Add a wrapper for open.

This centralizes the handling of O_BINARY and opens the way for hiding more
differences (like how open behaves with directories).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186447 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/FileSystem.h

@@ -611,6 +611,37 @@ error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
 error_code createUniqueDirectory(const Twine &Prefix,
                                  SmallVectorImpl<char> &ResultPath);
 
+enum OpenFlags {
+  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,
+
+  /// F_Binary - The file should be opened in binary mode on platforms that
+  /// make this distinction.
+  F_Binary = 4
+};
+
+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;
+}
+
+error_code openFileForWrite(const Twine &Name, int &ResultFD, OpenFlags Flags,
+                            unsigned Mode = 0666);
+
+error_code openFileForRead(const Twine &Name, int &ResultFD);
+
 /// @brief Canonicalize path.
 ///
 /// Sets result to the file system's idea of what path is. The result is always

include/llvm/Support/ToolOutputFile.h

@@ -47,7 +47,7 @@ public:
   /// tool_output_file - This constructor's arguments are passed to
   /// to raw_fd_ostream's constructor.
   tool_output_file(const char *filename, std::string &ErrorInfo,
-                   unsigned Flags = 0);
+                   sys::fs::OpenFlags Flags = sys::fs::F_None);
 
   tool_output_file(const char *Filename, int FD);
 

include/llvm/Support/raw_ostream.h

@@ -17,6 +17,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/FileSystem.h"
 
 namespace llvm {
   class format_object_base;
@@ -335,22 +336,6 @@ class raw_fd_ostream : public raw_ostream {
   void error_detected() { Error = true; }
 
 public:
-
-  enum {
-    /// 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,
-
-    /// F_Binary - The file should be opened in binary mode on platforms that
-    /// make this distinction.
-    F_Binary = 4
-  };
-
   /// raw_fd_ostream - Open the specified file for writing. If an error occurs,
   /// information about the error is put into ErrorInfo, and the stream should
   /// be immediately destroyed; the string will be empty if no error occurred.
@@ -362,7 +347,7 @@ public:
   /// file descriptor when it is done (this is necessary to detect
   /// output errors).
   raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
-                 unsigned Flags = 0);
+                 sys::fs::OpenFlags Flags = sys::fs::F_None);
 
   /// raw_fd_ostream ctor - FD is the file descriptor that this writes to.  If
   /// ShouldClose is true, this closes the file when the stream is destroyed.