[NaCl SDK] nacl_io: Added support for access() syscall.

native_client_sdk/src/libraries/nacl_io/mount.h

Index: native_client_sdk/src/libraries/nacl_io/mount.h
diff --git a/native_client_sdk/src/libraries/nacl_io/mount.h b/native_client_sdk/src/libraries/nacl_io/mount.h
index ddf1fd5c76814eb0b27be4793d938fff69a048bd..61b0648322f61a5e75f2021b3ce1835fa3f1c1b9 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount.h
+++ b/native_client_sdk/src/libraries/nacl_io/mount.h
@@ -52,6 +52,10 @@ class Mount : public RefObject {
 
   // All paths in functions below are expected to containing a leading "/".
 
+  // Test whether a file at a given path can be accessed.
+  // Returns 0 on success, or an appropriate errno value on failure.

[binji, 2013/06/19 16:46:28]

What is the behavior of access if given a directory?

[Matt Giuca, 2013/06/20 01:43:14]

Should be the same as for normal access. R_OK means you can GetDents on it, W_OK
means you can create files and subdirs in it, X_OK means you can cd to it. Do I
need to say this in comments here or do we assume the reader knows the semantics
of POSIX syscalls?

[binji, 2013/06/20 16:07:21]

Hm. I might like to have something similar to your explanation of why X_OK is
handled the way it is here. The semantics of X_OK w.r.t. directories would be
useful information in that discussion.

+  virtual Error Access(const Path& path, int a_mode) = 0;
+
   // Open a node at |path| with the specified open flags. The resulting
   // MountNode is created with a ref count of 1.
   // Assumes that |out_node| is non-NULL.