psmodule.c

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Author : Ben Wagner
Date : 2023-06-01 19:38:36
Hash : 2fb8eda5
Message : */*: Remove many function pointer casts. In C it is undefined behavior to call a function through a function pointer of a different type. This is now detected by the Control Flow Integrity Sanitizer. All known issues have already been fixed. Prevent any accidental re-introduction by removing function pointer casts when defining services. The services will call the service functions through the function pointers on the service. As a result the functions must have the same type so there should be no need to cast. Removing the casts allows compilers to warn about assignment to an incompatible function pointer type.
src/psnames/psmodule.c
/****************************************************************************
 *
 * psmodule.c
 *
 *   psnames module implementation (body).
 *
 * Copyright (C) 1996-2023 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 <freetype/internal/ftdebug.h>
#include <freetype/internal/ftobjs.h>
#include <freetype/internal/services/svpscmap.h>

#include "psmodule.h"

  /*
   * The file `pstables.h' with its arrays and its function
   * `ft_get_adobe_glyph_index' is useful for other projects also (for
   * example, `pdfium' is using it).  However, if used as a C++ header,
   * including it in two different source files makes it necessary to use
   * `extern const' for the declaration of its arrays, otherwise the data
   * would be duplicated as mandated by the C++ standard.
   *
   * For this reason, we use `DEFINE_PS_TABLES' to guard the function
   * definitions, and `DEFINE_PS_TABLES_DATA' to provide both proper array
   * declarations and definitions.
   */
#include "pstables.h"
#define  DEFINE_PS_TABLES
#define  DEFINE_PS_TABLES_DATA
#include "pstables.h"

#include "psnamerr.h"


#ifdef FT_CONFIG_OPTION_POSTSCRIPT_NAMES


#ifdef FT_CONFIG_OPTION_ADOBE_GLYPH_LIST


#define VARIANT_BIT         0x80000000UL
#define BASE_GLYPH( code )  ( (FT_UInt32)( (code) & ~VARIANT_BIT ) )


  /* Return the Unicode value corresponding to a given glyph.  Note that */
  /* we do deal with glyph variants by detecting a non-initial dot in    */
  /* the name, as in `A.swash' or `e.final'; in this case, the           */
  /* VARIANT_BIT is set in the return value.                             */
  /*                                                                     */
  FT_CALLBACK_DEF( FT_UInt32 )
  ps_unicode_value( const char*  glyph_name )
  {
    /* If the name begins with `uni', then the glyph name may be a */
    /* hard-coded unicode character code.                          */
    if ( glyph_name[0] == 'u' &&
         glyph_name[1] == 'n' &&
         glyph_name[2] == 'i' )
    {
      /* determine whether the next four characters following are */
      /* hexadecimal.                                             */

      /* XXX: Add code to deal with ligatures, i.e. glyph names like */
      /*      `uniXXXXYYYYZZZZ'...                                   */

      FT_Int       count;
      FT_UInt32    value = 0;
      const char*  p     = glyph_name + 3;


      for ( count = 4; count > 0; count--, p++ )
      {
        char          c = *p;
        unsigned int  d;


        d = (unsigned char)c - '0';
        if ( d >= 10 )
        {
          d = (unsigned char)c - 'A';
          if ( d >= 6 )
            d = 16;
          else
            d += 10;
        }

        /* Exit if a non-uppercase hexadecimal character was found   */
        /* -- this also catches character codes below `0' since such */
        /* negative numbers cast to `unsigned int' are far too big.  */
        if ( d >= 16 )
          break;

        value = ( value << 4 ) + d;
      }

      /* there must be exactly four hex digits */
      if ( count == 0 )
      {
        if ( *p == '\0' )
          return value;
        if ( *p == '.' )
          return (FT_UInt32)( value | VARIANT_BIT );
      }
    }

    /* If the name begins with `u', followed by four to six uppercase */
    /* hexadecimal digits, it is a hard-coded unicode character code. */
    if ( glyph_name[0] == 'u' )
    {
      FT_Int       count;
      FT_UInt32    value = 0;
      const char*  p     = glyph_name + 1;


      for ( count = 6; count > 0; count--, p++ )
      {
        char          c = *p;
        unsigned int  d;


        d = (unsigned char)c - '0';
        if ( d >= 10 )
        {
          d = (unsigned char)c - 'A';
          if ( d >= 6 )
            d = 16;
          else
            d += 10;
        }

        if ( d >= 16 )
          break;

        value = ( value << 4 ) + d;
      }

      if ( count <= 2 )
      {
        if ( *p == '\0' )
          return value;
        if ( *p == '.' )
          return (FT_UInt32)( value | VARIANT_BIT );
      }
    }

    /* Look for a non-initial dot in the glyph name in order to */
    /* find variants like `A.swash', `e.final', etc.            */
    {
      FT_UInt32    value = 0;
      const char*  p     = glyph_name;


      for ( ; *p && *p != '.'; p++ )
        ;

      /* now look up the glyph in the Adobe Glyph List;      */
      /* `.notdef', `.null' and the empty name are short cut */
      if ( p > glyph_name )
      {
        value = (FT_UInt32)ft_get_adobe_glyph_index( glyph_name, p );

        if ( *p == '.' )
          value |= (FT_UInt32)VARIANT_BIT;
      }

      return value;
    }
  }


  /* ft_qsort callback to sort the unicode map */
  FT_COMPARE_DEF( int )
  compare_uni_maps( const void*  a,
                    const void*  b )
  {
    PS_UniMap*  map1 = (PS_UniMap*)a;
    PS_UniMap*  map2 = (PS_UniMap*)b;
    FT_UInt32   unicode1 = BASE_GLYPH( map1->unicode );
    FT_UInt32   unicode2 = BASE_GLYPH( map2->unicode );


    /* sort base glyphs before glyph variants */
    if ( unicode1 == unicode2 )
    {
      if ( map1->unicode > map2->unicode )
        return 1;
      else if ( map1->unicode < map2->unicode )
        return -1;
      else
        return 0;
    }
    else
    {
      if ( unicode1 > unicode2 )
        return 1;
      else if ( unicode1 < unicode2 )
        return -1;
      else
        return 0;
    }
  }


  /* support for extra glyphs not handled (well) in AGL; */
  /* we add extra mappings for them if necessary         */

#define EXTRA_GLYPH_LIST_SIZE  10

  static const FT_UInt32  ft_extra_glyph_unicodes[EXTRA_GLYPH_LIST_SIZE] =
  {
    /* WGL 4 */
    0x0394,
    0x03A9,
    0x2215,
    0x00AD,
    0x02C9,
    0x03BC,
    0x2219,
    0x00A0,
    /* Romanian */
    0x021A,
    0x021B
  };

  static const char  ft_extra_glyph_names[] =
  {
    'D','e','l','t','a',0,
    'O','m','e','g','a',0,
    'f','r','a','c','t','i','o','n',0,
    'h','y','p','h','e','n',0,
    'm','a','c','r','o','n',0,
    'm','u',0,
    'p','e','r','i','o','d','c','e','n','t','e','r','e','d',0,
    's','p','a','c','e',0,
    'T','c','o','m','m','a','a','c','c','e','n','t',0,
    't','c','o','m','m','a','a','c','c','e','n','t',0
  };

  static const FT_Int
  ft_extra_glyph_name_offsets[EXTRA_GLYPH_LIST_SIZE] =
  {
     0,
     6,
    12,
    21,
    28,
    35,
    38,
    53,
    59,
    72
  };


  static void
  ps_check_extra_glyph_name( const char*  gname,
                             FT_UInt      glyph,
                             FT_UInt*     extra_glyphs,
                             FT_UInt     *states )
  {
    FT_UInt  n;


    for ( n = 0; n < EXTRA_GLYPH_LIST_SIZE; n++ )
    {
      if ( ft_strcmp( ft_extra_glyph_names +
                        ft_extra_glyph_name_offsets[n], gname ) == 0 )
      {
        if ( states[n] == 0 )
        {
          /* mark this extra glyph as a candidate for the cmap */
          states[n]     = 1;
          extra_glyphs[n] = glyph;
        }

        return;
      }
    }
  }


  static void
  ps_check_extra_glyph_unicode( FT_UInt32  uni_char,
                                FT_UInt   *states )
  {
    FT_UInt  n;


    for ( n = 0; n < EXTRA_GLYPH_LIST_SIZE; n++ )
    {
      if ( uni_char == ft_extra_glyph_unicodes[n] )
      {
        /* disable this extra glyph from being added to the cmap */
        states[n] = 2;

        return;
      }
    }
  }


  /* Build a table that maps Unicode values to glyph indices. */
  FT_CALLBACK_DEF( FT_Error )
  ps_unicodes_init( FT_Memory             memory,
                    PS_Unicodes           table,
                    FT_UInt               num_glyphs,
                    PS_GetGlyphNameFunc   get_glyph_name,
                    PS_FreeGlyphNameFunc  free_glyph_name,
                    FT_Pointer            glyph_data )
  {
    FT_Error  error;

    FT_UInt  extra_glyph_list_states[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
    FT_UInt  extra_glyphs[EXTRA_GLYPH_LIST_SIZE];


    /* we first allocate the table */
    table->num_maps = 0;

    if ( !FT_QNEW_ARRAY( table->maps, num_glyphs + EXTRA_GLYPH_LIST_SIZE ) )
    {
      FT_UInt     n;
      FT_UInt     count;
      PS_UniMap*  map;
      FT_UInt32   uni_char;


      map = table->maps;

      for ( n = 0; n < num_glyphs; n++ )
      {
        const char*  gname = get_glyph_name( glyph_data, n );


        if ( gname && *gname )
        {
          ps_check_extra_glyph_name( gname, n,
                                     extra_glyphs, extra_glyph_list_states );
          uni_char = ps_unicode_value( gname );

          if ( BASE_GLYPH( uni_char ) != 0 )
          {
            ps_check_extra_glyph_unicode( uni_char,
                                          extra_glyph_list_states );
            map->unicode     = uni_char;
            map->glyph_index = n;
            map++;
          }

          if ( free_glyph_name )
            free_glyph_name( glyph_data, gname );
        }
      }

      for ( n = 0; n < EXTRA_GLYPH_LIST_SIZE; n++ )
      {
        if ( extra_glyph_list_states[n] == 1 )
        {
          /* This glyph name has an additional representation. */
          /* Add it to the cmap.                               */

          map->unicode     = ft_extra_glyph_unicodes[n];
          map->glyph_index = extra_glyphs[n];
          map++;
        }
      }

      /* now compress the table a bit */
      count = (FT_UInt)( map - table->maps );

      if ( count == 0 )
      {
        /* No unicode chars here! */
        FT_FREE( table->maps );
        if ( !error )
          error = FT_THROW( No_Unicode_Glyph_Name );
      }
      else
      {
        /* Reallocate if the number of used entries is much smaller. */
        if ( count < num_glyphs / 2 )
        {
          FT_MEM_QRENEW_ARRAY( table->maps,
                               num_glyphs + EXTRA_GLYPH_LIST_SIZE,
                               count );
          error = FT_Err_Ok;
        }

        /* Sort the table in increasing order of unicode values, */
        /* taking care of glyph variants.                        */
        ft_qsort( table->maps, count, sizeof ( PS_UniMap ),
                  compare_uni_maps );
      }

      table->num_maps = count;
    }

    return error;
  }


  FT_CALLBACK_DEF( FT_UInt )
  ps_unicodes_char_index( PS_Unicodes  table,
                          FT_UInt32    unicode )
  {
    PS_UniMap  *result = NULL;
    PS_UniMap  *min = table->maps;
    PS_UniMap  *max = min + table->num_maps;
    PS_UniMap  *mid = min + ( ( max - min ) >> 1 );


    /* Perform a binary search on the table. */
    while ( min < max )
    {
      FT_UInt32  base_glyph;


      if ( mid->unicode == unicode )
      {
        result = mid;
        break;
      }

      base_glyph = BASE_GLYPH( mid->unicode );

      if ( base_glyph == unicode )
        result = mid; /* remember match but continue search for base glyph */

      if ( base_glyph < unicode )
        min = mid + 1;
      else
        max = mid;

      /* reasonable prediction in a continuous block */
      mid += unicode - base_glyph;
      if ( mid >= max || mid < min )
        mid = min + ( ( max - min ) >> 1 );
    }

    if ( result )
      return result->glyph_index;
    else
      return 0;
  }


  FT_CALLBACK_DEF( FT_UInt )
  ps_unicodes_char_next( PS_Unicodes  table,
                         FT_UInt32   *unicode )
  {
    FT_UInt    result    = 0;
    FT_UInt32  char_code = *unicode + 1;


    {
      FT_UInt     min = 0;
      FT_UInt     max = table->num_maps;
      FT_UInt     mid = min + ( ( max - min ) >> 1 );
      PS_UniMap*  map;
      FT_UInt32   base_glyph;


      while ( min < max )
      {
        map = table->maps + mid;

        if ( map->unicode == char_code )
        {
          result = map->glyph_index;
          goto Exit;
        }

        base_glyph = BASE_GLYPH( map->unicode );

        if ( base_glyph == char_code )
          result = map->glyph_index;

        if ( base_glyph < char_code )
          min = mid + 1;
        else
          max = mid;

        /* reasonable prediction in a continuous block */
        mid += char_code - base_glyph;
        if ( mid >= max || mid < min )
          mid = min + ( max - min ) / 2;
      }

      if ( result )
        goto Exit;               /* we have a variant glyph */

      /* we didn't find it; check whether we have a map just above it */
      char_code = 0;

      if ( min < table->num_maps )
      {
        map       = table->maps + min;
        result    = map->glyph_index;
        char_code = BASE_GLYPH( map->unicode );
      }
    }

  Exit:
    *unicode = char_code;
    return result;
  }


#endif /* FT_CONFIG_OPTION_ADOBE_GLYPH_LIST */


  FT_CALLBACK_DEF( const char* )
  ps_get_macintosh_name( FT_UInt  name_index )
  {
    if ( name_index >= FT_NUM_MAC_NAMES )
      name_index = 0;

    return ft_standard_glyph_names + ft_mac_names[name_index];
  }


  FT_CALLBACK_DEF( const char* )
  ps_get_standard_strings( FT_UInt  sid )
  {
    if ( sid >= FT_NUM_SID_NAMES )
      return 0;

    return ft_standard_glyph_names + ft_sid_names[sid];
  }


#ifdef FT_CONFIG_OPTION_ADOBE_GLYPH_LIST

  FT_DEFINE_SERVICE_PSCMAPSREC(
    pscmaps_interface,

    ps_unicode_value,         /* PS_Unicode_ValueFunc      unicode_value         */
    ps_unicodes_init,         /* PS_Unicodes_InitFunc      unicodes_init         */
    ps_unicodes_char_index,   /* PS_Unicodes_CharIndexFunc unicodes_char_index   */
    ps_unicodes_char_next,    /* PS_Unicodes_CharNextFunc  unicodes_char_next    */

    ps_get_macintosh_name,    /* PS_Macintosh_NameFunc     macintosh_name        */
    ps_get_standard_strings,  /* PS_Adobe_Std_StringsFunc  adobe_std_strings     */

    t1_standard_encoding,                               /* adobe_std_encoding    */
    t1_expert_encoding                                  /* adobe_expert_encoding */
  )

#else

  FT_DEFINE_SERVICE_PSCMAPSREC(
    pscmaps_interface,

    NULL,                     /* PS_Unicode_ValueFunc      unicode_value         */
    NULL,                     /* PS_Unicodes_InitFunc      unicodes_init         */
    NULL,                     /* PS_Unicodes_CharIndexFunc unicodes_char_index   */
    NULL,                     /* PS_Unicodes_CharNextFunc  unicodes_char_next    */

    ps_get_macintosh_name,    /* PS_Macintosh_NameFunc     macintosh_name        */
    ps_get_standard_strings,  /* PS_Adobe_Std_StringsFunc  adobe_std_strings     */

    t1_standard_encoding,                               /* adobe_std_encoding    */
    t1_expert_encoding                                  /* adobe_expert_encoding */
  )

#endif /* FT_CONFIG_OPTION_ADOBE_GLYPH_LIST */


  FT_DEFINE_SERVICEDESCREC1(
    pscmaps_services,

    FT_SERVICE_ID_POSTSCRIPT_CMAPS, &pscmaps_interface )


  static FT_Pointer
  psnames_get_service( FT_Module    module,
                       const char*  service_id )
  {
    FT_UNUSED( module );

    return ft_service_list_lookup( pscmaps_services, service_id );
  }

#endif /* FT_CONFIG_OPTION_POSTSCRIPT_NAMES */


#ifndef FT_CONFIG_OPTION_POSTSCRIPT_NAMES
#define PUT_PS_NAMES_SERVICE( a )  NULL
#else
#define PUT_PS_NAMES_SERVICE( a )  a
#endif

  FT_DEFINE_MODULE(
    psnames_module_class,

    0,  /* this is not a font driver, nor a renderer */
    sizeof ( FT_ModuleRec ),

    "psnames",  /* driver name                         */
    0x10000L,   /* driver version                      */
    0x20000L,   /* driver requires FreeType 2 or above */

    PUT_PS_NAMES_SERVICE(
      (void*)&pscmaps_interface ),   /* module specific interface */

    NULL,                                        /* FT_Module_Constructor module_init   */
    NULL,                                        /* FT_Module_Destructor  module_done   */
    PUT_PS_NAMES_SERVICE( psnames_get_service )  /* FT_Module_Requester   get_interface */
  )


/* END */
kc3-lang/freetype/src/psnames/psmodule.c

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kc3-lang/freetype /src/psnames/psmodule.c
