[WIP NOT FOR COMMIT] Switch Android to libc++

net/base/address_tracker_linux_unittest.cc

 // Copyright (c) 2012 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 "base/memory/scoped_ptr.h"
 #include "net/base/address_tracker_linux.h"
 
 #include <linux/if.h>
 
 #include <vector>
@@ skipping 104 matching lines @@
     attr.nla_type = type;
     Append(&attr, sizeof(attr));
     Align();
     Append(data, length);
     Align();
   }
 
   void AppendTo(Buffer* output) const {
     CHECK_EQ(NLMSG_ALIGN(output->size()), output->size());
     output->reserve(output->size() + NLMSG_LENGTH(buffer_.size()));
     output->insert(output->end(), buffer_.begin(), buffer_.end());

[Fabrice (no longer in Chrome), 2014/11/12 11:52:29]

That's the line that fails to compile with buffer_ defined with type Buffer. It
only fails with GCC, it's fine with Clang.

[Nico, 2014/11/13 06:21:12]

Bizarre, output and buffer_ have the same type. Oh, is it because this is a
const method and so the buffer_ begin / end() methods return const iterators?
…no, insert() is supposed to be templated on the type of the 2nd and 3rd
parameter. What's the error message?

[Fabrice (no longer in Chrome), 2014/11/13 10:52:07]

Turns out the issue is the same in both tests. I have managed to track it down
to what I think is a bug in GCC but I can't manage to reproduce consistently on
a smaller case.
Here's the error message:
[...]/ndk/sources/cxx-stl/llvm-libc++/libcxx/include/iterator:1232:31: error:
'std::__1::__wrap_iter<_Iter>::__wrap_iter(std::__1::__wrap_iter<_Iter>::iterator_type)
[with _Iter = const char*; std::__1::__wrap_iter<_Iter>::iterator_type = const
char*]' is private
     _LIBCPP_INLINE_VISIBILITY __wrap_iter(iterator_type __x) _NOEXCEPT :
__i(__x) {}
It is a private constructor used by the vector class. The __wrap_iter class
declares vector class as friend but for some reason it is ignored by GCC. I have
managed to "reproduce" the error message with Clang by commenting the friend
declaration in the iterator header.

   }
 
  private:
   void Append(const void* data, size_t length) {
     const char* chardata = reinterpret_cast<const char*>(data);
     buffer_.insert(buffer_.end(), chardata, chardata + length);
   }
 
   void Align() {
     header()->nlmsg_len = buffer_.size();
     buffer_.insert(buffer_.end(), NLMSG_ALIGN(buffer_.size()) - buffer_.size(),
                    0);
     CHECK(NLMSG_OK(header(), buffer_.size()));
   }
 
   struct nlmsghdr* header() {
     return reinterpret_cast<struct nlmsghdr*>(&buffer_[0]);
   }
 
-  Buffer buffer_;
+  std::vector<int8_t> buffer_;

[Fabrice (no longer in Chrome), 2014/11/12 11:52:29]

Sorry, I missed it. This only fails with GCC, Clang compiles it fine. I have
added a comment on the line failing to compile.

 };
 
 #define INFINITY_LIFE_TIME 0xFFFFFFFF
 
 void MakeAddrMessageWithCacheInfo(uint16 type,
                                   uint8 flags,
                                   uint8 family,
                                   const IPAddressNumber& address,
                                   const IPAddressNumber& local,
                                   uint32 preferred_lifetime,
@@ skipping 391 matching lines @@
 
 TEST_F(AddressTrackerLinuxTest, NonTrackingModeInit) {
   AddressTrackerLinux tracker;
   tracker.Init();
 }
 
 }  // namespace
 
 }  // namespace internal
 }  // namespace net