/modules/freetype2/include/freetype/internal/ftvalid.h

http://github.com/zpao/v8monkey · C Header · 150 lines · 46 code · 33 blank · 71 comment · 0 complexity · 778daadc124e4c9e83e6a80a6be8d05e MD5 · raw file 

    

  1. /***************************************************************************/
    2. 

  2. /*                                                                         */
    3. 

  3. /*  ftvalid.h                                                              */
    4. 

  4. /*                                                                         */
    5. 

  5. /*    FreeType validation support (specification).                         */
    6. 

  6. /*                                                                         */
    7. 

  7. /*  Copyright 2004 by                                                      */
    8. 

  8. /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
    9. 

  9. /*                                                                         */
    10. 

  10. /*  This file is part of the FreeType project, and may only be used,       */
    11. 

  11. /*  modified, and distributed under the terms of the FreeType project      */
    12. 

  12. /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
    13. 

  13. /*  this file you indicate that you have read the license and              */
    14. 

  14. /*  understand and accept it fully.                                        */
    15. 

  15. /*                                                                         */
    16. 

  16. /***************************************************************************/
    17. 

  17. 

  18. 

  19. #ifndef __FTVALID_H__
    20. 

  20. #define __FTVALID_H__
    21. 

  21. 

  22. #include <ft2build.h>
    23. 

  23. #include FT_CONFIG_STANDARD_LIBRARY_H   /* for ft_setjmp and ft_longjmp */
    24. 

  24. 

  25. 

  26. FT_BEGIN_HEADER
    27. 

  27. 

  28. 

  29.   /*************************************************************************/
    30. 

  30.   /*************************************************************************/
    31. 

  31.   /*************************************************************************/
    32. 

  32.   /****                                                                 ****/
    33. 

  33.   /****                                                                 ****/
    34. 

  34.   /****                    V A L I D A T I O N                          ****/
    35. 

  35.   /****                                                                 ****/
    36. 

  36.   /****                                                                 ****/
    37. 

  37.   /*************************************************************************/
    38. 

  38.   /*************************************************************************/
    39. 

  39.   /*************************************************************************/
    40. 

  40. 

  41.   /* handle to a validation object */
    42. 

  42.   typedef struct FT_ValidatorRec_ volatile*  FT_Validator;
    43. 

  43. 

  44. 

  45.   /*************************************************************************/
    46. 

  46.   /*                                                                       */
    47. 

  47.   /* There are three distinct validation levels defined here:              */
    48. 

  48.   /*                                                                       */
    49. 

  49.   /* FT_VALIDATE_DEFAULT ::                                                */
    50. 

  50.   /*   A table that passes this validation level can be used reliably by   */
    51. 

  51.   /*   FreeType.  It generally means that all offsets have been checked to */
    52. 

  52.   /*   prevent out-of-bound reads, that array counts are correct, etc.     */
    53. 

  53.   /*                                                                       */
    54. 

  54.   /* FT_VALIDATE_TIGHT ::                                                  */
    55. 

  55.   /*   A table that passes this validation level can be used reliably and  */
    56. 

  56.   /*   doesn't contain invalid data.  For example, a charmap table that    */
    57. 

  57.   /*   returns invalid glyph indices will not pass, even though it can     */
    58. 

  58.   /*   be used with FreeType in default mode (the library will simply      */
    59. 

  59.   /*   return an error later when trying to load the glyph).               */
    60. 

  60.   /*                                                                       */
    61. 

  61.   /*   It also checks that fields which must be a multiple of 2, 4, or 8,  */
    62. 

  62.   /*   don't have incorrect values, etc.                                   */
    63. 

  63.   /*                                                                       */
    64. 

  64.   /* FT_VALIDATE_PARANOID ::                                               */
    65. 

  65.   /*   Only for font debugging.  Checks that a table follows the           */
    66. 

  66.   /*   specification by 100%.  Very few fonts will be able to pass this    */
    67. 

  67.   /*   level anyway but it can be useful for certain tools like font       */
    68. 

  68.   /*   editors/converters.                                                 */
    69. 

  69.   /*                                                                       */
    70. 

  70.   typedef enum  FT_ValidationLevel_
    71. 

  71.   {
    72. 

  72.     FT_VALIDATE_DEFAULT = 0,
    73. 

  73.     FT_VALIDATE_TIGHT,
    74. 

  74.     FT_VALIDATE_PARANOID
    75. 

  75. 

  76.   } FT_ValidationLevel;
    77. 

  77. 

  78. 

  79.   /* validator structure */
    80. 

  80.   typedef struct  FT_ValidatorRec_
    81. 

  81.   {
    82. 

  82.     const FT_Byte*      base;        /* address of table in memory       */
    83. 

  83.     const FT_Byte*      limit;       /* `base' + sizeof(table) in memory */
    84. 

  84.     FT_ValidationLevel  level;       /* validation level                 */
    85. 

  85.     FT_Error            error;       /* error returned. 0 means success  */
    86. 

  86. 

  87.     ft_jmp_buf          jump_buffer; /* used for exception handling      */
    88. 

  88. 

  89.   } FT_ValidatorRec;
    90. 

  90. 

  91. 

  92. #define FT_VALIDATOR( x )  ((FT_Validator)( x ))
    93. 

  93. 

  94. 

  95.   FT_BASE( void )
    96. 

  96.   ft_validator_init( FT_Validator        valid,
    97. 

  97.                      const FT_Byte*      base,
    98. 

  98.                      const FT_Byte*      limit,
    99. 

  99.                      FT_ValidationLevel  level );
    100. 

  100. 

  101.   /* Do not use this. It's broken and will cause your validator to crash */
    102. 

  102.   /* if you run it on an invalid font.                                   */
    103. 

  103.   FT_BASE( FT_Int )
    104. 

  104.   ft_validator_run( FT_Validator  valid );
    105. 

  105. 

  106.   /* Sets the error field in a validator, then calls `longjmp' to return */
    107. 

  107.   /* to high-level caller.  Using `setjmp/longjmp' avoids many stupid    */
    108. 

  108.   /* error checks within the validation routines.                        */
    109. 

  109.   /*                                                                     */
    110. 

  110.   FT_BASE( void )
    111. 

  111.   ft_validator_error( FT_Validator  valid,
    112. 

  112.                       FT_Error      error );
    113. 

  113. 

  114. 

  115.   /* Calls ft_validate_error.  Assumes that the `valid' local variable */
    116. 

  116.   /* holds a pointer to the current validator object.                  */
    117. 

  117.   /*                                                                   */
    118. 

  118.   /* Use preprocessor prescan to pass FT_ERR_PREFIX.                   */
    119. 

  119.   /*                                                                   */
    120. 

  120. #define FT_INVALID( _prefix, _error )  FT_INVALID_( _prefix, _error )
    121. 

  121. #define FT_INVALID_( _prefix, _error ) \
    122. 

  122.           ft_validator_error( valid, _prefix ## _error )
    123. 

  123. 

  124.   /* called when a broken table is detected */
    125. 

  125. #define FT_INVALID_TOO_SHORT \
    126. 

  126.           FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
    127. 

  127. 

  128.   /* called when an invalid offset is detected */
    129. 

  129. #define FT_INVALID_OFFSET \
    130. 

  130.           FT_INVALID( FT_ERR_PREFIX, Invalid_Offset )
    131. 

  131. 

  132.   /* called when an invalid format/value is detected */
    133. 

  133. #define FT_INVALID_FORMAT \
    134. 

  134.           FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
    135. 

  135. 

  136.   /* called when an invalid glyph index is detected */
    137. 

  137. #define FT_INVALID_GLYPH_ID \
    138. 

  138.           FT_INVALID( FT_ERR_PREFIX, Invalid_Glyph_Index )
    139. 

  139. 

  140.   /* called when an invalid field value is detected */
    141. 

  141. #define FT_INVALID_DATA \
    142. 

  142.           FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
    143. 

  143. 

  144. 

  145. FT_END_HEADER
    146. 

  146. 

  147. #endif /* __FTVALID_H__ */
    148. 

  148. 

  149. 

  150. /* END */
    151.