Be consistent about using "const Twine &" for filenames.

On this file we had a mix of
* Twine
* const char *
* StringRef

The two that make sense are
* const Twine & (caller convenience)
* consc char * (that is what will eventually be passed to open.

Given that sys::fs::openFileForRead takes a "const Twine &", I picked that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219224 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/MemoryBuffer.h

@@ -72,7 +72,7 @@ public:
   /// changing, e.g. when libclang tries to parse while the user is
   /// editing/updating the file.
   static ErrorOr<std::unique_ptr<MemoryBuffer>>
-  getFile(Twine Filename, int64_t FileSize = -1,
+  getFile(const Twine &Filename, int64_t FileSize = -1,
           bool RequiresNullTerminator = true, bool IsVolatileSize = false);
 
   /// Given an already-open file descriptor, map some slice of it into a
@@ -83,7 +83,7 @@ public:
   /// changing, e.g. when libclang tries to parse while the user is
   /// editing/updating the file.
   static ErrorOr<std::unique_ptr<MemoryBuffer>>
-  getOpenFileSlice(int FD, const char *Filename, uint64_t MapSize,
+  getOpenFileSlice(int FD, const Twine &Filename, uint64_t MapSize,
                    int64_t Offset, bool IsVolatileSize = false);
 
   /// Given an already-open file descriptor, read the file and return a
@@ -93,7 +93,7 @@ public:
   /// changing, e.g. when libclang tries to parse while the user is
   /// editing/updating the file.
   static ErrorOr<std::unique_ptr<MemoryBuffer>>
-  getOpenFile(int FD, const char *Filename, uint64_t FileSize,
+  getOpenFile(int FD, const Twine &Filename, uint64_t FileSize,
               bool RequiresNullTerminator = true, bool IsVolatileSize = false);
 
   /// Open the specified memory range as a MemoryBuffer. Note that InputData
@@ -108,7 +108,7 @@ public:
   /// Open the specified memory range as a MemoryBuffer, copying the contents
   /// and taking ownership of it. InputData does not have to be null terminated.
   static std::unique_ptr<MemoryBuffer>
-  getMemBufferCopy(StringRef InputData, StringRef BufferName = "");
+  getMemBufferCopy(StringRef InputData, const Twine &BufferName = "");
 
   /// Allocate a new zero-initialized MemoryBuffer of the specified size. Note
   /// that the caller need not initialize the memory allocated by this method.
@@ -120,7 +120,7 @@ public:
   /// Note that the caller should initialize the memory allocated by this
   /// method. The memory is owned by the MemoryBuffer object.
   static std::unique_ptr<MemoryBuffer>
-  getNewUninitMemBuffer(size_t Size, StringRef BufferName = "");
+  getNewUninitMemBuffer(size_t Size, const Twine &BufferName = "");
 
   /// Read all of stdin into a file buffer, and return it.
   static ErrorOr<std::unique_ptr<MemoryBuffer>> getSTDIN();
@@ -128,7 +128,7 @@ public:
   /// Open the specified file as a MemoryBuffer, or open stdin if the Filename
   /// is "-".
   static ErrorOr<std::unique_ptr<MemoryBuffer>>
-  getFileOrSTDIN(StringRef Filename, int64_t FileSize = -1);
+  getFileOrSTDIN(const Twine &Filename, int64_t FileSize = -1);
 
   //===--------------------------------------------------------------------===//
   // Provided for performance analysis.

lib/Support/MemoryBuffer.cpp

@@ -64,14 +64,17 @@ static void CopyStringRef(char *Memory, StringRef Data) {
 
 namespace {
 struct NamedBufferAlloc {
-  StringRef Name;
+  const Twine &Name;
-  NamedBufferAlloc(StringRef Name) : Name(Name) {}
+  NamedBufferAlloc(const Twine &Name) : Name(Name) {}
 };
 }
 
 void *operator new(size_t N, const NamedBufferAlloc &Alloc) {
-  char *Mem = static_cast<char *>(operator new(N + Alloc.Name.size() + 1));
+  SmallString<256> NameBuf;
-  CopyStringRef(Mem + N, Alloc.Name);
+  StringRef NameRef = Alloc.Name.toStringRef(NameBuf);
+
+  char *Mem = static_cast<char *>(operator new(N + NameRef.size() + 1));
+  CopyStringRef(Mem + N, NameRef);
   return Mem;
 }
 
@@ -109,7 +112,7 @@ MemoryBuffer::getMemBuffer(MemoryBufferRef Ref, bool RequiresNullTerminator) {
 }
 
 std::unique_ptr<MemoryBuffer>
-MemoryBuffer::getMemBufferCopy(StringRef InputData, StringRef BufferName) {
+MemoryBuffer::getMemBufferCopy(StringRef InputData, const Twine &BufferName) {
   std::unique_ptr<MemoryBuffer> Buf =
       getNewUninitMemBuffer(InputData.size(), BufferName);
   if (!Buf)
@@ -120,20 +123,22 @@ MemoryBuffer::getMemBufferCopy(StringRef InputData, StringRef BufferName) {
 }
 
 std::unique_ptr<MemoryBuffer>
-MemoryBuffer::getNewUninitMemBuffer(size_t Size, StringRef BufferName) {
+MemoryBuffer::getNewUninitMemBuffer(size_t Size, const Twine &BufferName) {
   // Allocate space for the MemoryBuffer, the data and the name. It is important
   // that MemoryBuffer and data are aligned so PointerIntPair works with them.
   // TODO: Is 16-byte alignment enough?  We copy small object files with large
   // alignment expectations into this buffer.
+  SmallString<256> NameBuf;
+  StringRef NameRef = BufferName.toStringRef(NameBuf);
   size_t AlignedStringLen =
-      RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1, 16);
+      RoundUpToAlignment(sizeof(MemoryBufferMem) + NameRef.size() + 1, 16);
   size_t RealLen = AlignedStringLen + Size + 1;
   char *Mem = static_cast<char*>(operator new(RealLen, std::nothrow));
   if (!Mem)
     return nullptr;
 
   // The name is stored after the class itself.
-  CopyStringRef(Mem + sizeof(MemoryBufferMem), BufferName);
+  CopyStringRef(Mem + sizeof(MemoryBufferMem), NameRef);
 
   // The buffer begins after the name and must be aligned.
   char *Buf = Mem + AlignedStringLen;
@@ -153,8 +158,11 @@ MemoryBuffer::getNewMemBuffer(size_t Size, StringRef BufferName) {
 }
 
 ErrorOr<std::unique_ptr<MemoryBuffer>>
-MemoryBuffer::getFileOrSTDIN(StringRef Filename, int64_t FileSize) {
+MemoryBuffer::getFileOrSTDIN(const Twine &Filename, int64_t FileSize) {
-  if (Filename == "-")
+  SmallString<256> NameBuf;
+  StringRef NameRef = Filename.toStringRef(NameBuf);
+
+  if (NameRef == "-")
     return getSTDIN();
   return getFile(Filename, FileSize);
 }
@@ -206,7 +214,7 @@ public:
 }
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
-getMemoryBufferForStream(int FD, StringRef BufferName) {
+getMemoryBufferForStream(int FD, const Twine &BufferName) {
   const ssize_t ChunkSize = 4096*4;
   SmallString<ChunkSize> Buffer;
   ssize_t ReadBytes;
@@ -225,26 +233,23 @@ getMemoryBufferForStream(int FD, StringRef BufferName) {
 }
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
-getFileAux(const char *Filename, int64_t FileSize, bool RequiresNullTerminator,
+getFileAux(const Twine &Filename, int64_t FileSize, bool RequiresNullTerminator,
            bool IsVolatileSize);
 
 ErrorOr<std::unique_ptr<MemoryBuffer>>
-MemoryBuffer::getFile(Twine Filename, int64_t FileSize,
+MemoryBuffer::getFile(const Twine &Filename, int64_t FileSize,
                       bool RequiresNullTerminator, bool IsVolatileSize) {
-  // Ensure the path is null terminated.
+  return getFileAux(Filename, FileSize, RequiresNullTerminator,
-  SmallString<256> PathBuf;
-  StringRef NullTerminatedName = Filename.toNullTerminatedStringRef(PathBuf);
-  return getFileAux(NullTerminatedName.data(), FileSize, RequiresNullTerminator,
                     IsVolatileSize);
 }
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
-getOpenFileImpl(int FD, const char *Filename, uint64_t FileSize,
+getOpenFileImpl(int FD, const Twine &Filename, uint64_t FileSize,
                 uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
                 bool IsVolatileSize);
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
-getFileAux(const char *Filename, int64_t FileSize, bool RequiresNullTerminator,
+getFileAux(const Twine &Filename, int64_t FileSize, bool RequiresNullTerminator,
            bool IsVolatileSize) {
   int FD;
   std::error_code EC = sys::fs::openFileForRead(Filename, FD);
@@ -315,7 +320,7 @@ static bool shouldUseMmap(int FD,
 }
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
-getOpenFileImpl(int FD, const char *Filename, uint64_t FileSize,
+getOpenFileImpl(int FD, const Twine &Filename, uint64_t FileSize,
                 uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
                 bool IsVolatileSize) {
   static int PageSize = sys::process::get_self()->page_size();
@@ -393,14 +398,14 @@ getOpenFileImpl(int FD, const char *Filename, uint64_t FileSize,
 }
 
 ErrorOr<std::unique_ptr<MemoryBuffer>>
-MemoryBuffer::getOpenFile(int FD, const char *Filename, uint64_t FileSize,
+MemoryBuffer::getOpenFile(int FD, const Twine &Filename, uint64_t FileSize,
                           bool RequiresNullTerminator, bool IsVolatileSize) {
   return getOpenFileImpl(FD, Filename, FileSize, FileSize, 0,
                          RequiresNullTerminator, IsVolatileSize);
 }
 
 ErrorOr<std::unique_ptr<MemoryBuffer>>
-MemoryBuffer::getOpenFileSlice(int FD, const char *Filename, uint64_t MapSize,
+MemoryBuffer::getOpenFileSlice(int FD, const Twine &Filename, uint64_t MapSize,
                                int64_t Offset, bool IsVolatileSize) {
   return getOpenFileImpl(FD, Filename, -1, MapSize, Offset, false,
                          IsVolatileSize);