Index: lib/Fuzzer/CMakeLists.txt
===================================================================
--- lib/Fuzzer/CMakeLists.txt
+++ lib/Fuzzer/CMakeLists.txt
@@ -17,9 +17,6 @@
     FuzzerExtFunctionsDlsym.cpp
     FuzzerExtFunctionsWeak.cpp
     FuzzerExtFunctionsWeakAlias.cpp
-    FuzzerIO.cpp
-    FuzzerIOPosix.cpp
-    FuzzerIOWindows.cpp
     FuzzerLoop.cpp
     FuzzerMerge.cpp
     FuzzerMutate.cpp
Index: lib/Fuzzer/FuzzerCorpus.h
===================================================================
--- lib/Fuzzer/FuzzerCorpus.h
+++ lib/Fuzzer/FuzzerCorpus.h
@@ -13,10 +13,10 @@
 #define LLVM_FUZZER_CORPUS
 
 #include "FuzzerDefs.h"
-#include "FuzzerIO.h"
 #include "FuzzerRandom.h"
 #include "FuzzerSHA1.h"
 #include "FuzzerTracePC.h"
+#include "Support/UtilIO.h"
 #include <numeric>
 #include <random>
 #include <unordered_set>
Index: lib/Fuzzer/FuzzerDictionary.h
===================================================================
--- lib/Fuzzer/FuzzerDictionary.h
+++ lib/Fuzzer/FuzzerDictionary.h
@@ -13,8 +13,8 @@
 #define LLVM_FUZZER_DICTIONARY_H
 
 #include "FuzzerDefs.h"
-#include "FuzzerIO.h"
 #include "FuzzerUtil.h"
+#include "Support/UtilIO.h"
 #include <algorithm>
 #include <limits>
 
Index: lib/Fuzzer/FuzzerDriver.cpp
===================================================================
--- lib/Fuzzer/FuzzerDriver.cpp
+++ lib/Fuzzer/FuzzerDriver.cpp
@@ -12,11 +12,11 @@
 #include "FuzzerCorpus.h"
 #include "FuzzerInterface.h"
 #include "FuzzerInternal.h"
-#include "FuzzerIO.h"
 #include "FuzzerMutate.h"
 #include "FuzzerRandom.h"
 #include "FuzzerTracePC.h"
 #include "Support/Util.h"
+#include "Support/UtilIO.h"
 #include <algorithm>
 #include <atomic>
 #include <chrono>
Index: lib/Fuzzer/FuzzerExtFunctionsDlsym.cpp
===================================================================
--- lib/Fuzzer/FuzzerExtFunctionsDlsym.cpp
+++ lib/Fuzzer/FuzzerExtFunctionsDlsym.cpp
@@ -15,7 +15,7 @@
 #if LIBFUZZER_APPLE
 
 #include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
+#include "Support/UtilIO.h"
 #include <dlfcn.h>
 
 using namespace fuzzer;
Index: lib/Fuzzer/FuzzerExtFunctionsWeak.cpp
===================================================================
--- lib/Fuzzer/FuzzerExtFunctionsWeak.cpp
+++ lib/Fuzzer/FuzzerExtFunctionsWeak.cpp
@@ -16,7 +16,7 @@
 #if LIBFUZZER_LINUX
 
 #include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
+#include "Support/UtilIO.h"
 
 extern "C" {
 // Declare these symbols as weak to allow them to be optionally defined.
Index: lib/Fuzzer/FuzzerExtFunctionsWeakAlias.cpp
===================================================================
--- lib/Fuzzer/FuzzerExtFunctionsWeakAlias.cpp
+++ lib/Fuzzer/FuzzerExtFunctionsWeakAlias.cpp
@@ -12,7 +12,7 @@
 #if LIBFUZZER_WINDOWS
 
 #include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
+#include "Support/UtilIO.h"
 
 using namespace fuzzer;
 
Index: lib/Fuzzer/FuzzerLoop.cpp
===================================================================
--- lib/Fuzzer/FuzzerLoop.cpp
+++ lib/Fuzzer/FuzzerLoop.cpp
@@ -11,11 +11,11 @@
 
 #include "FuzzerCorpus.h"
 #include "FuzzerInternal.h"
-#include "FuzzerIO.h"
 #include "FuzzerMutate.h"
 #include "FuzzerRandom.h"
 #include "FuzzerTracePC.h"
 #include "Support/Util.h"
+#include "Support/UtilIO.h"
 #include <algorithm>
 #include <cstring>
 #include <memory>
Index: lib/Fuzzer/FuzzerMerge.cpp
===================================================================
--- lib/Fuzzer/FuzzerMerge.cpp
+++ lib/Fuzzer/FuzzerMerge.cpp
@@ -10,10 +10,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "FuzzerInternal.h"
-#include "FuzzerIO.h"
 #include "FuzzerMerge.h"
 #include "FuzzerTracePC.h"
 #include "Support/Util.h"
+#include "Support/UtilIO.h"
 
 #include <fstream>
 #include <iterator>
Index: lib/Fuzzer/FuzzerMutate.cpp
===================================================================
--- lib/Fuzzer/FuzzerMutate.cpp
+++ lib/Fuzzer/FuzzerMutate.cpp
@@ -12,10 +12,10 @@
 #include "FuzzerCorpus.h"
 #include "FuzzerDefs.h"
 #include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
 #include "FuzzerMutate.h"
 #include "FuzzerOptions.h"
 #include "Support/Util.h"
+#include "Support/UtilIO.h"
 
 namespace fuzzer {
 
Index: lib/Fuzzer/FuzzerTracePC.cpp
===================================================================
--- lib/Fuzzer/FuzzerTracePC.cpp
+++ lib/Fuzzer/FuzzerTracePC.cpp
@@ -16,10 +16,10 @@
 #include "FuzzerDefs.h"
 #include "FuzzerDictionary.h"
 #include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
 #include "FuzzerTracePC.h"
 #include "FuzzerValueBitMap.h"
 #include "Support/Util.h"
+#include "Support/UtilIO.h"
 #include <map>
 #include <set>
 #include <sstream>
Index: lib/Fuzzer/FuzzerTraceState.cpp
===================================================================
--- lib/Fuzzer/FuzzerTraceState.cpp
+++ lib/Fuzzer/FuzzerTraceState.cpp
@@ -11,11 +11,11 @@
 
 #include "FuzzerDictionary.h"
 #include "FuzzerInternal.h"
-#include "FuzzerIO.h"
 #include "FuzzerMutate.h"
 #include "FuzzerRandom.h"
 #include "FuzzerTracePC.h"
 #include "Support/Util.h"
+#include "Support/UtilIO.h"
 #include <algorithm>
 #include <cstring>
 #include <map>
Index: lib/Fuzzer/FuzzerUtil.cpp
===================================================================
--- lib/Fuzzer/FuzzerUtil.cpp
+++ lib/Fuzzer/FuzzerUtil.cpp
@@ -10,8 +10,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "FuzzerUtil.h"
-#include "FuzzerIO.h"
 #include "FuzzerInternal.h"
+#include "Support/UtilIO.h"
 #include <cassert>
 #include <chrono>
 #include <cstring>
Index: lib/Fuzzer/Support/CMakeLists.txt
===================================================================
--- lib/Fuzzer/Support/CMakeLists.txt
+++ lib/Fuzzer/Support/CMakeLists.txt
@@ -1,6 +1,9 @@
 add_library(LLVMFuzzerSupport STATIC
   Util.cpp
   UtilDarwin.cpp
+  UtilIO.cpp
+  UtilIOPosix.cpp
+  UtilIOWindows.cpp
   UtilLinux.cpp
   UtilPosix.cpp
   UtilWindows.cpp
Index: lib/Fuzzer/Support/Util.cpp
===================================================================
--- lib/Fuzzer/Support/Util.cpp
+++ lib/Fuzzer/Support/Util.cpp
@@ -10,7 +10,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "Util.h"
-#include "../FuzzerIO.h"
+#include "UtilIO.h"
 #include <cstring>
 #include <errno.h>
 #include <signal.h>
Index: lib/Fuzzer/Support/UtilDarwin.cpp
===================================================================
--- lib/Fuzzer/Support/UtilDarwin.cpp
+++ lib/Fuzzer/Support/UtilDarwin.cpp
@@ -11,7 +11,7 @@
 #include "Platform.h"
 #if LIBFUZZER_APPLE
 
-#include "../FuzzerIO.h"
+#include "UtilIO.h"
 #include <mutex>
 #include <signal.h>
 #include <spawn.h>
Index: lib/Fuzzer/Support/UtilIO.h
===================================================================
--- lib/Fuzzer/Support/UtilIO.h
+++ lib/Fuzzer/Support/UtilIO.h
@@ -1,4 +1,4 @@
-//===- FuzzerIO.h - Internal header for IO utils ----------------*- C++ -* ===//
+//===- UtilIO.h - Internal header for IO utils ------------------*- C++ -* ===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -9,13 +9,16 @@
 // IO interface.
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_FUZZER_IO_H
-#define LLVM_FUZZER_IO_H
+#ifndef LLVM_FUZZER_SUPPORT_UTIL_IO_H
+#define LLVM_FUZZER_SUPPORT_UTIL_IO_H
 
-#include "FuzzerDefs.h"
+#include <string>
+#include <vector>
 
 namespace fuzzer {
 
+typedef std::vector<uint8_t> Unit;
+
 long GetEpoch(const std::string &Path);
 
 Unit FileToVector(const std::string &Path, size_t MaxSize = 0,
@@ -61,4 +64,4 @@
 
 }  // namespace fuzzer
 
-#endif  // LLVM_FUZZER_IO_H
+#endif  // LLVM_FUZZER_SUPPORT_UTIL_IO_H
Index: lib/Fuzzer/Support/UtilIO.cpp
===================================================================
--- lib/Fuzzer/Support/UtilIO.cpp
+++ lib/Fuzzer/Support/UtilIO.cpp
@@ -1,4 +1,4 @@
-//===- FuzzerIO.cpp - IO utils. -------------------------------------------===//
+//===- UtilIO.cpp - IO utils. ---------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -9,9 +9,9 @@
 // IO functions.
 //===----------------------------------------------------------------------===//
 
-#include "FuzzerIO.h"
-#include "FuzzerDefs.h"
-#include "FuzzerExtFunctions.h"
+#include "UtilIO.h"
+#include "../FuzzerDefs.h"
+#include "../FuzzerExtFunctions.h"
 #include <algorithm>
 #include <cstdarg>
 #include <fstream>
Index: lib/Fuzzer/Support/UtilIOPosix.cpp
===================================================================
--- lib/Fuzzer/Support/UtilIOPosix.cpp
+++ lib/Fuzzer/Support/UtilIOPosix.cpp
@@ -1,4 +1,4 @@
-//===- FuzzerIOPosix.cpp - IO utils for Posix. ----------------------------===//
+//===- UtilIOPosix.cpp - IO utils for Posix. ------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -8,13 +8,13 @@
 //===----------------------------------------------------------------------===//
 // IO functions implementation using Posix API.
 //===----------------------------------------------------------------------===//
-#include "Support/Platform.h"
+#include "Platform.h"
 #if LIBFUZZER_POSIX
 
-#include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
+#include "UtilIO.h"
 #include <cstdarg>
 #include <cstdio>
+#include <cstring>
 #include <dirent.h>
 #include <fstream>
 #include <iterator>
Index: lib/Fuzzer/Support/UtilIOWindows.cpp
===================================================================
--- lib/Fuzzer/Support/UtilIOWindows.cpp
+++ lib/Fuzzer/Support/UtilIOWindows.cpp
@@ -1,4 +1,4 @@
-//===- FuzzerIOWindows.cpp - IO utils for Windows. ------------------------===//
+//===- UtilIOWindows.cpp - IO utils for Windows. --------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -8,11 +8,11 @@
 //===----------------------------------------------------------------------===//
 // IO functions implementation for Windows.
 //===----------------------------------------------------------------------===//
-#include "Support/Platform.h"
+#include "Platform.h"
 #if LIBFUZZER_WINDOWS
 
-#include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
+#include "UtilIO.h"
+#include <cassert>
 #include <cstdarg>
 #include <cstdio>
 #include <fstream>
Index: lib/Fuzzer/Support/UtilPosix.cpp
===================================================================
--- lib/Fuzzer/Support/UtilPosix.cpp
+++ lib/Fuzzer/Support/UtilPosix.cpp
@@ -10,7 +10,7 @@
 //===----------------------------------------------------------------------===//
 #include "Platform.h"
 #if LIBFUZZER_POSIX
-#include "../FuzzerIO.h"
+#include "UtilIO.h"
 #include "../FuzzerInternal.h"
 #include <cassert>
 #include <chrono>
Index: lib/Fuzzer/Support/UtilWindows.cpp
===================================================================
--- lib/Fuzzer/Support/UtilWindows.cpp
+++ lib/Fuzzer/Support/UtilWindows.cpp
@@ -10,7 +10,7 @@
 //===----------------------------------------------------------------------===//
 #include "Platform.h"
 #if LIBFUZZER_WINDOWS
-#include "../FuzzerIO.h"
+#include "UtilIO.h"
 #include "../FuzzerInternal.h"
 #include <cassert>
 #include <chrono>