Split the PNaCl IRT shim into 3 pieces, and include one piece into IRT.

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

+/*
+ * Copyright 2014 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 "ppapi/native_client/src/untrusted/pnacl_irt_shim/irt_shim_ppapi.h"
+
+#include "native_client/src/untrusted/irt/irt.h"
+#include "ppapi/nacl_irt/irt_ppapi.h"
+#include "ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.h"
+#include "ppapi/proxy/plugin_main_irt.h"
+
+/*
+ * Defines a version of the version irt_ppapi_start and of the irt_ppapihook
+ * that returns a shimmed GetInterface for PNaCl.
+ *
+ * The hook will be linked into the IRT but it is considered unstable.
+ * Stable nexes should not use that IRT hook (and a filter prevents
+ * it from being used). Instead PNaCl nexes should embed the
+ * irt_shim_ppapi_start and the shim functions directly into the nexe
+ * for ABI stability.
+ */
+
+static struct PP_StartFunctions g_user_start_functions;
+
+static int32_t shim_PPPInitializeModule(PP_Module module_id,
+                                        PPB_GetInterface get_browser_intf) {
+  /* Record the original PPB_GetInterface and provide a shimmed one. */
+  __set_real_Pnacl_PPBGetInterface(get_browser_intf);
+  return (*g_user_start_functions.PPP_InitializeModule)(
+      module_id,
+      &__Pnacl_PPBGetInterface);
+}
+
+static void shim_PPPShutdownModule() {
+  (*g_user_start_functions.PPP_ShutdownModule)();
+}
+
+#ifdef PNACL_SHIM_AOT
+ /*
+  * This will be discovered and set by the shim, since we cannot link
+  * against the IRT directly in the AOT library.
+  */
+int (*real_irt_ppapi_start)(const struct PP_StartFunctions *) = NULL;
+#else
+ /*
+  * Otherwise, when linking directly into the IRT, we can refer to the
+  * real irt_ppapi_start from irt_ppapi.
+  */
+extern int irt_ppapi_start(const struct PP_StartFunctions *);
+static int (* const real_irt_ppapi_start)(const struct PP_StartFunctions *) =
+    &irt_ppapi_start;
+#endif
+
+int irt_shim_ppapi_start(const struct PP_StartFunctions *funcs) {
+  g_user_start_functions = *funcs;
+  /*
+   * Record the original PPP_GetInterface and provide a shimmed one
+   * via wrapped_ppapi_methods.
+   */
+  const struct PP_StartFunctions wrapped_ppapi_methods = {
+    shim_PPPInitializeModule,
+    shim_PPPShutdownModule,
+    __Pnacl_PPPGetInterface
+  };
+  __set_real_Pnacl_PPPGetInterface(g_user_start_functions.PPP_GetInterface);
+  /*
+   * Invoke the IRT's ppapi_start interface with the wrapped interface.
+   */
+  return (*real_irt_ppapi_start)(&wrapped_ppapi_methods);
+}
+
+#ifndef PNACL_SHIM_AOT
+const struct nacl_irt_ppapihook nacl_irt_ppapihook_pnacl_private = {
+  irt_shim_ppapi_start,
+  PpapiPluginRegisterThreadCreator,
+};
+#endif