Add pnacl shims to the chrome build.

ppapi/native_client/src/untrusted/pnacl_irt_shim/shim_ppapi.c

+/*
+ * Copyright (c) 2012 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 "native_client/src/untrusted/pnacl_irt_shim/shim_ppapi.h"
+
+#include <string.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 "ppapi/generators/pnacl_shim.h"
+
+TYPE_nacl_irt_query __pnacl_real_irt_interface;
+
+/*
+ * These remember the interface pointers the user registers by calling the
+ * IRT entry point.
+ */
+static struct PP_StartFunctions user_start_functions;
+
+static int32_t wrap_PPPInitializeModule(PP_Module module_id,
+                                        PPB_GetInterface get_browser_intf) {
+  __set_real_Pnacl_PPBGetInterface(get_browser_intf);
+  /*
+   * Calls from user code to the PPB interfaces pass through here and may
+   * require shims to convert the ABI.
+   */
+  return (*user_start_functions.PPP_InitializeModule)(module_id,
+                                                      &__Pnacl_PPBGetInterface);
+}
+
+static void wrap_PPPShutdownModule() {
+  (*user_start_functions.PPP_ShutdownModule)();
+}
+
+static const struct PP_StartFunctions wrapped_ppapi_methods = {
+  wrap_PPPInitializeModule,
+  wrap_PPPShutdownModule,
+  /*
+   * Calls from the IRT to the user plugin pass through here and may require
+   * shims to convert the ABI.
+   */
+  __Pnacl_PPPGetInterface
+};
+
+static struct nacl_irt_ppapihook real_irt_ppapi_hook;
+
+static int wrap_ppapi_start(const struct PP_StartFunctions *funcs) {
+  /*
+   * Save the user's real bindings for the start functions.
+   */
+  user_start_functions = *funcs;
+  __set_real_Pnacl_PPPGetInterface(user_start_functions.PPP_GetInterface);
+
+  /*
+   * Invoke the IRT's ppapi_start interface with the wrapped interface.
+   */
+  return (*real_irt_ppapi_hook.ppapi_start)(&wrapped_ppapi_methods);
+}
+
+static struct nacl_irt_ppapihook ppapi_hook = {
+  wrap_ppapi_start,
+  NULL
+};
+
+size_t __pnacl_irt_interface_wrapper(const char *interface_ident,
+                                     void *table, size_t tablesize) {
+  /*
+   * Note there is a benign race in initializing the wrapper.
+   * We build the "hook" structure by copying from the IRT's hook and then
+   * writing our wrapper for the ppapi method.  Two threads may end up
+   * attempting to do this simultaneously, which should not be a problem,
+   * as they are writing the same values.
+   */
+  if (0 != strcmp(interface_ident, NACL_IRT_PPAPIHOOK_v0_1)) {
+    /*
+     * The interface is not wrapped, so use the real interface.
+     */
+    return (*__pnacl_real_irt_interface)(interface_ident, table, tablesize);
+  }
+  if ((*__pnacl_real_irt_interface)(NACL_IRT_PPAPIHOOK_v0_1,
+                                    &real_irt_ppapi_hook,
+                                    sizeof real_irt_ppapi_hook) !=
+      sizeof real_irt_ppapi_hook) {
+    return -1;
+  }
+  /*
+   * Copy the portion of the ppapihook interface that is not wrapped.
+   */
+  ppapi_hook.ppapi_register_thread_creator =
+      real_irt_ppapi_hook.ppapi_register_thread_creator;
+  /*
+   * Copy the interface structure into the client.
+   */
+  if (sizeof ppapi_hook <= tablesize) {
+    memcpy(table, &ppapi_hook, sizeof ppapi_hook);
+    return sizeof ppapi_hook;
+  }
+  return 0;
+}