Commit | Line | Data |
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94f582f8 RD |
1 | #ifndef __LINUX_COMPILER_H |
2 | #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead." | |
3 | #endif | |
1da177e4 LT |
4 | |
5 | /* | |
6 | * Common definitions for all gcc versions go here. | |
7 | */ | |
3f3f8d2f DS |
8 | #define GCC_VERSION (__GNUC__ * 10000 \ |
9 | + __GNUC_MINOR__ * 100 \ | |
10 | + __GNUC_PATCHLEVEL__) | |
1da177e4 LT |
11 | |
12 | ||
13 | /* Optimization barrier */ | |
14 | /* The "volatile" is due to gcc bugs */ | |
15 | #define barrier() __asm__ __volatile__("": : :"memory") | |
16 | ||
c8d52465 | 17 | /* |
85c210ed AK |
18 | * This macro obfuscates arithmetic on a variable address so that gcc |
19 | * shouldn't recognize the original var, and make assumptions about it. | |
20 | * | |
21 | * This is needed because the C standard makes it undefined to do | |
22 | * pointer arithmetic on "objects" outside their boundaries and the | |
23 | * gcc optimizers assume this is the case. In particular they | |
24 | * assume such arithmetic does not wrap. | |
25 | * | |
26 | * A miscompilation has been observed because of this on PPC. | |
27 | * To work around it we hide the relationship of the pointer and the object | |
28 | * using this macro. | |
29 | * | |
c8d52465 AB |
30 | * Versions of the ppc64 compiler before 4.1 had a bug where use of |
31 | * RELOC_HIDE could trash r30. The bug can be worked around by changing | |
32 | * the inline assembly constraint from =g to =r, in this particular | |
33 | * case either is valid. | |
34 | */ | |
1da177e4 LT |
35 | #define RELOC_HIDE(ptr, off) \ |
36 | ({ unsigned long __ptr; \ | |
c8d52465 | 37 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ |
1da177e4 | 38 | (typeof(ptr)) (__ptr + (off)); }) |
a1365647 | 39 | |
5bd7e6a3 KM |
40 | #ifdef __CHECKER__ |
41 | #define __must_be_array(arr) 0 | |
42 | #else | |
c5e631cf | 43 | /* &a[0] degrades to a pointer: a different type from an array */ |
ea6b101d | 44 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) |
5bd7e6a3 | 45 | #endif |
a1365647 | 46 | |
60a3cdd0 | 47 | /* |
ae3a0064 IM |
48 | * Force always-inline if the user requests it so via the .config, |
49 | * or if gcc is too old: | |
60a3cdd0 | 50 | */ |
765c68bd | 51 | #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ |
ae3a0064 | 52 | !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) |
93b3cca1 SR |
53 | # define inline inline __attribute__((always_inline)) notrace |
54 | # define __inline__ __inline__ __attribute__((always_inline)) notrace | |
55 | # define __inline __inline __attribute__((always_inline)) notrace | |
45959ee7 SR |
56 | #else |
57 | /* A lot of inline functions can cause havoc with function tracing */ | |
58 | # define inline inline notrace | |
59 | # define __inline__ __inline__ notrace | |
60 | # define __inline __inline notrace | |
60a3cdd0 IM |
61 | #endif |
62 | ||
a1365647 | 63 | #define __deprecated __attribute__((deprecated)) |
82ddcb04 RD |
64 | #define __packed __attribute__((packed)) |
65 | #define __weak __attribute__((weak)) | |
446c92b2 UKK |
66 | |
67 | /* | |
68 | * it doesn't make sense on ARM (currently the only user of __naked) to trace | |
69 | * naked functions because then mcount is called without stack and frame pointer | |
70 | * being set up and there is no chance to restore the lr register to the value | |
71 | * before mcount was called. | |
9c695203 MP |
72 | * |
73 | * The asm() bodies of naked functions often depend on standard calling conventions, | |
74 | * therefore they must be noinline and noclone. GCC 4.[56] currently fail to enforce | |
75 | * this, so we must do so ourselves. See GCC PR44290. | |
446c92b2 | 76 | */ |
9c695203 | 77 | #define __naked __attribute__((naked)) noinline __noclone notrace |
446c92b2 | 78 | |
82ddcb04 | 79 | #define __noreturn __attribute__((noreturn)) |
e8c44319 RB |
80 | |
81 | /* | |
82 | * From the GCC manual: | |
83 | * | |
84 | * Many functions have no effects except the return value and their | |
85 | * return value depends only on the parameters and/or global | |
86 | * variables. Such a function can be subject to common subexpression | |
87 | * elimination and loop optimization just as an arithmetic operator | |
88 | * would be. | |
89 | * [...] | |
90 | */ | |
82ddcb04 RD |
91 | #define __pure __attribute__((pure)) |
92 | #define __aligned(x) __attribute__((aligned(x))) | |
6061d949 JP |
93 | #define __printf(a, b) __attribute__((format(printf, a, b))) |
94 | #define __scanf(a, b) __attribute__((format(scanf, a, b))) | |
a1365647 | 95 | #define noinline __attribute__((noinline)) |
a1365647 | 96 | #define __attribute_const__ __attribute__((__const__)) |
0d7ebbbc | 97 | #define __maybe_unused __attribute__((unused)) |
7b2a3513 | 98 | #define __always_unused __attribute__((unused)) |
f153b821 LT |
99 | |
100 | #define __gcc_header(x) #x | |
101 | #define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h) | |
102 | #define gcc_header(x) _gcc_header(x) | |
103 | #include gcc_header(__GNUC__) | |
9c695203 MP |
104 | |
105 | #if !defined(__noclone) | |
106 | #define __noclone /* not needed */ | |
107 | #endif | |
c837fb37 BP |
108 | |
109 | /* | |
110 | * A trick to suppress uninitialized variable warning without generating any | |
111 | * code | |
112 | */ | |
113 | #define uninitialized_var(x) x = x | |
114 | ||
115 | #define __always_inline inline __attribute__((always_inline)) |