Enabling 64-bit mojo shell to launch 32-bit child to handle nonsfi content.

shell/context.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 "shell/context.h"
 
 #include <vector>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
@@ skipping 239 matching lines @@
 
 GURL Context::ResolveCommandLineURL(const std::string& path) {
   return command_line_cwd_.Resolve(path);
 }
 
 bool Context::Init() {
   base::FilePath shell_path = base::MakeAbsoluteFilePath(
       base::CommandLine::ForCurrentProcess()->GetProgram());
   base::FilePath shell_child_path =
       shell_path.DirName().AppendASCII("mojo_shell_child");
+  mojo_shell_child_path_32_bit_ =
+      shell_path.DirName().AppendASCII("clang_x86/mojo_shell_child");

[Sean Klein, 2015/09/14 18:10:33]

I'm not entirely sure if I should be dependent on the clang_x86 toolchain here.
I could potentially create another copy rule to move
"clang_x86/mojo_shell_child"
to
"mojo_shell_child_x86",
and call it regardless of the toolchain that built it.


(That being said, this current version does technically work)

[Mark Seaborn, 2015/09/14 18:38:58]

I think this depends how mojo_shell gets packaged.  Whether this is OK is up to
the owners of the code.

[Petr Hosek, 2015/09/14 19:13:52]

The path is an artifact of the build system (GN in this case) and I'd argue
against hardcoding it (we don't want to have a different code path for each
toolchain); instead I'd use a copy rule.

[Sean Klein, 2015/09/15 18:37:50]

Using a copy rule in the gn files -- now there are two binaries:
"mojo_shell_child" and
"mojo_shell_child_32".

The 32-bit version does not indicate which build system it originated from now.

   return InitWithPaths(shell_child_path);
 }
 
 bool Context::InitWithPaths(const base::FilePath& shell_child_path) {
   TRACE_EVENT0("mojo_shell", "Context::InitWithPaths");
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
 
   if (command_line.HasSwitch(switches::kWaitForDebugger))
     base::debug::WaitForDebugger(60, true);
@@ skipping 102 matching lines @@
     app_urls_.erase(url);
     if (app_urls_.empty() && base::MessageLoop::current()->is_running()) {
       DCHECK_EQ(base::MessageLoop::current()->task_runner(),
                 task_runners_->shell_runner());
       base::MessageLoop::current()->Quit();
     }
   }
 }
 
 }  // namespace shell