Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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#define notrace __attribute__((no_instrument_function))
48
49/* Intel compiler defines __GNUC__. So we will overwrite implementations
50 * coming from above header files here
51 */
52#ifdef __INTEL_COMPILER
53# include <linux/compiler-intel.h>
54#endif
55
56/*
57 * Generic compiler-dependent macros required for kernel
58 * build go below this comment. Actual compiler/compiler version
59 * specific implementations come from the above header files
60 */
61
62#define likely(x) __builtin_expect(!!(x), 1)
63#define unlikely(x) __builtin_expect(!!(x), 0)
64
65/* Optimization barrier */
66#ifndef barrier
67# define barrier() __memory_barrier()
68#endif
69
70#ifndef RELOC_HIDE
71# define RELOC_HIDE(ptr, off) \
72 ({ unsigned long __ptr; \
73 __ptr = (unsigned long) (ptr); \
74 (typeof(ptr)) (__ptr + (off)); })
75#endif
76
77#endif /* __KERNEL__ */
78
79#endif /* __ASSEMBLY__ */
80
81#ifdef __KERNEL__
82/*
83 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
84 * warning for each use, in hopes of speeding the functions removal.
85 * Usage is:
86 * int __deprecated foo(void)
87 */
88#ifndef __deprecated
89# define __deprecated /* unimplemented */
90#endif
91
92#ifdef MODULE
93#define __deprecated_for_modules __deprecated
94#else
95#define __deprecated_for_modules
96#endif
97
98#ifndef __must_check
99#define __must_check
100#endif
101
102#ifndef CONFIG_ENABLE_MUST_CHECK
103#undef __must_check
104#define __must_check
105#endif
106#ifndef CONFIG_ENABLE_WARN_DEPRECATED
107#undef __deprecated
108#undef __deprecated_for_modules
109#define __deprecated
110#define __deprecated_for_modules
111#endif
112
113/*
114 * Allow us to avoid 'defined but not used' warnings on functions and data,
115 * as well as force them to be emitted to the assembly file.
116 *
117 * As of gcc 3.4, static functions that are not marked with attribute((used))
118 * may be elided from the assembly file. As of gcc 3.4, static data not so
119 * marked will not be elided, but this may change in a future gcc version.
120 *
121 * NOTE: Because distributions shipped with a backported unit-at-a-time
122 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
123 * for gcc >=3.3 instead of 3.4.
124 *
125 * In prior versions of gcc, such functions and data would be emitted, but
126 * would be warned about except with attribute((unused)).
127 *
128 * Mark functions that are referenced only in inline assembly as __used so
129 * the code is emitted even though it appears to be unreferenced.
130 */
131#ifndef __used
132# define __used /* unimplemented */
133#endif
134
135#ifndef __maybe_unused
136# define __maybe_unused /* unimplemented */
137#endif
138
139#ifndef noinline
140#define noinline
141#endif
142
143/*
144 * Rather then using noinline to prevent stack consumption, use
145 * noinline_for_stack instead. For documentaiton reasons.
146 */
147#define noinline_for_stack noinline
148
149#ifndef __always_inline
150#define __always_inline inline
151#endif
152
153#endif /* __KERNEL__ */
154
155/*
156 * From the GCC manual:
157 *
158 * Many functions do not examine any values except their arguments,
159 * and have no effects except the return value. Basically this is
160 * just slightly more strict class than the `pure' attribute above,
161 * since function is not allowed to read global memory.
162 *
163 * Note that a function that has pointer arguments and examines the
164 * data pointed to must _not_ be declared `const'. Likewise, a
165 * function that calls a non-`const' function usually must not be
166 * `const'. It does not make sense for a `const' function to return
167 * `void'.
168 */
169#ifndef __attribute_const__
170# define __attribute_const__ /* unimplemented */
171#endif
172
173/*
174 * Tell gcc if a function is cold. The compiler will assume any path
175 * directly leading to the call is unlikely.
176 */
177
178#ifndef __cold
179#define __cold
180#endif
181
182/* Simple shorthand for a section definition */
183#ifndef __section
184# define __section(S) __attribute__ ((__section__(#S)))
185#endif
186
187/*
188 * Prevent the compiler from merging or refetching accesses. The compiler
189 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
190 * but only when the compiler is aware of some particular ordering. One way
191 * to make the compiler aware of ordering is to put the two invocations of
192 * ACCESS_ONCE() in different C statements.
193 *
194 * This macro does absolutely -nothing- to prevent the CPU from reordering,
195 * merging, or refetching absolutely anything at any time. Its main intended
196 * use is to mediate communication between process-level code and irq/NMI
197 * handlers, all running on the same CPU.
198 */
199#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
200
201#endif /* __LINUX_COMPILER_H */