[GROOVY-3904] groovyc hangs if a type is declared to extend itself

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.6.5, 1.7-beta-2
• Fix Version/s: 1.6.6, 1.7-rc-1
• Component/s: Compiler
• Assignee: Roshan Dawrani
• Reporter: Andy Clement
• Created: 25/Nov/09 13:13
• Updated: 09/Dec/09 18:16
• Resolved: 27/Nov/09 09:02

Description

This code will hang groovyc 1.7beta2:

class XXX extends XXX {
}

With stack:

 at org.codehaus.groovy.ast.ClassNode.getUnresolvedSuperClass(ClassNode.java:919)
 at org.codehaus.groovy.ast.ClassNode.getSuperClass(ClassNode.java:913)
 at org.codehaus.groovy.classgen.InnerClassVisitor.getObjectDistance(InnerClassVisitor.java:517)
 at org.codehaus.groovy.classgen.InnerClassVisitor.addDispatcherMethods(InnerClassVisitor.java:378)
 at org.codehaus.groovy.classgen.InnerClassVisitor.visitClass(InnerClassVisitor.java:67)
 at org.codehaus.groovy.control.CompilationUnit$3.call(CompilationUnit.java:173)
 at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:936)

basically this method loops indefinetly InnerClassVisitor.getObjectDistance():

    private int getObjectDistance(ClassNode node) {
        int count = 1;
        while (node!=null && node!=ClassHelper.OBJECT_TYPE) {
            count++;
            node = node.getSuperClass();
        }
        return count;
    }

whereas 1.6.5 prints:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed, cyclic inheritance involving XXX in class XXX

This variant will hang 1.6.5 and 1.7b2:

class XXX extends XXX {
  public static void main(String []argv) {
    print 'hey'
  }
}

it instead loops indefinetly 'around' this location:

at java.util.AbstractList.iterator(AbstractList.java:273)
at java.util.AbstractCollection.toArray(AbstractCollection.java:120)
at java.util.ArrayList.addAll(ArrayList.java:472)
at org.codehaus.groovy.ast.ClassNode.getMethods(ClassNode.java:807)
at org.codehaus.groovy.ast.ClassNode.hasPossibleStaticMethod(ClassNode.java:1169)
at org.codehaus.groovy.control.StaticImportVisitor.transformMethodCallExpression(StaticImportVisitor.java:189)
at org.codehaus.groovy.control.StaticImportVisitor.transform(StaticImportVisitor.java:77)
at org.codehaus.groovy.ast.ClassCodeExpressionTransformer.visitExpressionStatement(ClassCodeExpressionTransformer.java:139)
at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:40)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:35)