J2K: Detect @NotNull references in call chains

j2k/src/org/jetbrains/jet/j2k/ast/CallChainExpression.java

@@ -39,7 +39,7 @@ public class CallChainExpression extends Expression {
 
     @Override
     public boolean isNullable() {
-        return myIdentifier.isNullable();
+        return myExpression.isNullable() || myIdentifier.isNullable();
     }
 
     @NotNull

j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java

@@ -21,6 +21,7 @@ import com.intellij.psi.tree.IElementType;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.j2k.Converter;
+import org.jetbrains.jet.j2k.ConverterUtil;
 import org.jetbrains.jet.j2k.ast.*;
 import org.jetbrains.jet.lang.types.expressions.OperatorConventions;
 
@@ -345,7 +346,8 @@ public class ExpressionVisitor extends StatementVisitor {
         final boolean insideSecondaryConstructor = isInsideSecondaryConstructor(expression);
         final boolean hasReceiver = isFieldReference && insideSecondaryConstructor;
         final boolean isThis = isThisExpression(expression);
-        final boolean isNullable = getConverter().typeToType(expression.getType()).isNullable();
+        final boolean notNull = isResolvedToNotNull(expression);
+        final boolean isNullable = getConverter().typeToType(expression.getType(), notNull).isNullable();
         final String className = getClassNameWithConstructor(expression);
 
         Expression identifier = new IdentifierImpl(expression.getReferenceName(), isNullable);
@@ -364,6 +366,14 @@ public class ExpressionVisitor extends StatementVisitor {
         );
     }
 
+    private static boolean isResolvedToNotNull(PsiReference expression) {
+        PsiElement target = expression.resolve();
+        if (target instanceof PsiModifierListOwner) {
+            return ConverterUtil.isAnnotatedAsNotNull(((PsiModifierListOwner) target).getModifierList());
+        }
+        return false;
+    }
+
     @NotNull
     private static String getClassNameWithConstructor(@NotNull PsiReferenceExpression expression) {
         PsiElement context = expression.getContext();

j2k/tests/testData/ast/annotations/file/jetbrainsNotNullChainExpr.jav

@@ -0,0 +1,22 @@
+package test;
+
+import org.jetbrains.annotations.NotNull;
+
+class Foo {
+   void execute() {}
+}
+
+class Bar {
+  @NotNull
+  Foo fooNotNull = Foo();
+  Foo fooNullable = null;
+}
+
+class Test {
+  public void test(@NotNull Bar barNotNull, Bar barNullable) {
+    barNotNull.fooNotNull.execute();
+    barNotNull.fooNullable.execute();
+    barNullable.fooNotNull.execute();
+    barNullable.fooNullable.execute();
+  }
+}

j2k/tests/testData/ast/annotations/file/jetbrainsNotNullChainExpr.kt

@@ -0,0 +1,17 @@
+package test
+open class Foo() {
+open fun execute() : Unit {
+}
+}
+open class Bar() {
+var fooNotNull : Foo = Foo()
+var fooNullable : Foo? = null
+}
+open class Test() {
+public open fun test(barNotNull : Bar, barNullable : Bar?) : Unit {
+barNotNull.fooNotNull.execute()
+barNotNull.fooNullable?.execute()
+barNullable?.fooNotNull?.execute()
+barNullable?.fooNullable?.execute()
+}
+}