[NaCl SDK] nacl_io: big refactor to return error value (errno).

native_client_sdk/src/libraries/nacl_io/error.h

Index: native_client_sdk/src/libraries/nacl_io/error.h
diff --git a/native_client_sdk/src/libraries/nacl_io/error.h b/native_client_sdk/src/libraries/nacl_io/error.h
new file mode 100644
index 0000000000000000000000000000000000000000..b6f186f4a9d06bbd87789b9977d014c80d44a5a1
--- /dev/null
+++ b/native_client_sdk/src/libraries/nacl_io/error.h
@@ -0,0 +1,16 @@
+/* Copyright (c) 2013 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef LIBRARIES_NACL_IO_ERROR_H_
+#define LIBRARIES_NACL_IO_ERROR_H_
+
+// HACK(binji)

[Sam Clegg, 2013/05/31 18:40:29]

This whole file is a hack?  Why?

[binji, 2013/06/03 17:16:46]

Sorry, didn't remove this yet. I was planning on having Error be a typedef for
int, instead of its own struct.

The reason for having a struct here is to have the compiler catch errors --
though maybe it is worthwhile to keep (with a #define?)

+struct Error {
+  Error(int error) : error(error) {}

[noelallen1, 2013/06/07 21:48:43]

#ifdef DEBUG
  Error(int errno, const char *file, int line)
  #define Error(x) Error(x, __FILE__, __LINE__)
#endif

We could actually develop an error class that on debug versions could provide us
useful information.  This info could get logged to buffer and then periodically
scraped by the pepper thread, or even just available to via dubugging.
since we can't guaranty that we can safely printf due to reentrency/locking.

[binji, 2013/06/07 23:23:11]

Added TODO

+  operator int() const { return error; }
+
+  int error;
+};
+
+#endif  // LIBRARIES_NACL_IO_ERROR_H_