Import LLVM openFileForRead and openFileForWrite.

src/main/native/include/llvm/FileSystem.h

@@ -0,0 +1,84 @@
+//===- llvm/Support/FileSystem.h - File System OS Concept -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the llvm::sys::fs namespace. It is designed after
+// TR2/boost filesystem (v3), but modified to remove exception handling and the
+// path class.
+//
+// All functions return an error_code and their actual work via the last out
+// argument. The out argument is defined if and only if errc::success is
+// returned. A function may return any error code in the generic or system
+// category. However, they shall be equivalent to any error conditions listed
+// in each functions respective documentation if the condition applies. [ note:
+// this does not guarantee that error_code will be in the set of explicitly
+// listed codes, but it does guarantee that if any of the explicitly listed
+// errors occur, the correct error_code will be used ]. All functions may
+// return errc::not_enough_memory if there is not enough memory to complete the
+// operation.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_FILESYSTEM_H
+#define LLVM_SUPPORT_FILESYSTEM_H
+
+#include "llvm/Twine.h"
+#include <system_error>
+
+namespace llvm {
+
+template <typename T> class SmallVectorImpl;
+
+namespace sys {
+namespace fs {
+
+/// @name Physical Observers
+/// @{
+
+enum OpenFlags : unsigned {
+  F_None = 0,
+
+  /// F_Excl - When opening a file, this flag makes raw_fd_ostream
+  /// report an error if the file already exists.
+  F_Excl = 1,
+
+  /// F_Append - When opening a file, if it already exists append to the
+  /// existing file instead of returning an error.  This may not be specified
+  /// with F_Excl.
+  F_Append = 2,
+
+  /// The file should be opened in text mode on platforms that make this
+  /// distinction.
+  F_Text = 4,
+
+  /// Open the file for read and write.
+  F_RW = 8
+};
+
+inline OpenFlags operator|(OpenFlags A, OpenFlags B) {
+  return OpenFlags(unsigned(A) | unsigned(B));
+}
+
+inline OpenFlags &operator|=(OpenFlags &A, OpenFlags B) {
+  A = A | B;
+  return A;
+}
+
+std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
+                                 OpenFlags Flags, unsigned Mode = 0666);
+
+std::error_code openFileForRead(const Twine &Name, int &ResultFD,
+                                SmallVectorImpl<char> *RealPath = nullptr);
+
+/// @}
+
+} // end namespace fs
+} // end namespace sys
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_FILESYSTEM_H