--- /dev/null
+++ dyld/dyld-1340/cache_builder/Timer.h
@@ -0,0 +1,117 @@
+/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+*
+* 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 Timer_hpp
+#define Timer_hpp
+
+#include "BuilderOptions.h"
+
+#include <os/signpost.h>
+#include <string_view>
+
+namespace cache_builder
+{
+
+struct BuilderConfig;
+
+struct Timer
+{
+    Timer();
+
+    struct Scope
+    {
+        Scope(const BuilderConfig& config, std::string_view name);
+        ~Scope();
+
+    private:
+        const BuilderConfig&    config;
+        std::string_view        name;
+        os_log_t                log;
+        os_signpost_id_t        signpost;
+        uint64_t                startTimeNanos = 0;
+    };
+
+    // Similar to Scope, but aggregates multiple clients to a single time.  Eg, every dylib
+    // has a "binding" Timer::Scope, and its too noisy to print them all for 2000 dylibs
+    struct AggregateTimer
+    {
+        AggregateTimer(const BuilderConfig& config);
+        ~AggregateTimer();
+        void record(std::string_view name, uint64_t startTime, uint64_t endTime);
+
+        // FIXME: Should we just have an AggregateTimer* in Timer::Scope instead?
+        struct Scope
+        {
+            Scope(AggregateTimer& timer, std::string_view name);
+            ~Scope();
+
+        private:
+            AggregateTimer&         timer;
+            std::string_view        name;
+            uint64_t                startTimeNanos = 0;
+        };
+
+    private:
+        const BuilderConfig&                                config;
+        std::unordered_map<std::string_view, uint32_t>      timeMap;
+        std::vector<std::pair<std::string_view, uint64_t>>  timesNanos;
+        pthread_mutex_t                                     mapLock;
+    };
+
+private:
+    os_log_t            log;
+    os_signpost_id_t    signpost;
+};
+
+struct Stats
+{
+    Stats(const BuilderConfig& config);
+    ~Stats();
+
+    void add(const char* format, ...)  __attribute__((format(printf, 2, 3)));
+
+private:
+    const BuilderConfig& config;
+    std::vector<std::string> stats;
+};
+
+struct Logger
+{
+    Logger(const BuilderOptions& options);
+
+    void log(const char* format, ...)  const __attribute__((format(printf, 2, 3)));
+
+    bool printTimers            = false;
+    bool printStats             = false;
+    bool printDebug             = false;
+    bool printDebugIMPCaches    = false;
+    bool printDebugCacheLayout  = false;
+
+private:
+    std::string logPrefix;
+};
+
+} // namespace cache_builder
+
+#endif /* Timer_hpp */