Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1#ifndef __LINUX_COMPILER_H
2#define __LINUX_COMPILER_H
3
4#ifndef __ASSEMBLY__
5
6#ifdef __CHECKER__
7# define __user __attribute__((noderef, address_space(1)))
8# define __kernel /* default address space */
9# define __safe __attribute__((safe))
10# define __force __attribute__((force))
11# define __nocast __attribute__((nocast))
12# define __iomem __attribute__((noderef, address_space(2)))
13# define __acquires(x) __attribute__((context(x,0,1)))
14# define __releases(x) __attribute__((context(x,1,0)))
15# define __acquire(x) __context__(x,1)
16# define __release(x) __context__(x,-1)
17# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
18extern void __chk_user_ptr(const volatile void __user *);
19extern void __chk_io_ptr(const volatile void __iomem *);
20#else
21# define __user
22# define __kernel
23# define __safe
24# define __force
25# define __nocast
26# define __iomem
27# define __chk_user_ptr(x) (void)0
28# define __chk_io_ptr(x) (void)0
29# define __builtin_warning(x, y...) (1)
30# define __acquires(x)
31# define __releases(x)
32# define __acquire(x) (void)0
33# define __release(x) (void)0
34# define __cond_lock(x,c) (c)
35#endif
36
37#ifdef __KERNEL__
38
39#if __GNUC__ >= 4
40# include <linux/compiler-gcc4.h>
41#elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2
42# include <linux/compiler-gcc3.h>
43#else
44# error Sorry, your compiler is too old/not recognized.
45#endif
46
47/* Intel compiler defines __GNUC__. So we will overwrite implementations
48 * coming from above header files here
49 */
50#ifdef __INTEL_COMPILER
51# include <linux/compiler-intel.h>
52#endif
53
54/*
55 * Generic compiler-dependent macros required for kernel
56 * build go below this comment. Actual compiler/compiler version
57 * specific implementations come from the above header files
58 */
59
60#define likely(x) __builtin_expect(!!(x), 1)
61#define unlikely(x) __builtin_expect(!!(x), 0)
62
63/* Optimization barrier */
64#ifndef barrier
65# define barrier() __memory_barrier()
66#endif
67
68#ifndef RELOC_HIDE
69# define RELOC_HIDE(ptr, off) \
70 ({ unsigned long __ptr; \
71 __ptr = (unsigned long) (ptr); \
72 (typeof(ptr)) (__ptr + (off)); })
73#endif
74
75#endif /* __KERNEL__ */
76
77#endif /* __ASSEMBLY__ */
78
79#ifdef __KERNEL__
80/*
81 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
82 * warning for each use, in hopes of speeding the functions removal.
83 * Usage is:
84 * int __deprecated foo(void)
85 */
86#ifndef __deprecated
87# define __deprecated /* unimplemented */
88#endif
89
90#ifdef MODULE
91#define __deprecated_for_modules __deprecated
92#else
93#define __deprecated_for_modules
94#endif
95
96#ifndef __must_check
97#define __must_check
98#endif
99
100#ifndef CONFIG_ENABLE_MUST_CHECK
101#undef __must_check
102#define __must_check
103#endif
104
105/*
106 * Allow us to avoid 'defined but not used' warnings on functions and data,
107 * as well as force them to be emitted to the assembly file.
108 *
109 * As of gcc 3.4, static functions that are not marked with attribute((used))
110 * may be elided from the assembly file. As of gcc 3.4, static data not so
111 * marked will not be elided, but this may change in a future gcc version.
112 *
113 * NOTE: Because distributions shipped with a backported unit-at-a-time
114 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
115 * for gcc >=3.3 instead of 3.4.
116 *
117 * In prior versions of gcc, such functions and data would be emitted, but
118 * would be warned about except with attribute((unused)).
119 *
120 * Mark functions that are referenced only in inline assembly as __used so
121 * the code is emitted even though it appears to be unreferenced.
122 */
123#ifndef __attribute_used__
124# define __attribute_used__ /* deprecated */
125#endif
126
127#ifndef __used
128# define __used /* unimplemented */
129#endif
130
131#ifndef __maybe_unused
132# define __maybe_unused /* unimplemented */
133#endif
134
135/*
136 * From the GCC manual:
137 *
138 * Many functions have no effects except the return value and their
139 * return value depends only on the parameters and/or global
140 * variables. Such a function can be subject to common subexpression
141 * elimination and loop optimization just as an arithmetic operator
142 * would be.
143 * [...]
144 */
145#ifndef __attribute_pure__
146# define __attribute_pure__ /* unimplemented */
147#endif
148
149#ifndef noinline
150#define noinline
151#endif
152
153#ifndef __always_inline
154#define __always_inline inline
155#endif
156
157#endif /* __KERNEL__ */
158
159/*
160 * From the GCC manual:
161 *
162 * Many functions do not examine any values except their arguments,
163 * and have no effects except the return value. Basically this is
164 * just slightly more strict class than the `pure' attribute above,
165 * since function is not allowed to read global memory.
166 *
167 * Note that a function that has pointer arguments and examines the
168 * data pointed to must _not_ be declared `const'. Likewise, a
169 * function that calls a non-`const' function usually must not be
170 * `const'. It does not make sense for a `const' function to return
171 * `void'.
172 */
173#ifndef __attribute_const__
174# define __attribute_const__ /* unimplemented */
175#endif
176
177/*
178 * Tell gcc if a function is cold. The compiler will assume any path
179 * directly leading to the call is unlikely.
180 */
181
182#ifndef __cold
183#define __cold
184#endif
185
186#endif /* __LINUX_COMPILER_H */