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;
}
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;
}
@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;
}