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| Rev | Author | Line No. | Line |
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| 1408 | serge | 1 | #ifndef __LINUX_COMPILER_H |
| 2 | #error "Please don't include |
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| 3 | #endif |
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| 4 | |||
| 5 | /* |
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| 6 | * Common definitions for all gcc versions go here. |
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| 7 | */ |
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| 3480 | Serge | 8 | #define GCC_VERSION (__GNUC__ * 10000 \ |
| 9 | + __GNUC_MINOR__ * 100 \ |
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| 10 | + __GNUC_PATCHLEVEL__) |
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| 1408 | serge | 11 | |
| 12 | |||
| 13 | /* Optimization barrier */ |
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| 14 | /* The "volatile" is due to gcc bugs */ |
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| 15 | #define barrier() __asm__ __volatile__("": : :"memory") |
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| 16 | |||
| 17 | /* |
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| 18 | * This macro obfuscates arithmetic on a variable address so that gcc |
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| 19 | * shouldn't recognize the original var, and make assumptions about it. |
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| 20 | * |
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| 21 | * This is needed because the C standard makes it undefined to do |
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| 22 | * pointer arithmetic on "objects" outside their boundaries and the |
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| 23 | * gcc optimizers assume this is the case. In particular they |
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| 24 | * assume such arithmetic does not wrap. |
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| 25 | * |
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| 26 | * A miscompilation has been observed because of this on PPC. |
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| 27 | * To work around it we hide the relationship of the pointer and the object |
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| 28 | * using this macro. |
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| 29 | * |
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| 30 | * Versions of the ppc64 compiler before 4.1 had a bug where use of |
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| 31 | * RELOC_HIDE could trash r30. The bug can be worked around by changing |
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| 32 | * the inline assembly constraint from =g to =r, in this particular |
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| 33 | * case either is valid. |
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| 34 | */ |
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| 35 | #define RELOC_HIDE(ptr, off) \ |
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| 36 | ({ unsigned long __ptr; \ |
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| 37 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ |
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| 38 | (typeof(ptr)) (__ptr + (off)); }) |
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| 39 | |||
| 5056 | serge | 40 | /* Make the optimizer believe the variable can be manipulated arbitrarily. */ |
| 41 | #define OPTIMIZER_HIDE_VAR(var) __asm__ ("" : "=r" (var) : "0" (var)) |
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| 42 | |||
| 1970 | serge | 43 | #ifdef __CHECKER__ |
| 44 | #define __must_be_array(arr) 0 |
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| 45 | #else |
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| 1408 | serge | 46 | /* &a[0] degrades to a pointer: a different type from an array */ |
| 1964 | serge | 47 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) |
| 1970 | serge | 48 | #endif |
| 1408 | serge | 49 | |
| 50 | /* |
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| 51 | * Force always-inline if the user requests it so via the .config, |
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| 52 | * or if gcc is too old: |
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| 53 | */ |
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| 54 | #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ |
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| 55 | !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) |
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| 5056 | serge | 56 | # define inline inline __attribute__((always_inline)) notrace |
| 57 | # define __inline__ __inline__ __attribute__((always_inline)) notrace |
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| 58 | # define __inline __inline __attribute__((always_inline)) notrace |
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| 59 | #else |
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| 60 | /* A lot of inline functions can cause havoc with function tracing */ |
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| 61 | # define inline inline notrace |
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| 62 | # define __inline__ __inline__ notrace |
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| 63 | # define __inline __inline notrace |
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| 1408 | serge | 64 | #endif |
| 65 | |||
| 66 | #define __deprecated __attribute__((deprecated)) |
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| 67 | #define __packed __attribute__((packed)) |
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| 68 | #define __weak __attribute__((weak)) |
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| 69 | |||
| 70 | /* |
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| 71 | * it doesn't make sense on ARM (currently the only user of __naked) to trace |
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| 72 | * naked functions because then mcount is called without stack and frame pointer |
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| 73 | * being set up and there is no chance to restore the lr register to the value |
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| 74 | * before mcount was called. |
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| 1964 | serge | 75 | * |
| 76 | * The asm() bodies of naked functions often depend on standard calling conventions, |
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| 77 | * therefore they must be noinline and noclone. GCC 4.[56] currently fail to enforce |
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| 78 | * this, so we must do so ourselves. See GCC PR44290. |
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| 1408 | serge | 79 | */ |
| 1964 | serge | 80 | #define __naked __attribute__((naked)) noinline __noclone notrace |
| 1408 | serge | 81 | |
| 82 | #define __noreturn __attribute__((noreturn)) |
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| 83 | |||
| 84 | /* |
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| 85 | * From the GCC manual: |
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| 86 | * |
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| 87 | * Many functions have no effects except the return value and their |
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| 88 | * return value depends only on the parameters and/or global |
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| 89 | * variables. Such a function can be subject to common subexpression |
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| 90 | * elimination and loop optimization just as an arithmetic operator |
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| 91 | * would be. |
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| 92 | * [...] |
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| 93 | */ |
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| 94 | #define __pure __attribute__((pure)) |
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| 95 | #define __aligned(x) __attribute__((aligned(x))) |
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| 3031 | serge | 96 | #define __printf(a, b) __attribute__((format(printf, a, b))) |
| 97 | #define __scanf(a, b) __attribute__((format(scanf, a, b))) |
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| 1408 | serge | 98 | #define noinline __attribute__((noinline)) |
| 99 | #define __attribute_const__ __attribute__((__const__)) |
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| 100 | #define __maybe_unused __attribute__((unused)) |
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| 101 | #define __always_unused __attribute__((unused)) |
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| 102 | |||
| 103 | #define __gcc_header(x) #x |
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| 104 | #define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h) |
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| 105 | #define gcc_header(x) _gcc_header(x) |
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| 106 | #include gcc_header(__GNUC__) |
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| 1964 | serge | 107 | |
| 108 | #if !defined(__noclone) |
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| 109 | #define __noclone /* not needed */ |
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| 110 | #endif |
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| 1970 | serge | 111 | |
| 112 | /* |
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| 113 | * A trick to suppress uninitialized variable warning without generating any |
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| 114 | * code |
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| 115 | */ |
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| 116 | #define uninitialized_var(x) x = x |
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| 117 | |||
| 118 | #define __always_inline inline __attribute__((always_inline)) |