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