jdk/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-open-type-private.hh
changeset 34414 e496a8d8fc8a
child 40435 553eb1a50733
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-open-type-private.hh	Mon Nov 23 09:58:44 2015 -0800
@@ -0,0 +1,1046 @@
+/*
+ * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
+ * Copyright © 2012  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_OPEN_TYPE_PRIVATE_HH
+#define HB_OPEN_TYPE_PRIVATE_HH
+
+#include "hb-private.hh"
+
+
+namespace OT {
+
+
+
+/*
+ * Casts
+ */
+
+/* Cast to struct T, reference to reference */
+template<typename Type, typename TObject>
+static inline const Type& CastR(const TObject &X)
+{ return reinterpret_cast<const Type&> (X); }
+template<typename Type, typename TObject>
+static inline Type& CastR(TObject &X)
+{ return reinterpret_cast<Type&> (X); }
+
+/* Cast to struct T, pointer to pointer */
+template<typename Type, typename TObject>
+static inline const Type* CastP(const TObject *X)
+{ return reinterpret_cast<const Type*> (X); }
+template<typename Type, typename TObject>
+static inline Type* CastP(TObject *X)
+{ return reinterpret_cast<Type*> (X); }
+
+/* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory
+ * location pointed to by P plus Ofs bytes. */
+template<typename Type>
+static inline const Type& StructAtOffset(const void *P, unsigned int offset)
+{ return * reinterpret_cast<const Type*> ((const char *) P + offset); }
+template<typename Type>
+static inline Type& StructAtOffset(void *P, unsigned int offset)
+{ return * reinterpret_cast<Type*> ((char *) P + offset); }
+
+/* StructAfter<T>(X) returns the struct T& that is placed after X.
+ * Works with X of variable size also.  X must implement get_size() */
+template<typename Type, typename TObject>
+static inline const Type& StructAfter(const TObject &X)
+{ return StructAtOffset<Type>(&X, X.get_size()); }
+template<typename Type, typename TObject>
+static inline Type& StructAfter(TObject &X)
+{ return StructAtOffset<Type>(&X, X.get_size()); }
+
+
+
+/*
+ * Size checking
+ */
+
+/* Check _assertion in a method environment */
+#define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \
+  inline void _instance_assertion_on_line_##_line (void) const \
+  { \
+    ASSERT_STATIC (_assertion); \
+    ASSERT_INSTANCE_POD (*this); /* Make sure it's POD. */ \
+  }
+# define _DEFINE_INSTANCE_ASSERTION0(_line, _assertion) _DEFINE_INSTANCE_ASSERTION1 (_line, _assertion)
+# define DEFINE_INSTANCE_ASSERTION(_assertion) _DEFINE_INSTANCE_ASSERTION0 (__LINE__, _assertion)
+
+/* Check that _code compiles in a method environment */
+#define _DEFINE_COMPILES_ASSERTION1(_line, _code) \
+  inline void _compiles_assertion_on_line_##_line (void) const \
+  { _code; }
+# define _DEFINE_COMPILES_ASSERTION0(_line, _code) _DEFINE_COMPILES_ASSERTION1 (_line, _code)
+# define DEFINE_COMPILES_ASSERTION(_code) _DEFINE_COMPILES_ASSERTION0 (__LINE__, _code)
+
+
+#define DEFINE_SIZE_STATIC(size) \
+  DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size)); \
+  static const unsigned int static_size = (size); \
+  static const unsigned int min_size = (size)
+
+/* Size signifying variable-sized array */
+#define VAR 1
+
+#define DEFINE_SIZE_UNION(size, _member) \
+  DEFINE_INSTANCE_ASSERTION (this->u._member.static_size == (size)); \
+  static const unsigned int min_size = (size)
+
+#define DEFINE_SIZE_MIN(size) \
+  DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)); \
+  static const unsigned int min_size = (size)
+
+#define DEFINE_SIZE_ARRAY(size, array) \
+  DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \
+  DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \
+  static const unsigned int min_size = (size)
+
+#define DEFINE_SIZE_ARRAY2(size, array1, array2) \
+  DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \
+  DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].static_size) \
+  static const unsigned int min_size = (size)
+
+
+
+/*
+ * Null objects
+ */
+
+/* Global nul-content Null pool.  Enlarge as necessary. */
+/* TODO This really should be a extern HB_INTERNAL and defined somewhere... */
+static const void *_NullPool[(256+8) / sizeof (void *)];
+
+/* Generic nul-content Null objects. */
+template <typename Type>
+static inline const Type& Null (void) {
+  ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool));
+  return *CastP<Type> (_NullPool);
+}
+
+/* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
+#define DEFINE_NULL_DATA(Type, data) \
+static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \
+template <> \
+/*static*/ inline const Type& Null<Type> (void) { \
+  return *CastP<Type> (_Null##Type); \
+} /* The following line really exists such that we end in a place needing semicolon */ \
+ASSERT_STATIC (Type::min_size + 1 <= sizeof (_Null##Type))
+
+/* Accessor macro. */
+#define Null(Type) Null<Type>()
+
+
+/*
+ * Dispatch
+ */
+
+template <typename Context, typename Return, unsigned int MaxDebugDepth>
+struct hb_dispatch_context_t
+{
+  static const unsigned int max_debug_depth = MaxDebugDepth;
+  typedef Return return_t;
+  template <typename T, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
+  static return_t no_dispatch_return_value (void) { return Context::default_return_value (); }
+};
+
+
+/*
+ * Sanitize
+ */
+
+#ifndef HB_DEBUG_SANITIZE
+#define HB_DEBUG_SANITIZE (HB_DEBUG+0)
+#endif
+
+
+#define TRACE_SANITIZE(this) \
+        hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace \
+        (&c->debug_depth, c->get_name (), this, HB_FUNC, \
+         "");
+
+/* This limits sanitizing time on really broken fonts. */
+#ifndef HB_SANITIZE_MAX_EDITS
+#define HB_SANITIZE_MAX_EDITS 100
+#endif
+
+struct hb_sanitize_context_t :
+       hb_dispatch_context_t<hb_sanitize_context_t, bool, HB_DEBUG_SANITIZE>
+{
+  inline hb_sanitize_context_t (void) :
+        debug_depth (0),
+        start (NULL), end (NULL),
+        writable (false), edit_count (0),
+        blob (NULL) {}
+
+  inline const char *get_name (void) { return "SANITIZE"; }
+  template <typename T, typename F>
+  inline bool may_dispatch (const T *obj, const F *format)
+  { return format->sanitize (this); }
+  template <typename T>
+  inline return_t dispatch (const T &obj) { return obj.sanitize (this); }
+  static return_t default_return_value (void) { return true; }
+  static return_t no_dispatch_return_value (void) { return false; }
+  bool stop_sublookup_iteration (const return_t r) const { return !r; }
+
+  inline void init (hb_blob_t *b)
+  {
+    this->blob = hb_blob_reference (b);
+    this->writable = false;
+  }
+
+  inline void start_processing (void)
+  {
+    this->start = hb_blob_get_data (this->blob, NULL);
+    this->end = this->start + hb_blob_get_length (this->blob);
+    assert (this->start <= this->end); /* Must not overflow. */
+    this->edit_count = 0;
+    this->debug_depth = 0;
+
+    DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1,
+                     "start [%p..%p] (%lu bytes)",
+                     this->start, this->end,
+                     (unsigned long) (this->end - this->start));
+  }
+
+  inline void end_processing (void)
+  {
+    DEBUG_MSG_LEVEL (SANITIZE, this->start, 0, -1,
+                     "end [%p..%p] %u edit requests",
+                     this->start, this->end, this->edit_count);
+
+    hb_blob_destroy (this->blob);
+    this->blob = NULL;
+    this->start = this->end = NULL;
+  }
+
+  inline bool check_range (const void *base, unsigned int len) const
+  {
+    const char *p = (const char *) base;
+    bool ok = this->start <= p && p <= this->end && (unsigned int) (this->end - p) >= len;
+
+    DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
+       "check_range [%p..%p] (%d bytes) in [%p..%p] -> %s",
+       p, p + len, len,
+       this->start, this->end,
+       ok ? "OK" : "OUT-OF-RANGE");
+
+    return likely (ok);
+  }
+
+  inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
+  {
+    const char *p = (const char *) base;
+    bool overflows = _hb_unsigned_int_mul_overflows (len, record_size);
+    unsigned int array_size = record_size * len;
+    bool ok = !overflows && this->check_range (base, array_size);
+
+    DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
+       "check_array [%p..%p] (%d*%d=%d bytes) in [%p..%p] -> %s",
+       p, p + (record_size * len), record_size, len, (unsigned int) array_size,
+       this->start, this->end,
+       overflows ? "OVERFLOWS" : ok ? "OK" : "OUT-OF-RANGE");
+
+    return likely (ok);
+  }
+
+  template <typename Type>
+  inline bool check_struct (const Type *obj) const
+  {
+    return likely (this->check_range (obj, obj->min_size));
+  }
+
+  inline bool may_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED)
+  {
+    if (this->edit_count >= HB_SANITIZE_MAX_EDITS)
+      return false;
+
+    const char *p = (const char *) base;
+    this->edit_count++;
+
+    DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
+       "may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s",
+       this->edit_count,
+       p, p + len, len,
+       this->start, this->end,
+       this->writable ? "GRANTED" : "DENIED");
+
+    return this->writable;
+  }
+
+  template <typename Type, typename ValueType>
+  inline bool try_set (const Type *obj, const ValueType &v) {
+    if (this->may_edit (obj, obj->static_size)) {
+      const_cast<Type *> (obj)->set (v);
+      return true;
+    }
+    return false;
+  }
+
+  mutable unsigned int debug_depth;
+  const char *start, *end;
+  bool writable;
+  unsigned int edit_count;
+  hb_blob_t *blob;
+};
+
+
+
+/* Template to sanitize an object. */
+template <typename Type>
+struct Sanitizer
+{
+  static hb_blob_t *sanitize (hb_blob_t *blob) {
+    hb_sanitize_context_t c[1];
+    bool sane;
+
+    /* TODO is_sane() stuff */
+
+    c->init (blob);
+
+  retry:
+    DEBUG_MSG_FUNC (SANITIZE, c->start, "start");
+
+    c->start_processing ();
+
+    if (unlikely (!c->start)) {
+      c->end_processing ();
+      return blob;
+    }
+
+    Type *t = CastP<Type> (const_cast<char *> (c->start));
+
+    sane = t->sanitize (c);
+    if (sane) {
+      if (c->edit_count) {
+        DEBUG_MSG_FUNC (SANITIZE, c->start, "passed first round with %d edits; going for second round", c->edit_count);
+
+        /* sanitize again to ensure no toe-stepping */
+        c->edit_count = 0;
+        sane = t->sanitize (c);
+        if (c->edit_count) {
+          DEBUG_MSG_FUNC (SANITIZE, c->start, "requested %d edits in second round; FAILLING", c->edit_count);
+          sane = false;
+        }
+      }
+    } else {
+      unsigned int edit_count = c->edit_count;
+      if (edit_count && !c->writable) {
+        c->start = hb_blob_get_data_writable (blob, NULL);
+        c->end = c->start + hb_blob_get_length (blob);
+
+        if (c->start) {
+          c->writable = true;
+          /* ok, we made it writable by relocating.  try again */
+          DEBUG_MSG_FUNC (SANITIZE, c->start, "retry");
+          goto retry;
+        }
+      }
+    }
+
+    c->end_processing ();
+
+    DEBUG_MSG_FUNC (SANITIZE, c->start, sane ? "PASSED" : "FAILED");
+    if (sane)
+      return blob;
+    else {
+      hb_blob_destroy (blob);
+      return hb_blob_get_empty ();
+    }
+  }
+
+  static const Type* lock_instance (hb_blob_t *blob) {
+    hb_blob_make_immutable (blob);
+    const char *base = hb_blob_get_data (blob, NULL);
+    return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
+  }
+};
+
+
+
+/*
+ * Serialize
+ */
+
+#ifndef HB_DEBUG_SERIALIZE
+#define HB_DEBUG_SERIALIZE (HB_DEBUG+0)
+#endif
+
+
+#define TRACE_SERIALIZE(this) \
+        hb_auto_trace_t<HB_DEBUG_SERIALIZE, bool> trace \
+        (&c->debug_depth, "SERIALIZE", c, HB_FUNC, \
+         "");
+
+
+struct hb_serialize_context_t
+{
+  inline hb_serialize_context_t (void *start, unsigned int size)
+  {
+    this->start = (char *) start;
+    this->end = this->start + size;
+
+    this->ran_out_of_room = false;
+    this->head = this->start;
+    this->debug_depth = 0;
+  }
+
+  template <typename Type>
+  inline Type *start_serialize (void)
+  {
+    DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1,
+                     "start [%p..%p] (%lu bytes)",
+                     this->start, this->end,
+                     (unsigned long) (this->end - this->start));
+
+    return start_embed<Type> ();
+  }
+
+  inline void end_serialize (void)
+  {
+    DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1,
+                     "end [%p..%p] serialized %d bytes; %s",
+                     this->start, this->end,
+                     (int) (this->head - this->start),
+                     this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room");
+
+  }
+
+  template <typename Type>
+  inline Type *copy (void)
+  {
+    assert (!this->ran_out_of_room);
+    unsigned int len = this->head - this->start;
+    void *p = malloc (len);
+    if (p)
+      memcpy (p, this->start, len);
+    return reinterpret_cast<Type *> (p);
+  }
+
+  template <typename Type>
+  inline Type *allocate_size (unsigned int size)
+  {
+    if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) {
+      this->ran_out_of_room = true;
+      return NULL;
+    }
+    memset (this->head, 0, size);
+    char *ret = this->head;
+    this->head += size;
+    return reinterpret_cast<Type *> (ret);
+  }
+
+  template <typename Type>
+  inline Type *allocate_min (void)
+  {
+    return this->allocate_size<Type> (Type::min_size);
+  }
+
+  template <typename Type>
+  inline Type *start_embed (void)
+  {
+    Type *ret = reinterpret_cast<Type *> (this->head);
+    return ret;
+  }
+
+  template <typename Type>
+  inline Type *embed (const Type &obj)
+  {
+    unsigned int size = obj.get_size ();
+    Type *ret = this->allocate_size<Type> (size);
+    if (unlikely (!ret)) return NULL;
+    memcpy (ret, obj, size);
+    return ret;
+  }
+
+  template <typename Type>
+  inline Type *extend_min (Type &obj)
+  {
+    unsigned int size = obj.min_size;
+    assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
+    if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL;
+    return reinterpret_cast<Type *> (&obj);
+  }
+
+  template <typename Type>
+  inline Type *extend (Type &obj)
+  {
+    unsigned int size = obj.get_size ();
+    assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
+    if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL;
+    return reinterpret_cast<Type *> (&obj);
+  }
+
+  inline void truncate (void *head)
+  {
+    assert (this->start < head && head <= this->head);
+    this->head = (char *) head;
+  }
+
+  unsigned int debug_depth;
+  char *start, *end, *head;
+  bool ran_out_of_room;
+};
+
+template <typename Type>
+struct Supplier
+{
+  inline Supplier (const Type *array, unsigned int len_)
+  {
+    head = array;
+    len = len_;
+  }
+  inline const Type operator [] (unsigned int i) const
+  {
+    if (unlikely (i >= len)) return Type ();
+    return head[i];
+  }
+
+  inline void advance (unsigned int count)
+  {
+    if (unlikely (count > len))
+      count = len;
+    len -= count;
+    head += count;
+  }
+
+  private:
+  inline Supplier (const Supplier<Type> &); /* Disallow copy */
+  inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */
+
+  unsigned int len;
+  const Type *head;
+};
+
+
+
+
+/*
+ *
+ * The OpenType Font File: Data Types
+ */
+
+
+/* "The following data types are used in the OpenType font file.
+ *  All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
+
+/*
+ * Int types
+ */
+
+
+template <typename Type, int Bytes> struct BEInt;
+
+template <typename Type>
+struct BEInt<Type, 1>
+{
+  public:
+  inline void set (Type V)
+  {
+    v = V;
+  }
+  inline operator Type (void) const
+  {
+    return v;
+  }
+  private: uint8_t v;
+};
+template <typename Type>
+struct BEInt<Type, 2>
+{
+  public:
+  inline void set (Type V)
+  {
+    v[0] = (V >>  8) & 0xFF;
+    v[1] = (V      ) & 0xFF;
+  }
+  inline operator Type (void) const
+  {
+    return (v[0] <<  8)
+         + (v[1]      );
+  }
+  private: uint8_t v[2];
+};
+template <typename Type>
+struct BEInt<Type, 3>
+{
+  public:
+  inline void set (Type V)
+  {
+    v[0] = (V >> 16) & 0xFF;
+    v[1] = (V >>  8) & 0xFF;
+    v[2] = (V      ) & 0xFF;
+  }
+  inline operator Type (void) const
+  {
+    return (v[0] << 16)
+         + (v[1] <<  8)
+         + (v[2]      );
+  }
+  private: uint8_t v[3];
+};
+template <typename Type>
+struct BEInt<Type, 4>
+{
+  public:
+  inline void set (Type V)
+  {
+    v[0] = (V >> 24) & 0xFF;
+    v[1] = (V >> 16) & 0xFF;
+    v[2] = (V >>  8) & 0xFF;
+    v[3] = (V      ) & 0xFF;
+  }
+  inline operator Type (void) const
+  {
+    return (v[0] << 24)
+         + (v[1] << 16)
+         + (v[2] <<  8)
+         + (v[3]      );
+  }
+  private: uint8_t v[4];
+};
+
+/* Integer types in big-endian order and no alignment requirement */
+template <typename Type, unsigned int Size>
+struct IntType
+{
+  inline void set (Type i) { v.set (i); }
+  inline operator Type(void) const { return v; }
+  inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; }
+  inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); }
+  static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); }
+  inline int cmp (Type a) const
+  {
+    Type b = v;
+    if (sizeof (Type) < sizeof (int))
+      return (int) a - (int) b;
+    else
+      return a < b ? -1 : a == b ? 0 : +1;
+  }
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+  protected:
+  BEInt<Type, Size> v;
+  public:
+  DEFINE_SIZE_STATIC (Size);
+};
+
+typedef IntType<uint8_t , 1> BYTE;      /* 8-bit unsigned integer. */
+typedef IntType<uint16_t, 2> USHORT;    /* 16-bit unsigned integer. */
+typedef IntType<int16_t,  2> SHORT;     /* 16-bit signed integer. */
+typedef IntType<uint32_t, 4> ULONG;     /* 32-bit unsigned integer. */
+typedef IntType<int32_t,  4> LONG;      /* 32-bit signed integer. */
+typedef IntType<uint32_t, 3> UINT24;    /* 24-bit unsigned integer. */
+
+/* 16-bit signed integer (SHORT) that describes a quantity in FUnits. */
+typedef SHORT FWORD;
+
+/* 16-bit unsigned integer (USHORT) that describes a quantity in FUnits. */
+typedef USHORT UFWORD;
+
+/* Date represented in number of seconds since 12:00 midnight, January 1,
+ * 1904. The value is represented as a signed 64-bit integer. */
+struct LONGDATETIME
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+  protected:
+  LONG major;
+  ULONG minor;
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+/* Array of four uint8s (length = 32 bits) used to identify a script, language
+ * system, feature, or baseline */
+struct Tag : ULONG
+{
+  /* What the char* converters return is NOT nul-terminated.  Print using "%.4s" */
+  inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
+  inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
+  public:
+  DEFINE_SIZE_STATIC (4);
+};
+DEFINE_NULL_DATA (Tag, "    ");
+
+/* Glyph index number, same as uint16 (length = 16 bits) */
+struct GlyphID : USHORT {
+  static inline int cmp (const GlyphID *a, const GlyphID *b) { return b->USHORT::cmp (*a); }
+  inline int cmp (hb_codepoint_t a) const { return (int) a - (int) *this; }
+};
+
+/* Script/language-system/feature index */
+struct Index : USHORT {
+  static const unsigned int NOT_FOUND_INDEX = 0xFFFFu;
+};
+DEFINE_NULL_DATA (Index, "\xff\xff");
+
+/* Offset, Null offset = 0 */
+template <typename Type=USHORT>
+struct Offset : Type
+{
+  inline bool is_null (void) const { return 0 == *this; }
+  public:
+  DEFINE_SIZE_STATIC (sizeof(Type));
+};
+
+
+/* CheckSum */
+struct CheckSum : ULONG
+{
+  /* This is reference implementation from the spec. */
+  static inline uint32_t CalcTableChecksum (const ULONG *Table, uint32_t Length)
+  {
+    uint32_t Sum = 0L;
+    const ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size;
+
+    while (Table < EndPtr)
+      Sum += *Table++;
+    return Sum;
+  }
+
+  /* Note: data should be 4byte aligned and have 4byte padding at the end. */
+  inline void set_for_data (const void *data, unsigned int length)
+  { set (CalcTableChecksum ((const ULONG *) data, length)); }
+
+  public:
+  DEFINE_SIZE_STATIC (4);
+};
+
+
+/*
+ * Version Numbers
+ */
+
+struct FixedVersion
+{
+  inline uint32_t to_int (void) const { return (major << 16) + minor; }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  USHORT major;
+  USHORT minor;
+  public:
+  DEFINE_SIZE_STATIC (4);
+};
+
+
+
+/*
+ * Template subclasses of Offset that do the dereferencing.
+ * Use: (base+offset)
+ */
+
+template <typename Type, typename OffsetType=USHORT>
+struct OffsetTo : Offset<OffsetType>
+{
+  inline const Type& operator () (const void *base) const
+  {
+    unsigned int offset = *this;
+    if (unlikely (!offset)) return Null(Type);
+    return StructAtOffset<Type> (base, offset);
+  }
+
+  inline Type& serialize (hb_serialize_context_t *c, const void *base)
+  {
+    Type *t = c->start_embed<Type> ();
+    this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */
+    return *t;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!c->check_struct (this))) return_trace (false);
+    unsigned int offset = *this;
+    if (unlikely (!offset)) return_trace (true);
+    const Type &obj = StructAtOffset<Type> (base, offset);
+    return_trace (likely (obj.sanitize (c)) || neuter (c));
+  }
+  template <typename T>
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!c->check_struct (this))) return_trace (false);
+    unsigned int offset = *this;
+    if (unlikely (!offset)) return_trace (true);
+    const Type &obj = StructAtOffset<Type> (base, offset);
+    return_trace (likely (obj.sanitize (c, user_data)) || neuter (c));
+  }
+
+  /* Set the offset to Null */
+  inline bool neuter (hb_sanitize_context_t *c) const {
+    return c->try_set (this, 0);
+  }
+  DEFINE_SIZE_STATIC (sizeof(OffsetType));
+};
+template <typename Base, typename OffsetType, typename Type>
+static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); }
+template <typename Base, typename OffsetType, typename Type>
+static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); }
+
+
+/*
+ * Array Types
+ */
+
+/* An array with a number of elements. */
+template <typename Type, typename LenType=USHORT>
+struct ArrayOf
+{
+  const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
+  {
+    unsigned int count = len;
+    if (unlikely (start_offset > count))
+      count = 0;
+    else
+      count -= start_offset;
+    count = MIN (count, *pcount);
+    *pcount = count;
+    return array + start_offset;
+  }
+
+  inline const Type& operator [] (unsigned int i) const
+  {
+    if (unlikely (i >= len)) return Null(Type);
+    return array[i];
+  }
+  inline Type& operator [] (unsigned int i)
+  {
+    return array[i];
+  }
+  inline unsigned int get_size (void) const
+  { return len.static_size + len * Type::static_size; }
+
+  inline bool serialize (hb_serialize_context_t *c,
+                         unsigned int items_len)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    len.set (items_len); /* TODO(serialize) Overflow? */
+    if (unlikely (!c->extend (*this))) return_trace (false);
+    return_trace (true);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+                         Supplier<Type> &items,
+                         unsigned int items_len)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!serialize (c, items_len))) return_trace (false);
+    for (unsigned int i = 0; i < items_len; i++)
+      array[i] = items[i];
+    items.advance (items_len);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!sanitize_shallow (c))) return_trace (false);
+
+    /* Note: for structs that do not reference other structs,
+     * we do not need to call their sanitize() as we already did
+     * a bound check on the aggregate array size.  We just include
+     * a small unreachable expression to make sure the structs
+     * pointed to do have a simple sanitize(), ie. they do not
+     * reference other structs via offsets.
+     */
+    (void) (false && array[0].sanitize (c));
+
+    return_trace (true);
+  }
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!sanitize_shallow (c))) return_trace (false);
+    unsigned int count = len;
+    for (unsigned int i = 0; i < count; i++)
+      if (unlikely (!array[i].sanitize (c, base)))
+        return_trace (false);
+    return_trace (true);
+  }
+  template <typename T>
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!sanitize_shallow (c))) return_trace (false);
+    unsigned int count = len;
+    for (unsigned int i = 0; i < count; i++)
+      if (unlikely (!array[i].sanitize (c, base, user_data)))
+        return_trace (false);
+    return_trace (true);
+  }
+
+  template <typename SearchType>
+  inline int lsearch (const SearchType &x) const
+  {
+    unsigned int count = len;
+    for (unsigned int i = 0; i < count; i++)
+      if (!this->array[i].cmp (x))
+        return i;
+    return -1;
+  }
+
+  private:
+  inline bool sanitize_shallow (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && c->check_array (array, Type::static_size, len));
+  }
+
+  public:
+  LenType len;
+  Type array[VAR];
+  public:
+  DEFINE_SIZE_ARRAY (sizeof (LenType), array);
+};
+
+/* Array of Offset's */
+template <typename Type>
+struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
+
+/* Array of offsets relative to the beginning of the array itself. */
+template <typename Type>
+struct OffsetListOf : OffsetArrayOf<Type>
+{
+  inline const Type& operator [] (unsigned int i) const
+  {
+    if (unlikely (i >= this->len)) return Null(Type);
+    return this+this->array[i];
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (OffsetArrayOf<Type>::sanitize (c, this));
+  }
+  template <typename T>
+  inline bool sanitize (hb_sanitize_context_t *c, T user_data) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (OffsetArrayOf<Type>::sanitize (c, this, user_data));
+  }
+};
+
+
+/* An array starting at second element. */
+template <typename Type, typename LenType=USHORT>
+struct HeadlessArrayOf
+{
+  inline const Type& operator [] (unsigned int i) const
+  {
+    if (unlikely (i >= len || !i)) return Null(Type);
+    return array[i-1];
+  }
+  inline unsigned int get_size (void) const
+  { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
+
+  inline bool serialize (hb_serialize_context_t *c,
+                         Supplier<Type> &items,
+                         unsigned int items_len)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    len.set (items_len); /* TODO(serialize) Overflow? */
+    if (unlikely (!items_len)) return_trace (true);
+    if (unlikely (!c->extend (*this))) return_trace (false);
+    for (unsigned int i = 0; i < items_len - 1; i++)
+      array[i] = items[i];
+    items.advance (items_len - 1);
+    return_trace (true);
+  }
+
+  inline bool sanitize_shallow (hb_sanitize_context_t *c) const
+  {
+    return c->check_struct (this)
+        && c->check_array (this, Type::static_size, len);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!sanitize_shallow (c))) return_trace (false);
+
+    /* Note: for structs that do not reference other structs,
+     * we do not need to call their sanitize() as we already did
+     * a bound check on the aggregate array size.  We just include
+     * a small unreachable expression to make sure the structs
+     * pointed to do have a simple sanitize(), ie. they do not
+     * reference other structs via offsets.
+     */
+    (void) (false && array[0].sanitize (c));
+
+    return_trace (true);
+  }
+
+  LenType len;
+  Type array[VAR];
+  public:
+  DEFINE_SIZE_ARRAY (sizeof (LenType), array);
+};
+
+
+/* An array with sorted elements.  Supports binary searching. */
+template <typename Type, typename LenType=USHORT>
+struct SortedArrayOf : ArrayOf<Type, LenType>
+{
+  template <typename SearchType>
+  inline int bsearch (const SearchType &x) const
+  {
+    /* Hand-coded bsearch here since this is in the hot inner loop. */
+    int min = 0, max = (int) this->len - 1;
+    while (min <= max)
+    {
+      int mid = (min + max) / 2;
+      int c = this->array[mid].cmp (x);
+      if (c < 0)
+        max = mid - 1;
+      else if (c > 0)
+        min = mid + 1;
+      else
+        return mid;
+    }
+    return -1;
+  }
+};
+
+
+} /* namespace OT */
+
+
+#endif /* HB_OPEN_TYPE_PRIVATE_HH */