Fix getting built-in classes in frontend.java

getKotlinBuiltinClassDescriptor() worked only for classes in jet.* package and
was failing for classes like jet.Map.Entry, jet.MutableMap.MutableEntry

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

@@ -24,8 +24,6 @@ import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.BindingTrace;
 import org.jetbrains.jet.lang.resolve.java.provider.PsiDeclarationProviderFactory;
 import org.jetbrains.jet.lang.resolve.name.FqName;
-import org.jetbrains.jet.lang.resolve.name.Name;
-import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 
 import javax.inject.Inject;
 
@@ -91,16 +89,6 @@ public class JavaSemanticServices {
         return psiDeclarationProviderFactory;
     }
 
-    @Nullable
-    public ClassDescriptor getKotlinBuiltinClassDescriptor(@NotNull FqName qualifiedName) {
-        if (qualifiedName.firstSegmentIs(Name.identifier("jet")) && qualifiedName.pathSegments().size() == 2) {
-            return (ClassDescriptor) KotlinBuiltIns.getInstance().getBuiltInsScope().getClassifier(qualifiedName.pathSegments().get(1));
-        }
-        else {
-            return null;
-        }
-    }
-
     @Nullable
     public NamespaceDescriptor getKotlinNamespaceDescriptor(@NotNull FqName qualifiedName) {
         return trace.get(BindingContext.FQNAME_TO_NAMESPACE_DESCRIPTOR, qualifiedName);

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/resolver/JavaClassResolver.java

@@ -43,9 +43,11 @@ import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.FqNameBase;
 import org.jetbrains.jet.lang.resolve.name.FqNameUnsafe;
 import org.jetbrains.jet.lang.resolve.name.Name;
+import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.TypeUtils;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
+import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 
 import javax.inject.Inject;
 import java.util.ArrayList;
@@ -159,7 +161,7 @@ public final class JavaClassResolver {
             return null;
         }
 
-        ClassDescriptor builtinClassDescriptor = semanticServices.getKotlinBuiltinClassDescriptor(qualifiedName);
+        ClassDescriptor builtinClassDescriptor = getKotlinBuiltinClassDescriptor(qualifiedName);
         if (builtinClassDescriptor != null) {
             return builtinClassDescriptor;
         }
@@ -184,6 +186,24 @@ public final class JavaClassResolver {
         return doResolveClass(qualifiedName, tasks);
     }
 
+    @Nullable
+    private static ClassDescriptor getKotlinBuiltinClassDescriptor(@NotNull FqName qualifiedName) {
+        if (!qualifiedName.firstSegmentIs(KotlinBuiltIns.BUILT_INS_PACKAGE_NAME)) return null;
+
+        List<Name> segments = qualifiedName.pathSegments();
+        if (segments.size() < 2) return null;
+
+        JetScope scope = KotlinBuiltIns.getInstance().getBuiltInsScope();
+        for (int i = 1, size = segments.size(); i < size; i++) {
+            ClassifierDescriptor classifier = scope.getClassifier(segments.get(i));
+            if (classifier == null) return null;
+            assert classifier instanceof ClassDescriptor : "Unexpected classifier in built-ins: " + classifier;
+            scope = ((ClassDescriptor) classifier).getUnsubstitutedInnerClassesScope();
+        }
+
+        return (ClassDescriptor) scope.getContainingDeclaration();
+    }
+
     private ClassDescriptor doResolveClass(@NotNull FqName qualifiedName, @NotNull PostponedTasks tasks) {
         PsiClass psiClass = psiClassFinder.findPsiClass(qualifiedName, PsiClassFinder.RuntimeClassesHandleMode.REPORT_ERROR);
         if (psiClass == null) {

compiler/frontend/src/org/jetbrains/jet/lang/types/lang/KotlinBuiltIns.java

@@ -47,7 +47,7 @@ public class KotlinBuiltIns {
     public static final JetScope STUB = JetScope.EMPTY;
 
     public static final String BUILT_INS_PACKAGE_NAME_STRING = "jet";
-    /* package */ static final Name BUILT_INS_PACKAGE_NAME = Name.identifier(BUILT_INS_PACKAGE_NAME_STRING);
+    public static final Name BUILT_INS_PACKAGE_NAME = Name.identifier(BUILT_INS_PACKAGE_NAME_STRING);
     public static final FqName BUILT_INS_PACKAGE_FQ_NAME = FqName.topLevel(BUILT_INS_PACKAGE_NAME);
 
     public static final int FUNCTION_TRAIT_COUNT = 23;