KT-2247 Report name clashes between inner classes and members of class object

#KT-2247 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/MutableClassDescriptorLite.java

@@ -43,6 +43,7 @@ public abstract class MutableClassDescriptorLite extends ClassDescriptorBase
 
     private List<TypeParameterDescriptor> typeParameters;
     private Collection<JetType> supertypes = Lists.newArrayList();
+    private final Collection<ClassDescriptor> innerClasses = Lists.newArrayList();
 
     private TypeConstructor typeConstructor;
 
@@ -209,6 +210,11 @@ public abstract class MutableClassDescriptorLite extends ClassDescriptorBase
         return innerClassesScope;
     }
 
+    public Collection<ClassDescriptor> getInnerClasses() {
+        return innerClasses;
+    }
+
+
     public void addSupertype(@NotNull JetType supertype) {
         if (!ErrorUtils.isErrorType(supertype)) {
             if (TypeUtils.getClassDescriptor(supertype) != null) {
@@ -275,6 +281,7 @@ public abstract class MutableClassDescriptorLite extends ClassDescriptorBase
                 @Override
                 public void addClassifierDescriptor(@NotNull MutableClassDescriptorLite classDescriptor) {
                     getScopeForMemberLookupAsWritableScope().addClassifierDescriptor(classDescriptor);
+                    innerClasses.add(classDescriptor);
                 }
 
                 @Override

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

@@ -93,6 +93,7 @@ public class DeclarationResolver {
         resolveFunctionAndPropertyHeaders();
         importsResolver.processMembersImports(rootScope);
         checkRedeclarationsInNamespaces();
+        checkClassObjectInnerClassNames();
     }
 
 
@@ -314,4 +315,26 @@ public class DeclarationResolver {
         }
         return declarations;
     }
+
+    private void checkClassObjectInnerClassNames() {
+        for (MutableClassDescriptor classDescriptor : context.getClasses().values()) {
+            MutableClassDescriptorLite classObj = classDescriptor.getClassObjectDescriptor();
+            if (classObj == null) {
+                continue;
+            }
+
+            Collection<ClassDescriptor> myInnerClasses = classDescriptor.getInnerClasses();
+            Collection<ClassDescriptor> classObjInnerClasses = classObj.getInnerClasses();
+
+            for (ClassDescriptor myInnerClass : myInnerClasses) {
+                for (ClassDescriptor classObjInnerClass : classObjInnerClasses) {
+                    if (myInnerClass.getName().equals(classObjInnerClass.getName())) {
+                        trace.report(REDECLARATION.on(BindingContextUtils.classDescriptorToDeclaration(trace.getBindingContext(), myInnerClass), myInnerClass.getName().getName()));
+                        trace.report(REDECLARATION.on(BindingContextUtils.classDescriptorToDeclaration(trace.getBindingContext(), classObjInnerClass), classObjInnerClass.getName().getName()));
+                        break;
+                    }
+                }
+            }
+        }
+    }
 }

compiler/testData/diagnostics/tests/redeclarations/kt2247.kt

@@ -0,0 +1,14 @@
+//KT-2247 Report name clashes between inner classes and members of class object
+
+package kt2247
+
+class B {
+    class object {
+        class <!REDECLARATION!>Y<!> {
+        }
+    }
+
+    class <!REDECLARATION!>Y<!> {
+    }
+
+}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -15,12 +15,15 @@
  */
 package org.jetbrains.jet.checkers;
 
+import junit.framework.Assert;
 import junit.framework.Test;
 import junit.framework.TestSuite;
+
+import java.io.File;
 import org.jetbrains.jet.JetTestUtils;
 import org.jetbrains.jet.test.TestMetadata;
 
-import java.io.File;
+import org.jetbrains.jet.checkers.AbstractDiagnosticsTestWithEagerResolve;
 
 /** This class is generated by {@link org.jetbrains.jet.checkers.AbstractDiagnosticsTestWithEagerResolve}. DO NOT MODIFY MANUALLY */
 public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEagerResolve {
@@ -1766,6 +1769,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.checkers.AbstractDiagnosticsTestWithEagerResolve", new File("compiler/testData/diagnostics/tests/redeclarations"), "kt", false);
             }
             
+            @TestMetadata("kt2247.kt")
+            public void testKt2247() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/redeclarations/kt2247.kt");
+            }
+            
             @TestMetadata("MultiFilePackageRedeclaration.kt")
             public void testMultiFilePackageRedeclaration() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/redeclarations/MultiFilePackageRedeclaration.kt");