LXR linux/include/linux/bug.h

   1#ifndef _LINUX_BUG_H
   2#define _LINUX_BUG_H
   3
   4#include <asm/bug.h>
   5#include <linux/compiler.h>
   6
   7enum bug_trap_type {
   8        BUG_TRAP_TYPE_NONE = 0,
   9        BUG_TRAP_TYPE_WARN = 1,
  10        BUG_TRAP_TYPE_BUG = 2,
  11};
  12
  13struct pt_regs;
  14
  15#ifdef __CHECKER__
  16#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
  17#define BUILD_BUG_ON_ZERO(e) (0)
  18#define BUILD_BUG_ON_NULL(e) ((void*)0)
  19#define BUILD_BUG_ON_INVALID(e) (0)
  20#define BUILD_BUG_ON_MSG(cond, msg) (0)
  21#define BUILD_BUG_ON(condition) (0)
  22#define BUILD_BUG() (0)
  23#else /* __CHECKER__ */
  24
  25/* Force a compilation error if a constant expression is not a power of 2 */
  26#define BUILD_BUG_ON_NOT_POWER_OF_2(n)                  \
  27        BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
  28
  29/* Force a compilation error if condition is true, but also produce a
  30   result (of value 0 and type size_t), so the expression can be used
  31   e.g. in a structure initializer (or where-ever else comma expressions
  32   aren't permitted). */
  33#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
  34#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
  35
  36/*
  37 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
  38 * expression but avoids the generation of any code, even if that expression
  39 * has side-effects.
  40 */
  41#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
  42
  43/**
  44 * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
  45 *                    error message.
  46 * @condition: the condition which the compiler should know is false.
  47 *
  48 * See BUILD_BUG_ON for description.
  49 */
  50#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
  51
  52/**
  53 * BUILD_BUG_ON - break compile if a condition is true.
  54 * @condition: the condition which the compiler should know is false.
  55 *
  56 * If you have some code which relies on certain constants being equal, or
  57 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
  58 * detect if someone changes it.
  59 *
  60 * The implementation uses gcc's reluctance to create a negative array, but gcc
  61 * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
  62 * inline functions).  Luckily, in 4.3 they added the "error" function
  63 * attribute just for this type of case.  Thus, we use a negative sized array
  64 * (should always create an error on gcc versions older than 4.4) and then call
  65 * an undefined function with the error attribute (should always create an
  66 * error on gcc 4.3 and later).  If for some reason, neither creates a
  67 * compile-time error, we'll still have a link-time error, which is harder to
  68 * track down.
  69 */
  70#ifndef __OPTIMIZE__
  71#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
  72#else
  73#define BUILD_BUG_ON(condition) \
  74        BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
  75#endif
  76
  77/**
  78 * BUILD_BUG - break compile if used.
  79 *
  80 * If you have some code that you expect the compiler to eliminate at
  81 * build time, you should use BUILD_BUG to detect if it is
  82 * unexpectedly used.
  83 */
  84#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
  85
  86#endif  /* __CHECKER__ */
  87
  88#ifdef CONFIG_GENERIC_BUG
  89#include <asm-generic/bug.h>
  90
  91static inline int is_warning_bug(const struct bug_entry *bug)
  92{
  93        return bug->flags & BUGFLAG_WARNING;
  94}
  95
  96const struct bug_entry *find_bug(unsigned long bugaddr);
  97
  98enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
  99
 100/* These are defined by the architecture */
 101int is_valid_bugaddr(unsigned long addr);
 102
 103#else   /* !CONFIG_GENERIC_BUG */
 104
 105static inline enum bug_trap_type report_bug(unsigned long bug_addr,
 106                                            struct pt_regs *regs)
 107{
 108        return BUG_TRAP_TYPE_BUG;
 109}
 110
 111#endif  /* CONFIG_GENERIC_BUG */
 112#endif  /* _LINUX_BUG_H */
 113