Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 919 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-aat-layout-common.hh b/gfx/harfbuzz/src/hb-aat-layout-common.hh
new file mode 100644
index 0000000000..7d53c354da
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-aat-layout-common.hh
@@ -0,0 +1,919 @@
+/*
+ * Copyright © 2017  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.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_AAT_LAYOUT_COMMON_HH
+#define HB_AAT_LAYOUT_COMMON_HH
+
+#include "hb-aat-layout.hh"
+#include "hb-aat-map.hh"
+#include "hb-open-type.hh"
+
+namespace OT {
+struct GDEF;
+};
+
+namespace AAT {
+
+using namespace OT;
+
+
+struct ankr;
+
+struct hb_aat_apply_context_t :
+       hb_dispatch_context_t<hb_aat_apply_context_t, bool, HB_DEBUG_APPLY>
+{
+  const char *get_name () { return "APPLY"; }
+  template <typename T>
+  return_t dispatch (const T &obj) { return obj.apply (this); }
+  static return_t default_return_value () { return false; }
+  bool stop_sublookup_iteration (return_t r) const { return r; }
+
+  const hb_ot_shape_plan_t *plan;
+  hb_font_t *font;
+  hb_face_t *face;
+  hb_buffer_t *buffer;
+  hb_sanitize_context_t sanitizer;
+  const ankr *ankr_table;
+  const OT::GDEF *gdef_table;
+  const hb_sorted_vector_t<hb_aat_map_t::range_flags_t> *range_flags = nullptr;
+  hb_mask_t subtable_flags = 0;
+
+  /* Unused. For debug tracing only. */
+  unsigned int lookup_index;
+
+  HB_INTERNAL hb_aat_apply_context_t (const hb_ot_shape_plan_t *plan_,
+				      hb_font_t *font_,
+				      hb_buffer_t *buffer_,
+				      hb_blob_t *blob = const_cast<hb_blob_t *> (&Null (hb_blob_t)));
+
+  HB_INTERNAL ~hb_aat_apply_context_t ();
+
+  HB_INTERNAL void set_ankr_table (const AAT::ankr *ankr_table_);
+
+  void set_lookup_index (unsigned int i) { lookup_index = i; }
+};
+
+
+/*
+ * Lookup Table
+ */
+
+template <typename T> struct Lookup;
+
+template <typename T>
+struct LookupFormat0
+{
+  friend struct Lookup<T>;
+
+  private:
+  const T* get_value (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
+  {
+    if (unlikely (glyph_id >= num_glyphs)) return nullptr;
+    return &arrayZ[glyph_id];
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (arrayZ.sanitize (c, c->get_num_glyphs ()));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (arrayZ.sanitize (c, c->get_num_glyphs (), base));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier--format = 0 */
+  UnsizedArrayOf<T>
+		arrayZ;		/* Array of lookup values, indexed by glyph index. */
+  public:
+  DEFINE_SIZE_UNBOUNDED (2);
+};
+
+
+template <typename T>
+struct LookupSegmentSingle
+{
+  static constexpr unsigned TerminationWordCount = 2u;
+
+  int cmp (hb_codepoint_t g) const
+  { return g < first ? -1 : g <= last ? 0 : +1 ; }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && value.sanitize (c));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && value.sanitize (c, base));
+  }
+
+  HBGlyphID16	last;		/* Last GlyphID in this segment */
+  HBGlyphID16	first;		/* First GlyphID in this segment */
+  T		value;		/* The lookup value (only one) */
+  public:
+  DEFINE_SIZE_STATIC (4 + T::static_size);
+};
+
+template <typename T>
+struct LookupFormat2
+{
+  friend struct Lookup<T>;
+
+  private:
+  const T* get_value (hb_codepoint_t glyph_id) const
+  {
+    const LookupSegmentSingle<T> *v = segments.bsearch (glyph_id);
+    return v ? &v->value : nullptr;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (segments.sanitize (c));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (segments.sanitize (c, base));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier--format = 2 */
+  VarSizedBinSearchArrayOf<LookupSegmentSingle<T>>
+		segments;	/* The actual segments. These must already be sorted,
+				 * according to the first word in each one (the last
+				 * glyph in each segment). */
+  public:
+  DEFINE_SIZE_ARRAY (8, segments);
+};
+
+template <typename T>
+struct LookupSegmentArray
+{
+  static constexpr unsigned TerminationWordCount = 2u;
+
+  const T* get_value (hb_codepoint_t glyph_id, const void *base) const
+  {
+    return first <= glyph_id && glyph_id <= last ? &(base+valuesZ)[glyph_id - first] : nullptr;
+  }
+
+  int cmp (hb_codepoint_t g) const
+  { return g < first ? -1 : g <= last ? 0 : +1; }
+
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+		  first <= last &&
+		  valuesZ.sanitize (c, base, last - first + 1));
+  }
+  template <typename ...Ts>
+  bool sanitize (hb_sanitize_context_t *c, const void *base, Ts&&... ds) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+		  first <= last &&
+		  valuesZ.sanitize (c, base, last - first + 1, std::forward<Ts> (ds)...));
+  }
+
+  HBGlyphID16	last;		/* Last GlyphID in this segment */
+  HBGlyphID16	first;		/* First GlyphID in this segment */
+  NNOffset16To<UnsizedArrayOf<T>>
+		valuesZ;	/* A 16-bit offset from the start of
+				 * the table to the data. */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+template <typename T>
+struct LookupFormat4
+{
+  friend struct Lookup<T>;
+
+  private:
+  const T* get_value (hb_codepoint_t glyph_id) const
+  {
+    const LookupSegmentArray<T> *v = segments.bsearch (glyph_id);
+    return v ? v->get_value (glyph_id, this) : nullptr;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (segments.sanitize (c, this));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (segments.sanitize (c, this, base));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier--format = 4 */
+  VarSizedBinSearchArrayOf<LookupSegmentArray<T>>
+		segments;	/* The actual segments. These must already be sorted,
+				 * according to the first word in each one (the last
+				 * glyph in each segment). */
+  public:
+  DEFINE_SIZE_ARRAY (8, segments);
+};
+
+template <typename T>
+struct LookupSingle
+{
+  static constexpr unsigned TerminationWordCount = 1u;
+
+  int cmp (hb_codepoint_t g) const { return glyph.cmp (g); }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && value.sanitize (c));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && value.sanitize (c, base));
+  }
+
+  HBGlyphID16	glyph;		/* Last GlyphID */
+  T		value;		/* The lookup value (only one) */
+  public:
+  DEFINE_SIZE_STATIC (2 + T::static_size);
+};
+
+template <typename T>
+struct LookupFormat6
+{
+  friend struct Lookup<T>;
+
+  private:
+  const T* get_value (hb_codepoint_t glyph_id) const
+  {
+    const LookupSingle<T> *v = entries.bsearch (glyph_id);
+    return v ? &v->value : nullptr;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (entries.sanitize (c));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (entries.sanitize (c, base));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier--format = 6 */
+  VarSizedBinSearchArrayOf<LookupSingle<T>>
+		entries;	/* The actual entries, sorted by glyph index. */
+  public:
+  DEFINE_SIZE_ARRAY (8, entries);
+};
+
+template <typename T>
+struct LookupFormat8
+{
+  friend struct Lookup<T>;
+
+  private:
+  const T* get_value (hb_codepoint_t glyph_id) const
+  {
+    return firstGlyph <= glyph_id && glyph_id - firstGlyph < glyphCount ?
+	   &valueArrayZ[glyph_id - firstGlyph] : nullptr;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && valueArrayZ.sanitize (c, glyphCount));
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && valueArrayZ.sanitize (c, glyphCount, base));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier--format = 8 */
+  HBGlyphID16	firstGlyph;	/* First glyph index included in the trimmed array. */
+  HBUINT16	glyphCount;	/* Total number of glyphs (equivalent to the last
+				 * glyph minus the value of firstGlyph plus 1). */
+  UnsizedArrayOf<T>
+		valueArrayZ;	/* The lookup values (indexed by the glyph index
+				 * minus the value of firstGlyph). */
+  public:
+  DEFINE_SIZE_ARRAY (6, valueArrayZ);
+};
+
+template <typename T>
+struct LookupFormat10
+{
+  friend struct Lookup<T>;
+
+  private:
+  const typename T::type get_value_or_null (hb_codepoint_t glyph_id) const
+  {
+    if (!(firstGlyph <= glyph_id && glyph_id - firstGlyph < glyphCount))
+      return Null (T);
+
+    const HBUINT8 *p = &valueArrayZ[(glyph_id - firstGlyph) * valueSize];
+
+    unsigned int v = 0;
+    unsigned int count = valueSize;
+    for (unsigned int i = 0; i < count; i++)
+      v = (v << 8) | *p++;
+
+    return v;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+		  valueSize <= 4 &&
+		  valueArrayZ.sanitize (c, glyphCount * valueSize));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier--format = 8 */
+  HBUINT16	valueSize;	/* Byte size of each value. */
+  HBGlyphID16	firstGlyph;	/* First glyph index included in the trimmed array. */
+  HBUINT16	glyphCount;	/* Total number of glyphs (equivalent to the last
+				 * glyph minus the value of firstGlyph plus 1). */
+  UnsizedArrayOf<HBUINT8>
+		valueArrayZ;	/* The lookup values (indexed by the glyph index
+				 * minus the value of firstGlyph). */
+  public:
+  DEFINE_SIZE_ARRAY (8, valueArrayZ);
+};
+
+template <typename T>
+struct Lookup
+{
+  const T* get_value (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
+  {
+    switch (u.format) {
+    case 0: return u.format0.get_value (glyph_id, num_glyphs);
+    case 2: return u.format2.get_value (glyph_id);
+    case 4: return u.format4.get_value (glyph_id);
+    case 6: return u.format6.get_value (glyph_id);
+    case 8: return u.format8.get_value (glyph_id);
+    default:return nullptr;
+    }
+  }
+
+  const typename T::type get_value_or_null (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
+  {
+    switch (u.format) {
+      /* Format 10 cannot return a pointer. */
+      case 10: return u.format10.get_value_or_null (glyph_id);
+      default:
+      const T *v = get_value (glyph_id, num_glyphs);
+      return v ? *v : Null (T);
+    }
+  }
+
+  typename T::type get_class (hb_codepoint_t glyph_id,
+			      unsigned int num_glyphs,
+			      unsigned int outOfRange) const
+  {
+    const T *v = get_value (glyph_id, num_glyphs);
+    return v ? *v : outOfRange;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (!u.format.sanitize (c)) return_trace (false);
+    switch (u.format) {
+    case 0: return_trace (u.format0.sanitize (c));
+    case 2: return_trace (u.format2.sanitize (c));
+    case 4: return_trace (u.format4.sanitize (c));
+    case 6: return_trace (u.format6.sanitize (c));
+    case 8: return_trace (u.format8.sanitize (c));
+    case 10: return_trace (u.format10.sanitize (c));
+    default:return_trace (true);
+    }
+  }
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    if (!u.format.sanitize (c)) return_trace (false);
+    switch (u.format) {
+    case 0: return_trace (u.format0.sanitize (c, base));
+    case 2: return_trace (u.format2.sanitize (c, base));
+    case 4: return_trace (u.format4.sanitize (c, base));
+    case 6: return_trace (u.format6.sanitize (c, base));
+    case 8: return_trace (u.format8.sanitize (c, base));
+    case 10: return_trace (false); /* We don't support format10 here currently. */
+    default:return_trace (true);
+    }
+  }
+
+  protected:
+  union {
+  HBUINT16		format;		/* Format identifier */
+  LookupFormat0<T>	format0;
+  LookupFormat2<T>	format2;
+  LookupFormat4<T>	format4;
+  LookupFormat6<T>	format6;
+  LookupFormat8<T>	format8;
+  LookupFormat10<T>	format10;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+DECLARE_NULL_NAMESPACE_BYTES_TEMPLATE1 (AAT, Lookup, 2);
+
+enum { DELETED_GLYPH = 0xFFFF };
+
+/*
+ * (Extended) State Table
+ */
+
+template <typename T>
+struct Entry
+{
+  // This does seem like it's ever called.
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    /* Note, we don't recurse-sanitize data because we don't access it.
+     * That said, in our DEFINE_SIZE_STATIC we access T::static_size,
+     * which ensures that data has a simple sanitize(). To be determined
+     * if I need to remove that as well.
+     *
+     * HOWEVER! Because we are a template, our DEFINE_SIZE_STATIC
+     * assertion wouldn't be checked, hence the line below. */
+    static_assert (T::static_size, "");
+
+    return_trace (c->check_struct (this));
+  }
+
+  public:
+  HBUINT16	newState;	/* Byte offset from beginning of state table
+				 * to the new state. Really?!?! Or just state
+				 * number?  The latter in morx for sure. */
+  HBUINT16	flags;		/* Table specific. */
+  T		data;		/* Optional offsets to per-glyph tables. */
+  public:
+  DEFINE_SIZE_STATIC (4 + T::static_size);
+};
+
+template <>
+struct Entry<void>
+{
+  // This does seem like it's ever called.
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  public:
+  HBUINT16	newState;	/* Byte offset from beginning of state table to the new state. */
+  HBUINT16	flags;		/* Table specific. */
+  public:
+  DEFINE_SIZE_STATIC (4);
+};
+
+template <typename Types, typename Extra>
+struct StateTable
+{
+  typedef typename Types::HBUINT HBUINT;
+  typedef typename Types::HBUSHORT HBUSHORT;
+  typedef typename Types::ClassTypeNarrow ClassType;
+
+  enum State
+  {
+    STATE_START_OF_TEXT = 0,
+    STATE_START_OF_LINE = 1,
+  };
+  enum Class
+  {
+    CLASS_END_OF_TEXT = 0,
+    CLASS_OUT_OF_BOUNDS = 1,
+    CLASS_DELETED_GLYPH = 2,
+    CLASS_END_OF_LINE = 3,
+  };
+
+  int new_state (unsigned int newState) const
+  { return Types::extended ? newState : ((int) newState - (int) stateArrayTable) / (int) nClasses; }
+
+  unsigned int get_class (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
+  {
+    if (unlikely (glyph_id == DELETED_GLYPH)) return CLASS_DELETED_GLYPH;
+    return (this+classTable).get_class (glyph_id, num_glyphs, 1);
+  }
+
+  const Entry<Extra> *get_entries () const
+  { return (this+entryTable).arrayZ; }
+
+  const Entry<Extra> &get_entry (int state, unsigned int klass) const
+  {
+    if (unlikely (klass >= nClasses))
+      klass = StateTable::CLASS_OUT_OF_BOUNDS;
+
+    const HBUSHORT *states = (this+stateArrayTable).arrayZ;
+    const Entry<Extra> *entries = (this+entryTable).arrayZ;
+
+    unsigned int entry = states[state * nClasses + klass];
+    DEBUG_MSG (APPLY, nullptr, "e%u", entry);
+
+    return entries[entry];
+  }
+
+  bool sanitize (hb_sanitize_context_t *c,
+		 unsigned int *num_entries_out = nullptr) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!(c->check_struct (this) &&
+		    nClasses >= 4 /* Ensure pre-defined classes fit.  */ &&
+		    classTable.sanitize (c, this)))) return_trace (false);
+
+    const HBUSHORT *states = (this+stateArrayTable).arrayZ;
+    const Entry<Extra> *entries = (this+entryTable).arrayZ;
+
+    unsigned int num_classes = nClasses;
+    if (unlikely (hb_unsigned_mul_overflows (num_classes, states[0].static_size)))
+      return_trace (false);
+    unsigned int row_stride = num_classes * states[0].static_size;
+
+    /* Apple 'kern' table has this peculiarity:
+     *
+     * "Because the stateTableOffset in the state table header is (strictly
+     * speaking) redundant, some 'kern' tables use it to record an initial
+     * state where that should not be StartOfText. To determine if this is
+     * done, calculate what the stateTableOffset should be. If it's different
+     * from the actual stateTableOffset, use it as the initial state."
+     *
+     * We implement this by calling the initial state zero, but allow *negative*
+     * states if the start state indeed was not the first state.  Since the code
+     * is shared, this will also apply to 'mort' table.  The 'kerx' / 'morx'
+     * tables are not affected since those address states by index, not offset.
+     */
+
+    int min_state = 0;
+    int max_state = 0;
+    unsigned int num_entries = 0;
+
+    int state_pos = 0;
+    int state_neg = 0;
+    unsigned int entry = 0;
+    while (min_state < state_neg || state_pos <= max_state)
+    {
+      if (min_state < state_neg)
+      {
+	/* Negative states. */
+	if (unlikely (hb_unsigned_mul_overflows (min_state, num_classes)))
+	  return_trace (false);
+	if (unlikely (!c->check_range (&states[min_state * num_classes],
+				       -min_state,
+				       row_stride)))
+	  return_trace (false);
+	if ((c->max_ops -= state_neg - min_state) <= 0)
+	  return_trace (false);
+	{ /* Sweep new states. */
+	  const HBUSHORT *stop = &states[min_state * num_classes];
+	  if (unlikely (stop > states))
+	    return_trace (false);
+	  for (const HBUSHORT *p = states; stop < p; p--)
+	    num_entries = hb_max (num_entries, *(p - 1) + 1u);
+	  state_neg = min_state;
+	}
+      }
+
+      if (state_pos <= max_state)
+      {
+	/* Positive states. */
+	if (unlikely (!c->check_range (states,
+				       max_state + 1,
+				       row_stride)))
+	  return_trace (false);
+	if ((c->max_ops -= max_state - state_pos + 1) <= 0)
+	  return_trace (false);
+	{ /* Sweep new states. */
+	  if (unlikely (hb_unsigned_mul_overflows ((max_state + 1), num_classes)))
+	    return_trace (false);
+	  const HBUSHORT *stop = &states[(max_state + 1) * num_classes];
+	  if (unlikely (stop < states))
+	    return_trace (false);
+	  for (const HBUSHORT *p = &states[state_pos * num_classes]; p < stop; p++)
+	    num_entries = hb_max (num_entries, *p + 1u);
+	  state_pos = max_state + 1;
+	}
+      }
+
+      if (unlikely (!c->check_array (entries, num_entries)))
+	return_trace (false);
+      if ((c->max_ops -= num_entries - entry) <= 0)
+	return_trace (false);
+      { /* Sweep new entries. */
+	const Entry<Extra> *stop = &entries[num_entries];
+	for (const Entry<Extra> *p = &entries[entry]; p < stop; p++)
+	{
+	  int newState = new_state (p->newState);
+	  min_state = hb_min (min_state, newState);
+	  max_state = hb_max (max_state, newState);
+	}
+	entry = num_entries;
+      }
+    }
+
+    if (num_entries_out)
+      *num_entries_out = num_entries;
+
+    return_trace (true);
+  }
+
+  protected:
+  HBUINT	nClasses;	/* Number of classes, which is the number of indices
+				 * in a single line in the state array. */
+  NNOffsetTo<ClassType, HBUINT>
+		classTable;	/* Offset to the class table. */
+  NNOffsetTo<UnsizedArrayOf<HBUSHORT>, HBUINT>
+		stateArrayTable;/* Offset to the state array. */
+  NNOffsetTo<UnsizedArrayOf<Entry<Extra>>, HBUINT>
+		entryTable;	/* Offset to the entry array. */
+
+  public:
+  DEFINE_SIZE_STATIC (4 * sizeof (HBUINT));
+};
+
+template <typename HBUCHAR>
+struct ClassTable
+{
+  unsigned int get_class (hb_codepoint_t glyph_id, unsigned int outOfRange) const
+  {
+    unsigned int i = glyph_id - firstGlyph;
+    return i >= classArray.len ? outOfRange : classArray.arrayZ[i];
+  }
+  unsigned int get_class (hb_codepoint_t glyph_id,
+			  unsigned int num_glyphs HB_UNUSED,
+			  unsigned int outOfRange) const
+  {
+    return get_class (glyph_id, outOfRange);
+  }
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && classArray.sanitize (c));
+  }
+  protected:
+  HBGlyphID16		firstGlyph;	/* First glyph index included in the trimmed array. */
+  Array16Of<HBUCHAR>	classArray;	/* The class codes (indexed by glyph index minus
+					 * firstGlyph). */
+  public:
+  DEFINE_SIZE_ARRAY (4, classArray);
+};
+
+struct ObsoleteTypes
+{
+  static constexpr bool extended = false;
+  typedef HBUINT16 HBUINT;
+  typedef HBUINT8 HBUSHORT;
+  typedef ClassTable<HBUINT8> ClassTypeNarrow;
+  typedef ClassTable<HBUINT16> ClassTypeWide;
+
+  template <typename T>
+  static unsigned int offsetToIndex (unsigned int offset,
+				     const void *base,
+				     const T *array)
+  {
+    /* https://github.com/harfbuzz/harfbuzz/issues/3483 */
+    /* If offset is less than base, return an offset that would
+     * result in an address half a 32bit address-space away,
+     * to make sure sanitize fails even on 32bit builds. */
+    if (unlikely (offset < unsigned ((const char *) array - (const char *) base)))
+      return INT_MAX / T::static_size;
+
+    /* https://github.com/harfbuzz/harfbuzz/issues/2816 */
+    return (offset - unsigned ((const char *) array - (const char *) base)) / T::static_size;
+  }
+  template <typename T>
+  static unsigned int byteOffsetToIndex (unsigned int offset,
+					 const void *base,
+					 const T *array)
+  {
+    return offsetToIndex (offset, base, array);
+  }
+  template <typename T>
+  static unsigned int wordOffsetToIndex (unsigned int offset,
+					 const void *base,
+					 const T *array)
+  {
+    return offsetToIndex (2 * offset, base, array);
+  }
+};
+struct ExtendedTypes
+{
+  static constexpr bool extended = true;
+  typedef HBUINT32 HBUINT;
+  typedef HBUINT16 HBUSHORT;
+  typedef Lookup<HBUINT16> ClassTypeNarrow;
+  typedef Lookup<HBUINT16> ClassTypeWide;
+
+  template <typename T>
+  static unsigned int offsetToIndex (unsigned int offset,
+				     const void *base HB_UNUSED,
+				     const T *array HB_UNUSED)
+  {
+    return offset;
+  }
+  template <typename T>
+  static unsigned int byteOffsetToIndex (unsigned int offset,
+					 const void *base HB_UNUSED,
+					 const T *array HB_UNUSED)
+  {
+    return offset / 2;
+  }
+  template <typename T>
+  static unsigned int wordOffsetToIndex (unsigned int offset,
+					 const void *base HB_UNUSED,
+					 const T *array HB_UNUSED)
+  {
+    return offset;
+  }
+};
+
+template <typename Types, typename EntryData>
+struct StateTableDriver
+{
+  using StateTableT = StateTable<Types, EntryData>;
+  using EntryT = Entry<EntryData>;
+
+  StateTableDriver (const StateTableT &machine_,
+		    hb_buffer_t *buffer_,
+		    hb_face_t *face_) :
+	      machine (machine_),
+	      buffer (buffer_),
+	      num_glyphs (face_->get_num_glyphs ()) {}
+
+  template <typename context_t>
+  void drive (context_t *c, hb_aat_apply_context_t *ac)
+  {
+    if (!c->in_place)
+      buffer->clear_output ();
+
+    int state = StateTableT::STATE_START_OF_TEXT;
+    // If there's only one range, we already checked the flag.
+    auto *last_range = ac->range_flags && (ac->range_flags->length > 1) ? &(*ac->range_flags)[0] : nullptr;
+    for (buffer->idx = 0; buffer->successful;)
+    {
+      /* This block is copied in NoncontextualSubtable::apply. Keep in sync. */
+      if (last_range)
+      {
+	auto *range = last_range;
+	if (buffer->idx < buffer->len)
+	{
+	  unsigned cluster = buffer->cur().cluster;
+	  while (cluster < range->cluster_first)
+	    range--;
+	  while (cluster > range->cluster_last)
+	    range++;
+
+
+	  last_range = range;
+	}
+	if (!(range->flags & ac->subtable_flags))
+	{
+	  if (buffer->idx == buffer->len || unlikely (!buffer->successful))
+	    break;
+
+	  state = StateTableT::STATE_START_OF_TEXT;
+	  (void) buffer->next_glyph ();
+	  continue;
+	}
+      }
+
+      unsigned int klass = buffer->idx < buffer->len ?
+			   machine.get_class (buffer->cur().codepoint, num_glyphs) :
+			   (unsigned) StateTableT::CLASS_END_OF_TEXT;
+      DEBUG_MSG (APPLY, nullptr, "c%u at %u", klass, buffer->idx);
+      const EntryT &entry = machine.get_entry (state, klass);
+      const int next_state = machine.new_state (entry.newState);
+
+      /* Conditions under which it's guaranteed safe-to-break before current glyph:
+       *
+       * 1. There was no action in this transition; and
+       *
+       * 2. If we break before current glyph, the results will be the same. That
+       *    is guaranteed if:
+       *
+       *    2a. We were already in start-of-text state; or
+       *
+       *    2b. We are epsilon-transitioning to start-of-text state; or
+       *
+       *    2c. Starting from start-of-text state seeing current glyph:
+       *
+       *        2c'. There won't be any actions; and
+       *
+       *        2c". We would end up in the same state that we were going to end up
+       *             in now, including whether epsilon-transitioning.
+       *
+       *    and
+       *
+       * 3. If we break before current glyph, there won't be any end-of-text action
+       *    after previous glyph.
+       *
+       * This triples the transitions we need to look up, but is worth returning
+       * granular unsafe-to-break results. See eg.:
+       *
+       *   https://github.com/harfbuzz/harfbuzz/issues/2860
+       */
+      const EntryT *wouldbe_entry;
+      bool safe_to_break =
+	/* 1. */
+	!c->is_actionable (this, entry)
+      &&
+	/* 2. */
+	(
+	  /* 2a. */
+	  state == StateTableT::STATE_START_OF_TEXT
+	||
+	  /* 2b. */
+	  (
+	    (entry.flags & context_t::DontAdvance) &&
+	    next_state == StateTableT::STATE_START_OF_TEXT
+	  )
+	||
+	  /* 2c. */
+	  (
+	    wouldbe_entry = &machine.get_entry (StateTableT::STATE_START_OF_TEXT, klass)
+	  ,
+	    /* 2c'. */
+	    !c->is_actionable (this, *wouldbe_entry)
+	  &&
+	    /* 2c". */
+	    (
+	      next_state == machine.new_state (wouldbe_entry->newState)
+	    &&
+	      (entry.flags & context_t::DontAdvance) == (wouldbe_entry->flags & context_t::DontAdvance)
+	    )
+	  )
+	)
+      &&
+	/* 3. */
+	!c->is_actionable (this, machine.get_entry (state, StateTableT::CLASS_END_OF_TEXT))
+      ;
+
+      if (!safe_to_break && buffer->backtrack_len () && buffer->idx < buffer->len)
+	buffer->unsafe_to_break_from_outbuffer (buffer->backtrack_len () - 1, buffer->idx + 1);
+
+      c->transition (this, entry);
+
+      state = next_state;
+      DEBUG_MSG (APPLY, nullptr, "s%d", state);
+
+      if (buffer->idx == buffer->len || unlikely (!buffer->successful))
+	break;
+
+      if (!(entry.flags & context_t::DontAdvance) || buffer->max_ops-- <= 0)
+	(void) buffer->next_glyph ();
+    }
+
+    if (!c->in_place)
+      buffer->sync ();
+  }
+
+  public:
+  const StateTableT &machine;
+  hb_buffer_t *buffer;
+  unsigned int num_glyphs;
+};
+
+
+} /* namespace AAT */
+
+
+#endif /* HB_AAT_LAYOUT_COMMON_HH */