1 /*
2  * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3  * Copyright (c) 2015-2018 The strace developers.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef STRACE_GCC_COMPAT_H
30 #define STRACE_GCC_COMPAT_H
31 
32 #if defined __GNUC__ && defined __GNUC_MINOR__
33 # define GNUC_PREREQ(maj, min)	\
34 	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
35 #else
36 # define GNUC_PREREQ(maj, min)	0
37 #endif
38 
39 #if defined __clang__ && defined __clang_major__ && defined __clang_minor__
40 # define CLANG_PREREQ(maj, min)	\
41 	((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
42 #else
43 # define CLANG_PREREQ(maj, min)	0
44 #endif
45 
46 #if !(GNUC_PREREQ(2, 0) || CLANG_PREREQ(1, 0))
47 # define __attribute__(x)	/* empty */
48 #endif
49 
50 #if GNUC_PREREQ(2, 5)
51 # define ATTRIBUTE_NORETURN	__attribute__((__noreturn__))
52 #else
53 # define ATTRIBUTE_NORETURN	/* empty */
54 #endif
55 
56 #if GNUC_PREREQ(2, 7)
57 # define ATTRIBUTE_FORMAT(args)	__attribute__((__format__ args))
58 # define ATTRIBUTE_ALIGNED(arg)	__attribute__((__aligned__(arg)))
59 # define ATTRIBUTE_PACKED	__attribute__((__packed__))
60 #else
61 # define ATTRIBUTE_FORMAT(args)	/* empty */
62 # define ATTRIBUTE_ALIGNED(arg)	/* empty */
63 # define ATTRIBUTE_PACKED	/* empty */
64 #endif
65 
66 #if GNUC_PREREQ(3, 0)
67 # define SAME_TYPE(x, y)	__builtin_types_compatible_p(typeof(x), typeof(y))
68 # define FAIL_BUILD_ON_ZERO(expr) (sizeof(int[-1 + 2 * !!(expr)]) * 0)
69 /* &(a)[0] is a pointer and not an array, shouldn't be treated as the same */
70 # define MUST_BE_ARRAY(a) FAIL_BUILD_ON_ZERO(!SAME_TYPE((a), &(a)[0]))
71 #else
72 # define SAME_TYPE(x, y)	0
73 # define MUST_BE_ARRAY(a)	0
74 #endif
75 
76 #if GNUC_PREREQ(3, 0)
77 # define ATTRIBUTE_MALLOC	__attribute__((__malloc__))
78 #else
79 # define ATTRIBUTE_MALLOC	/* empty */
80 #endif
81 
82 #if GNUC_PREREQ(3, 1)
83 # define ATTRIBUTE_NOINLINE	__attribute__((__noinline__))
84 #else
85 # define ATTRIBUTE_NOINLINE	/* empty */
86 #endif
87 
88 #if GNUC_PREREQ(4, 0)
89 # define ATTRIBUTE_SENTINEL	__attribute__((__sentinel__))
90 #else
91 # define ATTRIBUTE_SENTINEL	/* empty */
92 #endif
93 
94 #if GNUC_PREREQ(4, 1)
95 # define ALIGNOF(t_)	__alignof__(t_)
96 #else
97 # define ALIGNOF(t_)	(sizeof(struct { char x_; t_ y_; }) - sizeof(t_))
98 #endif
99 
100 #if GNUC_PREREQ(4, 3)
101 # define ATTRIBUTE_ALLOC_SIZE(args)	__attribute__((__alloc_size__ args))
102 #else
103 # define ATTRIBUTE_ALLOC_SIZE(args)	/* empty */
104 #endif
105 
106 #if GNUC_PREREQ(7, 0)
107 # define ATTRIBUTE_FALLTHROUGH	__attribute__((__fallthrough__))
108 #else
109 # define ATTRIBUTE_FALLTHROUGH	((void) 0)
110 #endif
111 
112 #if CLANG_PREREQ(2, 8)
113 # define DIAG_PUSH_IGNORE_OVERRIDE_INIT					\
114 	_Pragma("clang diagnostic push");				\
115 	_Pragma("clang diagnostic ignored \"-Winitializer-overrides\"");
116 # define DIAG_POP_IGNORE_OVERRIDE_INIT					\
117 	_Pragma("clang diagnostic pop");
118 #elif GNUC_PREREQ(4, 2)
119 # define DIAG_PUSH_IGNORE_OVERRIDE_INIT					\
120 	_Pragma("GCC diagnostic push");					\
121 	_Pragma("GCC diagnostic ignored \"-Woverride-init\"");
122 # define DIAG_POP_IGNORE_OVERRIDE_INIT					\
123 	_Pragma("GCC diagnostic pop");
124 #else
125 # define DIAG_PUSH_IGNORE_OVERRIDE_INIT	/* empty */
126 # define DIAG_POP_IGNORE_OVERRIDE_INIT	/* empty */
127 #endif
128 
129 #if GNUC_PREREQ(6, 0)
130 # define DIAG_PUSH_IGNORE_TAUTOLOGICAL_COMPARE				\
131 	_Pragma("GCC diagnostic push");					\
132 	_Pragma("GCC diagnostic ignored \"-Wtautological-compare\"");
133 # define DIAG_POP_IGNORE_TAUTOLOGICAL_COMPARE				\
134 	_Pragma("GCC diagnostic pop");
135 #else
136 # define DIAG_PUSH_IGNORE_TAUTOLOGICAL_COMPARE	/* empty */
137 # define DIAG_POP_IGNORE_TAUTOLOGICAL_COMPARE	/* empty */
138 #endif
139 
140 #endif /* !STRACE_GCC_COMPAT_H */
141