1 | #ifndef Py_PYMACRO_H |
2 | #define Py_PYMACRO_H |
3 | |
4 | /* Minimum value between x and y */ |
5 | #define Py_MIN(x, y) (((x) > (y)) ? (y) : (x)) |
6 | |
7 | /* Maximum value between x and y */ |
8 | #define Py_MAX(x, y) (((x) > (y)) ? (x) : (y)) |
9 | |
10 | /* Absolute value of the number x */ |
11 | #define Py_ABS(x) ((x) < 0 ? -(x) : (x)) |
12 | |
13 | #define _Py_XSTRINGIFY(x) #x |
14 | |
15 | /* Convert the argument to a string. For example, Py_STRINGIFY(123) is replaced |
16 | with "123" by the preprocessor. Defines are also replaced by their value. |
17 | For example Py_STRINGIFY(__LINE__) is replaced by the line number, not |
18 | by "__LINE__". */ |
19 | #define Py_STRINGIFY(x) _Py_XSTRINGIFY(x) |
20 | |
21 | /* Get the size of a structure member in bytes */ |
22 | #define Py_MEMBER_SIZE(type, member) sizeof(((type *)0)->member) |
23 | |
24 | /* Argument must be a char or an int in [-128, 127] or [0, 255]. */ |
25 | #define Py_CHARMASK(c) ((unsigned char)((c) & 0xff)) |
26 | |
27 | /* Assert a build-time dependency, as an expression. |
28 | |
29 | Your compile will fail if the condition isn't true, or can't be evaluated |
30 | by the compiler. This can be used in an expression: its value is 0. |
31 | |
32 | Example: |
33 | |
34 | #define foo_to_char(foo) \ |
35 | ((char *)(foo) \ |
36 | + Py_BUILD_ASSERT_EXPR(offsetof(struct foo, string) == 0)) |
37 | |
38 | Written by Rusty Russell, public domain, http://ccodearchive.net/ */ |
39 | #define Py_BUILD_ASSERT_EXPR(cond) \ |
40 | (sizeof(char [1 - 2*!(cond)]) - 1) |
41 | |
42 | #define Py_BUILD_ASSERT(cond) do { \ |
43 | (void)Py_BUILD_ASSERT_EXPR(cond); \ |
44 | } while(0) |
45 | |
46 | /* Get the number of elements in a visible array |
47 | |
48 | This does not work on pointers, or arrays declared as [], or function |
49 | parameters. With correct compiler support, such usage will cause a build |
50 | error (see Py_BUILD_ASSERT_EXPR). |
51 | |
52 | Written by Rusty Russell, public domain, http://ccodearchive.net/ |
53 | |
54 | Requires at GCC 3.1+ */ |
55 | #if (defined(__GNUC__) && !defined(__STRICT_ANSI__) && \ |
56 | (((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1)) || (__GNUC__ >= 4))) |
57 | /* Two gcc extensions. |
58 | &a[0] degrades to a pointer: a different type from an array */ |
59 | #define Py_ARRAY_LENGTH(array) \ |
60 | (sizeof(array) / sizeof((array)[0]) \ |
61 | + Py_BUILD_ASSERT_EXPR(!__builtin_types_compatible_p(typeof(array), \ |
62 | typeof(&(array)[0])))) |
63 | #else |
64 | #define Py_ARRAY_LENGTH(array) \ |
65 | (sizeof(array) / sizeof((array)[0])) |
66 | #endif |
67 | |
68 | |
69 | /* Define macros for inline documentation. */ |
70 | #define PyDoc_VAR(name) static const char name[] |
71 | #define PyDoc_STRVAR(name,str) PyDoc_VAR(name) = PyDoc_STR(str) |
72 | #ifdef WITH_DOC_STRINGS |
73 | #define PyDoc_STR(str) str |
74 | #else |
75 | #define PyDoc_STR(str) "" |
76 | #endif |
77 | |
78 | /* Below "a" is a power of 2. */ |
79 | /* Round down size "n" to be a multiple of "a". */ |
80 | #define _Py_SIZE_ROUND_DOWN(n, a) ((size_t)(n) & ~(size_t)((a) - 1)) |
81 | /* Round up size "n" to be a multiple of "a". */ |
82 | #define _Py_SIZE_ROUND_UP(n, a) (((size_t)(n) + \ |
83 | (size_t)((a) - 1)) & ~(size_t)((a) - 1)) |
84 | /* Round pointer "p" down to the closest "a"-aligned address <= "p". */ |
85 | #define _Py_ALIGN_DOWN(p, a) ((void *)((uintptr_t)(p) & ~(uintptr_t)((a) - 1))) |
86 | /* Round pointer "p" up to the closest "a"-aligned address >= "p". */ |
87 | #define _Py_ALIGN_UP(p, a) ((void *)(((uintptr_t)(p) + \ |
88 | (uintptr_t)((a) - 1)) & ~(uintptr_t)((a) - 1))) |
89 | /* Check if pointer "p" is aligned to "a"-bytes boundary. */ |
90 | #define _Py_IS_ALIGNED(p, a) (!((uintptr_t)(p) & (uintptr_t)((a) - 1))) |
91 | |
92 | /* Use this for unused arguments in a function definition to silence compiler |
93 | * warnings. Example: |
94 | * |
95 | * int func(int a, int Py_UNUSED(b)) { return a; } |
96 | */ |
97 | #if defined(__GNUC__) || defined(__clang__) |
98 | # define Py_UNUSED(name) _unused_ ## name __attribute__((unused)) |
99 | #else |
100 | # define Py_UNUSED(name) _unused_ ## name |
101 | #endif |
102 | |
103 | #if defined(RANDALL_WAS_HERE) |
104 | # define Py_UNREACHABLE() \ |
105 | Py_FatalError( \ |
106 | "If you're seeing this, the code is in what I thought was\n" \ |
107 | "an unreachable state.\n\n" \ |
108 | "I could give you advice for what to do, but honestly, why\n" \ |
109 | "should you trust me? I clearly screwed this up. I'm writing\n" \ |
110 | "a message that should never appear, yet I know it will\n" \ |
111 | "probably appear someday.\n\n" \ |
112 | "On a deep level, I know I'm not up to this task.\n" \ |
113 | "I'm so sorry.\n" \ |
114 | "https://xkcd.com/2200") |
115 | #elif defined(Py_DEBUG) |
116 | # define Py_UNREACHABLE() \ |
117 | Py_FatalError( \ |
118 | "We've reached an unreachable state. Anything is possible.\n" \ |
119 | "The limits were in our heads all along. Follow your dreams.\n" \ |
120 | "https://xkcd.com/2200") |
121 | #elif defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)) |
122 | # define Py_UNREACHABLE() __builtin_unreachable() |
123 | #elif defined(__clang__) || defined(__INTEL_COMPILER) |
124 | # define Py_UNREACHABLE() __builtin_unreachable() |
125 | #elif defined(_MSC_VER) |
126 | # define Py_UNREACHABLE() __assume(0) |
127 | #else |
128 | # define Py_UNREACHABLE() \ |
129 | Py_FatalError("Unreachable C code path reached") |
130 | #endif |
131 | |
132 | #endif /* Py_PYMACRO_H */ |
133 | |