Relocating files in the nacl repo that belong in chrome.

ppapi/native_client/src/untrusted/irt_stub/ppapi_plugin_start.c

+/*
+ * Copyright (c) 2011 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.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "native_client/src/include/elf_auxv.h"
+#include "native_client/src/include/elf32.h"
+#include "native_client/src/shared/ppapi_proxy/ppruntime.h"
+#include "native_client/src/untrusted/irt/irt.h"
+#include "native_client/src/untrusted/irt/irt_ppapi.h"
+#include "native_client/src/untrusted/irt_stub/thread_creator.h"
+
+static void fatal_error(const char *message) {
+  write(2, message, strlen(message));
+  _exit(127);
+}
+
+/*
+ * TODO(mcgrathr): This extremely stupid function should not exist.
+ * If the startup calling sequence were sane, this would be done
+ * someplace that has the initial pointer locally rather than stealing
+ * it from environ.
+ * See http://code.google.com/p/nativeclient/issues/detail?id=651
+ */
+static Elf32_auxv_t *find_auxv(void) {
+  /*
+   * This presumes environ has its startup-time value on the stack.
+   */
+  char **ep = environ;
+  while (*ep != NULL)
+    ++ep;
+  return (void *) (ep + 1);
+}
+
+/*
+ * Scan the auxv for AT_SYSINFO, which is the pointer to the IRT query function.
+ * TODO(mcgrathr): Could get this from __nacl_irt_query, where the libnacl
+ * startup code stored it, but that would have to be also added as part of
+ * the glibc ABI.
+ */
+static TYPE_nacl_irt_query grok_auxv(const Elf32_auxv_t *auxv) {
+  const Elf32_auxv_t *av;
+  for (av = auxv; av->a_type != AT_NULL; ++av) {
+    if (av->a_type == AT_SYSINFO)
+      return (TYPE_nacl_irt_query) av->a_un.a_val;
+  }
+  return NULL;
+}
+
+int PpapiPluginStart(const struct PP_StartFunctions *funcs) {
+  TYPE_nacl_irt_query query_func = grok_auxv(find_auxv());
+
+  if (NULL == query_func)
+    fatal_error("PpapiPluginStart: No AT_SYSINFO item found in auxv, "
+                "so cannot start PPAPI.  Is the IRT library not present?\n");
+
+  struct nacl_irt_ppapihook hooks;
+  if (sizeof(hooks) != query_func(NACL_IRT_PPAPIHOOK_v0_1,
+                                  &hooks, sizeof(hooks)))
+    fatal_error("PpapiPluginStart: PPAPI hooks not found\n");
+
+  __nacl_register_thread_creator(&hooks);
+
+  return hooks.ppapi_start(funcs);
+}