Remove 'using std::errro_code' from lib.

llvm-svn: 210871
diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
index c395ce7..a8f3385 100644
--- a/llvm/lib/Support/MemoryBuffer.cpp
+++ b/llvm/lib/Support/MemoryBuffer.cpp
@@ -33,7 +33,6 @@
 #include <io.h>
 #endif
 using namespace llvm;
-using std::error_code;
 
 //===----------------------------------------------------------------------===//
 // MemoryBuffer implementation itself.
@@ -157,9 +156,10 @@
 /// if the Filename is "-".  If an error occurs, this returns null and fills
 /// in *ErrStr with a reason.  If stdin is empty, this API (unlike getSTDIN)
 /// returns an empty buffer.
-error_code MemoryBuffer::getFileOrSTDIN(StringRef Filename,
-                                        std::unique_ptr<MemoryBuffer> &Result,
-                                        int64_t FileSize) {
+std::error_code
+MemoryBuffer::getFileOrSTDIN(StringRef Filename,
+                             std::unique_ptr<MemoryBuffer> &Result,
+                             int64_t FileSize) {
   if (Filename == "-")
     return getSTDIN(Result);
   return getFile(Filename, Result, FileSize);
@@ -191,7 +191,7 @@
 
 public:
   MemoryBufferMMapFile(bool RequiresNullTerminator, int FD, uint64_t Len,
-                       uint64_t Offset, error_code EC)
+                       uint64_t Offset, std::error_code EC)
       : MFR(FD, false, sys::fs::mapped_file_region::readonly,
             getLegalMapSize(Len, Offset), getLegalMapOffset(Offset), EC) {
     if (!EC) {
@@ -211,9 +211,9 @@
 };
 }
 
-static error_code getMemoryBufferForStream(int FD,
-                                           StringRef BufferName,
-                                           std::unique_ptr<MemoryBuffer> &Result) {
+static std::error_code
+getMemoryBufferForStream(int FD, StringRef BufferName,
+                         std::unique_ptr<MemoryBuffer> &Result) {
   const ssize_t ChunkSize = 4096*4;
   SmallString<ChunkSize> Buffer;
   ssize_t ReadBytes;
@@ -223,26 +223,25 @@
     ReadBytes = read(FD, Buffer.end(), ChunkSize);
     if (ReadBytes == -1) {
       if (errno == EINTR) continue;
-      return error_code(errno, std::generic_category());
+      return std::error_code(errno, std::generic_category());
     }
     Buffer.set_size(Buffer.size() + ReadBytes);
   } while (ReadBytes != 0);
 
   Result.reset(MemoryBuffer::getMemBufferCopy(Buffer, BufferName));
-  return error_code();
+  return std::error_code();
 }
 
-static error_code getFileAux(const char *Filename,
-                             std::unique_ptr<MemoryBuffer> &Result,
-                             int64_t FileSize,
-                             bool RequiresNullTerminator,
-                             bool IsVolatileSize);
+static std::error_code getFileAux(const char *Filename,
+                                  std::unique_ptr<MemoryBuffer> &Result,
+                                  int64_t FileSize, bool RequiresNullTerminator,
+                                  bool IsVolatileSize);
 
-error_code MemoryBuffer::getFile(Twine Filename,
-                                 std::unique_ptr<MemoryBuffer> &Result,
-                                 int64_t FileSize,
-                                 bool RequiresNullTerminator,
-                                 bool IsVolatileSize) {
+std::error_code MemoryBuffer::getFile(Twine Filename,
+                                      std::unique_ptr<MemoryBuffer> &Result,
+                                      int64_t FileSize,
+                                      bool RequiresNullTerminator,
+                                      bool IsVolatileSize) {
   // Ensure the path is null terminated.
   SmallString<256> PathBuf;
   StringRef NullTerminatedName = Filename.toNullTerminatedStringRef(PathBuf);
@@ -250,23 +249,25 @@
                     RequiresNullTerminator, IsVolatileSize);
 }
 
-static error_code getOpenFileImpl(int FD, const char *Filename,
-                                  std::unique_ptr<MemoryBuffer> &Result,
-                                  uint64_t FileSize, uint64_t MapSize,
-                                  int64_t Offset, bool RequiresNullTerminator,
-                                  bool IsVolatileSize);
+static std::error_code getOpenFileImpl(int FD, const char *Filename,
+                                       std::unique_ptr<MemoryBuffer> &Result,
+                                       uint64_t FileSize, uint64_t MapSize,
+                                       int64_t Offset,
+                                       bool RequiresNullTerminator,
+                                       bool IsVolatileSize);
 
-static error_code getFileAux(const char *Filename,
-                             std::unique_ptr<MemoryBuffer> &Result, int64_t FileSize,
-                             bool RequiresNullTerminator,
-                             bool IsVolatileSize) {
+static std::error_code getFileAux(const char *Filename,
+                                  std::unique_ptr<MemoryBuffer> &Result,
+                                  int64_t FileSize, bool RequiresNullTerminator,
+                                  bool IsVolatileSize) {
   int FD;
-  error_code EC = sys::fs::openFileForRead(Filename, FD);
+  std::error_code EC = sys::fs::openFileForRead(Filename, FD);
   if (EC)
     return EC;
 
-  error_code ret = getOpenFileImpl(FD, Filename, Result, FileSize, FileSize, 0,
-                                   RequiresNullTerminator, IsVolatileSize);
+  std::error_code ret =
+      getOpenFileImpl(FD, Filename, Result, FileSize, FileSize, 0,
+                      RequiresNullTerminator, IsVolatileSize);
   close(FD);
   return ret;
 }
@@ -319,11 +320,12 @@
   return true;
 }
 
-static error_code getOpenFileImpl(int FD, const char *Filename,
-                                  std::unique_ptr<MemoryBuffer> &Result,
-                                  uint64_t FileSize, uint64_t MapSize,
-                                  int64_t Offset, bool RequiresNullTerminator,
-                                  bool IsVolatileSize) {
+static std::error_code getOpenFileImpl(int FD, const char *Filename,
+                                       std::unique_ptr<MemoryBuffer> &Result,
+                                       uint64_t FileSize, uint64_t MapSize,
+                                       int64_t Offset,
+                                       bool RequiresNullTerminator,
+                                       bool IsVolatileSize) {
   static int PageSize = sys::process::get_self()->page_size();
 
   // Default is to map the full file.
@@ -332,7 +334,7 @@
     // file descriptor is cheaper than stat on a random path.
     if (FileSize == uint64_t(-1)) {
       sys::fs::file_status Status;
-      error_code EC = sys::fs::status(FD, Status);
+      std::error_code EC = sys::fs::status(FD, Status);
       if (EC)
         return EC;
 
@@ -351,11 +353,11 @@
 
   if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
                     PageSize, IsVolatileSize)) {
-    error_code EC;
+    std::error_code EC;
     Result.reset(new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile(
         RequiresNullTerminator, FD, MapSize, Offset, EC));
     if (!EC)
-      return error_code();
+      return std::error_code();
   }
 
   MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(MapSize, Filename);
@@ -384,7 +386,7 @@
       if (errno == EINTR)
         continue;
       // Error while reading.
-      return error_code(errno, std::generic_category());
+      return std::error_code(errno, std::generic_category());
     }
     if (NumRead == 0) {
       memset(BufPtr, 0, BytesLeft); // zero-initialize rest of the buffer.
@@ -395,22 +397,21 @@
   }
 
   Result.swap(SB);
-  return error_code();
+  return std::error_code();
 }
 
-error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
-                                     std::unique_ptr<MemoryBuffer> &Result,
-                                     uint64_t FileSize,
-                                     bool RequiresNullTerminator,
-                                     bool IsVolatileSize) {
+std::error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
+                                          std::unique_ptr<MemoryBuffer> &Result,
+                                          uint64_t FileSize,
+                                          bool RequiresNullTerminator,
+                                          bool IsVolatileSize) {
   return getOpenFileImpl(FD, Filename, Result, FileSize, FileSize, 0,
                          RequiresNullTerminator, IsVolatileSize);
 }
 
-error_code MemoryBuffer::getOpenFileSlice(int FD, const char *Filename,
-                                          std::unique_ptr<MemoryBuffer> &Result,
-                                          uint64_t MapSize, int64_t Offset,
-                                          bool IsVolatileSize) {
+std::error_code MemoryBuffer::getOpenFileSlice(
+    int FD, const char *Filename, std::unique_ptr<MemoryBuffer> &Result,
+    uint64_t MapSize, int64_t Offset, bool IsVolatileSize) {
   return getOpenFileImpl(FD, Filename, Result, -1, MapSize, Offset, false,
                          IsVolatileSize);
 }
@@ -419,7 +420,7 @@
 // MemoryBuffer::getSTDIN implementation.
 //===----------------------------------------------------------------------===//
 
-error_code MemoryBuffer::getSTDIN(std::unique_ptr<MemoryBuffer> &Result) {
+std::error_code MemoryBuffer::getSTDIN(std::unique_ptr<MemoryBuffer> &Result) {
   // Read in all of the data from stdin, we cannot mmap stdin.
   //
   // FIXME: That isn't necessarily true, we should try to mmap stdin and