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1 | #ifndef __LINUX_COMPILER_H |
1 | #ifndef __LINUX_COMPILER_H |
2 | #error "Please don't include |
2 | #error "Please don't include |
3 | #endif |
3 | #endif |
4 | 4 | ||
5 | /* |
5 | /* |
6 | * Common definitions for all gcc versions go here. |
6 | * Common definitions for all gcc versions go here. |
7 | */ |
7 | */ |
8 | 8 | ||
9 | 9 | ||
10 | /* Optimization barrier */ |
10 | /* Optimization barrier */ |
11 | /* The "volatile" is due to gcc bugs */ |
11 | /* The "volatile" is due to gcc bugs */ |
12 | #define barrier() __asm__ __volatile__("": : :"memory") |
12 | #define barrier() __asm__ __volatile__("": : :"memory") |
13 | 13 | ||
14 | /* |
14 | /* |
15 | * This macro obfuscates arithmetic on a variable address so that gcc |
15 | * This macro obfuscates arithmetic on a variable address so that gcc |
16 | * shouldn't recognize the original var, and make assumptions about it. |
16 | * shouldn't recognize the original var, and make assumptions about it. |
17 | * |
17 | * |
18 | * This is needed because the C standard makes it undefined to do |
18 | * This is needed because the C standard makes it undefined to do |
19 | * pointer arithmetic on "objects" outside their boundaries and the |
19 | * pointer arithmetic on "objects" outside their boundaries and the |
20 | * gcc optimizers assume this is the case. In particular they |
20 | * gcc optimizers assume this is the case. In particular they |
21 | * assume such arithmetic does not wrap. |
21 | * assume such arithmetic does not wrap. |
22 | * |
22 | * |
23 | * A miscompilation has been observed because of this on PPC. |
23 | * A miscompilation has been observed because of this on PPC. |
24 | * To work around it we hide the relationship of the pointer and the object |
24 | * To work around it we hide the relationship of the pointer and the object |
25 | * using this macro. |
25 | * using this macro. |
26 | * |
26 | * |
27 | * Versions of the ppc64 compiler before 4.1 had a bug where use of |
27 | * Versions of the ppc64 compiler before 4.1 had a bug where use of |
28 | * RELOC_HIDE could trash r30. The bug can be worked around by changing |
28 | * RELOC_HIDE could trash r30. The bug can be worked around by changing |
29 | * the inline assembly constraint from =g to =r, in this particular |
29 | * the inline assembly constraint from =g to =r, in this particular |
30 | * case either is valid. |
30 | * case either is valid. |
31 | */ |
31 | */ |
32 | #define RELOC_HIDE(ptr, off) \ |
32 | #define RELOC_HIDE(ptr, off) \ |
33 | ({ unsigned long __ptr; \ |
33 | ({ unsigned long __ptr; \ |
34 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ |
34 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ |
35 | (typeof(ptr)) (__ptr + (off)); }) |
35 | (typeof(ptr)) (__ptr + (off)); }) |
36 | 36 | ||
37 | /* &a[0] degrades to a pointer: a different type from an array */ |
37 | /* &a[0] degrades to a pointer: a different type from an array */ |
38 | #define __must_be_array(a) \ |
- | |
39 | BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0]))) |
38 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) |
40 | 39 | ||
41 | /* |
40 | /* |
42 | * Force always-inline if the user requests it so via the .config, |
41 | * Force always-inline if the user requests it so via the .config, |
43 | * or if gcc is too old: |
42 | * or if gcc is too old: |
44 | */ |
43 | */ |
45 | #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ |
44 | #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ |
46 | !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) |
45 | !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) |
47 | # define inline inline __attribute__((always_inline)) |
46 | # define inline inline __attribute__((always_inline)) |
48 | # define __inline__ __inline__ __attribute__((always_inline)) |
47 | # define __inline__ __inline__ __attribute__((always_inline)) |
49 | # define __inline __inline __attribute__((always_inline)) |
48 | # define __inline __inline __attribute__((always_inline)) |
50 | #endif |
49 | #endif |
51 | 50 | ||
52 | #define __deprecated __attribute__((deprecated)) |
51 | #define __deprecated __attribute__((deprecated)) |
53 | #define __packed __attribute__((packed)) |
52 | #define __packed __attribute__((packed)) |
54 | #define __weak __attribute__((weak)) |
53 | #define __weak __attribute__((weak)) |
55 | 54 | ||
56 | /* |
55 | /* |
57 | * it doesn't make sense on ARM (currently the only user of __naked) to trace |
56 | * it doesn't make sense on ARM (currently the only user of __naked) to trace |
58 | * naked functions because then mcount is called without stack and frame pointer |
57 | * naked functions because then mcount is called without stack and frame pointer |
59 | * being set up and there is no chance to restore the lr register to the value |
58 | * being set up and there is no chance to restore the lr register to the value |
60 | * before mcount was called. |
59 | * before mcount was called. |
- | 60 | * |
|
- | 61 | * The asm() bodies of naked functions often depend on standard calling conventions, |
|
- | 62 | * therefore they must be noinline and noclone. GCC 4.[56] currently fail to enforce |
|
- | 63 | * this, so we must do so ourselves. See GCC PR44290. |
|
61 | */ |
64 | */ |
62 | #define __naked __attribute__((naked)) notrace |
65 | #define __naked __attribute__((naked)) noinline __noclone notrace |
63 | 66 | ||
64 | #define __noreturn __attribute__((noreturn)) |
67 | #define __noreturn __attribute__((noreturn)) |
65 | 68 | ||
66 | /* |
69 | /* |
67 | * From the GCC manual: |
70 | * From the GCC manual: |
68 | * |
71 | * |
69 | * Many functions have no effects except the return value and their |
72 | * Many functions have no effects except the return value and their |
70 | * return value depends only on the parameters and/or global |
73 | * return value depends only on the parameters and/or global |
71 | * variables. Such a function can be subject to common subexpression |
74 | * variables. Such a function can be subject to common subexpression |
72 | * elimination and loop optimization just as an arithmetic operator |
75 | * elimination and loop optimization just as an arithmetic operator |
73 | * would be. |
76 | * would be. |
74 | * [...] |
77 | * [...] |
75 | */ |
78 | */ |
76 | #define __pure __attribute__((pure)) |
79 | #define __pure __attribute__((pure)) |
77 | #define __aligned(x) __attribute__((aligned(x))) |
80 | #define __aligned(x) __attribute__((aligned(x))) |
78 | #define __printf(a,b) __attribute__((format(printf,a,b))) |
81 | #define __printf(a,b) __attribute__((format(printf,a,b))) |
79 | #define noinline __attribute__((noinline)) |
82 | #define noinline __attribute__((noinline)) |
80 | #define __attribute_const__ __attribute__((__const__)) |
83 | #define __attribute_const__ __attribute__((__const__)) |
81 | #define __maybe_unused __attribute__((unused)) |
84 | #define __maybe_unused __attribute__((unused)) |
82 | #define __always_unused __attribute__((unused)) |
85 | #define __always_unused __attribute__((unused)) |
83 | 86 | ||
84 | #define __gcc_header(x) #x |
87 | #define __gcc_header(x) #x |
85 | #define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h) |
88 | #define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h) |
86 | #define gcc_header(x) _gcc_header(x) |
89 | #define gcc_header(x) _gcc_header(x) |
87 | #include gcc_header(__GNUC__)> |
90 | #include gcc_header(__GNUC__) |
- | 91 | ||
- | 92 | #if !defined(__noclone) |
|
- | 93 | #define __noclone /* not needed */ |
|
- | 94 | #endif> |