| /***************************************************************************/ |
| /* */ |
| /* ftvalid.h */ |
| /* */ |
| /* FreeType validation support (specification). */ |
| /* */ |
| /* Copyright 2004-2018 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; |
| |
| |
| #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 */ |
