コード例 #1
0
  private Nullness calcInherentNullability() {
    PsiModifierListOwner var = getPsiVariable();
    Nullness nullability = DfaPsiUtil.getElementNullability(getVariableType(), var);
    if (nullability != Nullness.UNKNOWN) {
      return nullability;
    }

    Nullness defaultNullability =
        myFactory.isUnknownMembersAreNullable() && MEMBER_OR_METHOD_PARAMETER.accepts(var)
            ? Nullness.NULLABLE
            : Nullness.UNKNOWN;

    if (var instanceof PsiParameter && var.getParent() instanceof PsiForeachStatement) {
      PsiExpression iteratedValue = ((PsiForeachStatement) var.getParent()).getIteratedValue();
      if (iteratedValue != null) {
        PsiType itemType = JavaGenericsUtil.getCollectionItemType(iteratedValue);
        if (itemType != null) {
          return DfaPsiUtil.getElementNullability(itemType, var);
        }
      }
    }

    if (var instanceof PsiField
        && DfaPsiUtil.isFinalField((PsiVariable) var)
        && myFactory.isHonorFieldInitializers()) {
      List<PsiExpression> initializers = DfaPsiUtil.findAllConstructorInitializers((PsiField) var);
      if (initializers.isEmpty()) {
        return defaultNullability;
      }

      boolean hasUnknowns = false;
      for (PsiExpression expression : initializers) {
        Nullness nullness = getFieldInitializerNullness(expression);
        if (nullness == Nullness.NULLABLE) {
          return Nullness.NULLABLE;
        }
        if (nullness == Nullness.UNKNOWN) {
          hasUnknowns = true;
        }
      }

      if (hasUnknowns) {
        if (DfaPsiUtil.isInitializedNotNull((PsiField) var)) {
          return Nullness.NOT_NULL;
        }
        return defaultNullability;
      }

      return Nullness.NOT_NULL;
    }

    return defaultNullability;
  }
コード例 #2
0
 private static Nullness getFieldInitializerNullness(@NotNull PsiExpression expression) {
   if (expression.textMatches(PsiKeyword.NULL)) return Nullness.NULLABLE;
   if (expression instanceof PsiNewExpression
       || expression instanceof PsiLiteralExpression
       || expression instanceof PsiPolyadicExpression) return Nullness.NOT_NULL;
   if (expression instanceof PsiReferenceExpression) {
     PsiElement target = ((PsiReferenceExpression) expression).resolve();
     return DfaPsiUtil.getElementNullability(null, (PsiModifierListOwner) target);
   }
   if (expression instanceof PsiMethodCallExpression) {
     PsiMethod method = ((PsiMethodCallExpression) expression).resolveMethod();
     return method != null ? DfaPsiUtil.getElementNullability(null, method) : Nullness.UNKNOWN;
   }
   return Nullness.UNKNOWN;
 }
コード例 #3
0
  @Nullable
  private static Map<PsiExpression, PsiType> buildDataflowTypeMap(PsiExpression forPlace) {
    PsiElement scope = DfaPsiUtil.getTopmostBlockInSameClass(forPlace);
    if (scope == null) {
      PsiFile file = forPlace.getContainingFile();
      if (!(file instanceof PsiCodeFragment)) {
        return Collections.emptyMap();
      }

      scope = file;
    }

    DataFlowRunner runner =
        new DataFlowRunner() {
          @NotNull
          @Override
          protected DfaMemoryState createMemoryState() {
            return new ExpressionTypeMemoryState(getFactory());
          }
        };

    final ExpressionTypeInstructionVisitor visitor = new ExpressionTypeInstructionVisitor(forPlace);
    if (runner.analyzeMethod(scope, visitor) == RunnerResult.OK) {
      return visitor.getResult();
    }
    return null;
  }