Get mojo_shell building inside chromium checkout.

mojo/shell/desktop/main.cc

+// Copyright 2013 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 <stdio.h>
+#include <string.h>
+
+#include <algorithm>
+#include <iostream>
+
+#include "base/at_exit.h"
+#include "base/base_switches.h"
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "base/files/file_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/trace_event/trace_event.h"
+#include "mojo/shell/child_process.h"
+#include "mojo/shell/command_line_util.h"
+#include "mojo/shell/context.h"
+#include "mojo/shell/init.h"
+#include "mojo/shell/switches.h"
+
+namespace {
+
+void Usage() {
+  std::cerr << "Launch Mojo applications.\n";
+  std::cerr
+      << "Usage: mojo_shell"
+      << " [--" << switches::kArgsFor << "=<mojo-app>]"
+      << " [--" << switches::kContentHandlers << "=<handlers>]"
+      << " [--" << switches::kEnableExternalApplications << "]"
+      << " [--" << switches::kDisableCache << "]"
+      << " [--" << switches::kEnableMultiprocess << "]"
+      << " [--" << switches::kOrigin << "=<url-lib-path>]"
+      << " [--" << switches::kTraceStartup << "]"
+      << " [--" << switches::kURLMappings << "=from1=to1,from2=to2]"
+      << " [--" << switches::kPredictableAppFilenames << "]"
+      << " [--" << switches::kWaitForDebugger << "]"
+      << " <mojo-app> ...\n\n"
+      << "A <mojo-app> is a Mojo URL or a Mojo URL and arguments within "
+      << "quotes.\n"
+      << "Example: mojo_shell \"mojo:js_standalone test.js\".\n"
+      << "<url-lib-path> is searched for shared libraries named by mojo URLs.\n"
+      << "The value of <handlers> is a comma separated list like:\n"
+      << "text/html,mojo:html_viewer,"
+      << "application/javascript,mojo:js_content_handler\n";
+}
+
+// Whether we're currently tracing.
+bool g_tracing = false;
+
+// Number of tracing blocks written.
+uint32_t g_blocks = 0;
+
+// Trace file, if open.
+FILE* g_trace_file = nullptr;
+
+void WriteTraceDataCollected(
+    base::WaitableEvent* event,
+    const scoped_refptr<base::RefCountedString>& events_str,
+    bool has_more_events) {
+  if (g_blocks) {
+    fwrite(",", 1, 1, g_trace_file);
+  }
+
+  ++g_blocks;
+  fwrite(events_str->data().c_str(), 1, events_str->data().length(),
+         g_trace_file);
+  if (!has_more_events) {
+    static const char kEnd[] = "]}";
+    fwrite(kEnd, 1, strlen(kEnd), g_trace_file);
+    PCHECK(fclose(g_trace_file) == 0);
+    g_trace_file = nullptr;
+    event->Signal();
+  }
+}
+
+void EndTraceAndFlush(base::WaitableEvent* event) {
+  g_trace_file = fopen("mojo_shell.trace", "w+");
+  PCHECK(g_trace_file);
+  static const char kStart[] = "{\"traceEvents\":[";
+  fwrite(kStart, 1, strlen(kStart), g_trace_file);
+  base::trace_event::TraceLog::GetInstance()->SetDisabled();
+  base::trace_event::TraceLog::GetInstance()->Flush(
+      base::Bind(&WriteTraceDataCollected, base::Unretained(event)));
+}
+
+void StopTracingAndFlushToDisk() {
+  g_tracing = false;
+  base::trace_event::TraceLog::GetInstance()->SetDisabled();
+  base::WaitableEvent flush_complete_event(false, false);
+  // TraceLog::Flush requires a message loop but we've already shut ours down.
+  // Spin up a new thread to flush things out.
+  base::Thread flush_thread("mojo_shell_trace_event_flush");
+  flush_thread.Start();
+  flush_thread.message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(EndTraceAndFlush, base::Unretained(&flush_complete_event)));
+  flush_complete_event.Wait();
+}
+
+}  // namespace
+
+int main(int argc, char** argv) {
+  base::AtExitManager at_exit;
+  base::CommandLine::Init(argc, argv);
+
+  mojo::shell::InitializeLogging();
+
+  // TODO(vtl): Unify parent and child process cases to the extent possible.
+  if (scoped_ptr<mojo::shell::ChildProcess> child_process =
+          mojo::shell::ChildProcess::Create(
+              *base::CommandLine::ForCurrentProcess())) {
+    child_process->Main();
+  } else {
+    // Only check the command line for the main process.
+    const base::CommandLine& command_line =
+        *base::CommandLine::ForCurrentProcess();
+
+    const std::set<std::string> all_switches = switches::GetAllSwitches();
+    const base::CommandLine::SwitchMap switches = command_line.GetSwitches();
+    bool found_unknown_switch = false;
+    for (const auto& s : switches) {
+      if (all_switches.find(s.first) == all_switches.end()) {
+        std::cerr << "unknown switch: " << s.first << std::endl;
+        found_unknown_switch = true;
+      }
+    }
+
+    if (found_unknown_switch ||
+        (!command_line.HasSwitch(switches::kEnableExternalApplications) &&
+         (command_line.HasSwitch(switches::kHelp) ||
+          command_line.GetArgs().empty()))) {
+      Usage();
+      return 0;
+    }
+
+    if (command_line.HasSwitch(switches::kTraceStartup)) {
+      g_tracing = true;
+      base::trace_event::CategoryFilter category_filter(
+          command_line.GetSwitchValueASCII(switches::kTraceStartup));
+      base::trace_event::TraceLog::GetInstance()->SetEnabled(
+          category_filter, base::trace_event::TraceLog::RECORDING_MODE,
+          base::trace_event::TraceOptions(
+              base::trace_event::RECORD_UNTIL_FULL));
+    }
+
+    // We want the shell::Context to outlive the MessageLoop so that pipes are
+    // all gracefully closed / error-out before we try to shut the Context down.
+    mojo::shell::Context shell_context;
+    {
+      base::MessageLoop message_loop;
+      if (!shell_context.Init()) {
+        Usage();
+        return 0;
+      }
+      if (g_tracing) {
+        message_loop.PostDelayedTask(FROM_HERE,
+                                     base::Bind(StopTracingAndFlushToDisk),
+                                     base::TimeDelta::FromSeconds(5));
+      }
+
+      // The mojo_shell --args-for command-line switch is handled specially
+      // because it can appear more than once. The base::CommandLine class
+      // collapses multiple occurrences of the same switch.
+      for (int i = 1; i < argc; i++) {
+        ApplyApplicationArgs(&shell_context, argv[i]);
+      }
+
+      message_loop.PostTask(
+          FROM_HERE,
+          base::Bind(&mojo::shell::RunCommandLineApps, &shell_context));
+      message_loop.Run();
+
+      // Must be called before |message_loop| is destroyed.
+      shell_context.Shutdown();
+    }
+  }
+
+  if (g_tracing)
+    StopTracingAndFlushToDisk();
+  return 0;
+}