shithub: freetype+ttf2subf

ref: 55b0908ef5779f16d08ad4a60eee10a3d36bc2e6
dir: /src/gxvalid/gxvcommn.c/

View raw version
/***************************************************************************/
/*                                                                         */
/*  gxvcommn.c                                                             */
/*                                                                         */
/*    TrueTypeGX/AAT common tables validation (body).                      */
/*                                                                         */
/*  Copyright 2004, 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K., */
/*  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.                                        */
/*                                                                         */
/***************************************************************************/

/***************************************************************************/
/* gxvalid is derived from both gxlayout module and otvalid module.        */
/* Development of gxlayout was support of Information-technology Promotion */
/* Agency(IPA), Japan.                                                     */
/***************************************************************************/


#include "gxvcommn.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_gxvcommon


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       16bit offset sorter                     *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static int
  gxv_compare_ushort_offset( FT_UShort*  a,
                             FT_UShort*  b )
  {
    if ( *a < *b )
      return ( -1 );
    else if ( *a > *b )
      return ( 1 );
    else
      return ( 0 );
  }


  static void
  gxv_set_length_by_ushort_offset( FT_UShort*     offset,
                                   FT_UShort**    length,
                                   FT_UShort*     buff,
                                   FT_UInt        nmemb,
                                   FT_UShort      limit,
                                   GXV_Validator  valid)
  {
    FT_UInt    i;


    for ( i = 0; i < nmemb; i++ )
      *(length[i]) = 0;

    for ( i = 0; i < nmemb; i++ )
      buff[i] = offset[i];
    buff[nmemb] = limit;

    ft_qsort( buff, ( nmemb + 1 ), sizeof(FT_UShort),
              ( int(*)(const void*, const void*) )gxv_compare_ushort_offset );

    if ( buff[nmemb] > limit )
      FT_INVALID_OFFSET;

    for ( i = 0; i < nmemb; i++ )
    {
      FT_UInt j;


      for ( j = 0; j < nmemb; j++ )
        if ( buff[j] == offset[i] )
          break;

      if (j == nmemb)
        FT_INVALID_OFFSET;

      *(length[i]) = buff[j + 1] - buff[j];

      if ( 0 != offset[i] && 0 == *(length[i]) )
        FT_INVALID_OFFSET;
    }
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       32bit offset sorter                     *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static int
  gxv_compare_ulong_offset( FT_ULong*  a,
                            FT_ULong*  b )
  {
    if ( *a < *b )
      return ( -1 );
    else if ( *a > *b )
      return ( 1 );
    else
      return ( 0 );
  }


  static void
  gxv_set_length_by_ulong_offset( FT_ULong*      offset,
                                  FT_ULong**     length,
                                  FT_ULong*      buff,
                                  FT_UInt        nmemb,
                                  FT_ULong       limit,
                                  GXV_Validator  valid)
  {
    FT_UInt    i;


    for ( i = 0; i < nmemb; i++ )
      *(length[i]) = 0;

    for ( i = 0; i < nmemb; i++ )
      buff[i] = offset[i];
    buff[nmemb] = limit;

    ft_qsort( buff, ( nmemb + 1 ), sizeof(FT_ULong),
              ( int(*)(const void*, const void*) )gxv_compare_ulong_offset );

    if ( buff[nmemb] > limit )
      FT_INVALID_OFFSET;

    for ( i = 0; i < nmemb; i++ )
    {
      FT_UInt j;


      for ( j = 0; j < nmemb; j++ )
        if ( buff[j] == offset[i] )
          break;

      if (j == nmemb)
        FT_INVALID_OFFSET;

      *(length[i]) = buff[j + 1] - buff[j];

      if ( 0 != offset[i] && 0 == *(length[i]) )
        FT_INVALID_OFFSET;
    }
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****               scan value array and get min & max              *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  static void
  gxv_array_getlimits_byte( FT_Bytes       table,
                            FT_Bytes       limit,
                            FT_Byte*       min,
                            FT_Byte*       max,
                            GXV_Validator  valid )
  {
    FT_Bytes  p = table;


    *min = 0xFF;
    *max = 0x00;

    while ( p < limit )
    {
      FT_Byte  val;

      GXV_LIMIT_CHECK( 1 );
      val = FT_NEXT_BYTE( p );

      *min = FT_MIN( *min, val );
      *max = FT_MAX( *max, val );
    }

    valid->subtable_length = ( p - table );
  }


  static void
  gxv_array_getlimits_ushort( FT_Bytes       table,
                              FT_Bytes       limit,
                              FT_UShort*     min,
                              FT_UShort*     max,
                              GXV_Validator  valid )
  {
    FT_Bytes  p = table;


    *min = 0xFFFF;
    *max = 0x0000;

    while ( p < limit )
    {
      FT_UShort  val;

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

      *min = FT_MIN( *min, val );
      *max = FT_MAX( *max, val );
    }

    valid->subtable_length = ( p - table );
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       BINSEARCHHEADER                         *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  typedef struct GXV_BinSrchHeader_
  {
    FT_UShort unitSize;
    FT_UShort nUnits;
    FT_UShort searchRange;
    FT_UShort entrySelector;
    FT_UShort rangeShift;

  } GXV_BinSrchHeader;


  static void
  gxv_BinSrchHeader_check_consistency( GXV_BinSrchHeader*  binSrchHeader,
                                       GXV_Validator       valid )
  {
    FT_UShort searchRange;
    FT_UShort entrySelector;
    FT_UShort rangeShift;


    if ( binSrchHeader->unitSize == 0 )
      FT_INVALID_DATA;

    if ( binSrchHeader->nUnits == 0 )
    {
      if ( binSrchHeader->searchRange   == 0 &&
           binSrchHeader->entrySelector == 0 &&
           binSrchHeader->rangeShift    == 0 )
      {
        return;
      }
      else
      {
        FT_INVALID_DATA;
      }
    }

    for ( searchRange = 1, entrySelector = 1;
          ( searchRange * 2 ) <= binSrchHeader->nUnits && searchRange < 0x8000;
          searchRange *= 2, entrySelector++ )
      ;

    entrySelector --;
    searchRange *= ( binSrchHeader->unitSize );
    rangeShift   = ( binSrchHeader->nUnits ) * ( binSrchHeader->unitSize )
                   - searchRange;


    if ( searchRange   != binSrchHeader->searchRange   ||
         entrySelector != binSrchHeader->entrySelector ||
         rangeShift    != binSrchHeader->rangeShift    )
    {
      GXV_TRACE(( "Inconsistency found in BinSrchHeader\n" ));
      GXV_TRACE(( "originally: unitSize=%d, nUnits=%d, "
                  "searchRange=%d, entrySelector=%d, "
                  "rangeShift=%d\n",
                  binSrchHeader->unitSize, binSrchHeader->nUnits,
                  binSrchHeader->searchRange, binSrchHeader->entrySelector,
                  binSrchHeader->rangeShift ));
      GXV_TRACE(( "calculated: unitSize=%d, nUnits=%d, "
                  "searchRange=%d, entrySelector=%d, "
                  "rangeShift=%d\n",
                  binSrchHeader->unitSize, binSrchHeader->nUnits,
                  searchRange, entrySelector, rangeShift ));
      if ( valid->root->level >= FT_VALIDATE_PARANOID )
        FT_INVALID_DATA;
    }
  }


  /*
   * parser & validator of BinSrchHeader
   * which is used in LookupTable format 2, 4, 6.
   *
   * Essential parameters (unitSize, nUnits) are returned by
   * given pointer, others (searchRange, entrySelector, rangeShift)
   * can be calculated essential parameters, so they are just
   * validated and discarded.
   *
   * However, wrong values in searchRange, entrySelector, rangeShift
   * won't cause fatal errors, because these parameters might be
   * only used in old m68k font driver in MacOS.
   *   -- suzuki toshiya <[email protected]>
   */


  FT_LOCAL_DEF( void )
  gxv_BinSrchHeader_validate( FT_Bytes       table,
                              FT_Bytes       limit,
                              FT_UShort*     unitSize_p,
                              FT_UShort*     nUnits_p,
                              GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    GXV_BinSrchHeader  binSrchHeader;


    GXV_NAME_ENTER( "BinSrchHeader validate" );

    if ( *unitSize_p == 0 )
    {
      GXV_LIMIT_CHECK( 2 );
      binSrchHeader.unitSize =  FT_NEXT_USHORT( p );
    }
    else
      binSrchHeader.unitSize = *unitSize_p;

    if ( *nUnits_p == 0)
    {
      GXV_LIMIT_CHECK( 2 );
      binSrchHeader.nUnits = FT_NEXT_USHORT( p );
    }
    else
      binSrchHeader.nUnits = *nUnits_p;

    GXV_LIMIT_CHECK( 2 + 2 + 2 );
    binSrchHeader.searchRange   = FT_NEXT_USHORT( p );
    binSrchHeader.entrySelector = FT_NEXT_USHORT( p );
    binSrchHeader.rangeShift    = FT_NEXT_USHORT( p );
    GXV_TRACE(( "nUnits %d\n", binSrchHeader.nUnits ));

    gxv_BinSrchHeader_check_consistency( &binSrchHeader, valid );

    if ( *unitSize_p == 0 )
      *unitSize_p = binSrchHeader.unitSize;

    if ( *nUnits_p == 0 )
      *nUnits_p   = binSrchHeader.nUnits;

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

  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                         LOOKUP TABLE                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

#define GXV_LOOKUP_VALUE_LOAD(P, SIGNSPEC) \
  ( P += 2, gxv_lookup_value_load( P - 2, SIGNSPEC ) )

  static GXV_LookupValueDesc
  gxv_lookup_value_load( FT_Bytes  p,
                         int       signspec )
  {
    GXV_LookupValueDesc v;


    if ( signspec == GXV_LOOKUPVALUE_UNSIGNED )
      v.u = FT_NEXT_USHORT( p );
    else
      v.s = FT_NEXT_SHORT( p );

    return v;
  }

#define GXV_UNITSIZE_VALIDATE( FORMAT, UNITSIZE, NUNITS, CORRECTSIZE ) \
          FT_BEGIN_STMNT                                     \
            if ( UNITSIZE != CORRECTSIZE )                   \
            {                                                \
              FT_ERROR(( "unitSize=%d differs from"          \
                         "expected unitSize=%d"              \
                         "in LookupTable %s",                \
                          UNITSIZE, CORRECTSIZE, FORMAT ));  \
              if ( UNITSIZE != 0 && NUNITS != 0 )            \
              {                                              \
                FT_ERROR(( " cannot validate anymore\n" ));  \
                FT_INVALID_FORMAT;                           \
              }                                              \
              else                                           \
                FT_ERROR(( " forcibly continues\n" ));       \
            }                                                \
          FT_END_STMNT


  /* ================= Simple Array Format 0 Lookup Table ================= */
  static void
  gxv_LookupTable_fmt0_validate( FT_Bytes       table,
                                 FT_Bytes       limit,
                                 GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  i;

    GXV_LookupValueDesc  value;


    GXV_NAME_ENTER( " LookupTable format 0" );

    GXV_LIMIT_CHECK( 2 * valid->face->num_glyphs );

    for ( i = 0; i < valid->face->num_glyphs; i++ )
    {
      GXV_LIMIT_CHECK( 2 );
      if ( p + 2 >= limit ) /* some fonts has too-short fmt0 array */
      {
        GXV_TRACE(( "too-short, glyph %d - %d are missing\n",
                     i, valid->face->num_glyphs ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_GLYPH_ID;
        break;
      }
      value = GXV_LOOKUP_VALUE_LOAD( p, valid->lookupval_sign );
      valid->lookupval_func( i, value, valid );
    }

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

  /* ================= Segment Single Format 2 Loolup Table =============== */
  /*
   * Apple spec says: To guarantee that a binary search terminates,
   *   you must include one or more special "end of search table" values
   *   at the end of the data to be searched. The number of termination
   *   values that need to be included is table-specific. The value
   *   that indicates binary search termination is 0xFFFF.
   * The problem is that nUnits does not include this end-marker.
   * It's quite difficult to discriminate following 0xFFFF comes from
   * the end-marker or some next data.
   *   -- suzuki toshiya <[email protected]>
   */
  static void
  gxv_LookupTable_fmt2_skip_endmarkers( FT_Bytes       table,
                                        FT_UShort      unitSize,
                                        GXV_Validator  valid )
  {
    FT_Bytes  p = table;


    while ( ( p + 4 ) < valid->root->limit )
    {
      if ( p[0] != 0xFF || p[1] != 0xFF || /* lastGlyph */
           p[2] != 0xFF || p[3] != 0xFF )  /* firstGlyph */
      {
        break;
      }
      p += unitSize;
    }

    valid->subtable_length = ( p - table );
  }

  static void
  gxv_LookupTable_fmt2_validate( FT_Bytes       table,
                                 FT_Bytes       limit,
                                 GXV_Validator  valid )
  {
    FT_Bytes             p = table;
    FT_UShort            gid;

    FT_UShort            unitSize;
    FT_UShort            nUnits;
    FT_UShort            unit;
    FT_UShort            lastGlyph;
    FT_UShort            firstGlyph;
    GXV_LookupValueDesc  value;


    GXV_NAME_ENTER( " LookupTable format 2" );

    unitSize = nUnits = 0;
    gxv_BinSrchHeader_validate( p, limit, &unitSize, &nUnits, valid );
    p += valid->subtable_length;

    GXV_UNITSIZE_VALIDATE( "format2", unitSize, nUnits, 6 );


    for ( unit = 0, gid = 0; unit < nUnits; unit++ )
    {
      GXV_LIMIT_CHECK( 2 + 2 + 2 );
      lastGlyph  = FT_NEXT_USHORT( p );
      firstGlyph = FT_NEXT_USHORT( p );
      value      = GXV_LOOKUP_VALUE_LOAD( p, valid->lookupval_sign );

      gxv_glyphid_validate( firstGlyph, valid );
      gxv_glyphid_validate( lastGlyph, valid );


      if ( lastGlyph < gid )
      {
        GXV_TRACE(( "reverse ordered segment specification:"
                    " lastGlyph[%d]=%d < lastGlyph[%d]=%d\n",
                     unit, lastGlyph, unit - 1 , gid ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_GLYPH_ID;
      }


      if ( lastGlyph < firstGlyph )
      {
        GXV_TRACE(( "reverse ordered range specification at unit %d:",
                    " lastGlyph %d < firstGlyph %d ",
                      unit, lastGlyph, firstGlyph ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_GLYPH_ID;

        if ( valid->root->level == FT_VALIDATE_TIGHT )
          continue; /* ftxvalidator silently skips such entry */

        FT_TRACE4(( "continue with exchange\n" ));
        gid        = firstGlyph;
        firstGlyph = lastGlyph;
        lastGlyph  = gid;
      }


      for ( gid = firstGlyph; gid <= lastGlyph; gid++ )
        valid->lookupval_func( gid, value, valid );
    }

    gxv_LookupTable_fmt2_skip_endmarkers( p, unitSize, valid );
    p += valid->subtable_length;

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

  /* ================= Segment Array Format 4 Lookup Table ================ */
  static void
  gxv_LookupTable_fmt4_validate( FT_Bytes       table,
                                 FT_Bytes       limit,
                                 GXV_Validator  valid )
  {
    FT_Bytes             p = table;
    FT_UShort            unit;
    FT_UShort            gid;

    FT_UShort            unitSize;
    FT_UShort            nUnits;
    FT_UShort            lastGlyph;
    FT_UShort            firstGlyph;
    GXV_LookupValueDesc  base_value;
    GXV_LookupValueDesc  value;


    GXV_NAME_ENTER( " LookupTable format 4" );

    unitSize = nUnits = 0;
    gxv_BinSrchHeader_validate( p, limit, &unitSize, &nUnits, valid );
    p += valid->subtable_length;

    GXV_UNITSIZE_VALIDATE( "format4", unitSize, nUnits, 6 );

    for ( unit = 0, gid = 0; unit < nUnits; unit++ )
    {
      GXV_LIMIT_CHECK( 2 + 2 );
      lastGlyph  = FT_NEXT_USHORT( p );
      firstGlyph = FT_NEXT_USHORT( p );

      gxv_glyphid_validate( firstGlyph, valid );
      gxv_glyphid_validate( lastGlyph, valid );


      if ( lastGlyph < gid )
      {
        GXV_TRACE(( "reverse ordered segment specification:"
                    " lastGlyph[%d]=%d < lastGlyph[%d]=%d\n",
                     unit, lastGlyph, unit - 1 , gid ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_GLYPH_ID;
      }


      if ( lastGlyph < firstGlyph )
      {
        GXV_TRACE(( "reverse ordered range specification at unit %d:",
                    " lastGlyph %d < firstGlyph %d ",
                      unit, lastGlyph, firstGlyph ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_GLYPH_ID;

        if ( valid->root->level == FT_VALIDATE_TIGHT )
          continue; /* ftxvalidator silently skips such entry */

        FT_TRACE4(( "continue with exchange\n" ));
        gid        = firstGlyph;
        firstGlyph = lastGlyph;
        lastGlyph  = gid;
      }


      GXV_LIMIT_CHECK( 2 );
      base_value = GXV_LOOKUP_VALUE_LOAD( p, GXV_LOOKUPVALUE_UNSIGNED );

      for ( gid = firstGlyph; gid <= lastGlyph; gid++ )
      {
        value = valid->lookupfmt4_trans( gid - firstGlyph, base_value,
                                         limit, valid );
        valid->lookupval_func( gid, value, valid );
      }
    }

    gxv_LookupTable_fmt2_skip_endmarkers( p, unitSize, valid );
    p += valid->subtable_length;

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

  /* ================= Segment Table Format 6 Lookup Table ================ */
  static void
  gxv_LookupTable_fmt6_skip_endmarkers( FT_Bytes       table,
                                        FT_UShort      unitSize,
                                        GXV_Validator  valid )
  {
    FT_Bytes  p = table;


    while ( p < valid->root->limit )
    {
      if ( p[0] != 0xFF || p[1] != 0xFF )
        break;
      p += unitSize;
    }

    valid->subtable_length = ( p - table );
  }

  static void
  gxv_LookupTable_fmt6_validate( FT_Bytes       table,
                                 FT_Bytes       limit,
                                 GXV_Validator  valid )
  {
    FT_Bytes             p = table;
    FT_UShort            unit;
    FT_UShort            prev_glyph;

    FT_UShort            unitSize;
    FT_UShort            nUnits;
    FT_UShort            glyph;
    GXV_LookupValueDesc  value;


    GXV_NAME_ENTER( " LookupTable format 6" );

    unitSize = nUnits = 0;
    gxv_BinSrchHeader_validate( p, limit, &unitSize, &nUnits, valid );
    p += valid->subtable_length;

    GXV_UNITSIZE_VALIDATE( "format6", unitSize, nUnits, 4 );

    for ( unit = 0, prev_glyph = 0; unit < nUnits; unit++ )
    {
      GXV_LIMIT_CHECK( 2 + 2 );
      glyph = FT_NEXT_USHORT( p );
      value = GXV_LOOKUP_VALUE_LOAD( p, valid->lookupval_sign );


      if ( gxv_glyphid_validate( glyph, valid ) )
        GXV_TRACE(( " endmarker found within defined range"
                    " (entry %d < nUnits=%d)\n",
                    unit, nUnits ));

      if ( prev_glyph > glyph )
      {
        GXV_TRACE(( "current gid 0x%04x < previous gid 0x%04x\n",
                     glyph, prev_glyph ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_GLYPH_ID;
      }
      prev_glyph = glyph;


      valid->lookupval_func( glyph, value, valid );
    }

    gxv_LookupTable_fmt6_skip_endmarkers( p, unitSize, valid );
    p += valid->subtable_length;

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

  /* ================= Trimmed Array Format 8 Lookup Table ================ */
  static void
  gxv_LookupTable_fmt8_validate( FT_Bytes       table,
                                 FT_Bytes       limit,
                                 GXV_Validator  valid )
  {
    FT_Bytes              p = table;
    FT_UShort             i;

    GXV_LookupValueDesc   value;
    FT_UShort             firstGlyph;
    FT_UShort             glyphCount;


    GXV_NAME_ENTER( " LookupTable format 8" );

    /* firstGlyph + glyphCount */
    GXV_LIMIT_CHECK( 2 + 2 );
    firstGlyph = FT_NEXT_USHORT( p );
    glyphCount = FT_NEXT_USHORT( p );

    gxv_glyphid_validate( firstGlyph, valid );
    gxv_glyphid_validate( firstGlyph + glyphCount, valid );

    /* valueArray */
    for ( i = 0; i < glyphCount; i++ )
    {
      GXV_LIMIT_CHECK( 2 );
      value = GXV_LOOKUP_VALUE_LOAD( p, valid->lookupval_sign );
      valid->lookupval_func( firstGlyph + i, value, valid );
    }

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


  FT_LOCAL_DEF( void )
  gxv_LookupTable_validate( FT_Bytes       table,
                            FT_Bytes       limit,
                            GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UShort format;

    GXV_Validate_Func fmt_funcs_table [] =
    {
      gxv_LookupTable_fmt0_validate, /* 0 */
      NULL,                          /* 1 */
      gxv_LookupTable_fmt2_validate, /* 2 */
      NULL,                          /* 3 */
      gxv_LookupTable_fmt4_validate, /* 4 */
      NULL,                          /* 5 */
      gxv_LookupTable_fmt6_validate, /* 6 */
      NULL,                          /* 7 */
      gxv_LookupTable_fmt8_validate, /* 8 */
    };
    GXV_Validate_Func func;


    GXV_NAME_ENTER(" LookupTable" );

    /* lookuptbl_head may be used in fmt4 transit function. */
    valid->lookuptbl_head = table;

    /* format */
    GXV_LIMIT_CHECK( 2 );
    format = FT_NEXT_USHORT( p );
    GXV_TRACE(( " (format %d)\n", format ));

    if ( format > 8 )
      FT_INVALID_FORMAT;

    func = fmt_funcs_table[format];
    if ( func == NULL )
      FT_INVALID_FORMAT;

    func( p, limit, valid );
    p += valid->subtable_length;

    valid->subtable_length = ( p - table );

    GXV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                          Glyph ID                             *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  FT_LOCAL_DEF( FT_Int )
  gxv_glyphid_validate( FT_UShort      gid,
                        GXV_Validator  valid )
  {
    FT_Face       face;


    if ( gid == 0xFFFF )
    {
      GXV_EXIT;
      return 1;
    }

    face = valid->face;
    if ( face->num_glyphs < gid )
    {
      GXV_TRACE(( " gxv_glyphid_check() gid overflow: num_glyphs %d < %d\n",
                   face->num_glyphs, gid ));
      if ( valid->root->level >= FT_VALIDATE_PARANOID )
        FT_INVALID_GLYPH_ID;
    }

    return 0;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                        CONTROL POINT                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  FT_LOCAL_DEF( void )
  gxv_ctlPoint_validate( FT_UShort      gid,
                         FT_Short       ctl_point,
                         GXV_Validator  valid )
  {
    FT_Face       face;
    FT_Error      error;

    FT_GlyphSlot  glyph;
    FT_Outline    outline;
    short         n_points;


    face = valid->face;

    error = FT_Load_Glyph( face,
                           gid,
                           FT_LOAD_NO_BITMAP|FT_LOAD_IGNORE_TRANSFORM );
    if ( error )
      FT_INVALID_GLYPH_ID;

    glyph    = face->glyph;
    outline  = glyph->outline;
    n_points = outline.n_points;


    if ( !( ctl_point < n_points ) )
      FT_INVALID_DATA;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                          SFNT NAME                            *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  FT_LOCAL_DEF( void )
  gxv_sfntName_validate( FT_UShort      name_index,
                         FT_UShort      min_index,
                         FT_UShort      max_index,
                         GXV_Validator  valid )
  {
    FT_SfntName  name;
    FT_Int       i;
    FT_UInt      nnames;


    GXV_NAME_ENTER( "sfntName" );

    if ( name_index < min_index || max_index < name_index )
      FT_INVALID_FORMAT;

    nnames = FT_Get_Sfnt_Name_Count (valid->face);
    for ( i = 0; i < nnames; i++ )
    {
      if ( FT_Get_Sfnt_Name( valid->face, i, &name ) != FT_Err_Ok )
        continue ;

      if ( name.name_id == name_index )
        goto Out;
    }

    GXV_TRACE(( "  nameIndex = %d (UNTITLED)\n", name_index ));
    FT_INVALID_DATA;

  Out:
    FT_TRACE1(( "  nameIndex = %d (", name_index ));
    GXV_TRACE_HEXDUMP_SFNTNAME( name );
    FT_TRACE1(( ")\n" ));

    GXV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                          STATE TABLE                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /* -------------------------- Class Table --------------------------- */

  /*
   * highestClass is used to notice how many class are defined in this
   * Class Subtable. Apple spec does not mention about whether undefined
   * hole in the class (e.g.: 0-3 are predefined, 4 is unused, 5 is used)
   * is permitted. At present, hole in defined class is not checked.
   *   -- suzuki toshiya <[email protected]>
   */

  static void
  gxv_ClassTable_validate( FT_Bytes       table,
                           FT_UShort*     length_p,
                           FT_UShort      stateSize,
                           FT_Byte*       maxClassID_p,
                           GXV_Validator  valid )
  {
    FT_Bytes  p     = table;
    FT_Bytes  limit = table + *length_p;
    FT_UShort firstGlyph;
    FT_UShort nGlyphs;


    GXV_NAME_ENTER( "ClassTable" );

    *maxClassID_p = 3;  /* Class 0,2,3 are predefined */

    GXV_LIMIT_CHECK( 2 + 2 );
    firstGlyph = FT_NEXT_USHORT( p );
    nGlyphs    = FT_NEXT_USHORT( p );

    GXV_TRACE(( " (firstGlyph = %d, nGlyphs = %d)\n", firstGlyph, nGlyphs ));

    if ( !nGlyphs )
      goto Out;

    gxv_glyphid_validate( firstGlyph + nGlyphs, valid );

    {
      FT_Byte    nGlyphInClass[256];
      FT_Byte    classID;
      FT_UShort  i;


      ft_memset( nGlyphInClass, 0, 256 );


      for ( i = 0; i < nGlyphs; i++ )
      {
        GXV_LIMIT_CHECK( 1 );
        classID = FT_NEXT_BYTE( p );
        switch ( classID )
        {
          /* following class should not be appear in class array */
          case 0:  /* end of text */
          case 2:  /* out of bounds */
          case 3:  /* end of line */
            FT_INVALID_DATA;
            break;

          case 1:  /* out of bounds */
          default: /* user-defined: 4 - ( stateSize - 1 ) */
            if ( classID >= stateSize )
              FT_INVALID_DATA;   /* assign glyph to undefined state */
            nGlyphInClass[classID]++;
            break;
        }
      }
      *length_p = ( p - table );


      /* scan max ClassID in use */
      for ( i = 0; i < stateSize; i++ )
        if ((3 < i) && (nGlyphInClass[i] > 0))
          *maxClassID_p = i;
    }

Out:
    GXV_TRACE(( "Declared stateSize=0x%02x, Used maxClassID=0x%02x\n", stateSize, *maxClassID_p ));
    GXV_EXIT;
  }

  /* --------------------------- State Array ----------------------------- */

  static void
  gxv_StateArray_validate( FT_Bytes       table,
                           FT_UShort*     length_p,
                           FT_Byte        maxClassID,
                           FT_UShort      stateSize,
                           FT_Byte*       maxState_p,
                           FT_Byte*       maxEntry_p,
                           GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_Bytes  limit = table + *length_p;
    FT_Byte   class;
    FT_Byte   entry;


    GXV_NAME_ENTER( "StateArray" );

    GXV_TRACE(( "parse %d bytes by stateSize=%d maxClassID=%d\n",
                       (int)(*length_p), stateSize, (int)(maxClassID) ));

    /*
     * 2 states are predefined and must be described in StateArray
     * state 0 (start of text), 1 (start of line)
     */
    GXV_LIMIT_CHECK( ( 1 + maxClassID ) * 2 );

    *maxState_p = 0;
    *maxEntry_p = 0;

    /* read if enough to read another state */
    while ( p + ( 1 + maxClassID ) <= limit )
    {
      (*maxState_p) ++;
      for ( class = 0; class <= maxClassID; class++ )
      {
        entry = FT_NEXT_BYTE( p );
        *maxEntry_p = FT_MAX( *maxEntry_p, entry );
      }
    }
    GXV_TRACE(( "parsed: maxState=%d, maxEntry=%d\n",
                         *maxState_p, *maxEntry_p ));

    *length_p = ( p - table );

    GXV_EXIT;
  }

  /* --------------------------- Entry Table ----------------------------- */

  static void
  gxv_EntryTable_validate( FT_Bytes       table,
                           FT_UShort*     length_p,
                           FT_Byte        maxEntry,
                           FT_UShort      stateArray,
                           FT_UShort      stateArray_length,
                           FT_Byte        maxClassID,
                           FT_Bytes       statetable_table,
                           FT_Bytes       statetable_limit,
                           GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_Bytes  limit = table + *length_p;
    FT_Byte   entry;
    FT_Byte   state;
    FT_Int    entrySize = 2 + 2 + GXV_GLYPHOFFSET_SIZE( statetable );
    GXV_XStateTable_GlyphOffsetDesc  glyphOffset;


    GXV_NAME_ENTER( "EntryTable" );

    GXV_TRACE(( "maxEntry=%d entrySize=%d\n", maxEntry, entrySize ));

    if ( ( maxEntry + 1 ) * entrySize > *length_p )
    {
      if ( valid->root->level >= FT_VALIDATE_PARANOID )
        FT_INVALID_TOO_SHORT;

      /* ftxvalidator, FontValidator warns and continues */
      maxEntry = ( *length_p / entrySize ) - 1;
      GXV_TRACE(( "too large maxEntry, shrink to %d fit EntryTable length\n",
                   maxEntry ));
    }


    for ( entry = 0; entry <= maxEntry; entry++ )
    {
      FT_UShort  newState;
      FT_UShort  flags;


      GXV_LIMIT_CHECK( 2 + 2 );
      newState = FT_NEXT_USHORT( p );
      flags    = FT_NEXT_USHORT( p );


      if ( newState < stateArray || stateArray + stateArray_length < newState )
      {
        GXV_TRACE(( " newState offset 0x%04x is out of stateArray\n", newState ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_OFFSET;
        continue;
      }


      if ( 0 != (( newState - stateArray ) % ( 1 + maxClassID )) )
      {
        GXV_TRACE(( " newState offset 0x%04x is not aligned to %d-classes\n",
                                      newState,  1 + maxClassID ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_OFFSET;
        continue;
      }


      state =  ( newState - stateArray ) / ( 1 + maxClassID );


      switch ( GXV_GLYPHOFFSET_FMT( statetable ) )
      {
        case GXV_GLYPHOFFSET_NONE:
          break;

        case GXV_GLYPHOFFSET_UCHAR:
          glyphOffset.uc = FT_NEXT_BYTE( p );
          break;

        case GXV_GLYPHOFFSET_CHAR:
          glyphOffset.c = FT_NEXT_CHAR( p );
          break;

        case GXV_GLYPHOFFSET_USHORT:
          glyphOffset.u = FT_NEXT_USHORT( p );
          break;

        case GXV_GLYPHOFFSET_SHORT:
          glyphOffset.s = FT_NEXT_SHORT( p );
          break;

        case GXV_GLYPHOFFSET_ULONG:
          glyphOffset.ul = FT_NEXT_ULONG( p );
          break;

        case GXV_GLYPHOFFSET_LONG:
          glyphOffset.l = FT_NEXT_LONG( p );
          break;

        default:
          if ( valid->root->level >= FT_VALIDATE_PARANOID )
            FT_INVALID_FORMAT;
      }

      if ( NULL != valid->statetable.entry_validate_func )
        valid->statetable.entry_validate_func( state,
                                               flags,
                                               glyphOffset,
                                               statetable_table,
                                               statetable_limit,
                                               valid );
    }
    *length_p = ( p - table );

    GXV_EXIT;
  }

  /* =========================== State Table ============================= */

  FT_LOCAL_DEF( void )
  gxv_StateTable_subtable_setup( FT_UShort      table_size,
                                 FT_UShort      classTable,
                                 FT_UShort      stateArray,
                                 FT_UShort      entryTable,
                                 FT_UShort*     classTable_length_p,
                                 FT_UShort*     stateArray_length_p,
                                 FT_UShort*     entryTable_length_p,
                                 GXV_Validator  valid )
  {
    FT_UShort   o[3];
    FT_UShort*  l[3];
    FT_UShort   buff[4];

    o[0] = classTable;
    o[1] = stateArray;
    o[2] = entryTable;
    l[0] = classTable_length_p;
    l[1] = stateArray_length_p;
    l[2] = entryTable_length_p;

    gxv_set_length_by_ushort_offset( o, l, buff, 3, table_size, valid );
  }

  FT_LOCAL_DEF( void )
  gxv_StateTable_validate( FT_Bytes       table,
                           FT_Bytes       limit,
                           GXV_Validator  valid )
  {
    FT_UShort   stateSize;
    FT_UShort   classTable;  /* offset to Class(Sub)Table */
    FT_UShort   stateArray;  /* offset to StateArray */
    FT_UShort   entryTable;  /* offset to EntryTable */
#define GXV_STATETABLE_HEADER_SIZE ( 2 + 2 + 2 + 2 )
#define GXV_STATEHEADER_SIZE GXV_STATETABLE_HEADER_SIZE
    FT_UShort   classTable_length;
    FT_UShort   stateArray_length;
    FT_UShort   entryTable_length;
    FT_Byte     maxClassID;
    FT_Byte     maxState;
    FT_Byte     maxEntry;

    GXV_StateTable_Subtable_Setup_Func  setup_func;

    FT_Bytes    p = table;


    GXV_NAME_ENTER( "StateTable" );

    GXV_TRACE(( "StateTable header\n" ));

    GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
    stateSize  = FT_NEXT_USHORT( p );
    classTable = FT_NEXT_USHORT( p );
    stateArray = FT_NEXT_USHORT( p );
    entryTable = FT_NEXT_USHORT( p );

    GXV_TRACE(( "stateSize=0x%04x\n", stateSize ));
    GXV_TRACE(( "offset to classTable=0x%04x\n", classTable ));
    GXV_TRACE(( "offset to stateArray=0x%04x\n", stateArray ));
    GXV_TRACE(( "offset to entryTable=0x%04x\n", entryTable ));

    if (stateSize > 0xFF)
      FT_INVALID_DATA;

    if ( valid->statetable.optdata_load_func != NULL )
      valid->statetable.optdata_load_func( p, limit, valid );


    if ( valid->statetable.subtable_setup_func != NULL)
      setup_func = valid->statetable.subtable_setup_func;
    else
      setup_func = gxv_StateTable_subtable_setup;

    setup_func( limit - table,
                classTable,
                stateArray,
                entryTable,
                &classTable_length,
                &stateArray_length,
                &entryTable_length,
                valid );


    GXV_TRACE(( "StateTable Subtables\n" ));

    if (classTable != 0)
      gxv_ClassTable_validate( table + classTable,
                               &classTable_length,
                               stateSize,
                               &maxClassID,
                               valid );
    else
      maxClassID = stateSize - 1;

    if (stateArray != 0)
      gxv_StateArray_validate( table + stateArray,
                               &stateArray_length,
                               maxClassID,
                               stateSize,
                               &maxState,
                               &maxEntry,
                               valid );
    else
    {
      maxState = 1; /* 0:start of text, 1:start of line are predefined */
      maxEntry = 0;
    }

    if (maxEntry > 0 && entryTable == 0)
      FT_INVALID_OFFSET;

    if (entryTable != 0)
      gxv_EntryTable_validate( table + entryTable,
                               &entryTable_length,
                               maxEntry,
                               stateArray,
                               stateArray_length,
                               maxClassID,
                               table,
                               limit,
                               valid );

    GXV_EXIT;
  }

  /* ================ eXtended State Table (for morx) =================== */

  FT_LOCAL_DEF( void )
  gxv_XStateTable_subtable_setup( FT_ULong       table_size,
                                  FT_ULong       classTable,
                                  FT_ULong       stateArray,
                                  FT_ULong       entryTable,
                                  FT_ULong*      classTable_length_p,
                                  FT_ULong*      stateArray_length_p,
                                  FT_ULong*      entryTable_length_p,
                                  GXV_Validator  valid )
  {
    FT_ULong   o[3];
    FT_ULong*  l[3];
    FT_ULong   buff[4];

    o[0] = classTable;
    o[1] = stateArray;
    o[2] = entryTable;
    l[0] = classTable_length_p;
    l[1] = stateArray_length_p;
    l[2] = entryTable_length_p;

    gxv_set_length_by_ulong_offset( o, l, buff, 4, table_size, valid );
  }


  static void
  gxv_XClassTable_lookupval_validate( FT_UShort            glyph,
                                      GXV_LookupValueDesc  value,
                                      GXV_Validator        valid )
  {
    if ( value.u >= valid->xstatetable.nClasses )
      FT_INVALID_DATA;
    if ( value.u > valid->xstatetable.maxClassID )
      valid->xstatetable.maxClassID = value.u;
  }


  /*
    +===============+ --------+
    | lookup header |         |
    +===============+         |
    | BinSrchHeader |         |
    +===============+         |
    | lastGlyph[0]  |         |
    +---------------+         |
    | firstGlyph[0] |         |    head of lookup table
    +---------------+         |             +
    | offset[0]     |    ->   |          offset            [byte]
    +===============+         |             +
    | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
    +---------------+         |
    | firstGlyph[1] |         |
    +---------------+         |
    | offset[1]     |         |
    +===============+         |
                              |
     ....                     |
                              |
    16bit value array         |
    +===============+         |
    |     value     | <-------+
     ....
  */
  static GXV_LookupValueDesc
  gxv_XClassTable_lookupfmt4_transit( FT_UShort            relative_gindex,
                                      GXV_LookupValueDesc  base_value,
                                      FT_Bytes             lookuptbl_limit,
                                      GXV_Validator        valid )
  {
    FT_Bytes             p;
    FT_Bytes             limit;
    FT_UShort            offset;
    GXV_LookupValueDesc  value;

    offset = base_value.u + ( relative_gindex * sizeof ( FT_UShort ) );

    p     = valid->lookuptbl_head + offset;
    limit = lookuptbl_limit;

    GXV_LIMIT_CHECK ( 2 );
    value.u = FT_NEXT_USHORT( p );

    return value;
  }


  static void
  gxv_XStateArray_validate( FT_Bytes       table,
                            FT_ULong*      length_p,
                            FT_UShort      maxClassID,
                            FT_ULong       stateSize,
                            FT_UShort*     maxState_p,
                            FT_UShort*     maxEntry_p,
                            GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_Bytes   limit = table + *length_p;
    FT_UShort  class;
    FT_UShort  entry;


    GXV_NAME_ENTER( "XStateArray" );

    GXV_TRACE(( "parse % 3d bytes by stateSize=% 3d maxClassID=% 3d\n",
                       (int)(*length_p), stateSize, (int)(maxClassID) ));

    /*
     * 2 states are predefined and must be described
     * state 0 (start of text), 1 (start of line)
     */
    GXV_LIMIT_CHECK( ( 1 + maxClassID ) * 2 * 2 );

    *maxState_p = 0;
    *maxEntry_p = 0;

    /* read if enough to read another state */
    while ( p + ( ( 1 + maxClassID ) * 2 ) <= limit )
    {
      (*maxState_p) ++;
      for ( class = 0; class <= maxClassID; class++ )
      {
        entry = FT_NEXT_USHORT( p );
        *maxEntry_p = FT_MAX( *maxEntry_p, entry );
      }
    }
    GXV_TRACE(( "parsed: maxState=%d, maxEntry=%d\n",
                         *maxState_p, *maxEntry_p ));

    *length_p = ( p - table );

    GXV_EXIT;
  }


  static void
  gxv_XEntryTable_validate( FT_Bytes       table,
                            FT_ULong*      length_p,
                            FT_UShort      maxEntry,
                            FT_ULong       stateArray,
                            FT_ULong       stateArray_length,
                            FT_UShort      maxClassID,
                            FT_Bytes       xstatetable_table,
                            FT_Bytes       xstatetable_limit,
                            GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_Bytes   limit = table + *length_p;
    FT_UShort  entry;
    FT_UShort  state;
    FT_Int     entrySize = 2 + 2 + GXV_GLYPHOFFSET_SIZE( xstatetable );


    GXV_NAME_ENTER( "XEntryTable" );
    GXV_TRACE(( "maxEntry=%d entrySize=%d\n", maxEntry, entrySize ));

    if ( ( p + ( maxEntry + 1 ) * entrySize ) > limit )
      FT_INVALID_TOO_SHORT;

    for (entry = 0; entry <= maxEntry ; entry++ )
    {
      FT_UShort  newState_idx;
      FT_UShort  flags;
      GXV_XStateTable_GlyphOffsetDesc  glyphOffset;


      GXV_LIMIT_CHECK( 2 + 2 );
      newState_idx = FT_NEXT_USHORT( p );
      flags        = FT_NEXT_USHORT( p );

      if ( stateArray_length < ( newState_idx * 2 ) )
      {
        GXV_TRACE(( "  newState index 0x%04x points out of stateArray\n", newState_idx ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_OFFSET;
      }

      state =  newState_idx / ( 1 + maxClassID );
      if ( 0 != ( newState_idx % ( 1 + maxClassID ) ) )
      {
        FT_TRACE4(( "-> new state = %d (supposed) but newState index 0x%04x is not aligned to %d-classes\n",
                                      state, newState_idx,  1 + maxClassID ));
        if ( valid->root->level >= FT_VALIDATE_PARANOID )
          FT_INVALID_OFFSET;
      }


      switch ( GXV_GLYPHOFFSET_FMT( xstatetable ) )
      {
        case GXV_GLYPHOFFSET_NONE:
          break;

        case GXV_GLYPHOFFSET_UCHAR:
          glyphOffset.uc = FT_NEXT_BYTE( p );
          break;

        case GXV_GLYPHOFFSET_CHAR:
          glyphOffset.c = FT_NEXT_CHAR( p );
          break;

        case GXV_GLYPHOFFSET_USHORT:
          glyphOffset.u = FT_NEXT_USHORT( p );
          break;

        case GXV_GLYPHOFFSET_SHORT:
          glyphOffset.s = FT_NEXT_SHORT( p );
          break;

        case GXV_GLYPHOFFSET_ULONG:
          glyphOffset.ul = FT_NEXT_ULONG( p );
          break;

        case GXV_GLYPHOFFSET_LONG:
          glyphOffset.l = FT_NEXT_LONG( p );
          break;

        default:
          if ( valid->root->level >= FT_VALIDATE_PARANOID )
            FT_INVALID_FORMAT;
      }

      if ( NULL != valid->xstatetable.entry_validate_func )
        valid->xstatetable.entry_validate_func( state,
                                                flags,
                                                glyphOffset,
                                                xstatetable_table,
                                                xstatetable_limit,
                                                valid );
    }

    *length_p = ( p - table );

    GXV_EXIT;
  }

  FT_LOCAL_DEF( void )
  gxv_XStateTable_validate( FT_Bytes       table,
                            FT_Bytes       limit,
                            GXV_Validator  valid )
  {
    /* StateHeader members */
    FT_ULong    classTable;  /* offset to Class(Sub)Table */
    FT_ULong    stateArray;  /* offset to StateArray */
    FT_ULong    entryTable;  /* offset to EntryTable */
#define GXV_XSTATETABLE_HEADER_SIZE ( 4 + 4 + 4 + 4 )
#define GXV_XSTATEHEADER_SIZE GXV_XSTATETABLE_HEADER_SIZE
    FT_ULong    classTable_length;
    FT_ULong    stateArray_length;
    FT_ULong    entryTable_length;
    FT_UShort   maxState;
    FT_UShort   maxEntry;

    GXV_XStateTable_Subtable_Setup_Func  setup_func;

    FT_Bytes    p = table;

    GXV_NAME_ENTER( "XStateTable" );

    GXV_TRACE(( "XStateTable header\n" ));

    GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
    valid->xstatetable.nClasses  = FT_NEXT_ULONG( p );
    classTable = FT_NEXT_ULONG( p );
    stateArray = FT_NEXT_ULONG( p );
    entryTable = FT_NEXT_ULONG( p );

    GXV_TRACE(( "nClasses =0x%08x\n", valid->xstatetable.nClasses ));
    GXV_TRACE(( "offset to classTable=0x%08x\n", classTable ));
    GXV_TRACE(( "offset to stateArray=0x%08x\n", stateArray ));
    GXV_TRACE(( "offset to entryTable=0x%08x\n", entryTable ));

    if ( valid->xstatetable.nClasses > 0xFFFF )
      FT_INVALID_DATA;

    GXV_TRACE(( "StateTable Subtables\n" ));

    if ( valid->xstatetable.optdata_load_func != NULL )
      valid->xstatetable.optdata_load_func( p, limit, valid );


    if ( valid->xstatetable.subtable_setup_func != NULL)
      setup_func = valid->xstatetable.subtable_setup_func;
    else
      setup_func = gxv_XStateTable_subtable_setup;

    setup_func( limit - table,
                classTable,
                stateArray,
                entryTable,
                &classTable_length,
                &stateArray_length,
                &entryTable_length,
                valid );


    if (classTable != 0)
    {
      valid->xstatetable.maxClassID = 0;
      valid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
      valid->lookupval_func   = gxv_XClassTable_lookupval_validate;
      valid->lookupfmt4_trans = gxv_XClassTable_lookupfmt4_transit;
      gxv_LookupTable_validate( table + classTable,
                                table + classTable + classTable_length,
                                valid );
      if ( valid->subtable_length < classTable_length )
        classTable_length = valid->subtable_length;
    }
    else
      valid->xstatetable.maxClassID = valid->xstatetable.nClasses - 1;


    if (stateArray != 0)
    {
      gxv_XStateArray_validate( table + stateArray,
                                &stateArray_length,
                                valid->xstatetable.maxClassID,
                                valid->xstatetable.nClasses,
                                &maxState,
                                &maxEntry,
                                valid );
    }
    else
    {
      maxState = 1; /* 0:start of text, 1:start of line are predefined */
      maxEntry = 0;
    }

    if (maxEntry > 0 && entryTable == 0)
      FT_INVALID_OFFSET;

    if (entryTable != 0)
    {
      gxv_XEntryTable_validate( table + entryTable,
                                &entryTable_length,
                                maxEntry,
                                stateArray,
                                stateArray_length,
                                valid->xstatetable.maxClassID,
                                table,
                                limit,
                                valid );
    }

    GXV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                        Table overlapping                      *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  FT_LOCAL_DEF( int )
  gxv_compare_ranges( FT_Bytes       table1_start,
                      FT_ULong       table1_length,
                      FT_Bytes       table2_start,
                      FT_ULong       table2_length,
                      GXV_Validator  valid )
  {
    if ( table1_start == table2_start )
    {
      if ( ( table1_length == 0 || table2_length == 0 ) )
        goto Out;
    }
    else if ( table1_start < table2_start )
    {
      if ( ( table1_start + table1_length ) <= table2_start )
        goto Out;
    }
    else if ( table1_start > table2_start )
    {
      if ( ( table1_start >= table2_start + table2_length ) )
        goto Out;
    }
    return 1;

  Out:
    return 0;
  }


  FT_LOCAL_DEF( void )
  gxv_odtect_add_range( FT_Bytes          start,
                        FT_ULong          length,
                        FT_String*        name,
                        GXV_odtect_Range  odtect )
  {
    odtect->range[ odtect->nRanges ].start  = start;
    odtect->range[ odtect->nRanges ].length = length;
    odtect->range[ odtect->nRanges ].name   = name;
    odtect->nRanges ++;
  }

  FT_LOCAL_DEF( void )
  gxv_odtect_validate( GXV_odtect_Range  odtect,
                       GXV_Validator     valid   )
  {
    FT_UInt  i, j;


    GXV_NAME_ENTER( "check overlap among multi ranges" );

    for ( i = 0; i < odtect->nRanges; i ++ )
      for ( j = 0; j < i; j ++ )
        if ( 0 != gxv_compare_ranges( odtect->range[i].start,
                                      odtect->range[i].length,
                                      odtect->range[j].start,
                                      odtect->range[j].length,
                                      valid )                      )
        {
          if ( odtect->range[i].name || odtect->range[j].name )
            GXV_TRACE(( "found overlap between range-%d and range-%d\n",
                         i, j ));
          else
            GXV_TRACE(( "found overlap between \"%s\" and \"%s\"\n",
                         odtect->range[i].name,
                         odtect->range[j].name ));
          FT_INVALID_OFFSET;
        }

    GXV_EXIT;
  }


/* END */