[GROOVY-7538] Compiler crash in the static type checker with self-referencing generic type

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.4
• Fix Version/s: 2.4.6
• Component/s: Static Type Checker
• Labels: test
• Assignee: Pascal Schumacher
• Reporter: Frank Pavageau
• Created: 01/Aug/15 21:35
• Updated: 22/Feb/16 20:48
• Resolved: 28/Nov/15 20:00

Description

I'm writing unit tests in Groovy combined with AssertJ, and I got a compiler crash with the following code:

Assertions.assertThat("true").isNotEmpty().isNotEqualTo("false")

The matching stacktrace is

java.lang.ArrayIndexOutOfBoundsException: 1
    	at org.codehaus.groovy.ast.tools.GenericsUtils.extractPlaceholders(GenericsUtils.java:167)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.extractPlaceHolders(StaticTypeCheckingVisitor.java:4455)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.resolvePlaceHoldersFromDeclaration(StaticTypeCheckingVisitor.java:4416)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.inferReturnTypeGenerics(StaticTypeCheckingVisitor.java:4206)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:2924)
    	at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethodCallExpression(StaticCompilationVisitor.java:297)
    	at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:66)
    	at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:71)
    	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:196)
    	at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:42)
    	at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:37)
    	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:166)
    	at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:71)
    	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:104)
    	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:115)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitConstructorOrMethod(StaticTypeCheckingVisitor.java:1773)
    	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:126)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:2106)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethod(StaticTypeCheckingVisitor.java:2065)
    	at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethod(StaticCompilationVisitor.java:163)
    	at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1086)
    	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:53)
    	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitClass(StaticTypeCheckingVisitor.java:249)
    	at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitClass(StaticCompilationVisitor.java:122)
    	at org.codehaus.groovy.transform.sc.StaticCompileTransformation.visit(StaticCompileTransformation.java:63)
    	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.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite.invoke(PojoMetaMethodSite.java:192)
    	at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:56)
    	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
    	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:133)
    	at org.codehaus.groovy.control.customizers.ASTTransformationCustomizer.call(ASTTransformationCustomizer.groovy:294)
    	at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1055)
    	at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:591)
    	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:569)
    	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:546)
    	...

Also interesting is that if I swap the 2 assertions, the compiler doesn't crash anymore, but I still get a compilation error from the static type checker:

Assertions.assertThat("true").isNotEqualTo("false").isNotEmpty()

The error is then:

[Static type checking] - Cannot find matching method org.assertj.core.api.AbstractAssert#isNotEmpty(). Please check if the declared type is right and if the method exists.

Of course, both lines compile in Java.

I've created a test to reproduce the bugs, I'll create a pull request on github right afterwards.