--- /dev/null
+++ dyld/dyld-1335/cache_builder/Timer.cpp
@@ -0,0 +1,169 @@
+/* -*- 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@
+*/
+
+#include "Timer.h"
+#include "BuilderConfig.h"
+
+#include <mach/mach_time.h>
+
+using namespace cache_builder;
+
+//
+// MARK: --- cache_builder::Timer::Scope methods ---
+//
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+
+cache_builder::Timer::Scope::Scope(const BuilderConfig& config, std::string_view name)
+    : config(config)
+    , name(name)
+    , log(config.timer.log)
+    , signpost(config.timer.signpost)
+{
+    os_signpost_emit_with_type(this->log, OS_SIGNPOST_INTERVAL_BEGIN, this->signpost, "dyld", "%s", name.data());
+
+    // Record the start time if -time-passes was used.  We'll print it later when we go out of scope
+    if ( config.log.printTimers )
+        this->startTimeNanos = clock_gettime_nsec_np(CLOCK_UPTIME_RAW);
+}
+
+cache_builder::Timer::Scope::~Scope()
+{
+    os_signpost_emit_with_type(this->log, OS_SIGNPOST_INTERVAL_END, this->signpost, "dyld", "%s", name.data());
+
+    // Also print to stdout if -time-passes was passed to the builder
+    if ( this->config.log.printTimers ) {
+        uint64_t endTimeNanos   = clock_gettime_nsec_np(CLOCK_UPTIME_RAW);
+        uint64_t timeMillis     = (endTimeNanos - startTimeNanos) / 1000000;
+        this->config.log.log("%s = %lldms\n", name.data(), timeMillis);
+    }
+}
+
+#pragma clang diagnostic pop
+
+//
+// MARK: --- cache_builder::Timer methods ---
+//
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+
+cache_builder::Timer::Timer()
+{
+    this->log      = os_log_create("com.apple.dyld", "cache-builder");
+    this->signpost = os_signpost_id_generate(this->log);
+}
+
+#pragma clang diagnostic pop
+
+//
+// MARK: --- cache_builder::Timer::Scope methods ---
+//
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+
+cache_builder::Timer::AggregateTimer::Scope::Scope(AggregateTimer& timer, std::string_view name)
+    : timer(timer)
+    , name(name)
+{
+    this->startTimeNanos = clock_gettime_nsec_np(CLOCK_UPTIME_RAW);
+}
+
+cache_builder::Timer::AggregateTimer::Scope::~Scope()
+{
+    uint64_t endTimeNanos = clock_gettime_nsec_np(CLOCK_UPTIME_RAW);
+    this->timer.record(this->name, this->startTimeNanos, endTimeNanos);
+}
+
+#pragma clang diagnostic pop
+
+//
+// MARK: --- cache_builder::Timer::AggregateTimer methods ---
+//
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+
+cache_builder::Timer::AggregateTimer::AggregateTimer(const BuilderConfig& config)
+    : config(config)
+    , mapLock(PTHREAD_MUTEX_INITIALIZER)
+{
+}
+
+cache_builder::Timer::AggregateTimer::~AggregateTimer()
+{
+    if ( this->config.log.printTimers ) {
+        for ( const auto& nameAndTime : this->timesNanos ) {
+            uint64_t timeMillis = nameAndTime.second / 1000000;
+            this->config.log.log("%s = %lldms\n", nameAndTime.first.data(), timeMillis);
+        }
+    }
+}
+
+void cache_builder::Timer::AggregateTimer::record(std::string_view name, uint64_t startTime, uint64_t endTime)
+{
+    pthread_mutex_lock(&this->mapLock);
+    // Use the map to look up the index in to the vector
+    auto itAndInserted = timeMap.insert({ name, timesNanos.size() });
+    if ( itAndInserted.second ) {
+        // We added the name, so add a new element to the vector
+        timesNanos.emplace_back(name, 0);
+    }
+    timesNanos[itAndInserted.first->second].second += (endTime - startTime);
+    pthread_mutex_unlock(&this->mapLock);
+}
+
+#pragma clang diagnostic pop
+
+#pragma clang diagnostic pop
+
+//
+// MARK: --- cache_builder::Stats methods ---
+//
+
+cache_builder::Stats::Stats(const BuilderConfig& config)
+    : config(config)
+{
+}
+
+cache_builder::Stats::~Stats()
+{
+    for ( const std::string& str : this->stats )
+        this->config.log.log("%s", str.data());
+}
+
+void cache_builder::Stats::add(const char* format, ...)
+{
+    char*   output_string;
+    va_list list;
+    va_start(list, format);
+    vasprintf(&output_string, format, list);
+    va_end(list);
+
+    this->stats.push_back(output_string);
+
+    free(output_string);
+}