Creating a pexe content handler to translate and run pexes.

services/nacl/pnacl_link.cc

+// Copyright 2015 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 <fcntl.h>
+
+#include "base/at_exit.h"
+#include "base/files/file_util.h"
+#include "base/path_service.h"
+#include "mojo/nacl/nonsfi/nexe_launcher_nonsfi.h"
+#include "mojo/public/c/system/main.h"
+#include "mojo/public/cpp/application/application_connection.h"
+#include "mojo/public/cpp/application/application_delegate.h"
+#include "mojo/public/cpp/application/application_runner.h"
+#include "mojo/public/cpp/application/interface_factory.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "services/nacl/pnacl_link.mojom.h"
+
+namespace mojo {
+namespace nacl {
+
+class PexeLinkerImpl : public PexeLinkerInit {
+ public:
+  void PexeLinkerStart(ScopedMessagePipeHandle handle) override {
+    base::FilePath path;
+    if (!PathService::Get(base::DIR_MODULE, &path))
+      LOG(FATAL) << "Could not find mojo root directory";
+    path = path.Append("pnacl_translation_files/ld.nexe");
+    int nexe_fd = open(path.value().c_str(), O_RDONLY);
+    if (nexe_fd < 0)
+      LOG(FATAL) << "Could not open linker nexe: " << path.value();
+    ::nacl::MojoLaunchNexeNonsfi(nexe_fd,
+                                 handle.release().value(),
+                                 true /* enable_translate_irt */);
+  }
+};
+
+class StrongBindingPexeLinkerImpl : public PexeLinkerImpl {
+ public:
+  explicit StrongBindingPexeLinkerImpl(InterfaceRequest<PexeLinkerInit> request)
+      : strong_binding_(this, request.Pass()) {}
+
+ private:
+  StrongBinding<PexeLinkerInit> strong_binding_;
+};
+
+class MultiPexeLinker : public ApplicationDelegate,
+                        public InterfaceFactory<PexeLinkerInit> {
+ public:
+  MultiPexeLinker() {}
+
+  // From ApplicationDelegate
+  bool ConfigureIncomingConnection(ApplicationConnection* connection) override {
+    connection->AddService<PexeLinkerInit>(this);
+    return true;
+  }
+
+  // From InterfaceFactory
+  void Create(ApplicationConnection* connection,
+              InterfaceRequest<PexeLinkerInit> request) override {
+    new StrongBindingPexeLinkerImpl(request.Pass());
+  }
+};
+
+}  // namespace nacl
+}  // namespace mojo
+
+MojoResult MojoMain(MojoHandle application_request) {
+  base::AtExitManager at_exit;

[jamesr, 2015/11/02 23:00:02]

what needs a base::AtExitManager? mojo::ApplicationRunnerChromium creates a
base::AtExitManager for you but it's at a slightly different time than this code
is doing. normally I'd expect a particular app to either use base and use
mojo::ApplicationRunnerChromium or not use base concepts at all and use
mojo::ApplicationRunner

[Sean Klein, 2015/11/03 14:31:01]

The base::AtExitManager is needed for the call to PathService on line 26. I will
need to find a different mechanism to get the root mojo directory for Android
anyway -- something akin to calling Context::ResolveShellFileURL(""), but from a
Mojo application. Is this possible?

+  mojo::ApplicationRunner runner(new mojo::nacl::MultiPexeLinker());
+  return runner.Run(application_request);
+}