include/linux/compiler-gcc5.h

   1 #ifndef __LINUX_COMPILER_H
   2 #error "Please don't include <linux/compiler-gcc5.h> directly, include <linux/compiler.h> instead."
   3 #endif
   4
   5 #define __used                          __attribute__((__used__))
   6 #define __must_check                    __attribute__((warn_unused_result))
   7 #define __compiler_offsetof(a, b)       __builtin_offsetof(a, b)
   8
   9 /* Mark functions as cold. gcc will assume any path leading to a call
  10    to them will be unlikely.  This means a lot of manual unlikely()s
  11    are unnecessary now for any paths leading to the usual suspects
  12    like BUG(), printk(), panic() etc. [but let's keep them for now for
  13    older compilers]
  14
  15    Early snapshots of gcc 4.3 don't support this and we can't detect this
  16    in the preprocessor, but we can live with this because they're unreleased.
  17    Maketime probing would be overkill here.
  18
  19    gcc also has a __attribute__((__hot__)) to move hot functions into
  20    a special section, but I don't see any sense in this right now in
  21    the kernel context */
  22 #define __cold                  __attribute__((__cold__))
  23
  24 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
  25
  26 #ifndef __CHECKER__
  27 # define __compiletime_warning(message) __attribute__((warning(message)))
  28 # define __compiletime_error(message) __attribute__((error(message)))
  29 #endif /* __CHECKER__ */
  30
  31 #define __alloc_size(...)       __attribute((alloc_size(__VA_ARGS__)))
  32 #define __bos(ptr, arg)         __builtin_object_size((ptr), (arg))
  33 #define __bos0(ptr)             __bos((ptr), 0)
  34 #define __bos1(ptr)             __bos((ptr), 1)
  35
  36 #ifdef CONSTIFY_PLUGIN
  37 #error not yet
  38 #define __no_const __attribute__((no_const))
  39 #define __do_const __attribute__((do_const))
  40 #endif
  41
  42 #ifdef SIZE_OVERFLOW_PLUGIN
  43 #error not yet
  44 #define __size_overflow(...) __attribute__((size_overflow(__VA_ARGS__)))
  45 #define __intentional_overflow(...) __attribute__((intentional_overflow(__VA_ARGS__)))
  46 #endif
  47
  48 #ifdef LATENT_ENTROPY_PLUGIN
  49 #error not yet
  50 #define __latent_entropy __attribute__((latent_entropy))
  51 #endif
  52
  53 /*
  54  * Mark a position in code as unreachable.  This can be used to
  55  * suppress control flow warnings after asm blocks that transfer
  56  * control elsewhere.
  57  *
  58  * Early snapshots of gcc 4.5 don't support this and we can't detect
  59  * this in the preprocessor, but we can live with this because they're
  60  * unreleased.  Really, we need to have autoconf for the kernel.
  61  */
  62 #define unreachable() __builtin_unreachable()
  63
  64 /* Mark a function definition as prohibited from being cloned. */
  65 #define __noclone       __attribute__((__noclone__))
  66
  67 /*
  68  * Tell the optimizer that something else uses this function or variable.
  69  */
  70 #define __visible __attribute__((externally_visible))
  71
  72 /*
  73  * GCC 'asm goto' miscompiles certain code sequences:
  74  *
  75  *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
  76  *
  77  * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
  78  *
  79  * (asm goto is automatically volatile - the naming reflects this.)
  80  */
  81 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
  82
  83 #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
  84 #define __HAVE_BUILTIN_BSWAP32__
  85 #define __HAVE_BUILTIN_BSWAP64__
  86 #define __HAVE_BUILTIN_BSWAP16__
  87 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */