C++ GXV_LIMIT_CHECK函数代码示例

static void
gxv_mort_subtable_type1_substTable_validate( FT_Bytes       table,
        FT_Bytes       limit,
        GXV_Validator  valid )
{
    FT_Bytes   p = table;
    FT_UShort  num_gids = (FT_UShort)(
                              ((GXV_mort_subtable_type1_StateOptRec *)
                               (valid->statetable.optdata))->substitutionTable_length / 2 );
    FT_UShort  i;


    GXV_NAME_ENTER( "validating contents of substitutionTable" );
    for ( i = 0; i < num_gids ; i ++ )
    {
        FT_UShort  dst_gid;


        GXV_LIMIT_CHECK( 2 );
        dst_gid = FT_NEXT_USHORT( p );

        if ( dst_gid >= 0xFFFFU )
            continue;

        if ( dst_gid < valid->min_gid || valid->max_gid < dst_gid )
        {
            GXV_TRACE(( "substTable include a strange gid[%d]=%d >"
                        " out of define range (%d..%d)\n",
                        i, dst_gid, valid->min_gid, valid->max_gid ));
            GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
        }
    }

    GXV_EXIT;
}

  static void
  gxv_morx_chain_validate( FT_Bytes       table,
                           FT_Bytes       limit,
                           GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_ULong  defaultFlags;
    FT_ULong  chainLength;
    FT_ULong  nFeatureFlags;
    FT_ULong  nSubtables;


    GXV_NAME_ENTER( "morx chain header" );

    GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
    defaultFlags  = FT_NEXT_ULONG( p );
    chainLength   = FT_NEXT_ULONG( p );
    nFeatureFlags = FT_NEXT_ULONG( p );
    nSubtables    = FT_NEXT_ULONG( p );

    /* feature-array of morx is same with that of mort */
    gxv_mort_featurearray_validate( p, limit, nFeatureFlags, valid );
    p += valid->subtable_length;

    if ( nSubtables >= 0x10000L )
      FT_INVALID_DATA;

    gxv_morx_subtables_validate( p, table + chainLength,
                                 (FT_UShort)nSubtables, valid );

    valid->subtable_length = chainLength;

    GXV_EXIT;
  }

  static void
  gxv_morx_subtable_type2_ligatureTable_validate( FT_Bytes       table,
                                                  GXV_Validator  gxvalid )
  {
    GXV_morx_subtable_type2_StateOptRecData  optdata =
      (GXV_morx_subtable_type2_StateOptRecData)gxvalid->xstatetable.optdata;

    FT_Bytes p     = table + optdata->ligatureTable;
    FT_Bytes limit = table + optdata->ligatureTable
                           + optdata->ligatureTable_length;


    GXV_NAME_ENTER( "morx chain subtable type2 - substitutionTable" );

    if ( 0 != optdata->ligatureTable )
    {
      /* Apple does not give specification of ligatureTable format */
      while ( p < limit )
      {
        FT_UShort  lig_gid;


        GXV_LIMIT_CHECK( 2 );
        lig_gid = FT_NEXT_USHORT( p );
        if ( lig_gid < gxvalid->face->num_glyphs )
          GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
      }
    }

    GXV_EXIT;
  }

  gxv_morx_subtable_type1_validate( FT_Bytes       table,
                                    FT_Bytes       limit,
                                    GXV_Validator  valid )
  {
    FT_Bytes  p = table;

    GXV_morx_subtable_type1_StateOptRec  st_rec;


    GXV_NAME_ENTER( "morx chain subtable type1 (Contextual Glyph Subst)" );

    GXV_LIMIT_CHECK( GXV_MORX_SUBTABLE_TYPE1_HEADER_SIZE );

    st_rec.substitutionTable_num_lookupTables = 0;

    valid->xstatetable.optdata =
      &st_rec;
    valid->xstatetable.optdata_load_func =
      gxv_morx_subtable_type1_substitutionTable_load;
    valid->xstatetable.subtable_setup_func =
      gxv_morx_subtable_type1_subtable_setup;
    valid->xstatetable.entry_glyphoffset_fmt =
      GXV_GLYPHOFFSET_ULONG;
    valid->xstatetable.entry_validate_func =
      gxv_morx_subtable_type1_entry_validate;

    gxv_XStateTable_validate( p, limit, valid );

    gxv_morx_subtable_type1_substitutionTable_validate(
      table + st_rec.substitutionTable,
      table + st_rec.substitutionTable + st_rec.substitutionTable_length,
      valid );

    GXV_EXIT;
  }

  gxv_mort_subtable_type5_validate( FT_Bytes       table,
                                    FT_Bytes       limit,
                                    GXV_Validator  gxvalid )
  {
    FT_Bytes  p = table;

    GXV_mort_subtable_type5_StateOptRec      et_rec;
    GXV_mort_subtable_type5_StateOptRecData  et = &et_rec;


    GXV_NAME_ENTER( "mort chain subtable type5 (Glyph Insertion)" );

    GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE5_HEADER_SIZE );

    gxvalid->statetable.optdata =
      et;
    gxvalid->statetable.optdata_load_func =
      NULL;
    gxvalid->statetable.subtable_setup_func =
      gxv_mort_subtable_type5_subtable_setup;
    gxvalid->statetable.entry_glyphoffset_fmt =
      GXV_GLYPHOFFSET_ULONG;
    gxvalid->statetable.entry_validate_func =
      gxv_mort_subtable_type5_entry_validate;

    gxv_StateTable_validate( p, limit, gxvalid );

    GXV_EXIT;
  }

  static void
  gxv_feat_setting_validate( FT_Bytes       table,
                             FT_Bytes       limit,
                             FT_Bool        exclusive,
                             GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  setting;


    GXV_NAME_ENTER( "setting" );

    GXV_LIMIT_CHECK( 2 );

    setting = FT_NEXT_USHORT( p );

    /* If we have exclusive setting, the setting should be odd. */
    if ( exclusive && ( setting % 2 ) == 0 )
      FT_INVALID_DATA;

    gxv_feat_name_index_validate( p, limit, valid );

    GXV_FEAT_DATA( setting ) = setting;

    GXV_EXIT;
  }

  gxv_mort_featurearray_validate( FT_Bytes       table,
                                  FT_Bytes       limit,
                                  FT_ULong       nFeatureFlags,
                                  GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_ULong  i;

    GXV_mort_featureRec  f = GXV_MORT_FEATURE_OFF;


    GXV_NAME_ENTER( "mort feature list" );
    for ( i = 0; i < nFeatureFlags; i++ )
    {
      GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 );
      f.featureType    = FT_NEXT_USHORT( p );
      f.featureSetting = FT_NEXT_USHORT( p );
      f.enableFlags    = FT_NEXT_ULONG( p );
      f.disableFlags   = FT_NEXT_ULONG( p );

      gxv_mort_feature_validate( &f, valid );
    }

    if ( !IS_GXV_MORT_FEATURE_OFF( f ) )
      FT_INVALID_DATA;

    valid->subtable_length = p - table;
    GXV_EXIT;
  }

  static void
  gxv_mort_chain_validate( FT_Bytes       table,
                           FT_Bytes       limit,
                           GXV_Validator  gxvalid )
  {
    FT_Bytes   p = table;
#ifdef GXV_LOAD_UNUSED_VARS
    FT_ULong   defaultFlags;
#endif
    FT_ULong   chainLength;
    FT_UShort  nFeatureFlags;
    FT_UShort  nSubtables;


    GXV_NAME_ENTER( "mort chain header" );

    GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
#ifdef GXV_LOAD_UNUSED_VARS
    defaultFlags  = FT_NEXT_ULONG( p );
#else
    p += 4;
#endif
    chainLength   = FT_NEXT_ULONG( p );
    nFeatureFlags = FT_NEXT_USHORT( p );
    nSubtables    = FT_NEXT_USHORT( p );

    gxv_mort_featurearray_validate( p, table + chainLength,
                                    nFeatureFlags, gxvalid );
    p += gxvalid->subtable_length;
    gxv_mort_subtables_validate( p, table + chainLength, nSubtables, gxvalid );
    gxvalid->subtable_length = chainLength;

    /* TODO: validate defaultFlags */
    GXV_EXIT;
  }

  static void
  gxv_mort_chain_validate( FT_Bytes       table,
                           FT_Bytes       limit,
                           GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_ULong   defaultFlags;
    FT_ULong   chainLength;
    FT_UShort  nFeatureFlags;
    FT_UShort  nSubtables;


    GXV_NAME_ENTER( "mort chain header" );

    GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
    defaultFlags  = FT_NEXT_ULONG( p );
    chainLength   = FT_NEXT_ULONG( p );
    nFeatureFlags = FT_NEXT_USHORT( p );
    nSubtables    = FT_NEXT_USHORT( p );

    gxv_mort_featurearray_validate( p, table + chainLength,
                                    nFeatureFlags, valid );
    p += valid->subtable_length;
    gxv_mort_subtables_validate( p, table + chainLength, nSubtables, valid );
    valid->subtable_length = chainLength;

    GXV_EXIT;
  }

  static void
  gxv_just_actSubrecord_type4_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  gxvalid )
  {
    FT_Bytes  p = table;
    FT_ULong  variantsAxis;
    FT_Fixed  minimumLimit;
    FT_Fixed  noStretchValue;
    FT_Fixed  maximumLimit;


    GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
    variantsAxis   = FT_NEXT_ULONG( p );
    minimumLimit   = FT_NEXT_ULONG( p );
    noStretchValue = FT_NEXT_ULONG( p );
    maximumLimit   = FT_NEXT_ULONG( p );

    gxvalid->subtable_length = p - table;

    if ( variantsAxis != 0x64756374L ) /* 'duct' */
      GXV_TRACE(( "variantsAxis 0x%08x is non default value",
                   variantsAxis ));

    if ( minimumLimit > noStretchValue )
      GXV_TRACE(( "type4:minimumLimit 0x%08x > noStretchValue 0x%08x\n",
                  minimumLimit, noStretchValue ));
    else if ( noStretchValue > maximumLimit )
      GXV_TRACE(( "type4:noStretchValue 0x%08x > maximumLimit 0x%08x\n",
                  noStretchValue, maximumLimit ));
    else if ( !IS_PARANOID_VALIDATION )
      return;

    FT_INVALID_DATA;
  }

  gxv_morx_subtable_type2_validate( FT_Bytes       table,
                                    FT_Bytes       limit,
                                    GXV_Validator  gxvalid )
  {
    FT_Bytes  p = table;

    GXV_morx_subtable_type2_StateOptRec  lig_rec;


    GXV_NAME_ENTER( "morx chain subtable type2 (Ligature Substitution)" );

    GXV_LIMIT_CHECK( GXV_MORX_SUBTABLE_TYPE2_HEADER_SIZE );

    gxvalid->xstatetable.optdata =
      &lig_rec;
    gxvalid->xstatetable.optdata_load_func =
      gxv_morx_subtable_type2_opttable_load;
    gxvalid->xstatetable.subtable_setup_func =
      gxv_morx_subtable_type2_subtable_setup;
    gxvalid->xstatetable.entry_glyphoffset_fmt =
      GXV_GLYPHOFFSET_USHORT;
    gxvalid->xstatetable.entry_validate_func =
      gxv_morx_subtable_type2_entry_validate;

    gxv_XStateTable_validate( p, limit, gxvalid );

#if 0
    p += gxvalid->subtable_length;
#endif
    gxv_morx_subtable_type2_ligatureTable_validate( table, gxvalid );

    GXV_EXIT;
  }

  static void
  gxv_opbd_LookupValue_validate( FT_UShort            glyph,
                                 GXV_LookupValueCPtr  value_p,
                                 GXV_Validator        valid )
  {
    /* offset in LookupTable is measured from the head of opbd table */
    FT_Bytes   p     = valid->root->base + value_p->u;
    FT_Bytes   limit = valid->root->limit;
    FT_Short   delta_value;
    int        i;


    if ( value_p->u < GXV_OPBD_DATA( valueOffset_min ) )
      GXV_OPBD_DATA( valueOffset_min ) = value_p->u;

    for ( i = 0; i < 4; i++ )
    {
      GXV_LIMIT_CHECK( 2 );
      delta_value = FT_NEXT_SHORT( p );

      if ( GXV_OPBD_DATA( format ) )    /* format 1, value is ctrl pt. */
      {
        if ( delta_value == -1 )
          continue;

        gxv_ctlPoint_validate( glyph, delta_value, valid );
      }
      else                              /* format 0, value is distance */
        continue;
    }
  }

  static void
  gxv_just_justClassTable_validate ( FT_Bytes       table,
                                     FT_Bytes       limit,
                                     GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  length;
    FT_UShort  coverage;
    FT_ULong   subFeatureFlags;


    GXV_NAME_ENTER( "just justClassTable" );

    GXV_LIMIT_CHECK( 2 + 2 + 4 );
    length          = FT_NEXT_USHORT( p );
    coverage        = FT_NEXT_USHORT( p );
    subFeatureFlags = FT_NEXT_ULONG( p );

    GXV_TRACE(( "  justClassTable: coverage = 0x%04x (%s)",
                coverage,
                ( 0x4000 & coverage ) == 0 ? "ascending" : "descending" ));

    valid->statetable.optdata               = NULL;
    valid->statetable.optdata_load_func     = NULL;
    valid->statetable.subtable_setup_func   = NULL;
    valid->statetable.entry_glyphoffset_fmt = GXV_GLYPHOFFSET_NONE;
    valid->statetable.entry_validate_func   =
      gxv_just_classTable_entry_validate;

    gxv_StateTable_validate( p, table + length, valid );

    /* subtable_length is set by gxv_LookupTable_validate() */

    GXV_EXIT;
  }

  static void
  gxv_mort_subtable_type2_ligatureTable_validate( FT_Bytes       table,
                                                  GXV_Validator  valid )
  {
    GXV_mort_subtable_type2_StateOptRecData  optdata =
      (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;

    FT_Bytes p     = table + optdata->ligatureTable;
    FT_Bytes limit = table + optdata->ligatureTable
                           + optdata->ligatureTable_length;


    GXV_NAME_ENTER( "mort chain subtable type2 - substitutionTable" );
    if ( 0 != optdata->ligatureTable )
    {
      /* Apple does not give specification of ligatureTable format */
      while ( p < limit )
      {
        FT_UShort  lig_gid;


        GXV_LIMIT_CHECK( 2 );
        lig_gid = FT_NEXT_USHORT( p );
      }
    }
    GXV_EXIT;
  }

  gxv_mort_subtable_type2_validate( FT_Bytes       table,
                                    FT_Bytes       limit,
                                    GXV_Validator  valid )
  {
    FT_Bytes  p = table;

    GXV_mort_subtable_type2_StateOptRec  lig_rec;


    GXV_NAME_ENTER( "mort chain subtable type2 (Ligature Substitution)" );

    GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE );

    valid->statetable.optdata =
      &lig_rec;
    valid->statetable.optdata_load_func =
      gxv_mort_subtable_type2_opttable_load;
    valid->statetable.subtable_setup_func =
      gxv_mort_subtable_type2_subtable_setup;
    valid->statetable.entry_glyphoffset_fmt =
      GXV_GLYPHOFFSET_NONE;
    valid->statetable.entry_validate_func =
      gxv_mort_subtable_type2_entry_validate;

    gxv_StateTable_validate( p, limit, valid );

    p += valid->subtable_length;
    gxv_mort_subtable_type2_ligatureTable_validate( table, valid );

    valid->subtable_length = p - table;

    GXV_EXIT;
  }