--- /dev/null
+++ dyld/dyld-1162/common/ClosureFileSystem.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2017 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#ifndef ClosureFileSystem_h
+#define ClosureFileSystem_h
+
+// For MAXPATHLEN
+#include <sys/param.h>
+// For va_list
+#include <stdarg.h>
+// For uint64_t
+#include <stdint.h>
+
+namespace dyld3 {
+namespace closure {
+
+struct LoadedFileInfo {
+    const void*  fileContent                = nullptr;
+    uint64_t     fileContentLen             = 0;
+    uint64_t     sliceOffset                = 0;
+    uint64_t     sliceLen            : 63,
+                 isOSBinary          : 1;
+    uint64_t     inode                      = 0;
+    uint64_t     mtime                      = 0;
+    void (*unload)(const LoadedFileInfo&)   = nullptr;
+    const char*  path                       = nullptr;
+};
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnon-virtual-dtor"
+class FileSystem {
+protected:
+    FileSystem() { }
+
+public:
+
+    // Get the real path for a given path, if it exists.
+    // Returns true if the real path was found and updates the given buffer iff that is the case
+    virtual bool getRealPath(const char possiblePath[MAXPATHLEN], char realPath[MAXPATHLEN]) const = 0;
+
+    // Returns true on success.  If an error occurs the given callback will be called with the reason.
+    // On success, info is filled with info about the loaded file.  If the path supplied includes a symlink,
+    // the supplier realerPath is filled in with the real path of the file, otherwise it is set to the empty string.
+    virtual bool loadFile(const char* path, LoadedFileInfo& info, char realerPath[MAXPATHLEN], void (^error)(const char* format, ...)) const = 0;
+
+    // Frees the buffer allocated by loadFile()
+    virtual void unloadFile(const LoadedFileInfo& info) const = 0;
+
+    // Frees all but the requested range and adjusts info to new buffer location
+    // Remaining buffer can be freed later with unloadFile()
+    virtual void unloadPartialFile(LoadedFileInfo& info, uint64_t keepStartOffset, uint64_t keepLength) const = 0;
+
+    // If a file exists at path, returns true and sets inode and mtime
+    virtual bool fileExists(const char* path, uint64_t* inode=nullptr, uint64_t* mtime=nullptr,
+                            bool* issetuid=nullptr, bool* inodesMatchRuntime = nullptr) const = 0;
+};
+#pragma clang diagnostic pop
+
+} //  namespace closure
+} //  namespace dyld3
+
+#endif /* ClosureFileSystem_h */