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-rw-r--r--src/otvalid/otvgsub.c584
1 files changed, 584 insertions, 0 deletions
diff --git a/src/otvalid/otvgsub.c b/src/otvalid/otvgsub.c
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--- /dev/null
+++ b/src/otvalid/otvgsub.c
@@ -0,0 +1,584 @@
+/***************************************************************************/
+/* */
+/* otvgsub.c */
+/* */
+/* OpenType GSUB table validation (body). */
+/* */
+/* Copyright 2004, 2005 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 "otvalid.h"
+#include "otvcommn.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_otvgsub
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 1 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* uses valid->glyph_count */
+
+ static void
+ otv_SingleSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "SingleSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1: /* SingleSubstFormat1 */
+ {
+ FT_Bytes Coverage;
+ FT_Int DeltaGlyphID;
+ FT_Long idx;
+
+
+ OTV_LIMIT_CHECK( 4 );
+ Coverage = table + FT_NEXT_USHORT( p );
+ DeltaGlyphID = FT_NEXT_SHORT( p );
+
+ otv_Coverage_validate( Coverage, valid );
+
+ idx = otv_Coverage_get_first( Coverage ) + DeltaGlyphID;
+ if ( idx < 0 )
+ FT_INVALID_DATA;
+
+ idx = otv_Coverage_get_last( Coverage ) + DeltaGlyphID;
+ if ( (FT_UInt)idx >= valid->glyph_count )
+ FT_INVALID_DATA;
+ }
+ break;
+
+ case 2: /* SingleSubstFormat2 */
+ {
+ FT_UInt Coverage, GlyphCount;
+
+
+ OTV_LIMIT_CHECK( 4 );
+ Coverage = FT_NEXT_USHORT( p );
+ GlyphCount = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (GlyphCount = %d)\n", GlyphCount ));
+
+ otv_Coverage_validate( table + Coverage, valid );
+
+ OTV_LIMIT_CHECK( GlyphCount * 2 );
+
+ /* Substitute */
+ for ( ; GlyphCount > 0; GlyphCount-- )
+ if ( FT_NEXT_USHORT( p ) >= valid->glyph_count )
+ FT_INVALID_DATA;
+ }
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 2 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* sets valid->extra1 (glyph count) */
+
+ static void
+ otv_MultipleSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "MultipleSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1:
+ valid->extra1 = valid->glyph_count;
+ OTV_NEST2( MultipleSubstFormat1, Sequence );
+ OTV_RUN( table, valid );
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 3 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* sets valid->extra1 (glyph count) */
+
+ static void
+ otv_AlternateSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "AlternateSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1:
+ valid->extra1 = valid->glyph_count;
+ OTV_NEST2( AlternateSubstFormat1, AlternateSet );
+ OTV_RUN( table, valid );
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 4 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+#define LigatureFunc otv_Ligature_validate
+
+ /* uses valid->glyph_count */
+
+ static void
+ otv_Ligature_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt LigatureGlyph, CompCount;
+
+
+ OTV_ENTER;
+
+ OTV_LIMIT_CHECK( 4 );
+ LigatureGlyph = FT_NEXT_USHORT( p );
+ if ( LigatureGlyph >= valid->glyph_count )
+ FT_INVALID_DATA;
+
+ CompCount = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (CompCount = %d)\n", CompCount ));
+
+ if ( CompCount == 0 )
+ FT_INVALID_DATA;
+
+ CompCount--;
+
+ OTV_LIMIT_CHECK( CompCount * 2 ); /* Component */
+
+ /* no need to check the Component glyph indices */
+
+ OTV_EXIT;
+ }
+
+
+ static void
+ otv_LigatureSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "LigatureSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1:
+ OTV_NEST3( LigatureSubstFormat1, LigatureSet, Ligature );
+ OTV_RUN( table, valid );
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 5 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* sets valid->extra1 (lookup count) */
+
+ static void
+ otv_ContextSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "ContextSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1:
+ /* no need to check glyph indices/classes used as input for these */
+ /* context rules since even invalid glyph indices/classes return */
+ /* meaningful results */
+
+ valid->extra1 = valid->lookup_count;
+ OTV_NEST3( ContextSubstFormat1, SubRuleSet, SubRule );
+ OTV_RUN( table, valid );
+ break;
+
+ case 2:
+ /* no need to check glyph indices/classes used as input for these */
+ /* context rules since even invalid glyph indices/classes return */
+ /* meaningful results */
+
+ OTV_NEST3( ContextSubstFormat2, SubClassSet, SubClassRule );
+ OTV_RUN( table, valid );
+ break;
+
+ case 3:
+ OTV_NEST1( ContextSubstFormat3 );
+ OTV_RUN( table, valid );
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 6 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* sets valid->extra1 (lookup count) */
+
+ static void
+ otv_ChainContextSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "ChainContextSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1:
+ /* no need to check glyph indices/classes used as input for these */
+ /* context rules since even invalid glyph indices/classes return */
+ /* meaningful results */
+
+ valid->extra1 = valid->lookup_count;
+ OTV_NEST3( ChainContextSubstFormat1,
+ ChainSubRuleSet, ChainSubRule );
+ OTV_RUN( table, valid );
+ break;
+
+ case 2:
+ /* no need to check glyph indices/classes used as input for these */
+ /* context rules since even invalid glyph indices/classes return */
+ /* meaningful results */
+
+ OTV_NEST3( ChainContextSubstFormat2,
+ ChainSubClassSet, ChainSubClassRule );
+ OTV_RUN( table, valid );
+ break;
+
+ case 3:
+ OTV_NEST1( ChainContextSubstFormat3 );
+ OTV_RUN( table, valid );
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 7 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* uses valid->type_funcs */
+
+ static void
+ otv_ExtensionSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table;
+ FT_UInt SubstFormat;
+
+
+ OTV_NAME_ENTER( "ExtensionSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1: /* ExtensionSubstFormat1 */
+ {
+ FT_UInt ExtensionLookupType, ExtensionOffset;
+ OTV_Validate_Func validate;
+
+
+ OTV_LIMIT_CHECK( 6 );
+ ExtensionLookupType = FT_NEXT_USHORT( p );
+ ExtensionOffset = FT_NEXT_ULONG( p );
+
+ if ( ExtensionLookupType == 0 ||
+ ExtensionLookupType == 7 ||
+ ExtensionLookupType > 8 )
+ FT_INVALID_DATA;
+
+ validate = valid->type_funcs[ExtensionLookupType - 1];
+ validate( table + ExtensionOffset, valid );
+ }
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB LOOKUP TYPE 8 *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* uses valid->glyph_count */
+
+ static void
+ otv_ReverseChainSingleSubst_validate( FT_Bytes table,
+ OTV_Validator valid )
+ {
+ FT_Bytes p = table, Coverage;
+ FT_UInt SubstFormat;
+ FT_UInt BacktrackGlyphCount, LookaheadGlyphCount, GlyphCount;
+
+
+ OTV_NAME_ENTER( "ReverseChainSingleSubst" );
+
+ OTV_LIMIT_CHECK( 2 );
+ SubstFormat = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (format %d)\n", SubstFormat ));
+
+ switch ( SubstFormat )
+ {
+ case 1: /* ReverseChainSingleSubstFormat1 */
+ OTV_LIMIT_CHECK( 4 );
+ Coverage = table + FT_NEXT_USHORT( p );
+ BacktrackGlyphCount = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (BacktrackGlyphCount = %d)\n", BacktrackGlyphCount ));
+
+ otv_Coverage_validate( Coverage, valid );
+
+ OTV_LIMIT_CHECK( BacktrackGlyphCount * 2 + 2 );
+
+ for ( ; BacktrackGlyphCount > 0; BacktrackGlyphCount-- )
+ otv_Coverage_validate( table + FT_NEXT_USHORT( p ), valid );
+
+ LookaheadGlyphCount = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (LookaheadGlyphCount = %d)\n", LookaheadGlyphCount ));
+
+ OTV_LIMIT_CHECK( LookaheadGlyphCount * 2 + 2 );
+
+ for ( ; LookaheadGlyphCount > 0; LookaheadGlyphCount-- )
+ otv_Coverage_validate( table + FT_NEXT_USHORT( p ), valid );
+
+ GlyphCount = FT_NEXT_USHORT( p );
+
+ OTV_TRACE(( " (GlyphCount = %d)\n", GlyphCount ));
+
+ if ( GlyphCount != otv_Coverage_get_count( Coverage ) )
+ FT_INVALID_DATA;
+
+ OTV_LIMIT_CHECK( GlyphCount * 2 );
+
+ /* Substitute */
+ for ( ; GlyphCount > 0; GlyphCount-- )
+ if ( FT_NEXT_USHORT( p ) >= valid->glyph_count )
+ FT_INVALID_DATA;
+
+ break;
+
+ default:
+ FT_INVALID_DATA;
+ }
+
+ OTV_EXIT;
+ }
+
+
+ static const OTV_Validate_Func otv_gsub_validate_funcs[8] =
+ {
+ otv_SingleSubst_validate,
+ otv_MultipleSubst_validate,
+ otv_AlternateSubst_validate,
+ otv_LigatureSubst_validate,
+ otv_ContextSubst_validate,
+ otv_ChainContextSubst_validate,
+ otv_ExtensionSubst_validate,
+ otv_ReverseChainSingleSubst_validate
+ };
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** GSUB TABLE *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* sets valid->type_count */
+ /* sets valid->type_funcs */
+ /* sets valid->glyph_count */
+
+ FT_LOCAL_DEF( void )
+ otv_GSUB_validate( FT_Bytes table,
+ FT_UInt glyph_count,
+ FT_Validator ftvalid )
+ {
+ OTV_ValidatorRec validrec;
+ OTV_Validator valid = &validrec;
+ FT_Bytes p = table;
+ FT_UInt ScriptList, FeatureList, LookupList;
+
+
+ valid->root = ftvalid;
+
+ FT_TRACE3(( "validating GSUB table\n" ));
+ OTV_INIT;
+
+ OTV_LIMIT_CHECK( 10 );
+
+ if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */
+ FT_INVALID_DATA;
+
+ ScriptList = FT_NEXT_USHORT( p );
+ FeatureList = FT_NEXT_USHORT( p );
+ LookupList = FT_NEXT_USHORT( p );
+
+ valid->type_count = 8;
+ valid->type_funcs = (OTV_Validate_Func*)otv_gsub_validate_funcs;
+ valid->glyph_count = glyph_count;
+
+ otv_LookupList_validate( table + LookupList,
+ valid );
+ otv_FeatureList_validate( table + FeatureList, table + LookupList,
+ valid );
+ otv_ScriptList_validate( table + ScriptList, table + FeatureList,
+ valid );
+
+ FT_TRACE4(( "\n" ));
+ }
+
+
+/* END */
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-20 16:36:14 +0000