xref: /freebsd/contrib/llvm-project/libcxx/src/ostream.cpp (revision a0ca4af9455b844c5e094fc1b09b1390ffa979fc)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include <__availability>
10 #include <__config>
11 #ifndef _LIBCPP_HAS_NO_FILESYSTEM
12 #  include <fstream>
13 #endif
14 #include <ostream>
15 
16 #include "std_stream.h"
17 
18 _LIBCPP_BEGIN_NAMESPACE_STD
19 
20 _LIBCPP_EXPORTED_FROM_ABI FILE* __get_ostream_file(ostream& __os) {
21   // dynamic_cast requires RTTI, this only affects users whose vendor builds
22   // the dylib with RTTI disabled. It does not affect users who build with RTTI
23   // disabled but use a dylib where the RTTI is enabled.
24   //
25   // Returning a nullptr means the stream is not considered a terminal and the
26   // special terminal handling is not done. The terminal handling is mainly of
27   // importance on Windows.
28 #ifndef _LIBCPP_HAS_NO_RTTI
29   auto* __rdbuf = __os.rdbuf();
30 #  ifndef _LIBCPP_HAS_NO_FILESYSTEM
31   if (auto* __buffer = dynamic_cast<filebuf*>(__rdbuf))
32     return __buffer->__file_;
33 #  endif
34 
35   if (auto* __buffer = dynamic_cast<__stdoutbuf<char>*>(__rdbuf))
36     return __buffer->__file_;
37 #endif // _LIBCPP_HAS_NO_RTTI
38 
39   return nullptr;
40 }
41 
42 _LIBCPP_END_NAMESPACE_STD
43