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

native_client_sdk/src/libraries/nacl_io/mount_mem.cc

Index: native_client_sdk/src/libraries/nacl_io/mount_mem.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_mem.cc b/native_client_sdk/src/libraries/nacl_io/mount_mem.cc
index 356600b4ec07b9bc6f2f030266ae2ca1a5514b0f..290b5f8880c67d3c07bc87141b118c4f4fdde16f 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_mem.cc
+++ b/native_client_sdk/src/libraries/nacl_io/mount_mem.cc
@@ -6,6 +6,8 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <unistd.h>
+
 #include <string>
 
 #include "nacl_io/mount.h"
@@ -76,6 +78,24 @@ Error MountMem::FindNode(const Path& path, int type, MountNode** out_node) {
   return 0;
 }
 
+Error MountMem::Access(const Path& path, int a_mode) {
+  AutoLock lock(&lock_);
+  MountNode* node = NULL;
+  Error error = FindNode(path, 0, &node);
+
+  if (error)
+    return error;
+
+  int obj_mode = node->GetMode();
+  if (((a_mode & R_OK) && !(obj_mode & S_IREAD)) ||
+      ((a_mode & W_OK) && !(obj_mode & S_IWRITE)) ||
+      ((a_mode & X_OK) && !(obj_mode & S_IEXEC))) {
+    return EACCES;
+  }
+
+  return 0;
+}
+
 Error MountMem::Open(const Path& path, int mode, MountNode** out_node) {
   AutoLock lock(&lock_);
   MountNode* node = NULL;