[GROOVY-10701] NullPointerException in instruction selection phase when having conditionals with lambdas and function references

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.5, 3.0.18
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 22/Jul/22 09:20
• Updated: 15/Jun/23 15:23
• Resolved: 22/Jul/22 16:22

Description

I have the following program

import java.util.function.Function;

class Test {
    <T> void m1(Function<T, T> x) {}

    double m2(double x) {
        return x;
    }

    void m3() {
        m1((true) ? (Double x) -> x : this::m2);
    }
}

This program crashes the compiler with the following stacktrace

>>> a serious error occurred: BUG! exception in phase 'instruction selection' in source unit 'test.groovy' unexpected NullPointerException
>>> stacktrace:
BUG! exception in phase 'instruction selection' in source unit 'test.groovy' unexpected NullPointerException
        at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:942)
        at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:692)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:666)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:647)
        at org.codehaus.groovy.tools.FileSystemCompiler.compile(FileSystemCompiler.java:311)
        at org.codehaus.groovy.tools.FileSystemCompiler.doCompilation(FileSystemCompiler.java:240)
        at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompile(FileSystemCompiler.java:165)
        at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompileWithErrorHandling(FileSystemCompiler.java:205)
        at org.codehaus.groovy.tools.FileSystemCompiler.main(FileSystemCompiler.java:189)
Caused by: java.lang.NullPointerException: Cannot invoke "org.codehaus.groovy.ast.ClassNode.isInterface()" because "type" is null
        at org.codehaus.groovy.ast.ClassHelper.findSAM(ClassHelper.java:563)
        at org.codehaus.groovy.ast.ClassHelper.isSAMType(ClassHelper.java:538)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.checkForTargetType(StaticTypeCheckingVisitor.java:4281)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitValueExpression(StaticTypeCheckingVisitor.java:4255)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitTernaryExpression(StaticTypeCheckingVisitor.java:4226)
        at org.codehaus.groovy.ast.expr.TernaryExpression.visit(TernaryExpression.java:44)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallArguments(StaticTypeCheckingVisitor.java:2824)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:3370)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethodCallExpression(StaticCompilationVisitor.java:420)
        at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:77)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:117)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:204)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitExpressionStatement(StaticTypeCheckingVisitor.java:2205)
        at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:41)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:86)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:168)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitBlockStatement(StaticTypeCheckingVisitor.java:3991)
        at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:70)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:142)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:115)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitConstructorOrMethod(StaticTypeCheckingVisitor.java:2604)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:110)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:2587)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethod(StaticTypeCheckingVisitor.java:2566)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitConstructorOrMethod(StaticCompilationVisitor.java:235)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethod(StaticCompilationVisitor.java:250)
        at org.codehaus.groovy.ast.ClassNode.visitMethods(ClassNode.java:1131)
        at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1124)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:52)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitClass(StaticTypeCheckingVisitor.java:437)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitClass(StaticCompilationVisitor.java:196)
        at org.codehaus.groovy.transform.sc.StaticCompileTransformation.visit(StaticCompileTransformation.java:68)
        at org.codehaus.groovy.control.customizers.ASTTransformationCustomizer.call(ASTTransformationCustomizer.groovy:303)
        at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:937)

Tested against master (commit: b29512397d6ff199976dfb8709c5950e525ac8d6)

Issue Links

• is related to: GROOVY-10271 Wrong inference when using ternary operator with closure and variable
• is related to: GROOVY-10272 Wrong inference when using ternary operator with lambdas