--- /dev/null
+++ dyld/dyld-955/cache-builder/FileUtils.h
@@ -0,0 +1,110 @@
+/*
+ * 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 FileUtils_h
+#define FileUtils_h
+
+#include <stdint.h>
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+#include <unordered_map>
+#include <unordered_set>
+#include <dispatch/dispatch.h>
+
+#include "DyldSharedCache.h"
+#include "JSON.h"
+
+class Diagnostics;
+
+#if BUILDING_CACHE_BUILDER
+struct FileCache {
+    FileCache(void);
+    std::pair<uint8_t*, struct stat> cacheLoad(Diagnostics& diags, const std::string path);
+
+private:
+    std::pair<uint8_t*, struct stat> fill(Diagnostics& diags, const std::string& path);
+
+    std::unordered_map<std::string, std::pair<uint8_t*, struct stat>> entries;
+    dispatch_queue_t cache_queue;
+};
+
+extern FileCache fileCache;
+#endif
+
+//
+// recursively walk all files in a directory tree
+// symlinks are ignored
+// dirFilter should return true on directories which should not be recursed into
+// callback is called on each regular file found with stat() info about the file
+//
+void iterateDirectoryTree(const std::string& pathPrefix, const std::string& path, bool (^dirFilter)(const std::string& dirPath),
+                          void (^callback)(const std::string& path, const struct stat& statBuf), bool processFiles=true, bool recurse=true);
+
+
+//
+// writes the buffer to a temp file, then renames the file to the final path
+// returns true on success
+//
+bool safeSave(const void* buffer, size_t bufferLen, const std::string& path);
+
+
+const void* mapFileReadOnly(const char* path, size_t& mappedSize);
+
+bool fileExists(const std::string& path);
+
+std::unordered_map<std::string, uint32_t> parseOrderFile(const std::string& orderFileData);
+std::string loadOrderFile(const std::string& orderFilePath);
+
+std::string normalize_absolute_file_path(std::string path);
+std::string basePath(const std::string& path);
+std::string dirPath(const std::string& path);
+std::string realPath(const std::string& path);
+std::string realFilePath(const std::string& path);
+
+std::string toolDir();
+
+#if BUILDING_CACHE_BUILDER
+class SymlinkResolver {
+public:
+    SymlinkResolver() { }
+
+    void addFile(Diagnostics& diags, std::string path);
+
+    void addSymlink(Diagnostics& diags, std::string fromPath, std::string toPath);
+
+    std::string realPath(Diagnostics& diags, const std::string& path) const;
+
+    std::vector<DyldSharedCache::FileAlias> getResolvedSymlinks(Diagnostics& diags);
+
+private:
+    std::set<std::string> filePaths;
+    std::map<std::string, std::string> symlinks;
+};
+#endif  // BUILDING_CACHE_BUILDER
+
+
+#endif // FileUtils_h