[GROOVY-6947] NPE in compilation when assigning a value to 'this'

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.4
• Fix Version/s: 2.4.8
• Component/s: Compiler
• Assignee: Paul King
• Reporter: Rodolfo Cruz
• Created: 14/Jul/14 08:49
• Updated: 01/Feb/17 23:18
• Resolved: 11/Sep/16 22:40

Description

We're using Groovy to allow users to write some scripts inside a product and one of them tried to assign a value to the variable "this", leading to the following exception (test case is attached):

BUG! exception in phase 'semantic analysis' in source unit 'groovyTest.groovy' null
at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:927)
at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:585)
at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:534)
at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:286)
at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:259)
at groovy.lang.GroovyShell.parseClass(GroovyShell.java:674)
at groovy.lang.GroovyShell.run(GroovyShell.java:501)
at groovy.lang.GroovyShell.run(GroovyShell.java:481)
at groovy.lang.GroovyShell.run(GroovyShell.java:164)
at groovy.lang.GroovyShell$run$0.call(Unknown Source)
at groovy.ui.Console$_runScriptImpl_closure17.doCall(Console.groovy:977)
at groovy.ui.Console$_runScriptImpl_closure17.doCall(Console.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:278)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:909)
at groovy.lang.Closure.call(Closure.java:423)
at groovy.lang.Closure.call(Closure.java:417)
at groovy.lang.Closure.run(Closure.java:504)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
at org.codehaus.groovy.classgen.VariableScopeVisitor.checkForFinal(VariableScopeVisitor.java:392)
at org.codehaus.groovy.classgen.VariableScopeVisitor.checkFinalFieldAccess(VariableScopeVisitor.java:385)
at org.codehaus.groovy.classgen.VariableScopeVisitor.visitBinaryExpression(VariableScopeVisitor.java:369)
at org.codehaus.groovy.ast.expr.BinaryExpression.visit(BinaryExpression.java:49)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:69)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:193)
at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:40)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:35)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:163)
at org.codehaus.groovy.classgen.VariableScopeVisitor.visitBlockStatement(VariableScopeVisitor.java:312)
at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:69)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:101)
at org.codehaus.groovy.classgen.VariableScopeVisitor.visitConstructorOrMethod(VariableScopeVisitor.java:509)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:123)
at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1063)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:50)
at org.codehaus.groovy.classgen.VariableScopeVisitor.visitClass(VariableScopeVisitor.java:477)
at org.codehaus.groovy.control.CompilationUnit$11.call(CompilationUnit.java:640)
at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:923)
... 23 more

I know this is an issue that won't happen very often as this is invalid code (that's the reason of the lower priority), but it would nice if you could have a look into this and handle the exception, reporting it as a compilation issue.

Issue Links

• is related to: GROOVY-7921 using "this" as the target of an assignment not working with Category annotation