Make VFS and FileManager match the current MemoryBuffer API.

This eliminates converting back and forth between the 3 formats and
gives us a more homogeneous interface.

llvm-svn: 220657

3 files changed, 23 insertions, 29 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 1d7efb81827..29fa263bda8 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4074,19 +4074,18 @@ std::string ASTReader::getOriginalSourceFile(const std::string &ASTFileName,
                                              FileManager &FileMgr,
                                              DiagnosticsEngine &Diags) {
   // Open the AST file.
-  std::string ErrStr;
-  std::unique_ptr<llvm::MemoryBuffer> Buffer =
-      FileMgr.getBufferForFile(ASTFileName, &ErrStr);
+  auto Buffer = FileMgr.getBufferForFile(ASTFileName);
   if (!Buffer) {
-    Diags.Report(diag::err_fe_unable_to_read_pch_file) << ASTFileName << ErrStr;
+    Diags.Report(diag::err_fe_unable_to_read_pch_file)
+        << ASTFileName << Buffer.getError().message();
     return std::string();
   }
 
   // Initialize the stream
   llvm::BitstreamReader StreamFile;
   BitstreamCursor Stream;
-  StreamFile.init((const unsigned char *)Buffer->getBufferStart(),
-                  (const unsigned char *)Buffer->getBufferEnd());
+  StreamFile.init((const unsigned char *)(*Buffer)->getBufferStart(),
+                  (const unsigned char *)(*Buffer)->getBufferEnd());
   Stream.init(StreamFile);
 
   // Sniff for the signature.
@@ -4163,9 +4162,7 @@ bool ASTReader::readASTFileControlBlock(StringRef Filename,
                                         FileManager &FileMgr,
                                         ASTReaderListener &Listener) {
   // Open the AST file.
-  std::string ErrStr;
-  std::unique_ptr<llvm::MemoryBuffer> Buffer =
-      FileMgr.getBufferForFile(Filename, &ErrStr);
+  auto Buffer = FileMgr.getBufferForFile(Filename);
   if (!Buffer) {
     return true;
   }
@@ -4173,8 +4170,8 @@ bool ASTReader::readASTFileControlBlock(StringRef Filename,
   // Initialize the stream
   llvm::BitstreamReader StreamFile;
   BitstreamCursor Stream;
-  StreamFile.init((const unsigned char *)Buffer->getBufferStart(),
-                  (const unsigned char *)Buffer->getBufferEnd());
+  StreamFile.init((const unsigned char *)(*Buffer)->getBufferStart(),
+                  (const unsigned char *)(*Buffer)->getBufferEnd());
   Stream.init(StreamFile);
 
   // Sniff for the signature.
diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index 121478ce052..a67f9f36dbb 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -494,9 +494,7 @@ namespace {
 bool GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
   // Open the module file.
 
-  std::string ErrorStr;
-  std::unique_ptr<llvm::MemoryBuffer> Buffer =
-      FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true);
+  auto Buffer = FileMgr.getBufferForFile(File, /*isVolatile=*/true);
   if (!Buffer) {
     return true;
   }
@@ -504,8 +502,8 @@ bool GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
   // Initialize the input stream
   llvm::BitstreamReader InStreamFile;
   llvm::BitstreamCursor InStream;
-  InStreamFile.init((const unsigned char *)Buffer->getBufferStart(),
-                  (const unsigned char *)Buffer->getBufferEnd());
+  InStreamFile.init((const unsigned char *)(*Buffer)->getBufferStart(),
+                    (const unsigned char *)(*Buffer)->getBufferEnd());
   InStream.init(InStreamFile);
 
   // Sniff for the signature.
diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index c76a318805e..3baaa0a4b28 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -107,27 +107,26 @@ ModuleManager::addModule(StringRef FileName, ModuleKind Type,
       New->Buffer = std::move(Buffer);
     } else {
       // Open the AST file.
-      std::error_code ec;
+      llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buf(
+          (std::error_code()));
       if (FileName == "-") {
-        llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buf =
-            llvm::MemoryBuffer::getSTDIN();
-        ec = Buf.getError();
-        if (ec)
-          ErrorStr = ec.message();
-        else
-          New->Buffer = std::move(Buf.get());
+        Buf = llvm::MemoryBuffer::getSTDIN();
       } else {
         // Leave the FileEntry open so if it gets read again by another
         // ModuleManager it must be the same underlying file.
         // FIXME: Because FileManager::getFile() doesn't guarantee that it will
         // give us an open file, this may not be 100% reliable.
-        New->Buffer = FileMgr.getBufferForFile(New->File, &ErrorStr,
-                                               /*IsVolatile*/ false,
-                                               /*ShouldClose*/ false);
+        Buf = FileMgr.getBufferForFile(New->File,
+                                       /*IsVolatile=*/false,
+                                       /*ShouldClose=*/false);
       }
-      
-      if (!New->Buffer)
+
+      if (!Buf) {
+        ErrorStr = Buf.getError().message();
         return Missing;
+      }
+
+      New->Buffer = std::move(*Buf);
     }
     
     // Initialize the stream