2 * Copyright © 2014 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
27 /* Compute the size of an array */
29 # define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
34 * __builtin_expect macros
36 #if !defined(HAVE___BUILTIN_EXPECT)
37 # define __builtin_expect(x, y) (x)
41 # ifdef HAVE___BUILTIN_EXPECT
42 # define likely(x) __builtin_expect(!!(x), 1)
43 # define unlikely(x) __builtin_expect(!!(x), 0)
45 # define likely(x) (x)
46 # define unlikely(x) (x)
52 * Static (compile-time) assertion.
53 * Basically, use COND to dimension an array. If COND is false/zero the
54 * array size will be -1 and we'll get a compilation error.
56 #define STATIC_ASSERT(COND) \
58 (void) sizeof(char [1 - 2*!(COND)]); \
63 * Unreachable macro. Useful for suppressing "control reaches end of non-void
66 #ifdef HAVE___BUILTIN_UNREACHABLE
67 #define unreachable(str) \
70 __builtin_unreachable(); \
75 #define unreachable(str)
79 * Assume macro. Useful for expressing our assumptions to the compiler,
80 * typically for purposes of silencing warnings.
82 #ifdef HAVE___BUILTIN_UNREACHABLE
83 #define assume(expr) ((expr) ? ((void) 0) \
84 : (assert(!"assumption failed"), \
85 __builtin_unreachable()))
86 #elif _MSC_VER >= 1200
87 #define assume(expr) __assume(expr)
89 #define assume(expr) assert(expr)
92 #ifdef HAVE_FUNC_ATTRIBUTE_FLATTEN
93 #define FLATTEN __attribute__((__flatten__))
98 #ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
99 #define PRINTFLIKE(f, a) __attribute__ ((format(__printf__, f, a)))
101 #define PRINTFLIKE(f, a)
104 #ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
105 #define MALLOCLIKE __attribute__((__malloc__))
110 /* Used to optionally mark structures with misaligned elements or size as
111 * packed, to trade off performance for space.
113 #ifdef HAVE_FUNC_ATTRIBUTE_PACKED
114 #define PACKED __attribute__((__packed__))
121 * Macro function that evaluates to true if T is a trivially
122 * destructible type -- that is, if its (non-virtual) destructor
123 * performs no action and all member variables and base classes are
124 * trivially destructible themselves.
126 # if defined(__GNUC__)
127 # if ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3)))
128 # define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
130 # elif (defined(__clang__) && defined(__has_feature))
131 # if __has_feature(has_trivial_destructor)
132 # define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
135 # ifndef HAS_TRIVIAL_DESTRUCTOR
136 /* It's always safe (if inefficient) to assume that a
137 * destructor is non-trivial.
139 # define HAS_TRIVIAL_DESTRUCTOR(T) (false)
143 #endif /* UTIL_MACROS_H */