bug.h 3.6 KB

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