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/****************************************************************************
*
* ftvalid.h
*
* FreeType validation support (specification).
*
* Copyright (C) 2004-2024 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_jmpbuf */
#include "compiler-macros.h"
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;
#if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */
/* We disable the warning `structure was padded due to */
/* __declspec(align())' in order to compile cleanly with */
/* the maximum level of warnings. */
#pragma warning( push )
#pragma warning( disable : 4324 )
#endif /* _MSC_VER */
/* validator structure */
typedef struct FT_ValidatorRec_
{
ft_jmp_buf jump_buffer; /* used for exception handling */
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_ValidatorRec;
#if defined( _MSC_VER )
#pragma warning( pop )
#endif
#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. */
/* */
#define FT_INVALID( _error ) FT_INVALID_( _error )
#define FT_INVALID_( _error ) \
ft_validator_error( valid, FT_THROW( _error ) )
/* called when a broken table is detected */
#define FT_INVALID_TOO_SHORT \
FT_INVALID( Invalid_Table )
/* called when an invalid offset is detected */
#define FT_INVALID_OFFSET \
FT_INVALID( Invalid_Offset )
/* called when an invalid format/value is detected */
#define FT_INVALID_FORMAT \
FT_INVALID( Invalid_Table )
/* called when an invalid glyph index is detected */
#define FT_INVALID_GLYPH_ID \
FT_INVALID( Invalid_Glyph_Index )
/* called when an invalid field value is detected */
#define FT_INVALID_DATA \
FT_INVALID( Invalid_Table )
FT_END_HEADER
#endif /* FTVALID_H_ */
/* END */