diff --git a/platform/execution-impl/src/com/intellij/execution/impl/RunConfigurationInArbitraryFileScanner.kt b/platform/execution-impl/src/com/intellij/execution/impl/RunConfigurationInArbitraryFileScanner.kt
index e27bab344c6f..2339e7d1c68a 100644
--- a/platform/execution-impl/src/com/intellij/execution/impl/RunConfigurationInArbitraryFileScanner.kt
+++ b/platform/execution-impl/src/com/intellij/execution/impl/RunConfigurationInArbitraryFileScanner.kt
@@ -2,7 +2,7 @@
 package com.intellij.execution.impl
 
 import com.intellij.openapi.project.Project
-import com.intellij.openapi.roots.impl.IndexableFileScanner
+import com.intellij.util.indexing.roots.IndexableFileScanner
 import com.intellij.openapi.util.text.StringUtil
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.util.PathUtil
diff --git a/platform/projectModel-api/src/com/intellij/openapi/roots/impl/IndexableFileScanner.java b/platform/indexing-api/src/com/intellij/util/indexing/roots/IndexableFileScanner.java
similarity index 98%
rename from platform/projectModel-api/src/com/intellij/openapi/roots/impl/IndexableFileScanner.java
rename to platform/indexing-api/src/com/intellij/util/indexing/roots/IndexableFileScanner.java
index 7415568ee428..9428f50047c0 100644
--- a/platform/projectModel-api/src/com/intellij/openapi/roots/impl/IndexableFileScanner.java
+++ b/platform/indexing-api/src/com/intellij/util/indexing/roots/IndexableFileScanner.java
@@ -1,5 +1,5 @@
 // Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
-package com.intellij.openapi.roots.impl;
+package com.intellij.util.indexing.roots;
 
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.openapi.project.Project;
diff --git a/platform/projectModel-api/src/com/intellij/util/indexing/roots/IndexableFilesIterator.java b/platform/indexing-api/src/com/intellij/util/indexing/roots/IndexableFilesIterator.java
similarity index 100%
rename from platform/projectModel-api/src/com/intellij/util/indexing/roots/IndexableFilesIterator.java
rename to platform/indexing-api/src/com/intellij/util/indexing/roots/IndexableFilesIterator.java
diff --git a/platform/projectModel-impl/src/com/intellij/openapi/roots/SyntheticLibraryIndexableFilesIterator.java b/platform/indexing-api/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIterator.java
similarity index 79%
rename from platform/projectModel-impl/src/com/intellij/openapi/roots/SyntheticLibraryIndexableFilesIterator.java
rename to platform/indexing-api/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIterator.java
index 2548e780d553..eec360e7d629 100644
--- a/platform/projectModel-impl/src/com/intellij/openapi/roots/SyntheticLibraryIndexableFilesIterator.java
+++ b/platform/indexing-api/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIterator.java
@@ -1,7 +1,7 @@
 // Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
-package com.intellij.openapi.roots;
+package com.intellij.util.indexing.roots;
 
-import com.intellij.util.indexing.roots.IndexableFilesIterator;
+import com.intellij.openapi.roots.SyntheticLibrary;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
diff --git a/platform/lang-impl/src/com/intellij/openapi/roots/impl/PushedFilePropertiesUpdaterImpl.java b/platform/lang-impl/src/com/intellij/openapi/roots/impl/PushedFilePropertiesUpdaterImpl.java
index bbfd37af8b29..363083362688 100644
--- a/platform/lang-impl/src/com/intellij/openapi/roots/impl/PushedFilePropertiesUpdaterImpl.java
+++ b/platform/lang-impl/src/com/intellij/openapi/roots/impl/PushedFilePropertiesUpdaterImpl.java
@@ -35,10 +35,7 @@ import com.intellij.ui.GuiUtils;
 import com.intellij.util.containers.ConcurrentBitSet;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.indexing.*;
-import com.intellij.util.indexing.roots.IndexableFilesIterator;
-import com.intellij.util.indexing.roots.ModuleIndexableFilesIterator;
-import com.intellij.util.indexing.roots.ModuleIndexableFilesIteratorImpl;
-import com.intellij.util.indexing.roots.ProjectIndexableFilesIteratorImpl;
+import com.intellij.util.indexing.roots.*;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
diff --git a/platform/lang-impl/src/com/intellij/util/indexing/UnindexedFilesUpdater.java b/platform/lang-impl/src/com/intellij/util/indexing/UnindexedFilesUpdater.java
index f2291308e0c3..6b458bef09a6 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/UnindexedFilesUpdater.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/UnindexedFilesUpdater.java
@@ -4,16 +4,14 @@ package com.intellij.util.indexing;
 import com.intellij.diagnostic.PerformanceWatcher;
 import com.intellij.openapi.application.Application;
 import com.intellij.openapi.application.ApplicationManager;
-import com.intellij.openapi.diagnostic.Attachment;
 import com.intellij.openapi.diagnostic.ControlFlowException;
 import com.intellij.openapi.diagnostic.Logger;
-import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.impl.ProgressSuspender;
 import com.intellij.openapi.project.*;
 import com.intellij.openapi.roots.ContentIterator;
 import com.intellij.openapi.roots.ex.ProjectRootManagerEx;
-import com.intellij.openapi.roots.impl.IndexableFileScanner;
+import com.intellij.util.indexing.roots.IndexableFileScanner;
 import com.intellij.openapi.roots.impl.PushedFilePropertiesUpdater;
 import com.intellij.openapi.roots.impl.PushedFilePropertiesUpdaterImpl;
 import com.intellij.openapi.util.Key;
diff --git a/platform/lang-impl/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIteratorImpl.kt b/platform/lang-impl/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIteratorImpl.kt
index 449d0aa0931e..b94f417c55ca 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIteratorImpl.kt
+++ b/platform/lang-impl/src/com/intellij/util/indexing/roots/SyntheticLibraryIndexableFilesIteratorImpl.kt
@@ -6,7 +6,6 @@ import com.intellij.openapi.application.runReadAction
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.roots.ContentIterator
 import com.intellij.openapi.roots.SyntheticLibrary
-import com.intellij.openapi.roots.SyntheticLibraryIndexableFilesIterator
 import com.intellij.util.containers.ConcurrentBitSet
 import com.intellij.util.indexing.IndexingBundle
 
diff --git a/platform/projectModel-api/intellij.platform.projectModel.iml b/platform/projectModel-api/intellij.platform.projectModel.iml
index 4e28a96cc2bd..00e0a1665cea 100644
--- a/platform/projectModel-api/intellij.platform.projectModel.iml
+++ b/platform/projectModel-api/intellij.platform.projectModel.iml
@@ -15,5 +15,6 @@
     <orderEntry type="module" module-name="intellij.platform.concurrency" />
     <orderEntry type="module" module-name="intellij.platform.util.ex" />
     <orderEntry type="module" module-name="intellij.platform.util.ui" />
+    <orderEntry type="library" name="fastutil-min" level="project" />
   </component>
 </module>
\ No newline at end of file
diff --git a/platform/projectModel-api/resources/META-INF/ProjectModel.xml b/platform/projectModel-api/resources/META-INF/ProjectModel.xml
index 49a4b382105e..f9e87a8f40a2 100644
--- a/platform/projectModel-api/resources/META-INF/ProjectModel.xml
+++ b/platform/projectModel-api/resources/META-INF/ProjectModel.xml
@@ -3,7 +3,7 @@
     <extensionPoint name="moduleExtension" interface="com.intellij.openapi.roots.ModuleExtension" area="IDEA_MODULE" dynamic="true"/>
     <extensionPoint name="orderEnumerationHandlerFactory" interface="com.intellij.openapi.roots.OrderEnumerationHandler$Factory" dynamic="true"/>
     <extensionPoint name="filePropertyPusher" interface="com.intellij.openapi.roots.impl.FilePropertyPusher" dynamic="true"/>
-    <extensionPoint name="projectFileScanner" interface="com.intellij.openapi.roots.impl.IndexableFileScanner" dynamic="true"/>
+    <extensionPoint name="projectFileScanner" interface="com.intellij.util.indexing.roots.IndexableFileScanner" dynamic="true"/>
     <extensionPoint name="customLibraryTable" interface="com.intellij.openapi.roots.libraries.CustomLibraryTableDescription" dynamic="true"/>
     <extensionPoint name="orderRootType" interface="com.intellij.openapi.roots.OrderRootType"/>
   </extensionPoints>
diff --git a/platform/projectModel-impl/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java b/platform/projectModel-api/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java
similarity index 79%
rename from platform/projectModel-impl/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java
rename to platform/projectModel-api/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java
index 39af248e951e..ce1245c0d48b 100644
--- a/platform/projectModel-impl/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java
+++ b/platform/projectModel-api/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 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.
- */
+// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.roots;
 
 import com.intellij.openapi.extensions.ExtensionPointName;
diff --git a/platform/projectModel-impl/src/com/intellij/openapi/roots/ImmutableSyntheticLibrary.java b/platform/projectModel-api/src/com/intellij/openapi/roots/ImmutableSyntheticLibrary.java
similarity index 95%
rename from platform/projectModel-impl/src/com/intellij/openapi/roots/ImmutableSyntheticLibrary.java
rename to platform/projectModel-api/src/com/intellij/openapi/roots/ImmutableSyntheticLibrary.java
index a940ad36bf09..e48732b54c0d 100644
--- a/platform/projectModel-impl/src/com/intellij/openapi/roots/ImmutableSyntheticLibrary.java
+++ b/platform/projectModel-api/src/com/intellij/openapi/roots/ImmutableSyntheticLibrary.java
@@ -1,14 +1,16 @@
-// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.roots;
 
 import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
 
+@ApiStatus.Internal
 class ImmutableSyntheticLibrary extends SyntheticLibrary {
 
   private final List<VirtualFile> mySourceRoots;
diff --git a/platform/projectModel-impl/src/com/intellij/openapi/roots/SyntheticLibrary.java b/platform/projectModel-api/src/com/intellij/openapi/roots/SyntheticLibrary.java
similarity index 98%
rename from platform/projectModel-impl/src/com/intellij/openapi/roots/SyntheticLibrary.java
rename to platform/projectModel-api/src/com/intellij/openapi/roots/SyntheticLibrary.java
index 13521de83382..1f60b80ff8a0 100644
--- a/platform/projectModel-impl/src/com/intellij/openapi/roots/SyntheticLibrary.java
+++ b/platform/projectModel-api/src/com/intellij/openapi/roots/SyntheticLibrary.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.roots;
 
 import com.intellij.navigation.ItemPresentation;
@@ -8,7 +8,7 @@ import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.containers.ContainerUtil;
-import gnu.trove.THashSet;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -166,7 +166,7 @@ public abstract class SyntheticLibrary {
 
   @NotNull
   private static <T extends VirtualFile> Set<T> asSet(@NotNull Collection<? extends T> collection) {
-    return collection instanceof Set ? (Set<T>)collection : new THashSet<>(collection);
+    return collection instanceof Set ? (Set<T>)collection : new ObjectOpenHashSet<>(collection);
   }
 
   @NotNull