extension/SDL2_ttf-2.0.14/external/freetype-2.4.12/src/gxvalid/gxvmort2.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmort2.c                                                             */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT mort table validation                                 */
   6 /*    body for type2 (Ligature Substitution) subtable.                     */
   7 /*                                                                         */
   8 /*  Copyright 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K.,       */
   9 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  10 /*                                                                         */
  11 /*  This file is part of the FreeType project, and may only be used,       */
  12 /*  modified, and distributed under the terms of the FreeType project      */
  13 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  14 /*  this file you indicate that you have read the license and              */
  15 /*  understand and accept it fully.                                        */
  16 /*                                                                         */
  17 /***************************************************************************/
  18
  19 /***************************************************************************/
  20 /*                                                                         */
  21 /* gxvalid is derived from both gxlayout module and otvalid module.        */
  22 /* Development of gxlayout is supported by the Information-technology      */
  23 /* Promotion Agency(IPA), Japan.                                           */
  24 /*                                                                         */
  25 /***************************************************************************/
  26
  27
  28 #include "gxvmort.h"
  29
  30
  31   /*************************************************************************/
  32   /*                                                                       */
  33   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  34   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  35   /* messages during execution.                                            */
  36   /*                                                                       */
  37 #undef  FT_COMPONENT
  38 #define FT_COMPONENT  trace_gxvmort
  39
  40
  41   typedef struct  GXV_mort_subtable_type2_StateOptRec_
  42   {
  43     FT_UShort  ligActionTable;
  44     FT_UShort  componentTable;
  45     FT_UShort  ligatureTable;
  46     FT_UShort  ligActionTable_length;
  47     FT_UShort  componentTable_length;
  48     FT_UShort  ligatureTable_length;
  49
  50   }  GXV_mort_subtable_type2_StateOptRec,
  51     *GXV_mort_subtable_type2_StateOptRecData;
  52
  53 #define GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE \
  54           ( GXV_STATETABLE_HEADER_SIZE + 2 + 2 + 2 )
  55
  56
  57   static void
  58   gxv_mort_subtable_type2_opttable_load( FT_Bytes       table,
  59                                          FT_Bytes       limit,
  60                                          GXV_Validator  valid )
  61   {
  62     FT_Bytes p = table;
  63     GXV_mort_subtable_type2_StateOptRecData  optdata =
  64       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
  65
  66
  67     GXV_LIMIT_CHECK( 2 + 2 + 2 );
  68     optdata->ligActionTable = FT_NEXT_USHORT( p );
  69     optdata->componentTable = FT_NEXT_USHORT( p );
  70     optdata->ligatureTable  = FT_NEXT_USHORT( p );
  71
  72     GXV_TRACE(( "offset to ligActionTable=0x%04x\n",
  73                 optdata->ligActionTable ));
  74     GXV_TRACE(( "offset to componentTable=0x%04x\n",
  75                 optdata->componentTable ));
  76     GXV_TRACE(( "offset to ligatureTable=0x%04x\n",
  77                 optdata->ligatureTable ));
  78   }
  79
  80
  81   static void
  82   gxv_mort_subtable_type2_subtable_setup( FT_UShort      table_size,
  83                                           FT_UShort      classTable,
  84                                           FT_UShort      stateArray,
  85                                           FT_UShort      entryTable,
  86                                           FT_UShort      *classTable_length_p,
  87                                           FT_UShort      *stateArray_length_p,
  88                                           FT_UShort      *entryTable_length_p,
  89                                           GXV_Validator  valid )
  90   {
  91     FT_UShort  o[6];
  92     FT_UShort  *l[6];
  93     FT_UShort  buff[7];
  94
  95     GXV_mort_subtable_type2_StateOptRecData  optdata =
  96       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
  97
  98
  99     GXV_NAME_ENTER( "subtable boundaries setup" );
 100
 101     o[0] = classTable;
 102     o[1] = stateArray;
 103     o[2] = entryTable;
 104     o[3] = optdata->ligActionTable;
 105     o[4] = optdata->componentTable;
 106     o[5] = optdata->ligatureTable;
 107     l[0] = classTable_length_p;
 108     l[1] = stateArray_length_p;
 109     l[2] = entryTable_length_p;
 110     l[3] = &(optdata->ligActionTable_length);
 111     l[4] = &(optdata->componentTable_length);
 112     l[5] = &(optdata->ligatureTable_length);
 113
 114     gxv_set_length_by_ushort_offset( o, l, buff, 6, table_size, valid );
 115
 116     GXV_TRACE(( "classTable: offset=0x%04x length=0x%04x\n",
 117                 classTable, *classTable_length_p ));
 118     GXV_TRACE(( "stateArray: offset=0x%04x length=0x%04x\n",
 119                 stateArray, *stateArray_length_p ));
 120     GXV_TRACE(( "entryTable: offset=0x%04x length=0x%04x\n",
 121                 entryTable, *entryTable_length_p ));
 122     GXV_TRACE(( "ligActionTable: offset=0x%04x length=0x%04x\n",
 123                 optdata->ligActionTable,
 124                 optdata->ligActionTable_length ));
 125     GXV_TRACE(( "componentTable: offset=0x%04x length=0x%04x\n",
 126                 optdata->componentTable,
 127                 optdata->componentTable_length ));
 128     GXV_TRACE(( "ligatureTable:  offset=0x%04x length=0x%04x\n",
 129                 optdata->ligatureTable,
 130                 optdata->ligatureTable_length ));
 131
 132     GXV_EXIT;
 133   }
 134
 135
 136   static void
 137   gxv_mort_subtable_type2_ligActionOffset_validate(
 138     FT_Bytes       table,
 139     FT_UShort      ligActionOffset,
 140     GXV_Validator  valid )
 141   {
 142     /* access ligActionTable */
 143     GXV_mort_subtable_type2_StateOptRecData  optdata =
 144       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
 145
 146     FT_Bytes lat_base  = table + optdata->ligActionTable;
 147     FT_Bytes p         = table + ligActionOffset;
 148     FT_Bytes lat_limit = lat_base + optdata->ligActionTable;
 149
 150
 151     GXV_32BIT_ALIGNMENT_VALIDATE( ligActionOffset );
 152     if ( p < lat_base )
 153     {
 154       GXV_TRACE(( "too short offset 0x%04x: p < lat_base (%d byte rewind)\n",
 155                   ligActionOffset, lat_base - p ));
 156
 157       /* FontValidator, ftxvalidator, ftxdumperfuser warn but continue */
 158       GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 159     }
 160     else if ( lat_limit < p )
 161     {
 162       GXV_TRACE(( "too large offset 0x%04x: lat_limit < p (%d byte overrun)\n",
 163                   ligActionOffset, p - lat_limit ));
 164
 165       /* FontValidator, ftxvalidator, ftxdumperfuser warn but continue */
 166       GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 167     }
 168     else
 169     {
 170       /* validate entry in ligActionTable */
 171       FT_ULong   lig_action;
 172 #ifdef GXV_LOAD_UNUSED_VARS
 173       FT_UShort  last;
 174       FT_UShort  store;
 175 #endif
 176       FT_ULong   offset;
 177
 178
 179       lig_action = FT_NEXT_ULONG( p );
 180 #ifdef GXV_LOAD_UNUSED_VARS
 181       last   = (FT_UShort)( ( lig_action >> 31 ) & 1 );
 182       store  = (FT_UShort)( ( lig_action >> 30 ) & 1 );
 183 #endif
 184
 185       /* Apple spec defines this offset as a word offset */
 186       offset = lig_action & 0x3FFFFFFFUL;
 187       if ( offset * 2 < optdata->ligatureTable )
 188       {
 189         GXV_TRACE(( "too short offset 0x%08x:"
 190                     " 2 x offset < ligatureTable (%d byte rewind)\n",
 191                      offset, optdata->ligatureTable - offset * 2 ));
 192
 193         GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 194       } else if ( offset * 2 >
 195                   optdata->ligatureTable + optdata->ligatureTable_length )
 196       {
 197         GXV_TRACE(( "too long offset 0x%08x:"
 198                     " 2 x offset > ligatureTable + ligatureTable_length"
 199                     " (%d byte overrun)\n",
 200                      offset,
 201                      optdata->ligatureTable + optdata->ligatureTable_length
 202                      - offset * 2 ));
 203
 204         GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 205       }
 206     }
 207   }
 208
 209
 210   static void
 211   gxv_mort_subtable_type2_entry_validate(
 212     FT_Byte                         state,
 213     FT_UShort                       flags,
 214     GXV_StateTable_GlyphOffsetCPtr  glyphOffset_p,
 215     FT_Bytes                        table,
 216     FT_Bytes                        limit,
 217     GXV_Validator                   valid )
 218   {
 219 #ifdef GXV_LOAD_UNUSED_VARS
 220     FT_UShort setComponent;
 221     FT_UShort dontAdvance;
 222 #endif
 223     FT_UShort offset;
 224
 225     FT_UNUSED( state );
 226     FT_UNUSED( glyphOffset_p );
 227     FT_UNUSED( limit );
 228
 229
 230 #ifdef GXV_LOAD_UNUSED_VARS
 231     setComponent = (FT_UShort)( ( flags >> 15 ) & 1 );
 232     dontAdvance  = (FT_UShort)( ( flags >> 14 ) & 1 );
 233 #endif
 234
 235     offset = (FT_UShort)( flags & 0x3FFFU );
 236
 237     if ( 0 < offset )
 238       gxv_mort_subtable_type2_ligActionOffset_validate( table, offset,
 239                                                         valid );
 240   }
 241
 242
 243   static void
 244   gxv_mort_subtable_type2_ligatureTable_validate( FT_Bytes       table,
 245                                                   GXV_Validator  valid )
 246   {
 247     GXV_mort_subtable_type2_StateOptRecData  optdata =
 248       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
 249
 250     FT_Bytes p     = table + optdata->ligatureTable;
 251     FT_Bytes limit = table + optdata->ligatureTable
 252                            + optdata->ligatureTable_length;
 253
 254
 255     GXV_NAME_ENTER( "mort chain subtable type2 - substitutionTable" );
 256     if ( 0 != optdata->ligatureTable )
 257     {
 258       /* Apple does not give specification of ligatureTable format */
 259       while ( p < limit )
 260       {
 261         FT_UShort  lig_gid;
 262
 263
 264         GXV_LIMIT_CHECK( 2 );
 265         lig_gid = FT_NEXT_USHORT( p );
 266
 267         if ( valid->face->num_glyphs < lig_gid )
 268           GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
 269       }
 270     }
 271     GXV_EXIT;
 272   }
 273
 274
 275   FT_LOCAL_DEF( void )
 276   gxv_mort_subtable_type2_validate( FT_Bytes       table,
 277                                     FT_Bytes       limit,
 278                                     GXV_Validator  valid )
 279   {
 280     FT_Bytes  p = table;
 281
 282     GXV_mort_subtable_type2_StateOptRec  lig_rec;
 283
 284
 285     GXV_NAME_ENTER( "mort chain subtable type2 (Ligature Substitution)" );
 286
 287     GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE );
 288
 289     valid->statetable.optdata =
 290       &lig_rec;
 291     valid->statetable.optdata_load_func =
 292       gxv_mort_subtable_type2_opttable_load;
 293     valid->statetable.subtable_setup_func =
 294       gxv_mort_subtable_type2_subtable_setup;
 295     valid->statetable.entry_glyphoffset_fmt =
 296       GXV_GLYPHOFFSET_NONE;
 297     valid->statetable.entry_validate_func =
 298       gxv_mort_subtable_type2_entry_validate;
 299
 300     gxv_StateTable_validate( p, limit, valid );
 301
 302     p += valid->subtable_length;
 303     gxv_mort_subtable_type2_ligatureTable_validate( table, valid );
 304
 305     valid->subtable_length = p - table;
 306
 307     GXV_EXIT;
 308   }
 309
 310
 311 /* END */