xref: /llvm-project/libcxx/test/std/input.output/file.streams/fstreams/native_handle_test_helpers.h (revision 1636580b0a9afb2272d94b125313e4b35e9af2a9)
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 #ifndef TEST_STD_INPUT_OUTPUT_FILE_STREAMS_FSTREAMS_TEST_HELPERS_H
10 #define TEST_STD_INPUT_OUTPUT_FILE_STREAMS_FSTREAMS_TEST_HELPERS_H
11 
12 #include <cassert>
13 #include <cerrno>
14 #include <concepts>
15 #include <cstdio>
16 #include <fstream>
17 #include <filesystem>
18 #include <type_traits>
19 #include <utility>
20 
21 #if defined(_WIN32)
22 #  include <io.h>
23 #  include <windows.h>
24 #else
25 #  include <fcntl.h>
26 #endif
27 
28 #include "platform_support.h"
29 #include "types.h"
30 
31 #if TEST_STD_VER >= 26
32 
33 inline bool is_handle_valid(NativeHandleT handle) {
34 #  if defined(_WIN32)
35   BY_HANDLE_FILE_INFORMATION fileInformation;
36   return GetFileInformationByHandle(handle, &fileInformation);
37 #  elif __has_include(<unistd.h>) // POSIX
38   return fcntl(handle, F_GETFL) != -1 || errno != EBADF;
39 #  else
40 #    error "Provide a native file handle!"
41 #  endif
42 }
43 
44 template <typename CharT, typename StreamT>
45 inline void test_native_handle() {
46   static_assert(
47       std::is_same_v<typename std::basic_filebuf<CharT>::native_handle_type, typename StreamT::native_handle_type>);
48 
49   StreamT f;
50   std::filesystem::path p = get_temp_file_name();
51 
52   // non-const
53   {
54     f.open(p);
55     std::same_as<NativeHandleT> decltype(auto) handle = f.native_handle();
56     assert(is_handle_valid(handle));
57     assert(f.rdbuf()->native_handle() == handle);
58     assert(std::as_const(f).rdbuf()->native_handle() == handle);
59     f.close();
60     assert(!is_handle_valid(handle));
61     static_assert(noexcept(f.native_handle()));
62   }
63   // const
64   {
65     f.open(p);
66     std::same_as<NativeHandleT> decltype(auto) const_handle = std::as_const(f).native_handle();
67     assert(is_handle_valid(const_handle));
68     assert(f.rdbuf()->native_handle() == const_handle);
69     assert(std::as_const(f).rdbuf()->native_handle() == const_handle);
70     f.close();
71     assert(!is_handle_valid(const_handle));
72     static_assert(noexcept(std::as_const(f).native_handle()));
73   }
74 }
75 
76 template <typename StreamT>
77 inline void test_native_handle_type() {
78   static_assert(std::is_trivially_copyable_v<typename StreamT::native_handle_type>);
79   static_assert(std::semiregular<typename StreamT::native_handle_type>);
80   static_assert(std::is_same_v<typename StreamT::native_handle_type, NativeHandleT>);
81 }
82 
83 #endif // #if TEST_STD_VER >= 26
84 
85 #endif // TEST_STD_INPUT_OUTPUT_FILE_STREAMS_FSTREAMS_TEST_HELPERS_H
86