Update harfbuzz-ng to 1a5a91dc0d8bf4b72a2f22dc6300b06ad7000b79.

third_party/harfbuzz-ng/src/hb-ot-layout-gsub-private.hh

Index: third_party/harfbuzz-ng/src/hb-ot-layout-gsub-private.hh
diff --git a/third_party/harfbuzz-ng/src/hb-ot-layout-gsub-private.hh b/third_party/harfbuzz-ng/src/hb-ot-layout-gsub-private.hh
deleted file mode 100644
index ae1c5f3c5fdbdd12f61d779bda0f0a800ab0a4e6..0000000000000000000000000000000000000000
--- a/third_party/harfbuzz-ng/src/hb-ot-layout-gsub-private.hh
+++ /dev/null
@@ -1,931 +0,0 @@
-/*
- * Copyright (C) 2007,2008,2009,2010  Red Hat, Inc.
- * Copyright (C) 2010  Google, Inc.
- *
- *  This is part of HarfBuzz, a text shaping library.
- *
- * Permission is hereby granted, without written agreement and without
- * license or royalty fees, to use, copy, modify, and distribute this
- * software and its documentation for any purpose, provided that the
- * above copyright notice and the following two paragraphs appear in
- * all copies of this software.
- *
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
- * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
- * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
- * DAMAGE.
- *
- * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
- * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
- * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
- * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- *
- * Red Hat Author(s): Behdad Esfahbod
- * Google Author(s): Behdad Esfahbod
- */
-
-#ifndef HB_OT_LAYOUT_GSUB_PRIVATE_HH
-#define HB_OT_LAYOUT_GSUB_PRIVATE_HH
-
-#include "hb-ot-layout-gsubgpos-private.hh"
-
-HB_BEGIN_DECLS
-
-
-struct SingleSubstFormat1
-{
-  friend struct SingleSubst;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    hb_codepoint_t glyph_id = c->buffer->info[c->buffer->i].codepoint;
-    unsigned int index = (this+coverage) (glyph_id);
-    if (likely (index == NOT_COVERED))
-      return false;
-
-    glyph_id += deltaGlyphID;
-    c->replace_glyph (glyph_id);
-
-    return true;
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return coverage.sanitize (c, this)
-	&& deltaGlyphID.sanitize (c);
-  }
-
-  private:
-  USHORT	format;			/* Format identifier--format = 1 */
-  OffsetTo<Coverage>
-		coverage;		/* Offset to Coverage table--from
-					 * beginning of Substitution table */
-  SHORT		deltaGlyphID;		/* Add to original GlyphID to get
-					 * substitute GlyphID */
-  public:
-  DEFINE_SIZE_STATIC (6);
-};
-
-struct SingleSubstFormat2
-{
-  friend struct SingleSubst;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    hb_codepoint_t glyph_id = c->buffer->info[c->buffer->i].codepoint;
-    unsigned int index = (this+coverage) (glyph_id);
-    if (likely (index == NOT_COVERED))
-      return false;
-
-    if (unlikely (index >= substitute.len))
-      return false;
-
-    glyph_id = substitute[index];
-    c->replace_glyph (glyph_id);
-
-    return true;
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return coverage.sanitize (c, this)
-	&& substitute.sanitize (c);
-  }
-
-  private:
-  USHORT	format;			/* Format identifier--format = 2 */
-  OffsetTo<Coverage>
-		coverage;		/* Offset to Coverage table--from
-					 * beginning of Substitution table */
-  ArrayOf<GlyphID>
-		substitute;		/* Array of substitute
-					 * GlyphIDs--ordered by Coverage Index */
-  public:
-  DEFINE_SIZE_ARRAY (6, substitute);
-};
-
-struct SingleSubst
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    switch (u.format) {
-    case 1: return u.format1.apply (c);
-    case 2: return u.format2.apply (c);
-    default:return false;
-    }
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (!u.format.sanitize (c)) return false;
-    switch (u.format) {
-    case 1: return u.format1.sanitize (c);
-    case 2: return u.format2.sanitize (c);
-    default:return true;
-    }
-  }
-
-  private:
-  union {
-  USHORT		format;		/* Format identifier */
-  SingleSubstFormat1	format1;
-  SingleSubstFormat2	format2;
-  } u;
-};
-
-
-struct Sequence
-{
-  friend struct MultipleSubstFormat1;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    if (unlikely (!substitute.len))
-      return false;
-
-    if (c->property & HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE)
-      c->guess_glyph_class (HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH);
-    c->replace_glyphs_be16 (1, substitute.len, (const uint16_t *) substitute.array);
-
-    return true;
-  }
-
-  public:
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return substitute.sanitize (c);
-  }
-
-  private:
-  ArrayOf<GlyphID>
-		substitute;		/* String of GlyphIDs to substitute */
-  public:
-  DEFINE_SIZE_ARRAY (2, substitute);
-};
-
-struct MultipleSubstFormat1
-{
-  friend struct MultipleSubst;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-
-    unsigned int index = (this+coverage) (c->buffer->info[c->buffer->i].codepoint);
-    if (likely (index == NOT_COVERED))
-      return false;
-
-    return (this+sequence[index]).apply (c);
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return coverage.sanitize (c, this)
-	&& sequence.sanitize (c, this);
-  }
-
-  private:
-  USHORT	format;			/* Format identifier--format = 1 */
-  OffsetTo<Coverage>
-		coverage;		/* Offset to Coverage table--from
-					 * beginning of Substitution table */
-  OffsetArrayOf<Sequence>
-		sequence;		/* Array of Sequence tables
-					 * ordered by Coverage Index */
-  public:
-  DEFINE_SIZE_ARRAY (6, sequence);
-};
-
-struct MultipleSubst
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    switch (u.format) {
-    case 1: return u.format1.apply (c);
-    default:return false;
-    }
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (!u.format.sanitize (c)) return false;
-    switch (u.format) {
-    case 1: return u.format1.sanitize (c);
-    default:return true;
-    }
-  }
-
-  private:
-  union {
-  USHORT		format;		/* Format identifier */
-  MultipleSubstFormat1	format1;
-  } u;
-};
-
-
-typedef ArrayOf<GlyphID> AlternateSet;	/* Array of alternate GlyphIDs--in
-					 * arbitrary order */
-
-struct AlternateSubstFormat1
-{
-  friend struct AlternateSubst;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    hb_codepoint_t glyph_id = c->buffer->info[c->buffer->i].codepoint;
-    hb_mask_t glyph_mask = c->buffer->info[c->buffer->i].mask;
-    hb_mask_t lookup_mask = c->lookup_mask;
-
-    unsigned int index = (this+coverage) (glyph_id);
-    if (likely (index == NOT_COVERED))
-      return false;
-
-    const AlternateSet &alt_set = this+alternateSet[index];
-
-    if (unlikely (!alt_set.len))
-      return false;
-
-    /* Note: This breaks badly if two features enabled this lookup together. */
-    unsigned int shift = _hb_ctz (lookup_mask);
-    unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
-
-    if (unlikely (alt_index > alt_set.len || alt_index == 0))
-      return false;
-
-    glyph_id = alt_set[alt_index - 1];
-
-    c->replace_glyph (glyph_id);
-
-    return true;
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return coverage.sanitize (c, this)
-	&& alternateSet.sanitize (c, this);
-  }
-
-  private:
-  USHORT	format;			/* Format identifier--format = 1 */
-  OffsetTo<Coverage>
-		coverage;		/* Offset to Coverage table--from
-					 * beginning of Substitution table */
-  OffsetArrayOf<AlternateSet>
-		alternateSet;		/* Array of AlternateSet tables
-					 * ordered by Coverage Index */
-  public:
-  DEFINE_SIZE_ARRAY (6, alternateSet);
-};
-
-struct AlternateSubst
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    switch (u.format) {
-    case 1: return u.format1.apply (c);
-    default:return false;
-    }
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (!u.format.sanitize (c)) return false;
-    switch (u.format) {
-    case 1: return u.format1.sanitize (c);
-    default:return true;
-    }
-  }
-
-  private:
-  union {
-  USHORT		format;		/* Format identifier */
-  AlternateSubstFormat1	format1;
-  } u;
-};
-
-
-struct Ligature
-{
-  friend struct LigatureSet;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    unsigned int i, j;
-    unsigned int count = component.len;
-    unsigned int end = MIN (c->buffer->len, c->buffer->i + c->context_length);
-    if (unlikely (count < 2 || c->buffer->i + count > end))
-      return false;
-
-    bool first_was_mark = (c->property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
-    bool found_non_mark = false;
-
-    for (i = 1, j = c->buffer->i + 1; i < count; i++, j++)
-    {
-      unsigned int property;
-      while (_hb_ot_layout_skip_mark (c->layout->face, &c->buffer->info[j], c->lookup_props, &property))
-      {
-	if (unlikely (j + count - i == end))
-	  return false;
-	j++;
-      }
-
-      found_non_mark |= !(property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
-
-      if (likely (c->buffer->info[j].codepoint != component[i]))
-        return false;
-    }
-
-    if (first_was_mark && found_non_mark)
-      c->guess_glyph_class (HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE);
-
-    /* Allocate new ligature id */
-    unsigned int lig_id = allocate_lig_id (c->buffer);
-    c->buffer->info[c->buffer->i].lig_comp() = 0;
-    c->buffer->info[c->buffer->i].lig_id() = lig_id;
-
-    if (j == c->buffer->i + i) /* No input glyphs skipped */
-    {
-      c->replace_glyphs_be16 (i, 1, (const uint16_t *) &ligGlyph);
-    }
-    else
-    {
-      c->replace_glyph (ligGlyph);
-
-      /* Now we must do a second loop to copy the skipped glyphs to
-	 `out' and assign component values to it.  We start with the
-	 glyph after the first component.  Glyphs between component
-	 i and i+1 belong to component i.  Together with the lig_id
-	 value it is later possible to check whether a specific
-	 component value really belongs to a given ligature. */
-
-      for (i = 1; i < count; i++)
-      {
-	while (_hb_ot_layout_skip_mark (c->layout->face, &c->buffer->info[c->buffer->i], c->lookup_props, NULL))
-	{
-	  c->buffer->info[c->buffer->i].lig_comp() = i;
-	  c->buffer->info[c->buffer->i].lig_id() = lig_id;
-	  c->replace_glyph (c->buffer->info[c->buffer->i].codepoint);
-	}
-
-	/* Skip the base glyph */
-	c->buffer->i++;
-      }
-    }
-
-    return true;
-  }
-
-  inline uint16_t allocate_lig_id (hb_buffer_t *buffer) const {
-    uint16_t lig_id = buffer->next_serial ();
-    if (unlikely (!lig_id)) lig_id = buffer->next_serial (); /* in case of overflows */
-    return lig_id;
-  }
-
-  public:
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return ligGlyph.sanitize (c)
-        && component.sanitize (c);
-  }
-
-  private:
-  GlyphID	ligGlyph;		/* GlyphID of ligature to substitute */
-  HeadlessArrayOf<GlyphID>
-		component;		/* Array of component GlyphIDs--start
-					 * with the second  component--ordered
-					 * in writing direction */
-  public:
-  DEFINE_SIZE_ARRAY (4, component);
-};
-
-struct LigatureSet
-{
-  friend struct LigatureSubstFormat1;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    unsigned int num_ligs = ligature.len;
-    for (unsigned int i = 0; i < num_ligs; i++)
-    {
-      const Ligature &lig = this+ligature[i];
-      if (lig.apply (c))
-        return true;
-    }
-
-    return false;
-  }
-
-  public:
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return ligature.sanitize (c, this);
-  }
-
-  private:
-  OffsetArrayOf<Ligature>
-		ligature;		/* Array LigatureSet tables
-					 * ordered by preference */
-  public:
-  DEFINE_SIZE_ARRAY (2, ligature);
-};
-
-struct LigatureSubstFormat1
-{
-  friend struct LigatureSubst;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    hb_codepoint_t glyph_id = c->buffer->info[c->buffer->i].codepoint;
-
-    unsigned int index = (this+coverage) (glyph_id);
-    if (likely (index == NOT_COVERED))
-      return false;
-
-    const LigatureSet &lig_set = this+ligatureSet[index];
-    return lig_set.apply (c);
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    return coverage.sanitize (c, this)
-	&& ligatureSet.sanitize (c, this);
-  }
-
-  private:
-  USHORT	format;			/* Format identifier--format = 1 */
-  OffsetTo<Coverage>
-		coverage;		/* Offset to Coverage table--from
-					 * beginning of Substitution table */
-  OffsetArrayOf<LigatureSet>
-		ligatureSet;		/* Array LigatureSet tables
-					 * ordered by Coverage Index */
-  public:
-  DEFINE_SIZE_ARRAY (6, ligatureSet);
-};
-
-struct LigatureSubst
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    switch (u.format) {
-    case 1: return u.format1.apply (c);
-    default:return false;
-    }
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (!u.format.sanitize (c)) return false;
-    switch (u.format) {
-    case 1: return u.format1.sanitize (c);
-    default:return true;
-    }
-  }
-
-  private:
-  union {
-  USHORT		format;		/* Format identifier */
-  LigatureSubstFormat1	format1;
-  } u;
-};
-
-
-HB_BEGIN_DECLS
-static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index);
-HB_END_DECLS
-
-struct ContextSubst : Context
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    return Context::apply (c, substitute_lookup);
-  }
-};
-
-struct ChainContextSubst : ChainContext
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    return ChainContext::apply (c, substitute_lookup);
-  }
-};
-
-
-struct ExtensionSubst : Extension
-{
-  friend struct SubstLookupSubTable;
-  friend struct SubstLookup;
-
-  private:
-  inline const struct SubstLookupSubTable& get_subtable (void) const
-  {
-    unsigned int offset = get_offset ();
-    if (unlikely (!offset)) return Null(SubstLookupSubTable);
-    return StructAtOffset<SubstLookupSubTable> (this, offset);
-  }
-
-  inline bool apply (hb_apply_context_t *c) const;
-
-  inline bool sanitize (hb_sanitize_context_t *c);
-
-  inline bool is_reverse (void) const;
-};
-
-
-struct ReverseChainSingleSubstFormat1
-{
-  friend struct ReverseChainSingleSubst;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    if (unlikely (c->context_length != NO_CONTEXT))
-      return false; /* No chaining to this type */
-
-    unsigned int index = (this+coverage) (c->buffer->info[c->buffer->i].codepoint);
-    if (likely (index == NOT_COVERED))
-      return false;
-
-    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
-    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
-
-    if (match_backtrack (c,
-			 backtrack.len, (USHORT *) backtrack.array,
-			 match_coverage, this) &&
-        match_lookahead (c,
-			 lookahead.len, (USHORT *) lookahead.array,
-			 match_coverage, this,
-			 1))
-    {
-      c->buffer->info[c->buffer->i].codepoint = substitute[index];
-      c->buffer->i--; /* Reverse! */
-      return true;
-    }
-
-    return false;
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (!(coverage.sanitize (c, this)
-       && backtrack.sanitize (c, this)))
-      return false;
-    OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
-    if (!lookahead.sanitize (c, this))
-      return false;
-    ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
-    return substitute.sanitize (c);
-  }
-
-  private:
-  USHORT	format;			/* Format identifier--format = 1 */
-  OffsetTo<Coverage>
-		coverage;		/* Offset to Coverage table--from
-					 * beginning of table */
-  OffsetArrayOf<Coverage>
-		backtrack;		/* Array of coverage tables
-					 * in backtracking sequence, in  glyph
-					 * sequence order */
-  OffsetArrayOf<Coverage>
-		lookaheadX;		/* Array of coverage tables
-					 * in lookahead sequence, in glyph
-					 * sequence order */
-  ArrayOf<GlyphID>
-		substituteX;		/* Array of substitute
-					 * GlyphIDs--ordered by Coverage Index */
-  public:
-  DEFINE_SIZE_MIN (10);
-};
-
-struct ReverseChainSingleSubst
-{
-  friend struct SubstLookupSubTable;
-
-  private:
-  inline bool apply (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY ();
-    switch (u.format) {
-    case 1: return u.format1.apply (c);
-    default:return false;
-    }
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (!u.format.sanitize (c)) return false;
-    switch (u.format) {
-    case 1: return u.format1.sanitize (c);
-    default:return true;
-    }
-  }
-
-  private:
-  union {
-  USHORT				format;		/* Format identifier */
-  ReverseChainSingleSubstFormat1	format1;
-  } u;
-};
-
-
-
-/*
- * SubstLookup
- */
-
-struct SubstLookupSubTable
-{
-  friend struct SubstLookup;
-
-  enum {
-    Single		= 1,
-    Multiple		= 2,
-    Alternate		= 3,
-    Ligature		= 4,
-    Context		= 5,
-    ChainContext	= 6,
-    Extension		= 7,
-    ReverseChainSingle	= 8
-  };
-
-  inline bool apply (hb_apply_context_t *c, unsigned int lookup_type) const
-  {
-    TRACE_APPLY ();
-    switch (lookup_type) {
-    case Single:		return u.single.apply (c);
-    case Multiple:		return u.multiple.apply (c);
-    case Alternate:		return u.alternate.apply (c);
-    case Ligature:		return u.ligature.apply (c);
-    case Context:		return u.c.apply (c);
-    case ChainContext:		return u.chainContext.apply (c);
-    case Extension:		return u.extension.apply (c);
-    case ReverseChainSingle:	return u.reverseChainContextSingle.apply (c);
-    default:return false;
-    }
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
-    TRACE_SANITIZE ();
-    switch (lookup_type) {
-    case Single:		return u.single.sanitize (c);
-    case Multiple:		return u.multiple.sanitize (c);
-    case Alternate:		return u.alternate.sanitize (c);
-    case Ligature:		return u.ligature.sanitize (c);
-    case Context:		return u.c.sanitize (c);
-    case ChainContext:		return u.chainContext.sanitize (c);
-    case Extension:		return u.extension.sanitize (c);
-    case ReverseChainSingle:	return u.reverseChainContextSingle.sanitize (c);
-    default:return true;
-    }
-  }
-
-  private:
-  union {
-  USHORT			sub_format;
-  SingleSubst			single;
-  MultipleSubst			multiple;
-  AlternateSubst		alternate;
-  LigatureSubst			ligature;
-  ContextSubst			c;
-  ChainContextSubst		chainContext;
-  ExtensionSubst		extension;
-  ReverseChainSingleSubst	reverseChainContextSingle;
-  } u;
-  public:
-  DEFINE_SIZE_UNION (2, sub_format);
-};
-
-
-struct SubstLookup : Lookup
-{
-  inline const SubstLookupSubTable& get_subtable (unsigned int i) const
-  { return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
-
-  inline static bool lookup_type_is_reverse (unsigned int lookup_type)
-  { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
-
-  inline bool is_reverse (void) const
-  {
-    unsigned int type = get_type ();
-    if (unlikely (type == SubstLookupSubTable::Extension))
-      return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
-    return lookup_type_is_reverse (type);
-  }
-
-
-  inline bool apply_once (hb_ot_layout_context_t *layout,
-			  hb_buffer_t *buffer,
-			  hb_mask_t lookup_mask,
-			  unsigned int context_length,
-			  unsigned int nesting_level_left) const
-  {
-    unsigned int lookup_type = get_type ();
-    hb_apply_context_t c[1] = {{0}};
-
-    c->layout = layout;
-    c->buffer = buffer;
-    c->lookup_mask = lookup_mask;
-    c->context_length = context_length;
-    c->nesting_level_left = nesting_level_left;
-    c->lookup_props = get_props ();
-
-    if (!_hb_ot_layout_check_glyph_property (c->layout->face, &c->buffer->info[c->buffer->i], c->lookup_props, &c->property))
-      return false;
-
-    if (unlikely (lookup_type == SubstLookupSubTable::Extension))
-    {
-      /* The spec says all subtables should have the same type.
-       * This is specially important if one has a reverse type!
-       *
-       * This is rather slow to do this here for every glyph,
-       * but it's easiest, and who uses extension lookups anyway?!*/
-      unsigned int count = get_subtable_count ();
-      unsigned int type = get_subtable(0).u.extension.get_type ();
-      for (unsigned int i = 1; i < count; i++)
-        if (get_subtable(i).u.extension.get_type () != type)
-	  return false;
-    }
-
-    unsigned int count = get_subtable_count ();
-    for (unsigned int i = 0; i < count; i++)
-      if (get_subtable (i).apply (c, lookup_type))
-	return true;
-
-    return false;
-  }
-
-  inline bool apply_string (hb_ot_layout_context_t *layout,
-			    hb_buffer_t *buffer,
-			    hb_mask_t    mask) const
-  {
-    bool ret = false;
-
-    if (unlikely (!buffer->len))
-      return false;
-
-    if (likely (!is_reverse ()))
-    {
-	/* in/out forward substitution */
-	buffer->clear_output ();
-	buffer->i = 0;
-	while (buffer->i < buffer->len)
-	{
-	  if ((buffer->info[buffer->i].mask & mask) &&
-	      apply_once (layout, buffer, mask, NO_CONTEXT, MAX_NESTING_LEVEL))
-	    ret = true;
-	  else
-	    buffer->next_glyph ();
-
-	}
-	if (ret)
-	  buffer->swap ();
-    }
-    else
-    {
-	/* in-place backward substitution */
-	buffer->i = buffer->len - 1;
-	do
-	{
-	  if ((buffer->info[buffer->i].mask & mask) &&
-	      apply_once (layout, buffer, mask, NO_CONTEXT, MAX_NESTING_LEVEL))
-	    ret = true;
-	  else
-	    buffer->i--;
-
-	}
-	while ((int) buffer->i >= 0);
-    }
-
-    return ret;
-  }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (unlikely (!Lookup::sanitize (c))) return false;
-    OffsetArrayOf<SubstLookupSubTable> &list = CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable);
-    return list.sanitize (c, this, get_type ());
-  }
-};
-
-typedef OffsetListOf<SubstLookup> SubstLookupList;
-
-/*
- * GSUB
- */
-
-struct GSUB : GSUBGPOS
-{
-  static const hb_tag_t Tag	= HB_OT_TAG_GSUB;
-
-  inline const SubstLookup& get_lookup (unsigned int i) const
-  { return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
-
-  inline bool substitute_lookup (hb_ot_layout_context_t *layout,
-				 hb_buffer_t  *buffer,
-			         unsigned int  lookup_index,
-				 hb_mask_t     mask) const
-  { return get_lookup (lookup_index).apply_string (layout, buffer, mask); }
-
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE ();
-    if (unlikely (!GSUBGPOS::sanitize (c))) return false;
-    OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
-    return list.sanitize (c, this);
-  }
-  public:
-  DEFINE_SIZE_STATIC (10);
-};
-
-
-/* Out-of-class implementation for methods recursing */
-
-inline bool ExtensionSubst::apply (hb_apply_context_t *c) const
-{
-  TRACE_APPLY ();
-  return get_subtable ().apply (c, get_type ());
-}
-
-inline bool ExtensionSubst::sanitize (hb_sanitize_context_t *c)
-{
-  TRACE_SANITIZE ();
-  if (unlikely (!Extension::sanitize (c))) return false;
-  unsigned int offset = get_offset ();
-  if (unlikely (!offset)) return true;
-  return StructAtOffset<SubstLookupSubTable> (this, offset).sanitize (c, get_type ());
-}
-
-inline bool ExtensionSubst::is_reverse (void) const
-{
-  unsigned int type = get_type ();
-  if (unlikely (type == SubstLookupSubTable::Extension))
-    return CastR<ExtensionSubst> (get_subtable()).is_reverse ();
-  return SubstLookup::lookup_type_is_reverse (type);
-}
-
-static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index)
-{
-  const GSUB &gsub = *(c->layout->face->ot_layout->gsub);
-  const SubstLookup &l = gsub.get_lookup (lookup_index);
-
-  if (unlikely (c->nesting_level_left == 0))
-    return false;
-
-  if (unlikely (c->context_length < 1))
-    return false;
-
-  return l.apply_once (c->layout, c->buffer, c->lookup_mask, c->context_length, c->nesting_level_left - 1);
-}
-
-
-HB_END_DECLS
-
-#endif /* HB_OT_LAYOUT_GSUB_PRIVATE_HH */