/share/man/man9/KASSERT.9

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  3. .\" Copyright (c) 2000 Jonathan M. Bresler
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    31. 

  31. .Dd January 14, 2000
    32. 

  32. .Dt KASSERT 9
    33. 

  33. .Os
    34. 

  34. .Sh NAME
    35. 

  35. .Nm KASSERT
    36. 

  36. .Nd kernel expression verification macro
    37. 

  37. .Sh SYNOPSIS
    38. 

  38. .Cd "options INVARIANTS"
    39. 

  39. .Pp
    40. 

  40. .In sys/param.h
    41. 

  41. .In sys/systm.h
    42. 

  42. .Fn KASSERT expression msg
    43. 

  43. .Sh DESCRIPTION
    44. 

  44. In a kernel compiled with
    45. 

  45. .Cd "options INVARIANTS" ,
    46. 

  46. the
    47. 

  47. .Fn KASSERT
    48. 

  48. macro tests the given
    49. 

  49. .Fa expression
    50. 

  50. and if it is false,
    51. 

  51. calls the
    52. 

  52. .Xr panic 9
    53. 

  53. function, terminating the running system.
    54. 

  54. .Pp
    55. 

  55. In a kernel that does not have
    56. 

  56. .Cd "options INVARIANTS" ,
    57. 

  57. the
    58. 

  58. .Fn KASSERT
    59. 

  59. macro is defined to be a no-op.
    60. 

  60. The
    61. 

  61. second argument is a
    62. 

  62. .Xr printf 9
    63. 

  63. format string and its arguments,
    64. 

  64. enclosed in parentheses.
    65. 

  65. .Sh EXAMPLES
    66. 

  66. The kernel function
    67. 

  67. .Fn vput
    68. 

  68. must not be called with a
    69. 

  69. .Dv NULL
    70. 

  70. pointer.
    71. 

  71. .Bd -literal -offset indent
    72. 

  72. void
    73. 

  73. vput(vp)
    74. 

  74.         struct vnode *vp;
    75. 

  75. {
    76. 

  76. 	struct proc *p = curproc;
    77. 

  77. 	KASSERT(vp != NULL, ("vput: null vp"));
    78. 

  78. 	...
    79. 

  79. }
    80. 

  80. .Ed
    81. 

  81. .Sh SEE ALSO
    82. 

  82. .Xr config 8 ,
    83. 

  83. .Xr panic 9
    84. 

  84. .Sh AUTHORS
    85. 

  85. This manual page was written by
    86. 

  86. .An Jonathan M. Bresler
    87. 

  87. .Aq jmb@FreeBSD.org .
    88.