TouchGFX---new文件代码分析

硕果累累

1. // new standard header
   
2. 
   
3. // Copyright (c) Microsoft Corporation.
   
4. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   
5. 
   
6. #pragma once//为了避免同一个头文件被包含多次
   
7. #ifndef _NEW_
   
8. #define _NEW_
   
9. #include <yvals_core.h>
   
10. #if _STL_COMPILER_PREPROCESSOR
    
11. #include <exception>
    
12. #include <vcruntime_new.h>
    
13. 
    
14. #pragma pack(push, _CRT_PACKING)//#pragma pack指定结构、联合和类的包对齐方式
    
15. #pragma warning(push, _STL_WARNING_LEVEL)//#pragma warning该指令允许有选择的修改编译器的警告消息的行为
    
16. #pragma warning(disable : _STL_DISABLED_WARNINGS)
    
17. _STL_DISABLE_CLANG_WARNINGS
    
18. #pragma push_macro("new")
    
19. /*
    
20. *#pragma push_macro把括号中的内容（宏）的值压入堆栈
    
21. * #pragma pop_macro把括号中的内容（宏）的值弹出堆栈
    
22. */
    
23. #undef new
    
24. 
    
25. _STD_BEGIN
    
26. #ifdef __cpp_lib_destroying_delete
    
27. // STRUCT destroying_delete_t
    
28. struct destroying_delete_t {
    
29.     explicit destroying_delete_t() = default;
    
30. };
    
31. inline constexpr destroying_delete_t destroying_delete{};
    
32. #endif // __cpp_lib_destroying_delete
    
33. 
    
34. #if _HAS_CXX17
    
35. // FUNCTION TEMPLATE launder
    
36. template <class _Ty>
    
37. _NODISCARD constexpr _Ty* launder(_Ty* _Ptr) noexcept {
    
38.     static_assert(!is_function_v<_Ty> && !is_void_v<_Ty>,
    
39.         "N4727 21.6.4 [ptr.launder]/3: The program is ill-formed if T is a function type or cv void.");
    
40.     return __builtin_launder(_Ptr);
    
41. }
    
42. 
    
43. #if defined(_M_IX86) || defined(_M_X64) || defined(_M_ARM) || defined(_M_ARM64)
    
44. inline constexpr size_t hardware_constructive_interference_size = 64;
    
45. inline constexpr size_t hardware_destructive_interference_size  = 64;
    
46. #else // ^^^ supported hardware ^^^ // vvv unsupported hardware vvv
    
47. #error Unsupported architecture
    
48. //#error命令时C/C++语言的预处理命令之一，当预处理器预处理到#error命令时将停止编译并输出用户自定义的错误消息TOU
    
49. #endif // hardware
    
50. 
    
51. #endif // _HAS_CXX17
    
52. 
    
53. // SUPPORT TYPES
    
54. #if !defined(_INC_NEW) || !defined(_MSC_EXTENSIONS)
    
55. // handler for operator new failures
    
56. using new_handler = void(__CLRCALL_PURE_OR_CDECL*)();
    
57. #endif // !defined(_INC_NEW) || !defined(_MSC_EXTENSIONS)
    
58. 
    
59. // FUNCTION AND OBJECT DECLARATIONS
    
60. _CRTIMP2 new_handler __cdecl set_new_handler(_In_opt_ new_handler) noexcept;
    
61. _NODISCARD _CRTIMP2 new_handler __cdecl get_new_handler() noexcept;
    
62. _STD_END
    
63. 
    
64. #pragma pop_macro("new")
    
65. _STL_RESTORE_CLANG_WARNINGS
    
66. #pragma warning(pop)
    
67. #pragma pack(pop)
    
68. 
    
69. #endif // _STL_COMPILER_PREPROCESSOR
    
70. #endif // _NEW_
    

复制代码