Change FileExists to return tensorflow::Status.

Also done separately by @llhe at github.com/tensorflow/tensorflow/pull/5370. We needed to do this change internally to fix all callers.

Motivation: The existing FileExists interface doesn't allow callers to distinguish between file not found vs. filesystem errors.

Semantics changes:
- gfile.Exists in Python now throws an exception for filesystem errors. It continues to return true/false if it can accurately determine whether a file exists.
- RecursivelyCreateDir now returns errors for filesystem errors when calling FileExists.
Change: 138224013

1 files changed, 2 insertions, 2 deletions

diff --git a/tensorflow/stream_executor/lib/env.h b/tensorflow/stream_executor/lib/env.h
index 068fe7936f..f11a4cb25b 100644
--- a/tensorflow/stream_executor/lib/env.h
+++ b/tensorflow/stream_executor/lib/env.h
@@ -29,11 +29,11 @@ using tensorflow::ReadFileToString;
 using tensorflow::Thread;
 using tensorflow::WriteStringToFile;
 
-inline bool FileExists(const string& filename) {
+inline Status FileExists(const string& filename) {
   return Env::Default()->FileExists(filename);
 }
 
-inline bool FileExists(const port::StringPiece& filename) {
+inline Status FileExists(const port::StringPiece& filename) {
   return Env::Default()->FileExists(filename.ToString());
 }