Hacktoberfest 2026: le issue che i maintainer hanno segnato per ottobre, aperte e adatte ai principianti. Sfoglia le issue Hacktoberfest

Verifier crashes on `!` (or another unary operator) applied to a call whose type cannot be resolved

Aperta
  • Qualcosa non va?
#389 1 commento 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 2 giorni

@CatarinaGamboa ci sta già lavorando.

Dal 13/10/2026.

  • #391 di @CatarinaGamboa — aperta

Valutazione

Difficoltà
3/5
Tempo stimato
1-2 giorni
Idoneità per principianti
65/100
Tipo di issue
Bug
Chiarezza
Specificata chiaramente
Stato di attività
Attiva
Stack tecnologico
java
Ambito
compilers

Direzione di ricerca

Start with the stack trace: OperationsChecker.getUnaryOpRefinements (OperationsChecker.java:179) calls Context.addInstanceToContext (Context.java:164), which reaches Context.addInstanceVariable (Context.java:267) with a null type. Run the minimal Repro snippet from the issue, with org.example.missing absent from the classpath, to reproduce the NullPointerException. Done means the snippet verifies with the compilation warning instead of crashing, and the related reproducers for #388 and #390 are still considered.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

bug

Impact: verification stops with an internal error: 3 of the 53 real-world files below.

Description

!x.m() where x's class is not on the classpath: OperationsChecker.getUnaryOpRefinements adds the operand to the context, and Context.addInstanceVariable calls getSuperclass() on its type, which is null.

Minimal reproducer (org.example.missing is not on the classpath)

import org.example.missing.Settings;

public class Repro {
    static void start(Settings settings) {
        if (!settings.enabled()) {
            return;
        }
    }
}

Expected

Correct! Passed Verification. (with the "Java compilation encountered issues" warning).

Actual

Exception in thread "main" java.lang.RuntimeException: 
Error while checking CtMethodImpl
  on start(Settings settings) { 
  at Repro.java:4
  with 
Error while checking CtBlockImpl
  on { 
  at Repro.java:4
  with 
Error while checking CtIfImpl
  on if (!settings.enabled()) { 
  at Repro.java:5
  with Cannot invoke "spoon.reflect.reference.CtTypeReference.getSuperclass()" because "type" is null
	at liquidjava.processor.refinement_checker.TypeChecker.scan(TypeChecker.java:80)
	at spoon.reflect.visitor.CtScanner.scan(CtScanner.java:189)
	at spoon.reflect.visitor.CtScanner.scan(CtScanner.java:154)
	at spoon.reflect.visitor.CtScanner.visitCtClass(CtScanner.java:363)
	at liquidjava.processor.refinement_checker.RefinementTypeChecker.visitCtClass(RefinementTypeChecker.java:97)
	at spoon.support.reflect.declaration.CtClassImpl.accept(CtClassImpl.java:63)
	at liquidjava.processor.RefinementProcessor.lambda$processPackage$3(RefinementProcessor.java:51)
	at java.base/java.lang.Iterable.forEach(Iterable.java:75)
	at liquidjava.processor.RefinementProcessor.processPackage(RefinementProcessor.java:50)
	at liquidjava.processor.RefinementProcessor.process(RefinementProcessor.java:35)
	at liquidjava.processor.RefinementProcessor.process(RefinementProcessor.java:15)
	at spoon.support.visitor.ProcessingVisitor.scan(ProcessingVisitor.java:72)
	at spoon.support.QueueProcessingManager.process(QueueProcessingManager.java:118)
	at spoon.support.QueueProcessingManager.process(QueueProcessingManager.java:132)
	at liquidjava.api.CommandLineLauncher.launch(CommandLineLauncher.java:92)
	at liquidjava.api.CommandLineLauncher.main(CommandLineLauncher.java:41)
...
Caused by: java.lang.NullPointerException: Cannot invoke "spoon.reflect.reference.CtTypeReference.getSuperclass()" because "type" is null
	at liquidjava.processor.context.Context.addInstanceVariable(Context.java:267)
	at liquidjava.processor.context.Context.addInstanceToContext(Context.java:164)
	at liquidjava.processor.refinement_checker.general_checkers.OperationsChecker.getUnaryOpRefinements(OperationsChecker.java:179)

Reproduced on main at dcfc4eb2 (liquidjava-verifier 0.0.35).

Real-world files that hit it

  • if (!appProperties.simulator().enabled()) { — skyleedevzero86/carebridge-platform (file)
  • if (!Game.isInNoGUIMode()) { — gurkenlabs/litiengine (file)
  • (!context.isExportedEquipment(identifiable) || extensions.isEmpty()) { — stvzhou/powsybl-core (file)

Context

Found while running LiquidJava on the original repository files of 53 real-world typestate and refinement bugs (the same files as our study exercises, before simplification). Each file is verified on its own, as a user would on one file of a project, so the project's other classes and its dependencies are not on the classpath. On main this crash and the two related ones (#388 binary operator, #389 unary operator, #390 field read) stop verification in 33 of the 53 files.

Lingua principale
Java
Stelle
69
Fork
36
Merge medio
2g 1h
PR unite (30g)
35

Preparare l'ambiente

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di liquid-java/liquidjava

Tutte le issue di liquid-java/liquidjava

Issue simili

Altre issue su Java

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.