xref: /freebsd/contrib/llvm-project/libcxx/include/__thread/formatter.h (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef _LIBCPP___THREAD_FORMATTER_H
11 #define _LIBCPP___THREAD_FORMATTER_H
12 
13 #include <__concepts/arithmetic.h>
14 #include <__config>
15 #include <__format/concepts.h>
16 #include <__format/format_parse_context.h>
17 #include <__format/formatter.h>
18 #include <__format/formatter_integral.h>
19 #include <__format/parser_std_format_spec.h>
20 #include <__thread/id.h>
21 #include <__type_traits/conditional.h>
22 #include <__type_traits/is_pointer.h>
23 #include <__type_traits/is_same.h>
24 #include <cstdint>
25 
26 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
27 #  pragma GCC system_header
28 #endif
29 
30 #if _LIBCPP_STD_VER >= 23
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 #  ifndef _LIBCPP_HAS_NO_THREADS
35 
36 template <__fmt_char_type _CharT>
37 struct _LIBCPP_TEMPLATE_VIS formatter<__thread_id, _CharT> {
38 public:
39   template <class _ParseContext>
40   _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
41     return __parser_.__parse(__ctx, __format_spec::__fields_fill_align_width);
42   }
43 
44   template <class _FormatContext>
45   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(__thread_id __id, _FormatContext& __ctx) const {
46     // In __threading_support __libcpp_thread_id is either a
47     // unsigned long long or a pthread_t.
48     //
49     // The type of pthread_t is left unspecified in POSIX so it can be any
50     // type. The most logical types are an integral or pointer.
51     // On Linux systems pthread_t is an unsigned long long.
52     // On Apple systems pthread_t is a pointer type.
53     //
54     // Note the output should match what the stream operator does. Since
55     // the ostream operator has been shipped years before this formatter
56     // was added to the Standard, this formatter does what the stream
57     // operator does. This may require platform specific changes.
58 
59     using _Tp = decltype(__get_underlying_id(__id));
60     using _Cp = conditional_t<integral<_Tp>, _Tp, conditional_t<is_pointer_v<_Tp>, uintptr_t, void>>;
61     static_assert(!is_same_v<_Cp, void>, "unsupported thread::id type, please file a bug report");
62 
63     __format_spec::__parsed_specifications<_CharT> __specs = __parser_.__get_parsed_std_specifications(__ctx);
64     if constexpr (is_pointer_v<_Tp>) {
65       __specs.__std_.__alternate_form_ = true;
66       __specs.__std_.__type_           = __format_spec::__type::__hexadecimal_lower_case;
67     }
68     return __formatter::__format_integer(reinterpret_cast<_Cp>(__get_underlying_id(__id)), __ctx, __specs);
69   }
70 
71   __format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__right};
72 };
73 
74 #  endif // !_LIBCPP_HAS_NO_THREADS
75 
76 _LIBCPP_END_NAMESPACE_STD
77 
78 #endif // _LIBCPP_STD_VER >= 23
79 
80 #endif // _LIBCPP___THREAD_FORMATTER_H
81