[Git][freetype/freetype][master] [sfnt] Clean up CMAP{4,12,13} handling.

Alexei Podtelezhnikov pushed to branch master at FreeType / FreeType

Commits:

d2544433

by Alexei Podtelezhnikov at 2023-04-08T23:15:41-04:00

[sfnt] Clean up CMAP{4,12,13} handling.

This moves the charcode overflow checks upstream and turns some
while-loops into the do-while ones to avoid the uninitialized warnings.
This should slightly reduce the number of checks and jumps.

* src/sfnt/ttcmap.c (tt_cmap{4,12,13}_next,
tt_cmap{4.12.13}_char_map_linear): Remove the charcode overflow check.
(tt_cmap{4,12,13}_char_map_binary): Ditto and use do-while.
(tt_cmap{12,13}_char_next): Add the overflow check.

1 changed file:

src/sfnt/ttcmap.c

Changes:

src/sfnt/ttcmap.c

@@ -794,9 +794,6 @@
      FT_UInt  charcode;
 -    if ( cmap->cur_charcode >= 0xFFFFUL )
 -      goto Fail;
+-
      charcode = (FT_UInt)cmap->cur_charcode + 1;
      if ( charcode < cmap->cur_start )
@@ -882,7 +879,6 @@
          charcode = cmap->cur_start;
+     }
 -  Fail:
      cmap->cur_charcode = (FT_UInt32)0xFFFFFFFFUL;
      cmap->cur_gindex   = 0;
+   }
@@ -1104,25 +1100,19 @@
      FT_UInt    num_segs2, start, end, offset;
      FT_Int     delta;
      FT_UInt    i, num_segs;
 -    FT_UInt32  charcode = *pcharcode;
 +    FT_UInt32  charcode = *pcharcode + next;
      FT_UInt    gindex   = 0;
      FT_Byte*   p;
      FT_Byte*   q;
      p = cmap->data + 6;
 -    num_segs2 = FT_PAD_FLOOR( TT_PEEK_USHORT( p ), 2 );
+-
 -    num_segs = num_segs2 >> 1;
 +    num_segs = TT_PEEK_USHORT( p ) >> 1;
      if ( !num_segs )
        return 0;
 -    if ( next )
 -      charcode++;
+-
 -    if ( charcode > 0xFFFFU )
 -      return 0;
 +    num_segs2 = num_segs << 1;
      /* linear search */
      p = cmap->data + 14;               /* ends table   */
@@ -1238,31 +1228,24 @@
      FT_UInt   num_segs2, start, end, offset;
      FT_Int    delta;
      FT_UInt   max, min, mid, num_segs;
 -    FT_UInt   charcode = (FT_UInt)*pcharcode;
 +    FT_UInt   charcode = (FT_UInt)*pcharcode + next;
      FT_UInt   gindex   = 0;
      FT_Byte*  p;
      p = cmap->data + 6;
 -    num_segs2 = FT_PAD_FLOOR( TT_PEEK_USHORT( p ), 2 );
 +    num_segs = TT_PEEK_USHORT( p ) >> 1;
 -    if ( !num_segs2 )
 +    if ( !num_segs )
        return 0;
 -    num_segs = num_segs2 >> 1;
+-
 -    /* make compiler happy */
 -    mid = num_segs;
 -    end = 0xFFFFU;
+-
 -    if ( next )
 -      charcode++;
 +    num_segs2 = num_segs << 1;
      min = 0;
      max = num_segs;
      /* binary search */
 -    while ( min < max )
 +    do
+     {
        mid    = ( min + max ) >> 1;
        p      = cmap->data + 14 + mid * 2;
@@ -1445,6 +1428,7 @@
          break;
+       }
+     }
 +    while ( min < max );
      if ( next )
+     {
@@ -1454,12 +1438,8 @@
        /* if `charcode' is not in any segment, then `mid' is */
        /* the segment nearest to `charcode'                  */
 -      if ( charcode > end )
 -      {
 -        mid++;
 -        if ( mid == num_segs )
 -          return 0;
 -      }
 +      if ( charcode > end && ++mid == num_segs )
 +        return 0;
        if ( tt_cmap4_set_range( cmap4, mid ) )
+       {
@@ -1474,7 +1454,6 @@
            cmap4->cur_gindex = gindex;
          else
+         {
 -          cmap4->cur_charcode = charcode;
            tt_cmap4_next( cmap4 );
            gindex = cmap4->cur_gindex;
+         }
@@ -2340,9 +2319,6 @@
      FT_UInt   gindex;
 -    if ( cmap->cur_charcode >= 0xFFFFFFFFUL )
 -      goto Fail;
+-
      char_code = cmap->cur_charcode + 1;
      for ( n = cmap->cur_group; n < cmap->num_groups; n++ )
@@ -2400,7 +2376,7 @@
      FT_UInt    gindex     = 0;
      FT_Byte*   p          = cmap->data + 12;
      FT_UInt32  num_groups = TT_PEEK_ULONG( p );
 -    FT_UInt32  char_code  = *pchar_code;
 +    FT_UInt32  char_code  = *pchar_code + next;
      FT_UInt32  start, end, start_id;
      FT_UInt32  max, min, mid;
@@ -2408,23 +2384,11 @@
      if ( !num_groups )
        return 0;
 -    /* make compiler happy */
 -    mid = num_groups;
 -    end = 0xFFFFFFFFUL;
+-
 -    if ( next )
 -    {
 -      if ( char_code >= 0xFFFFFFFFUL )
 -        return 0;
+-
 -      char_code++;
 -    }
+-
      min = 0;
      max = num_groups;
      /* binary search */
 -    while ( min < max )
 +    do
+     {
        mid = ( min + max ) >> 1;
        p   = cmap->data + 16 + 12 * mid;
@@ -2448,6 +2412,7 @@
          break;
+       }
+     }
 +    while ( min < max );
      if ( next )
+     {
@@ -2458,12 +2423,8 @@
        /* if `char_code' is not in any group, then `mid' is */
        /* the group nearest to `char_code'                  */
 -      if ( char_code > end )
 -      {
 -        mid++;
 -        if ( mid == num_groups )
 -          return 0;
 -      }
 +      if ( char_code > end && ++mid == num_groups )
 +        return 0;
        cmap12->valid        = 1;
        cmap12->cur_charcode = char_code;
@@ -2505,6 +2466,9 @@
      FT_UInt    gindex;
 +    if ( *pchar_code >= 0xFFFFFFFFUL )
 +      return 0;
++
      /* no need to search */
      if ( cmap12->valid && cmap12->cur_charcode == *pchar_code )
+     {
@@ -2688,9 +2652,6 @@
      FT_UInt   gindex;
 -    if ( cmap->cur_charcode >= 0xFFFFFFFFUL )
 -      goto Fail;
+-
      char_code = cmap->cur_charcode + 1;
      for ( n = cmap->cur_group; n < cmap->num_groups; n++ )
@@ -2718,7 +2679,6 @@
+       }
+     }
 -  Fail:
      cmap->valid = 0;
+   }
@@ -2731,7 +2691,7 @@
      FT_UInt    gindex     = 0;
      FT_Byte*   p          = cmap->data + 12;
      FT_UInt32  num_groups = TT_PEEK_ULONG( p );
 -    FT_UInt32  char_code  = *pchar_code;
 +    FT_UInt32  char_code  = *pchar_code + next;
      FT_UInt32  start, end;
      FT_UInt32  max, min, mid;
@@ -2739,23 +2699,11 @@
      if ( !num_groups )
        return 0;
 -    /* make compiler happy */
 -    mid = num_groups;
 -    end = 0xFFFFFFFFUL;
+-
 -    if ( next )
 -    {
 -      if ( char_code >= 0xFFFFFFFFUL )
 -        return 0;
+-
 -      char_code++;
 -    }
+-
      min = 0;
      max = num_groups;
      /* binary search */
 -    while ( min < max )
 +    do
+     {
        mid = ( min + max ) >> 1;
        p   = cmap->data + 16 + 12 * mid;
@@ -2774,6 +2722,7 @@
          break;
+       }
+     }
 +    while ( min < max );
      if ( next )
+     {
@@ -2784,12 +2733,8 @@
        /* if `char_code' is not in any group, then `mid' is */
        /* the group nearest to `char_code'                  */
 -      if ( char_code > end )
 -      {
 -        mid++;
 -        if ( mid == num_groups )
 -          return 0;
 -      }
 +      if ( char_code > end && ++mid == num_groups )
 +        return 0;
        cmap13->valid        = 1;
        cmap13->cur_charcode = char_code;
@@ -2831,6 +2776,9 @@
      FT_UInt    gindex;
 +    if ( *pchar_code >= 0xFFFFFFFFUL )
 +      return 0;
++
      /* no need to search */
      if ( cmap13->valid && cmap13->cur_charcode == *pchar_code )
+     {

From:	Alexei Podtelezhnikov (@apodtele)
Subject:	[Git][freetype/freetype][master] [sfnt] Clean up CMAP{4,12,13} handling.
Date:	Sun, 09 Apr 2023 03:33:28 +0000