive some pointers.
I have created a github repo with a maven project containing a unit test that demonstrates the issue: https://github.com/l-atanasov/groovy-static-compile-issue
Note, that I have extended the CompilationUnit a little to allow to run the static compiler without source.

Also, if I am not using the static compiler, everything works as expected.

Update: reformatted code for readability