Allow Mach shm to be passed to NaCl.

components/nacl/loader/nacl_ipc_adapter.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 "components/nacl/loader/nacl_ipc_adapter.h"
 
 #include <limits.h>
 #include <string.h>
 
 #include "base/basictypes.h"
@@ skipping 523 matching lines @@
       return false;
 
     // Now add any descriptors we found to rewritten_msg. |handles| is usually
     // empty, unless we read a message containing a FD or handle.
     for (Handles::const_iterator iter = handles.begin();
          iter != handles.end();
          ++iter) {
       scoped_ptr<NaClDescWrapper> nacl_desc;
       switch (iter->type()) {
         case ppapi::proxy::SerializedHandle::SHARED_MEMORY: {
           const base::SharedMemoryHandle& shm_handle = iter->shmem();

[Mark Seaborn, 2015/11/20 18:55:54]

For readability, how about splitting out this conversion into a function like
this one? --

NaClDescWrapper MakeShmNaClDesc(const base::SharedMemoryHandle& handle, uint32_t
size);

[erikchen, 2015/11/20 21:51:12]

Done.

           uint32_t size = iter->size();
+#if defined(OS_MACOSX) && !defined(OS_IOS)

[Mark Seaborn, 2015/11/20 18:55:54]

This file shouldn't be getting compiled for iOS.  It would be better to omit the
check for iOS so as not to mislead readers about what this code supports.

[erikchen, 2015/11/20 21:51:12]

Done.

+          switch (shm_handle.GetType()) {
+            case base::SharedMemoryHandle::MACH:
+              nacl_desc.reset(new NaClDescWrapper(NaClDescImcShmMachMake(
+                  shm_handle.GetMemoryObject(),
+                  static_cast<size_t>(size))));
+              break;
+            case base::SharedMemoryHandle::POSIX:
+              nacl_desc.reset(new NaClDescWrapper(NaClDescImcShmMake(

[Mark Seaborn, 2015/11/20 18:55:54]

This is the same as the code in the #else, so you could reduce duplication with:

#if defined(OS_MACOSX)
if (shm_handle.GetType() == base::SharedMemoryHandle::MACH) {
  return new NaClDescWrapper(...);
}
CHECK_EQ(shm_handle.GetType(), base::SharedMemoryHandle::POSIX);
#endif
// Generic case...

[erikchen, 2015/11/20 21:51:12]

Done.

+                  base::SharedMemory::GetFdFromSharedMemoryHandle(shm_handle),
+                  static_cast<size_t>(size))));
+              break;
+          }
+#else
           nacl_desc.reset(new NaClDescWrapper(NaClDescImcShmMake(
 #if defined(OS_WIN)
               shm_handle.GetHandle(),
 #else
               base::SharedMemory::GetFdFromSharedMemoryHandle(shm_handle),
-#endif
+#endif  // defined(OS_WIN)
               static_cast<size_t>(size))));
+#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
           break;
         }
         case ppapi::proxy::SerializedHandle::SOCKET: {
           nacl_desc.reset(new NaClDescWrapper(NaClDescSyncSocketMake(
 #if defined(OS_WIN)
               iter->descriptor()
 #else
               iter->descriptor().fd
 #endif
           )));
@@ skipping 264 matching lines @@
   header.flags = msg.flags();
   header.num_fds = static_cast<uint16>(rewritten_msg->desc_count());
 
   rewritten_msg->SetData(header, msg.payload(), msg.payload_size());
   locked_data_.to_be_received_.push(rewritten_msg);
 }
 
 int TranslatePepperFileReadWriteOpenFlagsForTesting(int32_t pp_open_flags) {
   return TranslatePepperFileReadWriteOpenFlags(pp_open_flags);
 }