xref: /llvm-project/libcxx/include/source_location (revision f69585235ec85d54e0f3fc41b2d5700430907f99)
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_SOURCE_LOCATION
11#define _LIBCPP_SOURCE_LOCATION
12
13/* source_location synopsis
14
15namespace std {
16  struct source_location {
17    static consteval source_location current() noexcept;
18    constexpr source_location() noexcept;
19
20    constexpr uint_least32_t line() const noexcept;
21    constexpr uint_least32_t column() const noexcept;
22    constexpr const char* file_name() const noexcept;
23    constexpr const char* function_name() const noexcept;
24  };
25}
26*/
27
28#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
29#  include <__cxx03/source_location>
30#else
31#  include <__config>
32#  include <cstdint>
33#  include <version>
34
35#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
36#    pragma GCC system_header
37#  endif
38
39_LIBCPP_BEGIN_NAMESPACE_STD
40
41#  if _LIBCPP_STD_VER >= 20
42
43class source_location {
44  // The names source_location::__impl, _M_file_name, _M_function_name, _M_line, and _M_column
45  // are hard-coded in the compiler and must not be changed here.
46  struct __impl {
47    const char* _M_file_name;
48    const char* _M_function_name;
49    unsigned _M_line;
50    unsigned _M_column;
51  };
52  const __impl* __ptr_ = nullptr;
53  // GCC returns the type 'const void*' from the builtin, while clang returns
54  // `const __impl*`. Per C++ [expr.const], casts from void* are not permitted
55  // in constant evaluation, so we don't want to use `void*` as the argument
56  // type unless the builtin returned that, anyhow, and the invalid cast is
57  // unavoidable.
58  using __bsl_ty _LIBCPP_NODEBUG = decltype(__builtin_source_location());
59
60public:
61  // The defaulted __ptr argument is necessary so that the builtin is evaluated
62  // in the context of the caller. An explicit value should never be provided.
63  static consteval source_location current(__bsl_ty __ptr = __builtin_source_location()) noexcept {
64    source_location __sl;
65    __sl.__ptr_ = static_cast<const __impl*>(__ptr);
66    return __sl;
67  }
68  _LIBCPP_HIDE_FROM_ABI constexpr source_location() noexcept = default;
69
70  _LIBCPP_HIDE_FROM_ABI constexpr uint_least32_t line() const noexcept {
71    return __ptr_ != nullptr ? __ptr_->_M_line : 0;
72  }
73  _LIBCPP_HIDE_FROM_ABI constexpr uint_least32_t column() const noexcept {
74    return __ptr_ != nullptr ? __ptr_->_M_column : 0;
75  }
76  _LIBCPP_HIDE_FROM_ABI constexpr const char* file_name() const noexcept {
77    return __ptr_ != nullptr ? __ptr_->_M_file_name : "";
78  }
79  _LIBCPP_HIDE_FROM_ABI constexpr const char* function_name() const noexcept {
80    return __ptr_ != nullptr ? __ptr_->_M_function_name : "";
81  }
82};
83
84#  endif // _LIBCPP_STD_VER >= 20
85
86_LIBCPP_END_NAMESPACE_STD
87
88#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
89
90#endif // _LIBCPP_SOURCE_LOCATION
91