VFS: Avoid some unnecessary std::string copies

Thread Twine a little deeper through the VFS to avoid unnecessarily
constructing the same std::string twice in a parameter sequence:

    Twine -> std::string -> StringRef -> std::string

Changing a few parameters from StringRef to Twine avoids the early call
to `Twine::str()`.

llvm-svn: 354739

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/include/llvm/Support/VirtualFileSystem.h b/llvm/include/llvm/Support/VirtualFileSystem.h
index 7c57dd3a31e..0bb574e1b12 100644
--- a/llvm/include/llvm/Support/VirtualFileSystem.h
+++ b/llvm/include/llvm/Support/VirtualFileSystem.h
@@ -58,15 +58,15 @@ public:
 
   Status() = default;
   Status(const llvm::sys::fs::file_status &Status);
-  Status(StringRef Name, llvm::sys::fs::UniqueID UID,
+  Status(const Twine &Name, llvm::sys::fs::UniqueID UID,
          llvm::sys::TimePoint<> MTime, uint32_t User, uint32_t Group,
          uint64_t Size, llvm::sys::fs::file_type Type,
          llvm::sys::fs::perms Perms);
 
   /// Get a copy of a Status with a different name.
-  static Status copyWithNewName(const Status &In, StringRef NewName);
+  static Status copyWithNewName(const Status &In, const Twine &NewName);
   static Status copyWithNewName(const llvm::sys::fs::file_status &In,
-                                StringRef NewName);
+                                const Twine &NewName);
 
   /// Returns the name that should be used for this file or directory.
   StringRef getName() const { return Name; }