added classes visibility check

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java

@@ -56,6 +56,7 @@ public interface Errors {
     });
 
     UnresolvedReferenceDiagnosticFactory UNRESOLVED_REFERENCE = UnresolvedReferenceDiagnosticFactory.create("Unresolved reference");
+    DiagnosticFactory2<JetSimpleNameExpression, DeclarationDescriptor, DeclarationDescriptor> INVISIBLE_MEMBER = DiagnosticFactory2.create(ERROR, "''{0}'' has private access in ''{1}''", NAME, NAME);
 
     RedeclarationDiagnosticFactory REDECLARATION = RedeclarationDiagnosticFactory.REDECLARATION;
     RedeclarationDiagnosticFactory NAME_SHADOWING = RedeclarationDiagnosticFactory.NAME_SHADOWING;

compiler/frontend/src/org/jetbrains/jet/lang/resolve/TypeResolver.java

@@ -274,6 +274,11 @@ public class TypeResolver {
             .lookupDescriptorsForUserType(userType, scope, trace);
         for (DeclarationDescriptor descriptor : descriptors) {
             if (descriptor instanceof ClassifierDescriptor) {
+                if (descriptor instanceof ClassDescriptor && !Visibilities.isVisible((ClassDescriptor)descriptor, scope.getContainingDeclaration())) {
+                    JetSimpleNameExpression referenceExpression = userType.getReferenceExpression();
+                    assert referenceExpression != null;
+                    trace.report(INVISIBLE_MEMBER.on(referenceExpression, descriptor, ((ClassDescriptor)descriptor).getContainingDeclaration()));
+                }
                 return (ClassifierDescriptor) descriptor;
             }
         }

compiler/testData/diagnostics/tests/scopes/visibility2.jet

@@ -1,7 +1,7 @@
 //FILE:a.kt
 package a
 
-private class A {
+private open class A {
     fun bar() {}
 }
 
@@ -9,7 +9,10 @@ private fun foo() {}
 
 fun makeA() = A()
 
+private object PO {}
+
 //FILE:b.kt
+//+JDK
 package a.b
 
 import a.*
@@ -18,14 +21,20 @@ fun test() {
     val y = makeA()
     y.<!UNRESOLVED_REFERENCE!>bar<!>()
     <!UNRESOLVED_REFERENCE!>foo<!>()
+
+    val <!UNUSED_VARIABLE!>u<!> : <!INVISIBLE_MEMBER!>A<!> = <!UNRESOLVED_REFERENCE!>A<!>()
+    val <!UNUSED_VARIABLE!>a<!> : java.util.Arrays.<!INVISIBLE_MEMBER!>ArrayList<!><Int>;
+
+    val <!UNUSED_VARIABLE!>po<!> = <!UNRESOLVED_REFERENCE!>PO<!>()
 }
 
-class A {
+class B : <!INVISIBLE_MEMBER!>A<!>() {}
-    class B {
+
+class Q {
+    class W {
         fun foo() {
-            val y = makeA() //assure that 'makeA' is visible
+            val <!UNUSED_VARIABLE!>y<!> = makeA() //assure that 'makeA' is visible
         }
     }
 }
 
-