Index: clang/lib/Frontend/CompilerInstance.cpp
===================================================================
--- clang/lib/Frontend/CompilerInstance.cpp
+++ clang/lib/Frontend/CompilerInstance.cpp
@@ -50,8 +50,6 @@
 #include "llvm/Support/TimeProfiler.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
-#include <sys/stat.h>
-#include <system_error>
 #include <time.h>
 #include <utility>
 
@@ -1388,16 +1386,16 @@
 /// Prune the module cache of modules that haven't been accessed in
 /// a long time.
 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
-  struct stat StatBuf;
+  llvm::sys::fs::file_status StatBuf;
   llvm::SmallString<128> TimestampFile;
   TimestampFile = HSOpts.ModuleCachePath;
   assert(!TimestampFile.empty());
   llvm::sys::path::append(TimestampFile, "modules.timestamp");
 
   // Try to stat() the timestamp file.
-  if (::stat(TimestampFile.c_str(), &StatBuf)) {
+  if (std::error_code EC = llvm::sys::fs::status(TimestampFile, StatBuf)) {
     // If the timestamp file wasn't there, create one now.
-    if (errno == ENOENT) {
+    if (EC == std::errc::no_such_file_or_directory) {
       writeTimestampFile(TimestampFile);
     }
     return;
@@ -1405,7 +1403,8 @@
 
   // Check whether the time stamp is older than our pruning interval.
   // If not, do nothing.
-  time_t TimeStampModTime = StatBuf.st_mtime;
+  time_t TimeStampModTime =
+      llvm::sys::toTimeT(StatBuf.getLastModificationTime());
   time_t CurrentTime = time(nullptr);
   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
     return;
@@ -1437,11 +1436,11 @@
 
       // Look at this file. If we can't stat it, there's nothing interesting
       // there.
-      if (::stat(File->path().c_str(), &StatBuf))
+      if (llvm::sys::fs::status(File->path(), StatBuf))
         continue;
 
       // If the file has been used recently enough, leave it there.
-      time_t FileAccessTime = StatBuf.st_atime;
+      time_t FileAccessTime = llvm::sys::toTimeT(StatBuf.getLastAccessedTime());
       if (CurrentTime - FileAccessTime <=
               time_t(HSOpts.ModuleCachePruneAfter)) {
         continue;
Index: clang/tools/libclang/CIndexCodeCompletion.cpp
===================================================================
--- clang/tools/libclang/CIndexCodeCompletion.cpp
+++ clang/tools/libclang/CIndexCodeCompletion.cpp
@@ -803,8 +803,8 @@
           os << arg << ".pth";
         }
         pchName.push_back('\0');
-        struct stat stat_results;
-        if (stat(pchName.str().c_str(), &stat_results) == 0)
+        llvm::sys::fs::file_status stat_results;
+        if (!llvm::sys::fs::status(pchName, stat_results))
           usesPCH = true;
         continue;
       }