Cleanup various includes and namespace references.

base/debug/stack_trace_android.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/debug/stack_trace.h"
 
 #include <android/log.h>
 #include <unwind.h>
 
 #include "base/debug/proc_maps_linux.h"
@@ skipping 99 matching lines @@
       ++iter;
     }
 
     *os << base::StringPrintf("#%02zd " FMT_ADDR " ", i, address);
 
     if (iter != regions.end()) {
       uintptr_t rel_pc = address - iter->start + iter->offset;
       const char* path = iter->path.c_str();
       *os << base::StringPrintf("%s+" FMT_ADDR, path, rel_pc);
     } else {
-      *os << "<unknown>";
+      *os << std::string("<unknown>");

[Nico, 2014/10/31 14:30:08]

Out of interest, what happens without this? Writing char pointers to ostreams is
supposed to work, and this builds fine for me with libc++:

#include <iostream>
int main() {
  std::ostream* os = &std::cout;
  *os << "hi";
}

[Fabrice (no longer in Chrome), 2014/10/31 15:45:23]

Maybe it works with Clang and not GCC? I noticed that happened a few times.
Either way, it's going to do an implicit conversion to std::string, right?

/usr/local/google/code/clankium/src/third_party/android_tools/ndk/sources/cxx-stl/llvm-libc++/libcxx/include/string:4185:1:
note:   template argument deduction/substitution failed:
../../base/debug/stack_trace_android.cc:120:14: note:   mismatched types 'const
std::__1::basic_string<_CharT, _Traits, _Allocator>' and 'const char [10]'
       *os << "<unknown>";
              ^

[Nico, 2014/10/31 16:10:03]

Oh, that's a good point. Works with gcc on my mac though:

$ gcc-4.8.1 -c test.cc  -isysroot $(xcrun -show-sdk-path) -I
~/src/libcxx/include/

(I checked it's actually picking up the libcxx iostream by rerunning this with
-H. I also tried the same with -std=gnu++11.)
$ clang -c test.cc  -Xclang -ast-dump | tail -8

`-FunctionDecl 0x103eb6e70 <test.cc:2:1, line:4:1> main 'int (void)'
  `-CompoundStmt 0x103ebaef8 <line:2:12, line:4:1>
    `-CXXOperatorCallExpr 0x103ebaeb0 <line:3:3, col:16> 'basic_ostream<char,
struct std::__1::char_traits<char> >':'class std::__1::basic_ostream<char>'
lvalue
      |-ImplicitCastExpr 0x103ebae98 <col:13> 'basic_ostream<char, struct
std::__1::char_traits<char> > &(*)(basic_ostream<char, struct
std::__1::char_traits<char> > &, const char *)' <FunctionToPointerDecay>
      | `-DeclRefExpr 0x103ebae18 <col:13> 'basic_ostream<char, struct
std::__1::char_traits<char> > &(basic_ostream<char, struct
std::__1::char_traits<char> > &, const char *)' lvalue Function 0x103eb7f00
'operator<<' 'basic_ostream<char, struct std::__1::char_traits<char> >
&(basic_ostream<char, struct std::__1::char_traits<char> > &, const char *)'
      |-DeclRefExpr 0x103eb6f48 <col:3, col:8> 'ostream':'class
std::__1::basic_ostream<char>' lvalue Var 0x103eb6830 'cout' 'ostream':'class
std::__1::basic_ostream<char>'
      `-ImplicitCastExpr 0x103ebae00 <col:16> 'const char *'
<ArrayToPointerDecay>
        `-StringLiteral 0x103eb6f80 <col:16> 'const char [3]' lvalue "hi"

(look for "operator<< on line 5)

On my system, `operator<<(basic_ostream<char, _Traits>& __os, const char*
__str)` is defined around line 846 in libcxx/include/ostream – maybe this file
is just missing an `#include <ostream>`?

[Fabrice (no longer in Chrome), 2014/10/31 17:01:15]

Yes, that was it, thanks!

     }
 
-    *os << "\n";
+    *os << std::string("\n");
   }
 }
 
 }  // namespace debug
 }  // namespace base