/***************************************************************************/
/* */
/* ftvalid.h */
/* */
/* FreeType validation support (specification). */
/* */
/* Copyright 2004 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#ifndef __FTVALID_H__
#define __FTVALID_H__
#include <ft2build.h>
#include FT_CONFIG_STANDARD_LIBRARY_H /* for ft_setjmp and ft_longjmp */
FT_BEGIN_HEADER
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** V A L I D A T I O N ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* handle to a validation object */
typedef struct FT_ValidatorRec_ volatile* FT_Validator;
/*************************************************************************/
/* */
/* There are three distinct validation levels defined here: */
/* */
/* FT_VALIDATE_DEFAULT :: */
/* A table that passes this validation level can be used reliably by */
/* FreeType. It generally means that all offsets have been checked to */
/* prevent out-of-bound reads, that array counts are correct, etc. */
/* */
/* FT_VALIDATE_TIGHT :: */
/* A table that passes this validation level can be used reliably and */
/* doesn't contain invalid data. For example, a charmap table that */
/* returns invalid glyph indices will not pass, even though it can */
/* be used with FreeType in default mode (the library will simply */
/* return an error later when trying to load the glyph). */
/* */
/* It also checks that fields which must be a multiple of 2, 4, or 8, */
/* don't have incorrect values, etc. */
/* */
/* FT_VALIDATE_PARANOID :: */
/* Only for font debugging. Checks that a table follows the */
/* specification by 100%. Very few fonts will be able to pass this */
/* level anyway but it can be useful for certain tools like font */
/* editors/converters. */
/* */
typedef enum FT_ValidationLevel_
{
FT_VALIDATE_DEFAULT = 0,
FT_VALIDATE_TIGHT,
FT_VALIDATE_PARANOID
} FT_ValidationLevel;
/* validator structure */
typedef struct FT_ValidatorRec_
{
const FT_Byte* base; /* address of table in memory */
const FT_Byte* limit; /* `base' + sizeof(table) in memory */
FT_ValidationLevel level; /* validation level */
FT_Error error; /* error returned. 0 means success */
ft_jmp_buf jump_buffer; /* used for exception handling */
} FT_ValidatorRec;
#define FT_VALIDATOR( x ) ((FT_Validator)( x ))
FT_BASE( void )
ft_validator_init( FT_Validator valid,
const FT_Byte* base,
const FT_Byte* limit,
FT_ValidationLevel level );
/* Do not use this. It's broken and will cause your validator to crash */
/* if you run it on an invalid font. */
FT_BASE( FT_Int )
ft_validator_run( FT_Validator valid );
/* Sets the error field in a validator, then calls `longjmp' to return */
/* to high-level caller. Using `setjmp/longjmp' avoids many stupid */
/* error checks within the validation routines. */
/* */
FT_BASE( void )
ft_validator_error( FT_Validator valid,
FT_Error error );
/* Calls ft_validate_error. Assumes that the `valid' local variable */
/* holds a pointer to the current validator object. */
/* */
/* Use preprocessor prescan to pass FT_ERR_PREFIX. */
/* */
#define FT_INVALID( _prefix, _error ) FT_INVALID_( _prefix, _error )
#define FT_INVALID_( _prefix, _error ) \
ft_validator_error( valid, _prefix ## _error )
/* called when a broken table is detected */
#define FT_INVALID_TOO_SHORT \
FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
/* called when an invalid offset is detected */
#define FT_INVALID_OFFSET \
FT_INVALID( FT_ERR_PREFIX, Invalid_Offset )
/* called when an invalid format/value is detected */
#define FT_INVALID_FORMAT \
FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
/* called when an invalid glyph index is detected */
#define FT_INVALID_GLYPH_ID \
FT_INVALID( FT_ERR_PREFIX, Invalid_Glyph_Index )
/* called when an invalid field value is detected */
#define FT_INVALID_DATA \
FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
FT_END_HEADER
#endif /* __FTVALID_H__ */
/* END */
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