4 files changed, 19 insertions, 14 deletions
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 19fafa3370a..1d8c6a15586 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -638,7 +638,12 @@ ASTDeserializationListener *ASTUnit::getDeserializationListener() {
 std::unique_ptr<llvm::MemoryBuffer>
 ASTUnit::getBufferForFile(StringRef Filename, std::string *ErrorStr) {
   assert(FileMgr);
-  return FileMgr->getBufferForFile(Filename, ErrorStr);
+  auto Buffer = FileMgr->getBufferForFile(Filename);
+  if (Buffer)
+    return std::move(*Buffer);
+  if (ErrorStr)
+    *ErrorStr = Buffer.getError().message();
+  return nullptr;
 }
 
 /// \brief Configure the diagnostics object for use with ASTUnit.
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 1f336b48e29..03ab20b083e 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -717,14 +717,14 @@ bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
     // pick up the correct size, and simply override their contents as we do for
     // STDIN.
     if (File->isNamedPipe()) {
-      std::string ErrorStr;
-      if (std::unique_ptr<llvm::MemoryBuffer> MB =
-              FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
+      auto MB = FileMgr.getBufferForFile(File, /*isVolatile=*/true);
+      if (MB) {
         // Create a new virtual file that will have the correct size.
-        File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
-        SourceMgr.overrideFileContents(File, std::move(MB));
+        File = FileMgr.getVirtualFile(InputFile, (*MB)->getBufferSize(), 0);
+        SourceMgr.overrideFileContents(File, std::move(*MB));
       } else {
-        Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
+        Diags.Report(diag::err_cannot_open_file) << InputFile
+                                                 << MB.getError().message();
         return false;
       }
     }
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 99cd4a2e6d6..6634e19fc2c 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -683,10 +683,10 @@ void PrintPreambleAction::ExecuteAction() {
   }
 
   CompilerInstance &CI = getCompilerInstance();
-  if (std::unique_ptr<llvm::MemoryBuffer> Buffer =
-          CI.getFileManager().getBufferForFile(getCurrentFile())) {
+  auto Buffer = CI.getFileManager().getBufferForFile(getCurrentFile());
+  if (Buffer) {
     unsigned Preamble =
-        Lexer::ComputePreamble(Buffer->getBuffer(), CI.getLangOpts()).first;
-    llvm::outs().write(Buffer->getBufferStart(), Preamble);
+        Lexer::ComputePreamble((*Buffer)->getBuffer(), CI.getLangOpts()).first;
+    llvm::outs().write((*Buffer)->getBufferStart(), Preamble);
   }
 }
diff --git a/clang/lib/Frontend/SerializedDiagnosticReader.cpp b/clang/lib/Frontend/SerializedDiagnosticReader.cpp
index 6d692e4059e..197132d6162 100644
--- a/clang/lib/Frontend/SerializedDiagnosticReader.cpp
+++ b/clang/lib/Frontend/SerializedDiagnosticReader.cpp
@@ -21,13 +21,13 @@ std::error_code SerializedDiagnosticReader::readDiagnostics(StringRef File) {
   FileSystemOptions FO;
   FileManager FileMgr(FO);
 
-  std::unique_ptr<llvm::MemoryBuffer> Buffer = FileMgr.getBufferForFile(File);
+  auto Buffer = FileMgr.getBufferForFile(File);
   if (!Buffer)
     return SDError::CouldNotLoad;
 
   llvm::BitstreamReader StreamFile;
-  StreamFile.init((const unsigned char *)Buffer->getBufferStart(),
-                  (const unsigned char *)Buffer->getBufferEnd());
+  StreamFile.init((const unsigned char *)(*Buffer)->getBufferStart(),
+                  (const unsigned char *)(*Buffer)->getBufferEnd());
 
   llvm::BitstreamCursor Stream;
   Stream.init(StreamFile);