implement KtFile.getClasses() in plugin (required to have coverage work, among other things)

compiler/frontend/src/org/jetbrains/kotlin/psi/KtFile.java

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.psi;
 import com.intellij.extapi.psi.PsiFileBase;
 import com.intellij.lang.ASTNode;
 import com.intellij.lang.FileASTNode;
+import com.intellij.openapi.components.ServiceManager;
 import com.intellij.openapi.fileTypes.FileType;
 import com.intellij.psi.*;
 import com.intellij.psi.stubs.StubElement;
@@ -163,6 +164,11 @@ public class KtFile extends PsiFileBase implements KtDeclarationContainer, KtAnn
     @NotNull
     @Override
     public PsiClass[] getClasses() {
+        KtFileClassProvider fileClassProvider = ServiceManager.getService(getProject(), KtFileClassProvider.class);
+        // TODO We don't currently support finding light classes for scripts
+        if (fileClassProvider != null && !isScript()) {
+            return fileClassProvider.getFileClasses(this);
+        }
         return PsiClass.EMPTY_ARRAY;
     }
 

compiler/frontend/src/org/jetbrains/kotlin/psi/KtFileClassProvider.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.psi
+
+import com.intellij.psi.PsiClass
+
+interface KtFileClassProvider {
+    fun getFileClasses(file: KtFile): Array<PsiClass>
+}