ref: 95120928592c4d977abbef3b6582eae12b4058c2
dir: /src/cff/cffparse.c/
/***************************************************************************/ /* */ /* cffparse.c */ /* */ /* CFF token stream parser (body) */ /* */ /* Copyright 1996-2001, 2002, 2003, 2004, 2007, 2008 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. */ /* */ /***************************************************************************/ #include <ft2build.h> #include "cffparse.h" #include FT_INTERNAL_STREAM_H #include FT_INTERNAL_DEBUG_H #include "cfferrs.h" /*************************************************************************/ /* */ /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ /* messages during execution. */ /* */ #undef FT_COMPONENT #define FT_COMPONENT trace_cffparse enum { cff_kind_none = 0, cff_kind_num, cff_kind_fixed, cff_kind_fixed_thousand, cff_kind_string, cff_kind_bool, cff_kind_delta, cff_kind_callback, cff_kind_max /* do not remove */ }; /* now generate handlers for the most simple fields */ typedef FT_Error (*CFF_Field_Reader)( CFF_Parser parser ); typedef struct CFF_Field_Handler_ { int kind; int code; FT_UInt offset; FT_Byte size; CFF_Field_Reader reader; FT_UInt array_max; FT_UInt count_offset; } CFF_Field_Handler; FT_LOCAL_DEF( void ) cff_parser_init( CFF_Parser parser, FT_UInt code, void* object ) { FT_MEM_ZERO( parser, sizeof ( *parser ) ); parser->top = parser->stack; parser->object_code = code; parser->object = object; } /* read an integer */ static FT_Long cff_parse_integer( FT_Byte* start, FT_Byte* limit ) { FT_Byte* p = start; FT_Int v = *p++; FT_Long val = 0; if ( v == 28 ) { if ( p + 2 > limit ) goto Bad; val = (FT_Short)( ( (FT_Int)p[0] << 8 ) | p[1] ); p += 2; } else if ( v == 29 ) { if ( p + 4 > limit ) goto Bad; val = ( (FT_Long)p[0] << 24 ) | ( (FT_Long)p[1] << 16 ) | ( (FT_Long)p[2] << 8 ) | p[3]; p += 4; } else if ( v < 247 ) { val = v - 139; } else if ( v < 251 ) { if ( p + 1 > limit ) goto Bad; val = ( v - 247 ) * 256 + p[0] + 108; p++; } else { if ( p + 1 > limit ) goto Bad; val = -( v - 251 ) * 256 - p[0] - 108; p++; } Exit: return val; Bad: val = 0; goto Exit; } static const FT_Long power_tens[] = { 1L, 10L, 100L, 1000L, 10000L, 100000L, 1000000L, 10000000L, 100000000L, 1000000000L }; /* read a real */ static FT_Fixed cff_parse_real( FT_Byte* start, FT_Byte* limit, FT_Int power_ten, FT_Int* scaling ) { FT_Byte* p = start; FT_UInt nib; FT_UInt phase; FT_Long result, number, rest, exponent; FT_Int sign = 0, exponent_sign = 0; FT_Int exponent_add, integer_length, fraction_length; if ( scaling ) *scaling = 0; result = 0; number = 0; rest = 0; exponent = 0; exponent_add = 0; integer_length = 0; fraction_length = 0; /* First of all, read the integer part. */ phase = 4; for (;;) { /* If we entered this iteration with phase == 4, we need to */ /* read a new byte. This also skips past the initial 0x1E. */ if ( phase ) { p++; /* Make sure we don't read past the end. */ if ( p >= limit ) goto Exit; } /* Get the nibble. */ nib = ( p[0] >> phase ) & 0xF; phase = 4 - phase; if ( nib == 0xE ) sign = 1; else if ( nib > 9 ) break; else { /* Increase exponent if we can't add the digit. */ if ( number >= 0xCCCCCCCL ) exponent_add++; /* Skip leading zeros. */ else if ( nib || number ) { integer_length++; number = number * 10 + nib; } } } /* Read fraction part, if any. */ if ( nib == 0xa ) for (;;) { /* If we entered this iteration with phase == 4, we need */ /* to read a new byte. */ if ( phase ) { p++; /* Make sure we don't read past the end. */ if ( p >= limit ) goto Exit; } /* Get the nibble. */ nib = ( p[0] >> phase ) & 0xF; phase = 4 - phase; if ( nib >= 10 ) break; /* Skip leading zeros if possible. */ if ( !nib && !number ) exponent_add--; /* Only add digit if we don't overflow. */ else if ( number < 0xCCCCCCCL ) { fraction_length++; number = number * 10 + nib; } } /* Read exponent, if any. */ if ( nib == 12 ) { exponent_sign = 1; nib = 11; } if ( nib == 11 ) { for (;;) { /* If we entered this iteration with phase == 4, */ /* we need to read a new byte. */ if ( phase ) { p++; /* Make sure we don't read past the end. */ if ( p >= limit ) goto Exit; } /* Get the nibble. */ nib = ( p[0] >> phase ) & 0xF; phase = 4 - phase; if ( nib >= 10 ) break; exponent = exponent * 10 + nib; /* Arbitrarily limit exponent. */ if ( exponent > 1000 ) goto Exit; } if ( exponent_sign ) exponent = -exponent; } /* We don't check `power_ten' and `exponent_add'. */ exponent += power_ten + exponent_add; if ( scaling ) { /* Only use `fraction_length'. */ fraction_length += integer_length; exponent += integer_length; if ( fraction_length <= 5 ) { if ( number > 0x7FFFL ) { result = FT_DivFix( number, 10 ); *scaling = exponent - fraction_length + 1; } else { if ( exponent > 0 ) { FT_Int new_fraction_length, shift; /* Make `scaling' as small as possible. */ new_fraction_length = FT_MIN( exponent, 5 ); exponent -= new_fraction_length; shift = new_fraction_length - fraction_length; number *= power_tens[shift]; if ( number > 0x7FFFL ) { number /= 10; exponent += 1; } } else exponent -= fraction_length; result = number << 16; *scaling = exponent; } } else { if ( ( number / power_tens[fraction_length - 5] ) > 0x7FFFL ) { result = FT_DivFix( number, power_tens[fraction_length - 4] ); *scaling = exponent - 4; } else { result = FT_DivFix( number, power_tens[fraction_length - 5] ); *scaling = exponent - 5; } } } else { integer_length += exponent; fraction_length -= exponent; /* Check for overflow and underflow. */ if ( FT_ABS( integer_length ) > 5 ) goto Exit; /* Convert into 16.16 format. */ if ( fraction_length > 0 ) { if ( ( number / power_tens[fraction_length] ) > 0x7FFFL ) goto Exit; result = FT_DivFix( number, power_tens[fraction_length] ); } else { number *= power_tens[-fraction_length]; if ( number > 0x7FFFL ) goto Exit; result = number << 16; } } if ( sign ) result = -result; Exit: return result; } /* read a number, either integer or real */ static FT_Long cff_parse_num( FT_Byte** d ) { return **d == 30 ? ( cff_parse_real( d[0], d[1], 0, NULL ) >> 16 ) : cff_parse_integer( d[0], d[1] ); } /* read a floating point number, either integer or real */ static FT_Fixed cff_parse_fixed( FT_Byte** d ) { return **d == 30 ? cff_parse_real( d[0], d[1], 0, NULL ) : cff_parse_integer( d[0], d[1] ) << 16; } /* read a floating point number, either integer or real, */ /* but return `10^scaling' times the number read in */ static FT_Fixed cff_parse_fixed_scaled( FT_Byte** d, FT_Int scaling ) { return **d == 30 ? cff_parse_real( d[0], d[1], scaling, NULL ) : ( cff_parse_integer( d[0], d[1] ) * power_tens[scaling] ) << 16; } /* read a floating point number, either integer or real, */ /* and return it as precise as possible -- `scaling' returns */ /* the scaling factor (as a power of 10) */ static FT_Fixed cff_parse_fixed_dynamic( FT_Byte** d, FT_Int* scaling ) { FT_ASSERT( scaling ); if ( **d == 30 ) return cff_parse_real( d[0], d[1], 0, scaling ); else { FT_Long number; FT_Int integer_length; number = cff_parse_integer( d[0], d[1] ); if ( number > 0x7FFFL ) { for ( integer_length = 5; integer_length < 10; integer_length++ ) if ( number < power_tens[integer_length] ) break; if ( ( number / power_tens[integer_length - 5] ) > 0x7FFFL ) { *scaling = integer_length - 4; return FT_DivFix( number, power_tens[integer_length - 4] ); } else { *scaling = integer_length - 5; return FT_DivFix( number, power_tens[integer_length - 5] ); } } else { *scaling = 0; return number << 16; } } } static FT_Error cff_parse_font_matrix( CFF_Parser parser ) { CFF_FontRecDict dict = (CFF_FontRecDict)parser->object; FT_Matrix* matrix = &dict->font_matrix; FT_Vector* offset = &dict->font_offset; FT_ULong* upm = &dict->units_per_em; FT_Byte** data = parser->stack; FT_Error error = CFF_Err_Stack_Underflow; if ( parser->top >= parser->stack + 6 ) { FT_Int scaling; error = CFF_Err_Ok; /* We expect a well-formed font matrix, this is, the matrix elements */ /* `xx' and `yy' are of approximately the same magnitude. To avoid */ /* loss of precision, we use the magnitude of element `xx' to scale */ /* all other elements. The scaling factor is then contained in the */ /* `units_per_em' value. */ matrix->xx = cff_parse_fixed_dynamic( data++, &scaling ); scaling = -scaling; if ( scaling < 0 || scaling > 9 ) { /* Return default matrix in case of unlikely values. */ matrix->xx = 0x10000L; matrix->yx = 0; matrix->yx = 0; matrix->yy = 0x10000L; offset->x = 0; offset->y = 0; *upm = 1; goto Exit; } matrix->yx = cff_parse_fixed_scaled( data++, scaling ); matrix->xy = cff_parse_fixed_scaled( data++, scaling ); matrix->yy = cff_parse_fixed_scaled( data++, scaling ); offset->x = cff_parse_fixed_scaled( data++, scaling ); offset->y = cff_parse_fixed_scaled( data, scaling ); *upm = power_tens[scaling]; } Exit: return error; } static FT_Error cff_parse_font_bbox( CFF_Parser parser ) { CFF_FontRecDict dict = (CFF_FontRecDict)parser->object; FT_BBox* bbox = &dict->font_bbox; FT_Byte** data = parser->stack; FT_Error error; error = CFF_Err_Stack_Underflow; if ( parser->top >= parser->stack + 4 ) { bbox->xMin = FT_RoundFix( cff_parse_fixed( data++ ) ); bbox->yMin = FT_RoundFix( cff_parse_fixed( data++ ) ); bbox->xMax = FT_RoundFix( cff_parse_fixed( data++ ) ); bbox->yMax = FT_RoundFix( cff_parse_fixed( data ) ); error = CFF_Err_Ok; } return error; } static FT_Error cff_parse_private_dict( CFF_Parser parser ) { CFF_FontRecDict dict = (CFF_FontRecDict)parser->object; FT_Byte** data = parser->stack; FT_Error error; error = CFF_Err_Stack_Underflow; if ( parser->top >= parser->stack + 2 ) { dict->private_size = cff_parse_num( data++ ); dict->private_offset = cff_parse_num( data ); error = CFF_Err_Ok; } return error; } static FT_Error cff_parse_cid_ros( CFF_Parser parser ) { CFF_FontRecDict dict = (CFF_FontRecDict)parser->object; FT_Byte** data = parser->stack; FT_Error error; error = CFF_Err_Stack_Underflow; if ( parser->top >= parser->stack + 3 ) { dict->cid_registry = (FT_UInt)cff_parse_num ( data++ ); dict->cid_ordering = (FT_UInt)cff_parse_num ( data++ ); dict->cid_supplement = (FT_ULong)cff_parse_num( data ); error = CFF_Err_Ok; } return error; } #define CFF_FIELD_NUM( code, name ) \ CFF_FIELD( code, name, cff_kind_num ) #define CFF_FIELD_FIXED( code, name ) \ CFF_FIELD( code, name, cff_kind_fixed ) #define CFF_FIELD_FIXED_1000( code, name ) \ CFF_FIELD( code, name, cff_kind_fixed_thousand ) #define CFF_FIELD_STRING( code, name ) \ CFF_FIELD( code, name, cff_kind_string ) #define CFF_FIELD_BOOL( code, name ) \ CFF_FIELD( code, name, cff_kind_bool ) #define CFF_FIELD_DELTA( code, name, max ) \ CFF_FIELD( code, name, cff_kind_delta ) #define CFF_FIELD_CALLBACK( code, name ) \ { \ cff_kind_callback, \ code | CFFCODE, \ 0, 0, \ cff_parse_ ## name, \ 0, 0 \ }, #undef CFF_FIELD #define CFF_FIELD( code, name, kind ) \ { \ kind, \ code | CFFCODE, \ FT_FIELD_OFFSET( name ), \ FT_FIELD_SIZE( name ), \ 0, 0, 0 \ }, #undef CFF_FIELD_DELTA #define CFF_FIELD_DELTA( code, name, max ) \ { \ cff_kind_delta, \ code | CFFCODE, \ FT_FIELD_OFFSET( name ), \ FT_FIELD_SIZE_DELTA( name ), \ 0, \ max, \ FT_FIELD_OFFSET( num_ ## name ) \ }, #define CFFCODE_TOPDICT 0x1000 #define CFFCODE_PRIVATE 0x2000 static const CFF_Field_Handler cff_field_handlers[] = { #include "cfftoken.h" { 0, 0, 0, 0, 0, 0, 0 } }; FT_LOCAL_DEF( FT_Error ) cff_parser_run( CFF_Parser parser, FT_Byte* start, FT_Byte* limit ) { FT_Byte* p = start; FT_Error error = CFF_Err_Ok; parser->top = parser->stack; parser->start = start; parser->limit = limit; parser->cursor = start; while ( p < limit ) { FT_UInt v = *p; if ( v >= 27 && v != 31 ) { /* it's a number; we will push its position on the stack */ if ( parser->top - parser->stack >= CFF_MAX_STACK_DEPTH ) goto Stack_Overflow; *parser->top ++ = p; /* now, skip it */ if ( v == 30 ) { /* skip real number */ p++; for (;;) { if ( p >= limit ) goto Syntax_Error; v = p[0] >> 4; if ( v == 15 ) break; v = p[0] & 0xF; if ( v == 15 ) break; p++; } } else if ( v == 28 ) p += 2; else if ( v == 29 ) p += 4; else if ( v > 246 ) p += 1; } else { /* This is not a number, hence it's an operator. Compute its code */ /* and look for it in our current list. */ FT_UInt code; FT_UInt num_args = (FT_UInt) ( parser->top - parser->stack ); const CFF_Field_Handler* field; *parser->top = p; code = v; if ( v == 12 ) { /* two byte operator */ p++; if ( p >= limit ) goto Syntax_Error; code = 0x100 | p[0]; } code = code | parser->object_code; for ( field = cff_field_handlers; field->kind; field++ ) { if ( field->code == (FT_Int)code ) { /* we found our field's handler; read it */ FT_Long val; FT_Byte* q = (FT_Byte*)parser->object + field->offset; /* check that we have enough arguments -- except for */ /* delta encoded arrays, which can be empty */ if ( field->kind != cff_kind_delta && num_args < 1 ) goto Stack_Underflow; switch ( field->kind ) { case cff_kind_bool: case cff_kind_string: case cff_kind_num: val = cff_parse_num( parser->stack ); goto Store_Number; case cff_kind_fixed: val = cff_parse_fixed( parser->stack ); goto Store_Number; case cff_kind_fixed_thousand: val = cff_parse_fixed_scaled( parser->stack, 3 ); Store_Number: switch ( field->size ) { case (8 / FT_CHAR_BIT): *(FT_Byte*)q = (FT_Byte)val; break; case (16 / FT_CHAR_BIT): *(FT_Short*)q = (FT_Short)val; break; case (32 / FT_CHAR_BIT): *(FT_Int32*)q = (FT_Int)val; break; default: /* for 64-bit systems */ *(FT_Long*)q = val; } break; case cff_kind_delta: { FT_Byte* qcount = (FT_Byte*)parser->object + field->count_offset; FT_Byte** data = parser->stack; if ( num_args > field->array_max ) num_args = field->array_max; /* store count */ *qcount = (FT_Byte)num_args; val = 0; while ( num_args > 0 ) { val += cff_parse_num( data++ ); switch ( field->size ) { case (8 / FT_CHAR_BIT): *(FT_Byte*)q = (FT_Byte)val; break; case (16 / FT_CHAR_BIT): *(FT_Short*)q = (FT_Short)val; break; case (32 / FT_CHAR_BIT): *(FT_Int32*)q = (FT_Int)val; break; default: /* for 64-bit systems */ *(FT_Long*)q = val; } q += field->size; num_args--; } } break; default: /* callback */ error = field->reader( parser ); if ( error ) goto Exit; } goto Found; } } /* this is an unknown operator, or it is unsupported; */ /* we will ignore it for now. */ Found: /* clear stack */ parser->top = parser->stack; } p++; } Exit: return error; Stack_Overflow: error = CFF_Err_Invalid_Argument; goto Exit; Stack_Underflow: error = CFF_Err_Invalid_Argument; goto Exit; Syntax_Error: error = CFF_Err_Invalid_Argument; goto Exit; } /* END */