[GROOVY-5601] static type checker NPE when instantiating generic interface (with and without diamond)

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.1
• Component/s: Static Type Checker
• Labels: exception

Environment

$ java -version
java version "1.7.0_04"
Java(TM) SE Runtime Environment (build 1.7.0_04-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.0-b21, mixed mode)

$ uname -a
Linux studio 3.2.0-25-generic #40-Ubuntu SMP Wed May 23 20:30:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

• Assignee: Cédric Champeau
• Reporter: wujek srujek
• Created: 14/Jul/12 06:27
• Updated: 26/Jul/12 16:49
• Resolved: 16/Jul/12 03:47

Description

package compile

import groovy.transform.TypeChecked

interface Mapper<F, T> {
    T to(F from)
}

@TypeChecked
class Main {
    static void main(String[] args) {
        Mapper<String, Integer> mapper = new Mapper<String, Integer>() { //        Mapper<String, Integer> mapper = new Mapper<>() {
            Integer to(String from) {
                17
            }
        };
    }
}

Results in:

$ ~/Apps/groovy/bin/groovyc -e compile/Mapper.groovy 
null
>>> stacktrace:
java.lang.NullPointerException
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.inferDiamondType(StaticTypeCheckingVisitor.java:456)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitBinaryExpression(StaticTypeCheckingVisitor.java:394)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitDeclarationExpression(CodeVisitorSupport.java:245)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitDeclarationExpression(ClassCodeVisitorSupport.java:107)
        at org.codehaus.groovy.ast.expr.DeclarationExpression.visit(DeclarationExpression.java:87)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:69)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:195)
        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:165)
        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.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:112)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitConstructorOrMethod(StaticTypeCheckingVisitor.java:1051)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:123)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:1252)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethod(StaticTypeCheckingVisitor.java:1226)
        at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1056)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:50)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitClass(StaticTypeCheckingVisitor.java:216)
        at org.codehaus.groovy.transform.StaticTypesTransformation.visit(StaticTypesTransformation.java:70)
        at org.codehaus.groovy.transform.ASTTransformationVisitor.visitClass(ASTTransformationVisitor.java:132)
        at org.codehaus.groovy.transform.ASTTransformationVisitor$2.call(ASTTransformationVisitor.java:176)
        at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1024)
        at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:562)
        at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:540)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:517)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:496)
        at org.codehaus.groovy.tools.FileSystemCompiler.compile(FileSystemCompiler.java:57)
        at org.codehaus.groovy.tools.FileSystemCompiler.doCompilation(FileSystemCompiler.java:213)
        at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompile(FileSystemCompiler.java:146)
        at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompileWithErrorHandling(FileSystemCompiler.java:176)
        at org.codehaus.groovy.tools.FileSystemCompiler.main(FileSystemCompiler.java:160)
        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:601)
        at org.codehaus.groovy.tools.GroovyStarter.rootLoader(GroovyStarter.java:106)
        at org.codehaus.groovy.tools.GroovyStarter.main(GroovyStarter.java:128)

It doesn't matter if I explicitly specify the parameters during creation, or whether I let the diamong operator kick in. Without @TypeChecked, it works fine. I am not sure whether the problem happens only with anonymous inner classes or is more general.

Issue Links

• is related to: GROOVY-5614 Diamond Inference broken with Static Compilation