Provide IRT process interface

src/untrusted/nacl/stubs/getppid.c

Index: src/untrusted/nacl/stubs/getppid.c
diff --git a/src/untrusted/nacl/stubs/getppid.c b/src/untrusted/nacl/stubs/getppid.c
index a4160b56b4264872546132796056fbad94df8257..ce6a982d603e6e2fe10d5db5e4dba22dc7b6edac 100644
--- a/src/untrusted/nacl/stubs/getppid.c
+++ b/src/untrusted/nacl/stubs/getppid.c
@@ -1,19 +1,27 @@
 /*
- * Copyright 2010 The Native Client Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can
- * be found in the LICENSE file.
- */
-
-
-/*
- * Stub routine for `getppid' for porting support.
+ * Copyright (c) 2013 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
  */
 
+#include <errno.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <errno.h>
+
+#include "native_client/src/untrusted/nacl/nacl_irt.h"
 
 pid_t getppid(void) {
-  errno = ENOSYS;
-  return -1;
+  if (!__libnacl_irt_init_fn(&__libnacl_irt_dev_process.getppid,
+                             __libnacl_irt_dev_process_init)) {
+    return -1;
+  }
+
+  pid_t ppid;
+  int error = __libnacl_irt_dev_process.getppid(&ppid);
+  if (error) {
+    errno = error;
+    return -1;
+  }
+
+  return ppid;
 }