diff --git a/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java b/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java
index 3c86ad0029c8..923e6688ba27 100644
--- a/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java
+++ b/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java
@@ -20,7 +20,6 @@ import com.intellij.openapi.application.Application;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.PathManager;
 import com.intellij.openapi.components.ApplicationComponent;
-import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.fileTypes.FileTypeManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.project.ProjectManager;
@@ -53,7 +52,6 @@ import java.util.Set;
  * 2. corresponding source file has been deleted
  */
 public class TranslatingCompilerFilesMonitor implements ApplicationComponent {
-  private static final Logger LOG = Logger.getInstance("#com.intellij.compiler.impl.TranslatingCompilerFilesMonitor");
   public static boolean ourDebugMode = false;
 
   public TranslatingCompilerFilesMonitor(VirtualFileManager vfsManager, Application application) {
diff --git a/platform/core-api/src/com/intellij/openapi/project/ProjectCoreUtil.java b/platform/core-api/src/com/intellij/openapi/project/ProjectCoreUtil.java
index 40ac91ccffea..472e6970d423 100644
--- a/platform/core-api/src/com/intellij/openapi/project/ProjectCoreUtil.java
+++ b/platform/core-api/src/com/intellij/openapi/project/ProjectCoreUtil.java
@@ -27,15 +27,17 @@ import org.jetbrains.annotations.Nullable;
  * @author dmitrylomov
  */
 public class ProjectCoreUtil {
-  /** @deprecated use {@link Project#DIRECTORY_STORE_FOLDER} (to be removed in IDEA 17) */
-  public static final String DIRECTORY_BASED_PROJECT_DIR = Project.DIRECTORY_STORE_FOLDER;
+  public static volatile Project theProject;
 
   public static boolean isProjectOrWorkspaceFile(@NotNull VirtualFile file) {
     return isProjectOrWorkspaceFile(file, file.getFileType());
   }
 
   public static boolean isProjectOrWorkspaceFile(@NotNull VirtualFile file, @Nullable FileType fileType) {
-    if (fileType instanceof InternalFileType) return true;
+    if (fileType instanceof InternalFileType) {
+      return true;
+    }
+
     VirtualFile parent = file.isDirectory() ? file: file.getParent();
     while (parent != null) {
       if (Comparing.equal(parent.getNameSequence(), Project.DIRECTORY_STORE_FOLDER, SystemInfoRt.isFileSystemCaseSensitive)) return true;
@@ -51,5 +53,4 @@ public class ProjectCoreUtil {
   public static Project theOnlyOpenProject() {
     return theProject;
   }
-  public static volatile Project theProject;
 }
\ No newline at end of file
diff --git a/platform/lang-api/src/com/intellij/openapi/project/ProjectUtil.java b/platform/lang-api/src/com/intellij/openapi/project/ProjectUtil.java
index 0792a22f57df..61e71da6f236 100644
--- a/platform/lang-api/src/com/intellij/openapi/project/ProjectUtil.java
+++ b/platform/lang-api/src/com/intellij/openapi/project/ProjectUtil.java
@@ -22,7 +22,6 @@ import com.intellij.openapi.fileEditor.UniqueVFilePathBuilder;
 import com.intellij.openapi.fileTypes.FileType;
 import com.intellij.openapi.fileTypes.FileTypeManager;
 import com.intellij.openapi.roots.ProjectRootManager;
-import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.vfs.VirtualFilePathWrapper;
 import org.jetbrains.annotations.NotNull;
@@ -37,11 +36,6 @@ public class ProjectUtil {
   private ProjectUtil() {
   }
 
-  @Nullable
-  public static String getProjectLocationString(@NotNull final Project project) {
-    return FileUtil.getLocationRelativeToUserHome(project.getBasePath());
-  }
-
   @NotNull
   public static String calcRelativeToProjectPath(@NotNull final VirtualFile file,
                                                  @Nullable final Project project,
@@ -93,7 +87,7 @@ public class ProjectUtil {
    */
   @Nullable
   public static Project guessProjectForContentFile(@NotNull VirtualFile file, @NotNull FileType fileType) {
-    if (isProjectOrWorkspaceFile(file, fileType)) {
+    if (ProjectCoreUtil.isProjectOrWorkspaceFile(file, fileType)) {
       return null;
     }
 
@@ -106,13 +100,9 @@ public class ProjectUtil {
     return null;
   }
 
-  public static boolean isProjectOrWorkspaceFile(final VirtualFile file) {
+  public static boolean isProjectOrWorkspaceFile(@NotNull VirtualFile file) {
     // do not use file.getFileType() to avoid autodetection by content loading for arbitrary files
-    return isProjectOrWorkspaceFile(file, FileTypeManager.getInstance().getFileTypeByFileName(file.getName()));
-  }
-
-  public static boolean isProjectOrWorkspaceFile(@NotNull VirtualFile file, @Nullable FileType fileType) {
-    return ProjectCoreUtil.isProjectOrWorkspaceFile(file, fileType);
+    return ProjectCoreUtil.isProjectOrWorkspaceFile(file, FileTypeManager.getInstance().getFileTypeByFileName(file.getName()));
   }
 
   @NotNull
diff --git a/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java b/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java
index 736035590a94..c8e7da0ab930 100644
--- a/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java
+++ b/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java
@@ -21,16 +21,13 @@ import com.intellij.internal.statistic.beans.GroupDescriptor;
 import com.intellij.internal.statistic.beans.UsageDescriptor;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.util.io.FileUtil;
+import com.intellij.project.ProjectKt;
 import com.intellij.psi.search.FileTypeIndex;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.util.NotNullFunction;
-import com.intellij.util.ThreeState;
 import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
-import java.io.File;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -38,7 +35,6 @@ import java.util.Set;
  * @author Nikolay Matveev
  */
 public class FileTypeUsagesCollector extends AbstractApplicationUsagesCollector {
-
   private static final String GROUP_ID = "file-type";
 
   @NotNull
@@ -60,11 +56,10 @@ public class FileTypeUsagesCollector extends AbstractApplicationUsagesCollector
       if (project.isDisposed()) {
         throw new CollectUsagesException("Project is disposed");
       }
-      final String ideaDirPath = getIdeaDirPath(project);
       ApplicationManager.getApplication().runReadAction(() -> {
         FileTypeIndex.processFiles(fileType, file -> {
           //skip files from .idea directory otherwise 99% of projects would have XML and PLAIN_TEXT file types
-          if (ideaDirPath == null || FileUtil.isAncestorThreeState(ideaDirPath, file.getPath(), true) == ThreeState.NO) {
+          if (!ProjectKt.getStateStore(project).isProjectFile(file)) {
             usedFileTypes.add(fileType);
             return false;
           }
@@ -74,16 +69,4 @@ public class FileTypeUsagesCollector extends AbstractApplicationUsagesCollector
     }
     return ContainerUtil.map2Set(usedFileTypes, (NotNullFunction<FileType, UsageDescriptor>)fileType -> new UsageDescriptor(fileType.getName(), 1));
   }
-
-  @Nullable
-  private static String getIdeaDirPath(@NotNull Project project) {
-    String projectPath = project.getBasePath();
-    if (projectPath != null) {
-      String ideaDirPath = projectPath + "/" + Project.DIRECTORY_STORE_FOLDER;
-      if (new File(ideaDirPath).isDirectory()) {
-        return ideaDirPath;
-      }
-    }
-    return null;
-  }
 }