private void reportNullableReturns(
      DataFlowInstructionVisitor visitor,
      ProblemsHolder holder,
      Set<PsiElement> reportedAnchors,
      @NotNull PsiElement block) {
    final PsiMethod method = getScopeMethod(block);
    if (method == null || NullableStuffInspectionBase.isNullableNotInferred(method, true)) return;

    boolean notNullRequired = NullableNotNullManager.isNotNull(method);
    if (!notNullRequired && !SUGGEST_NULLABLE_ANNOTATIONS) return;

    PsiType returnType = method.getReturnType();
    // no warnings in void lambdas, where the expression is not returned anyway
    if (block instanceof PsiExpression
        && block.getParent() instanceof PsiLambdaExpression
        && returnType == PsiType.VOID) return;

    // no warnings for Void methods, where only null can be possibly returned
    if (returnType == null || returnType.equalsToText(CommonClassNames.JAVA_LANG_VOID)) return;

    for (PsiElement statement : visitor.getProblems(NullabilityProblem.nullableReturn)) {
      assert statement instanceof PsiExpression;
      final PsiExpression expr = (PsiExpression) statement;
      if (!reportedAnchors.add(expr)) continue;

      if (notNullRequired) {
        final String text =
            isNullLiteralExpression(expr)
                ? InspectionsBundle.message("dataflow.message.return.null.from.notnull")
                : InspectionsBundle.message("dataflow.message.return.nullable.from.notnull");
        holder.registerProblem(expr, text);
      } else if (AnnotationUtil.isAnnotatingApplicable(statement)) {
        final NullableNotNullManager manager =
            NullableNotNullManager.getInstance(expr.getProject());
        final String defaultNullable = manager.getDefaultNullable();
        final String presentableNullable = StringUtil.getShortName(defaultNullable);
        final String text =
            isNullLiteralExpression(expr)
                ? InspectionsBundle.message(
                    "dataflow.message.return.null.from.notnullable", presentableNullable)
                : InspectionsBundle.message(
                    "dataflow.message.return.nullable.from.notnullable", presentableNullable);
        final LocalQuickFix[] fixes =
            PsiTreeUtil.getParentOfType(expr, PsiMethod.class, PsiLambdaExpression.class)
                    instanceof PsiLambdaExpression
                ? LocalQuickFix.EMPTY_ARRAY
                : new LocalQuickFix[] {
                  new AnnotateMethodFix(
                      defaultNullable, ArrayUtil.toStringArray(manager.getNotNulls())) {
                    @Override
                    public int shouldAnnotateBaseMethod(
                        PsiMethod method, PsiMethod superMethod, Project project) {
                      return 1;
                    }
                  }
                };
        holder.registerProblem(expr, text, fixes);
      }
    }
  }
 private void handleBranchingInstruction(
     ProblemsHolder holder,
     StandardInstructionVisitor visitor,
     Set<Instruction> trueSet,
     Set<Instruction> falseSet,
     HashSet<PsiElement> reportedAnchors,
     BranchingInstruction instruction,
     final boolean onTheFly) {
   PsiElement psiAnchor = instruction.getPsiAnchor();
   boolean underBinary = isAtRHSOfBooleanAnd(psiAnchor);
   if (instruction instanceof InstanceofInstruction
       && visitor.isInstanceofRedundant((InstanceofInstruction) instruction)) {
     if (visitor.canBeNull((BinopInstruction) instruction)) {
       holder.registerProblem(
           psiAnchor,
           InspectionsBundle.message("dataflow.message.redundant.instanceof"),
           new RedundantInstanceofFix());
     } else {
       final LocalQuickFix localQuickFix = createSimplifyBooleanExpressionFix(psiAnchor, true);
       holder.registerProblem(
           psiAnchor,
           InspectionsBundle.message(
               underBinary
                   ? "dataflow.message.constant.condition.when.reached"
                   : "dataflow.message.constant.condition",
               Boolean.toString(true)),
           localQuickFix == null ? null : new LocalQuickFix[] {localQuickFix});
     }
   } else if (psiAnchor instanceof PsiSwitchLabelStatement) {
     if (falseSet.contains(instruction)) {
       holder.registerProblem(
           psiAnchor, InspectionsBundle.message("dataflow.message.unreachable.switch.label"));
     }
   } else if (psiAnchor != null
       && !reportedAnchors.contains(psiAnchor)
       && !isFlagCheck(psiAnchor)) {
     boolean evaluatesToTrue = trueSet.contains(instruction);
     final PsiElement parent = psiAnchor.getParent();
     if (parent instanceof PsiAssignmentExpression
         && ((PsiAssignmentExpression) parent).getLExpression() == psiAnchor) {
       holder.registerProblem(
           psiAnchor,
           InspectionsBundle.message(
               "dataflow.message.pointless.assignment.expression",
               Boolean.toString(evaluatesToTrue)),
           createConditionalAssignmentFixes(
               evaluatesToTrue, (PsiAssignmentExpression) parent, onTheFly));
     } else if (!skipReportingConstantCondition(visitor, psiAnchor, evaluatesToTrue)) {
       final LocalQuickFix fix = createSimplifyBooleanExpressionFix(psiAnchor, evaluatesToTrue);
       String message =
           InspectionsBundle.message(
               underBinary
                   ? "dataflow.message.constant.condition.when.reached"
                   : "dataflow.message.constant.condition",
               Boolean.toString(evaluatesToTrue));
       holder.registerProblem(psiAnchor, message, fix == null ? null : new LocalQuickFix[] {fix});
     }
     reportedAnchors.add(psiAnchor);
   }
 }
  private static void reportOptionalOfNullableImprovements(
      ProblemsHolder holder, Set<PsiElement> reportedAnchors, Instruction[] instructions) {
    for (Instruction instruction : instructions) {
      if (instruction instanceof MethodCallInstruction) {
        final PsiExpression[] args = ((MethodCallInstruction) instruction).getArgs();
        if (args.length != 1) continue;

        final PsiExpression expr = args[0];

        if (((MethodCallInstruction) instruction).isOptionalAlwaysNullProblem()) {
          if (!reportedAnchors.add(expr)) continue;
          holder.registerProblem(
              expr,
              "Passing <code>null</code> argument to <code>Optional</code>",
              DfaOptionalSupport.createReplaceOptionalOfNullableWithEmptyFix(expr));
        } else if (((MethodCallInstruction) instruction).isOptionalAlwaysNotNullProblem()) {
          if (!reportedAnchors.add(expr)) continue;
          holder.registerProblem(
              expr,
              "Passing a non-null argument to <code>Optional</code>",
              DfaOptionalSupport.createReplaceOptionalOfNullableWithOfFix());
        }
      }
    }
  }
 private void reportFieldAccessMayProduceNpe(
     ProblemsHolder holder, PsiElement elementToAssert, PsiExpression expression) {
   if (expression instanceof PsiArrayAccessExpression) {
     LocalQuickFix[] fix =
         createNPEFixes((PsiExpression) elementToAssert, expression, holder.isOnTheFly());
     holder.registerProblem(
         expression, InspectionsBundle.message("dataflow.message.npe.array.access"), fix);
   } else {
     LocalQuickFix[] fix =
         createNPEFixes((PsiExpression) elementToAssert, expression, holder.isOnTheFly());
     assert elementToAssert != null;
     holder.registerProblem(
         elementToAssert, InspectionsBundle.message("dataflow.message.npe.field.access"), fix);
   }
 }
  private void reportNullableArguments(
      DataFlowInstructionVisitor visitor, ProblemsHolder holder, Set<PsiElement> reportedAnchors) {
    for (PsiElement expr :
        visitor.getProblems(NullabilityProblem.passingNullableToNotNullParameter)) {
      if (!reportedAnchors.add(expr)) continue;

      final String text =
          isNullLiteralExpression(expr)
              ? InspectionsBundle.message("dataflow.message.passing.null.argument")
              : InspectionsBundle.message("dataflow.message.passing.nullable.argument");
      LocalQuickFix[] fixes =
          createNPEFixes((PsiExpression) expr, (PsiExpression) expr, holder.isOnTheFly());
      holder.registerProblem(expr, text, fixes);
    }
  }
 private static void reportUnboxedNullables(
     DataFlowInstructionVisitor visitor, ProblemsHolder holder, Set<PsiElement> reportedAnchors) {
   for (PsiElement expr : visitor.getProblems(NullabilityProblem.unboxingNullable)) {
     if (!reportedAnchors.add(expr)) continue;
     holder.registerProblem(expr, InspectionsBundle.message("dataflow.message.unboxing"));
   }
 }
  private void analyzeDfaWithNestedClosures(
      PsiElement scope,
      ProblemsHolder holder,
      StandardDataFlowRunner dfaRunner,
      Collection<DfaMemoryState> initialStates) {
    final DataFlowInstructionVisitor visitor = new DataFlowInstructionVisitor(dfaRunner);
    final RunnerResult rc =
        dfaRunner.analyzeMethod(scope, visitor, IGNORE_ASSERT_STATEMENTS, initialStates);
    if (rc == RunnerResult.OK) {
      createDescription(dfaRunner, holder, visitor);

      MultiMap<PsiElement, DfaMemoryState> nestedClosures = dfaRunner.getNestedClosures();
      for (PsiElement closure : nestedClosures.keySet()) {
        analyzeDfaWithNestedClosures(closure, holder, dfaRunner, nestedClosures.get(closure));
      }
    } else if (rc == RunnerResult.TOO_COMPLEX) {
      if (scope.getParent() instanceof PsiMethod) {
        PsiMethod method = (PsiMethod) scope.getParent();
        final PsiIdentifier name = method.getNameIdentifier();
        if (name != null) { // Might be null for synthetic methods like JSP page.
          holder.registerProblem(
              name,
              InspectionsBundle.message("dataflow.too.complex"),
              ProblemHighlightType.WEAK_WARNING);
        }
      }
    }
  }
 private static void checkSillyAssignment(
     PsiAssignmentExpression assignment, ProblemsHolder holder) {
   if (assignment.getOperationTokenType() != JavaTokenType.EQ) return;
   PsiExpression lExpression = assignment.getLExpression();
   PsiExpression rExpression = assignment.getRExpression();
   if (rExpression == null) return;
   lExpression = PsiUtil.deparenthesizeExpression(lExpression);
   rExpression = PsiUtil.deparenthesizeExpression(rExpression);
   if (!(lExpression instanceof PsiReferenceExpression)) return;
   PsiReferenceExpression rRef;
   if (!(rExpression instanceof PsiReferenceExpression)) {
     if (!(rExpression instanceof PsiAssignmentExpression)) return;
     final PsiAssignmentExpression rAssignmentExpression = (PsiAssignmentExpression) rExpression;
     final PsiExpression assignee =
         PsiUtil.deparenthesizeExpression(rAssignmentExpression.getLExpression());
     if (!(assignee instanceof PsiReferenceExpression)) return;
     rRef = (PsiReferenceExpression) assignee;
   } else {
     rRef = (PsiReferenceExpression) rExpression;
   }
   PsiReferenceExpression lRef = (PsiReferenceExpression) lExpression;
   PsiManager manager = assignment.getManager();
   if (!sameInstanceReferences(lRef, rRef, manager)) return;
   final PsiVariable variable = (PsiVariable) lRef.resolve();
   if (variable == null) return;
   holder.registerProblem(
       assignment,
       InspectionsBundle.message("assignment.to.itself.problem.descriptor", variable.getName()),
       ProblemHighlightType.LIKE_UNUSED_SYMBOL);
 }
 private static void reportCastMayFail(ProblemsHolder holder, TypeCastInstruction instruction) {
   PsiTypeCastExpression typeCast = instruction.getCastExpression();
   PsiExpression operand = typeCast.getOperand();
   PsiTypeElement castType = typeCast.getCastType();
   assert castType != null;
   assert operand != null;
   holder.registerProblem(
       castType, InspectionsBundle.message("dataflow.message.cce", operand.getText()));
 }
 @NotNull
 @Override
 public PsiElementVisitor buildVisitor(@NotNull final ProblemsHolder holder, boolean isOnTheFly) {
   if (!PsiUtil.isLanguageLevel8OrHigher(holder.getFile())) {
     return PsiElementVisitor.EMPTY_VISITOR;
   }
   return new PsiElementVisitor() {
     @Override
     public void visitElement(PsiElement element) {
       if (element instanceof PsiMethodCallExpression) {
         final PsiMethodCallExpression methodCallExpression = (PsiMethodCallExpression) element;
         String qName = methodCallExpression.getMethodExpression().getQualifiedName();
         if (qName == null) {
           return;
         }
         qName = StringUtil.getShortName(qName);
         final Collection<StaticPseudoFunctionalStyleMethodOptions.PipelineElement> handlerInfos =
             myOptions.findElementsByMethodName(qName);
         if (handlerInfos.isEmpty()) {
           return;
         }
         final PsiMethod method = methodCallExpression.resolveMethod();
         if (method == null) {
           return;
         }
         final PsiClass aClass = method.getContainingClass();
         if (aClass == null) {
           return;
         }
         final String classQualifiedName = aClass.getQualifiedName();
         if (classQualifiedName == null) {
           return;
         }
         StaticPseudoFunctionalStyleMethodOptions.PipelineElement suitableHandler = null;
         for (StaticPseudoFunctionalStyleMethodOptions.PipelineElement h : handlerInfos) {
           if (h.getHandlerClass().equals(classQualifiedName)) {
             suitableHandler = h;
             break;
           }
         }
         if (suitableHandler == null) {
           return;
         }
         final PseudoLambdaReplaceTemplate.ValidationInfo validationInfo =
             suitableHandler.getTemplate().validate(methodCallExpression);
         if (validationInfo != null) {
           holder.registerProblem(
               methodCallExpression.getMethodExpression(),
               "Pseudo functional style code",
               new ReplacePseudoLambdaWithLambda(suitableHandler));
         }
       }
     }
   };
 }
  private void reportCallMayProduceNpe(
      ProblemsHolder holder, PsiMethodCallExpression callExpression, boolean onTheFly) {
    LocalQuickFix[] fix =
        createNPEFixes(
            callExpression.getMethodExpression().getQualifierExpression(),
            callExpression,
            onTheFly);

    holder.registerProblem(
        callExpression, InspectionsBundle.message("dataflow.message.npe.method.invocation"), fix);
  }
  private static void reportNullableAssignments(
      DataFlowInstructionVisitor visitor, ProblemsHolder holder, Set<PsiElement> reportedAnchors) {
    for (PsiElement expr : visitor.getProblems(NullabilityProblem.assigningToNotNull)) {
      if (!reportedAnchors.add(expr)) continue;

      final String text =
          isNullLiteralExpression(expr)
              ? InspectionsBundle.message("dataflow.message.assigning.null")
              : InspectionsBundle.message("dataflow.message.assigning.nullable");
      holder.registerProblem(expr, text);
    }
  }
  private static void reportNullableReturns(
      StandardDataFlowRunner runner,
      DataFlowInstructionVisitor visitor,
      ProblemsHolder holder,
      Set<PsiElement> reportedAnchors) {
    for (PsiElement statement : visitor.getProblems(NullabilityProblem.nullableReturn)) {
      assert statement instanceof PsiExpression;
      final PsiExpression expr = (PsiExpression) statement;
      if (!reportedAnchors.add(expr)) continue;

      if (runner.isInNotNullMethod()) {
        final String text =
            isNullLiteralExpression(expr)
                ? InspectionsBundle.message("dataflow.message.return.null.from.notnull")
                : InspectionsBundle.message("dataflow.message.return.nullable.from.notnull");
        holder.registerProblem(expr, text);
      } else if (AnnotationUtil.isAnnotatingApplicable(statement)) {
        final NullableNotNullManager manager =
            NullableNotNullManager.getInstance(expr.getProject());
        final String defaultNullable = manager.getDefaultNullable();
        final String presentableNullable = StringUtil.getShortName(defaultNullable);
        final String text =
            isNullLiteralExpression(expr)
                ? InspectionsBundle.message(
                    "dataflow.message.return.null.from.notnullable", presentableNullable)
                : InspectionsBundle.message(
                    "dataflow.message.return.nullable.from.notnullable", presentableNullable);
        holder.registerProblem(
            expr,
            text,
            new AnnotateMethodFix(defaultNullable, ArrayUtil.toStringArray(manager.getNotNulls())) {
              @Override
              public int shouldAnnotateBaseMethod(
                  PsiMethod method, PsiMethod superMethod, Project project) {
                return 1;
              }
            });
      }
    }
  }
  private void reportNullableArgumentsPassedToNonAnnotated(
      DataFlowInstructionVisitor visitor, ProblemsHolder holder, Set<PsiElement> reportedAnchors) {
    for (PsiElement expr :
        visitor.getProblems(NullabilityProblem.passingNullableArgumentToNonAnnotatedParameter)) {
      if (reportedAnchors.contains(expr)) continue;

      final String text =
          isNullLiteralExpression(expr)
              ? "Passing <code>null</code> argument to non annotated parameter"
              : "Argument <code>#ref</code> #loc might be null but passed to non annotated parameter";
      LocalQuickFix[] fixes =
          createNPEFixes((PsiExpression) expr, (PsiExpression) expr, holder.isOnTheFly());
      final PsiElement parent = expr.getParent();
      if (parent instanceof PsiExpressionList) {
        final int idx = ArrayUtilRt.find(((PsiExpressionList) parent).getExpressions(), expr);
        if (idx > -1) {
          final PsiElement gParent = parent.getParent();
          if (gParent instanceof PsiCallExpression) {
            final PsiMethod psiMethod = ((PsiCallExpression) gParent).resolveMethod();
            if (psiMethod != null
                && psiMethod.getManager().isInProject(psiMethod)
                && AnnotationUtil.isAnnotatingApplicable(psiMethod)) {
              final PsiParameter[] parameters = psiMethod.getParameterList().getParameters();
              if (idx < parameters.length) {
                final AddNullableAnnotationFix addNullableAnnotationFix =
                    new AddNullableAnnotationFix(parameters[idx]);
                fixes =
                    fixes == null
                        ? new LocalQuickFix[] {addNullableAnnotationFix}
                        : ArrayUtil.append(fixes, addNullableAnnotationFix);
                holder.registerProblem(expr, text, fixes);
                reportedAnchors.add(expr);
              }
            }
          }
        }
      }
    }
  }
Exemple #15
0
  private static ProblemDescriptor runLocalTool(
      @NotNull PsiElement psiElement,
      @NotNull InspectionManager inspectionManager,
      @NotNull OfflineProblemDescriptor offlineProblemDescriptor,
      @NotNull LocalInspectionToolWrapper toolWrapper) {
    PsiFile containingFile = psiElement.getContainingFile();
    final ProblemsHolder holder = new ProblemsHolder(inspectionManager, containingFile, false);
    final LocalInspectionTool localTool = toolWrapper.getTool();
    final int startOffset = psiElement.getTextRange().getStartOffset();
    final int endOffset = psiElement.getTextRange().getEndOffset();
    LocalInspectionToolSession session =
        new LocalInspectionToolSession(containingFile, startOffset, endOffset);
    final PsiElementVisitor visitor = localTool.buildVisitor(holder, false, session);
    localTool.inspectionStarted(session, false);
    final PsiElement[] elementsInRange =
        getElementsIntersectingRange(containingFile, startOffset, endOffset);
    for (PsiElement element : elementsInRange) {
      element.accept(visitor);
    }
    localTool.inspectionFinished(session, holder);
    if (holder.hasResults()) {
      final List<ProblemDescriptor> list = holder.getResults();
      final int idx = offlineProblemDescriptor.getProblemIndex();
      int curIdx = 0;
      for (ProblemDescriptor descriptor : list) {
        final PsiNamedElement member = localTool.getProblemElement(descriptor.getPsiElement());
        if (psiElement instanceof PsiFile || member != null && member.equals(psiElement)) {
          if (curIdx == idx) {
            return descriptor;
          }
          curIdx++;
        }
      }
    }

    return null;
  }
    @Override
    public void visitXmlAttributeValue(XmlAttributeValue value) {
      for (PsiReference reference : value.getReferences()) {
        if (!(reference instanceof OnClickConverter.MyReference)) {
          continue;
        }
        final OnClickConverter.MyReference ref = (OnClickConverter.MyReference) reference;
        final String methodName = ref.getValue();

        if (methodName.isEmpty()) {
          continue;
        }
        final ResolveResult[] results = ref.multiResolve(false);
        final Set<PsiClass> resolvedClasses = new HashSet<PsiClass>();
        final Set<PsiClass> resolvedClassesWithMistake = new HashSet<PsiClass>();

        for (ResolveResult result : results) {
          if (result instanceof OnClickConverter.MyResolveResult) {
            final PsiElement element = result.getElement();

            if (element != null) {
              final PsiClass aClass = PsiTreeUtil.getParentOfType(element, PsiClass.class);

              if (aClass != null) {
                resolvedClasses.add(aClass);

                if (!((OnClickConverter.MyResolveResult) result).hasCorrectSignature()) {
                  resolvedClassesWithMistake.add(aClass);
                }
              }
            }
          }
        }
        PsiClass activity = null;
        for (PsiClass relatedActivity : myRelatedActivities) {
          if (!containsOrExtends(resolvedClasses, relatedActivity)) {
            activity = relatedActivity;
            break;
          } else if (activity == null
              && containsOrExtends(resolvedClassesWithMistake, relatedActivity)) {
            activity = relatedActivity;
          }
        }

        if (activity != null) {
          reportMissingOnClickProblem(
              ref, activity, methodName, resolvedClassesWithMistake.contains(activity));
        } else if (results.length == 0) {
          myResult.add(
              myInspectionManager.createProblemDescriptor(
                  value,
                  reference.getRangeInElement(),
                  ProblemsHolder.unresolvedReferenceMessage(reference),
                  ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
                  myOnTheFly));
        } else if (resolvedClassesWithMistake.size() > 0) {
          reportMissingOnClickProblem(
              ref, resolvedClassesWithMistake.iterator().next(), methodName, true);
        }
      }
    }
  @NotNull
  @Override
  public PsiElementVisitor buildVisitor(@NotNull final ProblemsHolder holder, boolean isOnTheFly) {
    if (!PsiUtil.isLanguageLevel8OrHigher(holder.getFile())) {
      return PsiElementVisitor.EMPTY_VISITOR;
    }
    return new JavaElementVisitor() {
      private final AtomicNotNullLazyValue<Map<String, PsiClass>> myGuavaClassConversions =
          new AtomicNotNullLazyValue<Map<String, PsiClass>>() {
            @NotNull
            @Override
            protected Map<String, PsiClass> compute() {
              Map<String, PsiClass> map = new HashMap<String, PsiClass>();
              for (TypeConversionRule rule : TypeConversionRule.EP_NAME.getExtensions()) {
                if (rule instanceof BaseGuavaTypeConversionRule) {
                  final String fromClass = ((BaseGuavaTypeConversionRule) rule).ruleFromClass();
                  final String toClass = ((BaseGuavaTypeConversionRule) rule).ruleToClass();

                  final Project project = holder.getProject();
                  final JavaPsiFacade javaPsiFacade = JavaPsiFacade.getInstance(project);
                  final PsiClass targetClass =
                      javaPsiFacade.findClass(toClass, GlobalSearchScope.allScope(project));

                  if (targetClass != null) {
                    map.put(fromClass, targetClass);
                  }
                }
              }
              return map;
            }
          };

      @Override
      public void visitVariable(PsiVariable variable) {
        final PsiType type = variable.getType();
        if (type instanceof PsiClassType) {
          final PsiClassType.ClassResolveResult resolveResult =
              ((PsiClassType) type).resolveGenerics();
          final PsiClass psiClass = resolveResult.getElement();
          if (psiClass != null) {
            final String qName = psiClass.getQualifiedName();
            final PsiClass targetClass = myGuavaClassConversions.getValue().get(qName);
            if (targetClass != null) {
              final VariableTypeFix fix =
                  TypeMigrationVariableTypeFixProvider.createTypeMigrationFix(
                      variable, addTypeParameters(type, resolveResult, targetClass));
              holder.registerProblem(variable, PROBLEM_DESCRIPTION_FOR_VARIABLE, fix);
            }
          }
        }
      }

      private PsiClassType addTypeParameters(
          PsiType currentType,
          PsiClassType.ClassResolveResult currentTypeResolveResult,
          PsiClass targetClass) {
        final Map<PsiTypeParameter, PsiType> substitutionMap =
            currentTypeResolveResult.getSubstitutor().getSubstitutionMap();
        final PsiElementFactory elementFactory =
            JavaPsiFacade.getElementFactory(holder.getProject());
        if (substitutionMap.size() == 1) {
          return elementFactory.createType(
              targetClass, ContainerUtil.getFirstItem(substitutionMap.values()));
        } else {
          LOG.assertTrue(substitutionMap.size() == 2);
          LOG.assertTrue(
              GuavaFunctionConversionRule.JAVA_UTIL_FUNCTION_FUNCTION.equals(
                  targetClass.getQualifiedName()));
          final PsiType returnType = LambdaUtil.getFunctionalInterfaceReturnType(currentType);
          final List<PsiType> types = new ArrayList<PsiType>(substitutionMap.values());
          types.remove(returnType);
          final PsiType parameterType = types.get(0);
          return elementFactory.createType(targetClass, parameterType, returnType);
        }
      }
    };
  }
  private static void reportConstantReferenceValues(
      ProblemsHolder holder, StandardInstructionVisitor visitor, Set<PsiElement> reportedAnchors) {
    for (Pair<PsiReferenceExpression, DfaConstValue> pair : visitor.getConstantReferenceValues()) {
      PsiReferenceExpression ref = pair.first;
      if (ref.getParent() instanceof PsiReferenceExpression || !reportedAnchors.add(ref)) {
        continue;
      }

      final Object value = pair.second.getValue();
      PsiVariable constant = pair.second.getConstant();
      final String presentableName = constant != null ? constant.getName() : String.valueOf(value);
      final String exprText = String.valueOf(value);
      if (presentableName == null || exprText == null) {
        continue;
      }

      holder.registerProblem(
          ref,
          "Value <code>#ref</code> #loc is always '" + presentableName + "'",
          new LocalQuickFix() {
            @NotNull
            @Override
            public String getName() {
              return "Replace with '" + presentableName + "'";
            }

            @NotNull
            @Override
            public String getFamilyName() {
              return "Replace with constant value";
            }

            @Override
            public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
              if (!FileModificationService.getInstance()
                  .preparePsiElementsForWrite(descriptor.getPsiElement())) {
                return;
              }

              PsiElement problemElement = descriptor.getPsiElement();
              if (problemElement == null) return;

              PsiMethodCallExpression call =
                  problemElement.getParent() instanceof PsiExpressionList
                          && problemElement.getParent().getParent()
                              instanceof PsiMethodCallExpression
                      ? (PsiMethodCallExpression) problemElement.getParent().getParent()
                      : null;
              PsiMethod targetMethod = call == null ? null : call.resolveMethod();

              JavaPsiFacade facade = JavaPsiFacade.getInstance(project);
              problemElement.replace(
                  facade.getElementFactory().createExpressionFromText(exprText, null));

              if (targetMethod != null) {
                ExtractMethodUtil.addCastsToEnsureResolveTarget(targetMethod, call);
              }
            }
          });
    }
  }
  private void createDescription(
      StandardDataFlowRunner runner, ProblemsHolder holder, DataFlowInstructionVisitor visitor) {
    Pair<Set<Instruction>, Set<Instruction>> constConditions =
        runner.getConstConditionalExpressions();
    Set<Instruction> trueSet = constConditions.getFirst();
    Set<Instruction> falseSet = constConditions.getSecond();

    ArrayList<Instruction> allProblems = new ArrayList<Instruction>();
    allProblems.addAll(trueSet);
    allProblems.addAll(falseSet);
    allProblems.addAll(runner.getCCEInstructions());
    allProblems.addAll(StandardDataFlowRunner.getRedundantInstanceofs(runner, visitor));

    HashSet<PsiElement> reportedAnchors = new HashSet<PsiElement>();
    for (PsiElement element : visitor.getProblems(NullabilityProblem.callNPE)) {
      if (reportedAnchors.add(element)) {
        reportCallMayProduceNpe(holder, (PsiMethodCallExpression) element, holder.isOnTheFly());
      }
    }
    for (PsiElement element : visitor.getProblems(NullabilityProblem.fieldAccessNPE)) {
      if (reportedAnchors.add(element)) {
        PsiElement parent = element.getParent();
        PsiElement fieldAccess =
            parent instanceof PsiArrayAccessExpression || parent instanceof PsiReferenceExpression
                ? parent
                : element;
        reportFieldAccessMayProduceNpe(holder, element, (PsiExpression) fieldAccess);
      }
    }

    for (Instruction instruction : allProblems) {
      if (instruction instanceof TypeCastInstruction
          && reportedAnchors.add(
              ((TypeCastInstruction) instruction).getCastExpression().getCastType())) {
        reportCastMayFail(holder, (TypeCastInstruction) instruction);
      } else if (instruction instanceof BranchingInstruction) {
        handleBranchingInstruction(
            holder,
            visitor,
            trueSet,
            falseSet,
            reportedAnchors,
            (BranchingInstruction) instruction);
      }
    }

    reportNullableArguments(visitor, holder, reportedAnchors);
    reportNullableAssignments(visitor, holder, reportedAnchors);
    reportUnboxedNullables(visitor, holder, reportedAnchors);
    if (!runner.isInNullableMethod()
        && runner.isInMethod()
        && (runner.isInNotNullMethod() || SUGGEST_NULLABLE_ANNOTATIONS)) {
      reportNullableReturns(runner, visitor, holder, reportedAnchors);
    }
    if (SUGGEST_NULLABLE_ANNOTATIONS) {
      reportNullableArgumentsPassedToNonAnnotated(visitor, holder, reportedAnchors);
    }

    if (REPORT_CONSTANT_REFERENCE_VALUES) {
      reportConstantReferenceValues(holder, visitor, reportedAnchors);
    }
  }
  private static void reportConstantReferenceValues(
      ProblemsHolder holder, StandardInstructionVisitor visitor, Set<PsiElement> reportedAnchors) {
    for (Pair<PsiReferenceExpression, DfaConstValue> pair : visitor.getConstantReferenceValues()) {
      PsiReferenceExpression ref = pair.first;
      if (!reportedAnchors.add(ref)) {
        continue;
      }

      final Object value = pair.second.getValue();
      PsiVariable constant = pair.second.getConstant();
      final String presentableName = constant != null ? constant.getName() : String.valueOf(value);
      final String exprText = getConstantValueText(value, constant);
      if (presentableName == null || exprText == null) {
        continue;
      }

      holder.registerProblem(
          ref,
          "Value <code>#ref</code> #loc is always '" + presentableName + "'",
          new LocalQuickFix() {
            @NotNull
            @Override
            public String getName() {
              return "Replace with '" + presentableName + "'";
            }

            @NotNull
            @Override
            public String getFamilyName() {
              return "Replace with constant value";
            }

            @Override
            public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
              if (!FileModificationService.getInstance()
                  .preparePsiElementsForWrite(descriptor.getPsiElement())) {
                return;
              }

              JavaPsiFacade facade = JavaPsiFacade.getInstance(project);
              PsiElement newElement =
                  descriptor
                      .getPsiElement()
                      .replace(facade.getElementFactory().createExpressionFromText(exprText, null));
              newElement =
                  JavaCodeStyleManager.getInstance(project).shortenClassReferences(newElement);
              if (newElement instanceof PsiJavaCodeReferenceElement) {
                PsiJavaCodeReferenceElement ref = (PsiJavaCodeReferenceElement) newElement;
                PsiElement target = ref.resolve();
                String shortName = ref.getReferenceName();
                if (target != null
                    && shortName != null
                    && ref.isQualified()
                    && facade.getResolveHelper().resolveReferencedVariable(shortName, newElement)
                        == target) {
                  newElement.replace(
                      facade.getElementFactory().createExpressionFromText(shortName, null));
                }
              }
            }
          });
    }
  }
  @NotNull
  @Override
  public PsiElementVisitor buildVisitor(@NotNull final ProblemsHolder holder, boolean isOnTheFly) {
    if (!PsiUtil.isLanguageLevel8OrHigher(holder.getFile())) {
      return PsiElementVisitor.EMPTY_VISITOR;
    }
    return new JavaElementVisitor() {
      void handleIteratorLoop(
          PsiLoopStatement statement, PsiJavaToken endToken, IteratorDeclaration declaration) {
        if (endToken == null || declaration == null || !declaration.isCollection()) return;
        PsiStatement body = statement.getBody();
        if (!(body instanceof PsiBlockStatement)) return;
        PsiStatement[] statements = ((PsiBlockStatement) body).getCodeBlock().getStatements();
        if (statements.length == 2 && statements[1] instanceof PsiIfStatement) {
          PsiVariable element = declaration.getNextElementVariable(statements[0]);
          if (element == null) return;
          PsiIfStatement ifStatement = (PsiIfStatement) statements[1];
          if (checkAndExtractCondition(declaration, ifStatement) == null) return;
          registerProblem(statement, endToken);
        } else if (statements.length == 1 && statements[0] instanceof PsiIfStatement) {
          PsiIfStatement ifStatement = (PsiIfStatement) statements[0];
          PsiExpression condition = checkAndExtractCondition(declaration, ifStatement);
          if (condition == null) return;
          PsiElement ref = declaration.findOnlyIteratorRef(condition);
          if (ref != null
              && declaration.isIteratorMethodCall(ref.getParent().getParent(), "next")
              && isAlwaysExecuted(condition, ref)) {
            registerProblem(statement, endToken);
          }
        }
      }

      private boolean isAlwaysExecuted(PsiExpression condition, PsiElement ref) {
        while (ref != condition) {
          PsiElement parent = ref.getParent();
          if (parent instanceof PsiPolyadicExpression) {
            PsiPolyadicExpression polyadicExpression = (PsiPolyadicExpression) parent;
            IElementType type = polyadicExpression.getOperationTokenType();
            if ((type.equals(JavaTokenType.ANDAND) || type.equals(JavaTokenType.OROR))
                && polyadicExpression.getOperands()[0] != ref) {
              return false;
            }
          }
          if (parent instanceof PsiConditionalExpression
              && ((PsiConditionalExpression) parent).getCondition() != ref) {
            return false;
          }
          ref = parent;
        }
        return true;
      }

      private void registerProblem(PsiLoopStatement statement, PsiJavaToken endToken) {
        //noinspection DialogTitleCapitalization
        holder.registerProblem(
            statement,
            new TextRange(0, endToken.getTextOffset() - statement.getTextOffset() + 1),
            QuickFixBundle.message("java.8.collection.removeif.inspection.description"),
            new ReplaceWithRemoveIfQuickFix());
      }

      @Nullable
      private PsiExpression checkAndExtractCondition(
          IteratorDeclaration declaration, PsiIfStatement ifStatement) {
        PsiExpression condition = ifStatement.getCondition();
        if (condition == null || ifStatement.getElseBranch() != null) return null;
        PsiStatement thenStatement = ControlFlowUtils.stripBraces(ifStatement.getThenBranch());
        if (!(thenStatement instanceof PsiExpressionStatement)) return null;
        if (!declaration.isIteratorMethodCall(
            ((PsiExpressionStatement) thenStatement).getExpression(), "remove")) return null;
        if (!LambdaGenerationUtil.canBeUncheckedLambda(condition)) return null;
        return condition;
      }

      @Override
      public void visitForStatement(PsiForStatement statement) {
        super.visitForStatement(statement);
        IteratorDeclaration declaration = IteratorDeclaration.fromLoop(statement);
        handleIteratorLoop(statement, statement.getRParenth(), declaration);
      }

      @Override
      public void visitWhileStatement(PsiWhileStatement statement) {
        super.visitWhileStatement(statement);
        IteratorDeclaration declaration = IteratorDeclaration.fromLoop(statement);
        handleIteratorLoop(statement, statement.getRParenth(), declaration);
      }
    };
  }