src/hb-private.hh

/*
 * Copyright © 2007,2008,2009  Red Hat, Inc.
 * Copyright © 2011,2012  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_PRIVATE_HH
#define HB_PRIVATE_HH

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "hb.h"
#define HB_H_IN
#ifdef HAVE_OT
#include "hb-ot.h"
#define HB_OT_H_IN
#endif

#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <assert.h>

/* We only use these two for debug output.  However, the debug code is
 * always seen by the compiler (and optimized out in non-debug builds.
 * If including these becomes a problem, we can start thinking about
 * someway around that. */
#include <stdio.h>
#include <errno.h>
#include <stdarg.h>


/* Compile-time custom allocator support. */

#if defined(hb_malloc_impl) \
 && defined(hb_calloc_impl) \
 && defined(hb_realloc_impl) \
 && defined(hb_free_impl)
extern "C" void* hb_malloc_impl(size_t size);
extern "C" void* hb_calloc_impl(size_t nmemb, size_t size);
extern "C" void* hb_realloc_impl(void *ptr, size_t size);
extern "C" void  hb_free_impl(void *ptr);
#define malloc hb_malloc_impl
#define calloc hb_calloc_impl
#define realloc hb_realloc_impl
#define free hb_free_impl
#endif


/* Compiler attributes */


#if __cplusplus < 201103L

// Null pointer literal
// Source: SC22/WG21/N2431 = J16/07-0301
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf

const                        // this is a const object...
class {
public:
    template<class T>          // convertible to any type
    operator T*() const {    // of null non-member
        return 0;    // pointer...
    }
    template<class C, class T> // or any type of null
    operator T C::*() const { // member pointer...
        return 0;
    }
private:
    void operator&() const;    // whose address can't be taken
} _hb_nullptr = {};            // and whose name is nullptr
#define nullptr _hb_nullptr

// Static assertions
#ifndef static_assert
#define _PASTE1(a,b) a##b
#define _PASTE(a,b) _PASTE1(a,b)
#define static_assert(e, msg) \
	HB_UNUSED typedef int _PASTE(static_assertion_failed_at_line_, __LINE__) [(e) ? 1 : -1]
#endif // static_assert

#endif // __cplusplus < 201103L


#if (defined(__GNUC__) || defined(__clang__)) && defined(__OPTIMIZE__)
#define likely(expr) (__builtin_expect (!!(expr), 1))
#define unlikely(expr) (__builtin_expect (!!(expr), 0))
#else
#define likely(expr) (expr)
#define unlikely(expr) (expr)
#endif

#if !defined(__GNUC__) && !defined(__clang__)
#undef __attribute__
#define __attribute__(x)
#endif

#if __GNUC__ >= 3
#define HB_PURE_FUNC	__attribute__((pure))
#define HB_CONST_FUNC	__attribute__((const))
#define HB_PRINTF_FUNC(format_idx, arg_idx) __attribute__((__format__ (__printf__, format_idx, arg_idx)))
#else
#define HB_PURE_FUNC
#define HB_CONST_FUNC
#define HB_PRINTF_FUNC(format_idx, arg_idx)
#endif
#if __GNUC__ >= 4
#define HB_UNUSED	__attribute__((unused))
#else
#define HB_UNUSED
#endif

#ifndef HB_INTERNAL
# if !defined(__MINGW32__) && !defined(__CYGWIN__)
#  define HB_INTERNAL __attribute__((__visibility__("hidden")))
# else
#  define HB_INTERNAL
# endif
#endif

#if __GNUC__ >= 3
#define HB_FUNC __PRETTY_FUNCTION__
#elif defined(_MSC_VER)
#define HB_FUNC __FUNCSIG__
#else
#define HB_FUNC __func__
#endif

/*
 * Borrowed from https://bugzilla.mozilla.org/show_bug.cgi?id=1215411
 * HB_FALLTHROUGH is an annotation to suppress compiler warnings about switch
 * cases that fall through without a break or return statement. HB_FALLTHROUGH
 * is only needed on cases that have code:
 *
 * switch (foo) {
 *   case 1: // These cases have no code. No fallthrough annotations are needed.
 *   case 2:
 *   case 3:
 *     foo = 4; // This case has code, so a fallthrough annotation is needed:
 *     HB_FALLTHROUGH;
 *   default:
 *     return foo;
 * }
 */
#if defined(__clang__) && __cplusplus >= 201103L
   /* clang's fallthrough annotations are only available starting in C++11. */
#  define HB_FALLTHROUGH [[clang::fallthrough]]
#elif defined(_MSC_VER)
   /*
    * MSVC's __fallthrough annotations are checked by /analyze (Code Analysis):
    * https://msdn.microsoft.com/en-us/library/ms235402%28VS.80%29.aspx
    */
#  include <sal.h>
#  define HB_FALLTHROUGH __fallthrough
#else
#  define HB_FALLTHROUGH /* FALLTHROUGH */
#endif

#if defined(_WIN32) || defined(__CYGWIN__)
   /* We need Windows Vista for both Uniscribe backend and for
    * MemoryBarrier.  We don't support compiling on Windows XP,
    * though we run on it fine. */
#  if defined(_WIN32_WINNT) && _WIN32_WINNT < 0x0600
#    undef _WIN32_WINNT
#  endif
#  ifndef _WIN32_WINNT
#    define _WIN32_WINNT 0x0600
#  endif
#  ifndef WIN32_LEAN_AND_MEAN
#    define WIN32_LEAN_AND_MEAN 1
#  endif
#  ifndef STRICT
#    define STRICT 1
#  endif

#  if defined(_WIN32_WCE)
     /* Some things not defined on Windows CE. */
#    define vsnprintf _vsnprintf
#    define getenv(Name) nullptr
#    if _WIN32_WCE < 0x800
#      define setlocale(Category, Locale) "C"
static int errno = 0; /* Use something better? */
#    endif
#  elif defined(WINAPI_FAMILY) && (WINAPI_FAMILY==WINAPI_FAMILY_PC_APP || WINAPI_FAMILY==WINAPI_FAMILY_PHONE_APP)
#    define getenv(Name) nullptr
#  endif
#  if defined(_MSC_VER) && _MSC_VER < 1900
#    define snprintf _snprintf
#  endif
#endif

#if HAVE_ATEXIT
/* atexit() is only safe to be called from shared libraries on certain
 * platforms.  Whitelist.
 * https://bugs.freedesktop.org/show_bug.cgi?id=82246 */
#  if defined(__linux) && defined(__GLIBC_PREREQ)
#    if __GLIBC_PREREQ(2,3)
/* From atexit() manpage, it's safe with glibc 2.2.3 on Linux. */
#      define HB_USE_ATEXIT 1
#    endif
#  elif defined(_MSC_VER) || defined(__MINGW32__)
/* For MSVC:
 * http://msdn.microsoft.com/en-ca/library/tze57ck3.aspx
 * http://msdn.microsoft.com/en-ca/library/zk17ww08.aspx
 * mingw32 headers say atexit is safe to use in shared libraries.
 */
#    define HB_USE_ATEXIT 1
#  elif defined(__ANDROID__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
/* This was fixed in Android NKD r8 or r8b:
 * https://code.google.com/p/android/issues/detail?id=6455
 * which introduced GCC 4.6:
 * https://developer.android.com/tools/sdk/ndk/index.html
 */
#    define HB_USE_ATEXIT 1
#  endif
#endif

/* Basics */

#undef MIN
template <typename Type>
static inline Type MIN (const Type &a, const Type &b) { return a < b ? a : b; }

#undef MAX
template <typename Type>
static inline Type MAX (const Type &a, const Type &b) { return a > b ? a : b; }

static inline unsigned int DIV_CEIL (const unsigned int a, unsigned int b)
{ return (a + (b - 1)) / b; }


#undef  ARRAY_LENGTH
template <typename Type, unsigned int n>
static inline unsigned int ARRAY_LENGTH (const Type (&)[n]) { return n; }
/* A const version, but does not detect erratically being called on pointers. */
#define ARRAY_LENGTH_CONST(__array) ((signed int) (sizeof (__array) / sizeof (__array[0])))

#define HB_STMT_START do
#define HB_STMT_END   while (0)

template <unsigned int cond> class hb_assert_constant_t;
template <> class hb_assert_constant_t<1> {};

#define ASSERT_STATIC_EXPR_ZERO(_cond) (0 * (unsigned int) sizeof (hb_assert_constant_t<_cond>))

/* Lets assert int types.  Saves trouble down the road. */

static_assert ((sizeof (int8_t) == 1), "");
static_assert ((sizeof (uint8_t) == 1), "");
static_assert ((sizeof (int16_t) == 2), "");
static_assert ((sizeof (uint16_t) == 2), "");
static_assert ((sizeof (int32_t) == 4), "");
static_assert ((sizeof (uint32_t) == 4), "");
static_assert ((sizeof (int64_t) == 8), "");
static_assert ((sizeof (uint64_t) == 8), "");

static_assert ((sizeof (hb_codepoint_t) == 4), "");
static_assert ((sizeof (hb_position_t) == 4), "");
static_assert ((sizeof (hb_mask_t) == 4), "");
static_assert ((sizeof (hb_var_int_t) == 4), "");


/* We like our types POD */

#define _ASSERT_TYPE_POD1(_line, _type)	union _type_##_type##_on_line_##_line##_is_not_POD { _type instance; }
#define _ASSERT_TYPE_POD0(_line, _type)	_ASSERT_TYPE_POD1 (_line, _type)
#define ASSERT_TYPE_POD(_type)		_ASSERT_TYPE_POD0 (__LINE__, _type)

#ifdef __GNUC__
# define _ASSERT_INSTANCE_POD1(_line, _instance) \
	HB_STMT_START { \
		typedef __typeof__(_instance) _type_##_line; \
		_ASSERT_TYPE_POD1 (_line, _type_##_line); \
	} HB_STMT_END
#else
# define _ASSERT_INSTANCE_POD1(_line, _instance)	typedef int _assertion_on_line_##_line##_not_tested
#endif
# define _ASSERT_INSTANCE_POD0(_line, _instance)	_ASSERT_INSTANCE_POD1 (_line, _instance)
# define ASSERT_INSTANCE_POD(_instance)			_ASSERT_INSTANCE_POD0 (__LINE__, _instance)

/* Check _assertion in a method environment */
#define _ASSERT_POD1(_line) \
	HB_UNUSED inline void _static_assertion_on_line_##_line (void) const \
	{ _ASSERT_INSTANCE_POD1 (_line, *this); /* Make sure it's POD. */ }
# define _ASSERT_POD0(_line)	_ASSERT_POD1 (_line)
# define ASSERT_POD()		_ASSERT_POD0 (__LINE__)



/* Misc */

/* Void! */
struct _hb_void_t {};
typedef const _hb_void_t *hb_void_t;
#define HB_VOID ((const _hb_void_t *) nullptr)

/* Return the number of 1 bits in mask. */
static inline HB_CONST_FUNC unsigned int
_hb_popcount32 (uint32_t mask)
{
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
  return __builtin_popcount (mask);
#else
  /* "HACKMEM 169" */
  uint32_t y;
  y = (mask >> 1) &033333333333;
  y = mask - y - ((y >>1) & 033333333333);
  return (((y + (y >> 3)) & 030707070707) % 077);
#endif
}
static inline HB_CONST_FUNC unsigned int
_hb_popcount64 (uint64_t mask)
{
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
  return __builtin_popcountl (mask);
#else
  return _hb_popcount32 (mask) + _hb_popcount32 (mask >> 32);
#endif
}
template <typename T> static inline unsigned int _hb_popcount (T mask);
template <> inline unsigned int _hb_popcount<uint32_t> (uint32_t mask) { return _hb_popcount32 (mask); }
template <> inline unsigned int _hb_popcount<uint64_t> (uint64_t mask) { return _hb_popcount64 (mask); }

/* Returns the number of bits needed to store number */
static inline HB_CONST_FUNC unsigned int
_hb_bit_storage (unsigned int number)
{
#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(__OPTIMIZE__)
  return likely (number) ? (sizeof (unsigned int) * 8 - __builtin_clz (number)) : 0;
#else
  unsigned int n_bits = 0;
  while (number) {
    n_bits++;
    number >>= 1;
  }
  return n_bits;
#endif
}

/* Returns the number of zero bits in the least significant side of number */
static inline HB_CONST_FUNC unsigned int
_hb_ctz (unsigned int number)
{
#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(__OPTIMIZE__)
  return likely (number) ? __builtin_ctz (number) : 0;
#else
  unsigned int n_bits = 0;
  if (unlikely (!number)) return 0;
  while (!(number & 1)) {
    n_bits++;
    number >>= 1;
  }
  return n_bits;
#endif
}

static inline bool
_hb_unsigned_int_mul_overflows (unsigned int count, unsigned int size)
{
  return (size > 0) && (count >= ((unsigned int) -1) / size);
}


/* Type of bsearch() / qsort() compare function */
typedef int (*hb_compare_func_t) (const void *, const void *);




/* arrays and maps */


#define HB_PREALLOCED_ARRAY_INIT {0, 0, nullptr}
template <typename Type, unsigned int StaticSize=16>
struct hb_prealloced_array_t
{
  unsigned int len;
  unsigned int allocated;
  Type *array;
  Type static_array[StaticSize];

  void init (void) { memset (this, 0, sizeof (*this)); }

  inline Type& operator [] (unsigned int i) { return array[i]; }
  inline const Type& operator [] (unsigned int i) const { return array[i]; }

  inline Type *push (void)
  {
    if (!array) {
      array = static_array;
      allocated = ARRAY_LENGTH (static_array);
    }
    if (likely (len < allocated))
      return &array[len++];

    /* Need to reallocate */
    unsigned int new_allocated = allocated + (allocated >> 1) + 8;
    Type *new_array = nullptr;

    if (array == static_array) {
      new_array = (Type *) calloc (new_allocated, sizeof (Type));
      if (new_array)
        memcpy (new_array, array, len * sizeof (Type));
    } else {
      bool overflows = (new_allocated < allocated) || _hb_unsigned_int_mul_overflows (new_allocated, sizeof (Type));
      if (likely (!overflows)) {
	new_array = (Type *) realloc (array, new_allocated * sizeof (Type));
      }
    }

    if (unlikely (!new_array))
      return nullptr;

    array = new_array;
    allocated = new_allocated;
    return &array[len++];
  }

  inline void pop (void)
  {
    len--;
  }

  inline void remove (unsigned int i)
  {
     if (unlikely (i >= len))
       return;
     memmove (static_cast<void *> (&array[i]),
	      static_cast<void *> (&array[i + 1]),
	      (len - i - 1) * sizeof (Type));
     len--;
  }

  inline void shrink (unsigned int l)
  {
     if (l < len)
       len = l;
  }

  template <typename T>
  inline Type *find (T v) {
    for (unsigned int i = 0; i < len; i++)
      if (array[i] == v)
	return &array[i];
    return nullptr;
  }
  template <typename T>
  inline const Type *find (T v) const {
    for (unsigned int i = 0; i < len; i++)
      if (array[i] == v)
	return &array[i];
    return nullptr;
  }

  inline void qsort (void)
  {
    ::qsort (array, len, sizeof (Type), (hb_compare_func_t) Type::cmp);
  }

  inline void qsort (unsigned int start, unsigned int end)
  {
    ::qsort (array + start, end - start, sizeof (Type), (hb_compare_func_t) Type::cmp);
  }

  template <typename T>
  inline Type *bsearch (T *x)
  {
    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 &this->array[mid];
    }
    return nullptr;
  }
  template <typename T>
  inline const Type *bsearch (T *x) const
  {
    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 &this->array[mid];
    }
    return nullptr;
  }

  inline void finish (void)
  {
    if (array != static_array)
      free (array);
    array = nullptr;
    allocated = len = 0;
  }
};

template <typename Type>
struct hb_auto_array_t : hb_prealloced_array_t <Type>
{
  hb_auto_array_t (void) { hb_prealloced_array_t<Type>::init (); }
  ~hb_auto_array_t (void) { hb_prealloced_array_t<Type>::finish (); }
};


#define HB_LOCKABLE_SET_INIT {HB_PREALLOCED_ARRAY_INIT}
template <typename item_t, typename lock_t>
struct hb_lockable_set_t
{
  hb_prealloced_array_t <item_t, 2> items;

  inline void init (void) { items.init (); }

  template <typename T>
  inline item_t *replace_or_insert (T v, lock_t &l, bool replace)
  {
    l.lock ();
    item_t *item = items.find (v);
    if (item) {
      if (replace) {
	item_t old = *item;
	*item = v;
	l.unlock ();
	old.finish ();
      }
      else {
        item = nullptr;
	l.unlock ();
      }
    } else {
      item = items.push ();
      if (likely (item))
	*item = v;
      l.unlock ();
    }
    return item;
  }

  template <typename T>
  inline void remove (T v, lock_t &l)
  {
    l.lock ();
    item_t *item = items.find (v);
    if (item) {
      item_t old = *item;
      *item = items[items.len - 1];
      items.pop ();
      l.unlock ();
      old.finish ();
    } else {
      l.unlock ();
    }
  }

  template <typename T>
  inline bool find (T v, item_t *i, lock_t &l)
  {
    l.lock ();
    item_t *item = items.find (v);
    if (item)
      *i = *item;
    l.unlock ();
    return !!item;
  }

  template <typename T>
  inline item_t *find_or_insert (T v, lock_t &l)
  {
    l.lock ();
    item_t *item = items.find (v);
    if (!item) {
      item = items.push ();
      if (likely (item))
        *item = v;
    }
    l.unlock ();
    return item;
  }

  inline void finish (lock_t &l)
  {
    if (!items.len) {
      /* No need for locking. */
      items.finish ();
      return;
    }
    l.lock ();
    while (items.len) {
      item_t old = items[items.len - 1];
	items.pop ();
	l.unlock ();
	old.finish ();
	l.lock ();
    }
    items.finish ();
    l.unlock ();
  }

};


/* ASCII tag/character handling */

static inline bool ISALPHA (unsigned char c)
{ return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); }
static inline bool ISALNUM (unsigned char c)
{ return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'); }
static inline bool ISSPACE (unsigned char c)
{ return c == ' ' || c =='\f'|| c =='\n'|| c =='\r'|| c =='\t'|| c =='\v'; }
static inline unsigned char TOUPPER (unsigned char c)
{ return (c >= 'a' && c <= 'z') ? c - 'a' + 'A' : c; }
static inline unsigned char TOLOWER (unsigned char c)
{ return (c >= 'A' && c <= 'Z') ? c - 'A' + 'a' : c; }

#define HB_TAG_CHAR4(s)   (HB_TAG(((const char *) s)[0], \
				  ((const char *) s)[1], \
				  ((const char *) s)[2], \
				  ((const char *) s)[3]))


/* C++ helpers */

/* Makes class uncopyable.  Use in private: section. */
#define NO_COPY(T) \
  T (const T &o); \
  T &operator = (const T &o)


/* Debug */


/* HB_NDEBUG disables some sanity checks that are very safe to disable and
 * should be disabled in production systems.  If NDEBUG is defined, enable
 * HB_NDEBUG; but if it's desirable that normal assert()s (which are very
 * light-weight) to be enabled, then HB_DEBUG can be defined to disable
 * the costlier checks. */
#ifdef NDEBUG
#define HB_NDEBUG
#endif

#ifndef HB_DEBUG
#define HB_DEBUG 0
#endif

static inline bool
_hb_debug (unsigned int level,
	   unsigned int max_level)
{
  return level < max_level;
}

#define DEBUG_LEVEL_ENABLED(WHAT, LEVEL) (_hb_debug ((LEVEL), HB_DEBUG_##WHAT))
#define DEBUG_ENABLED(WHAT) (DEBUG_LEVEL_ENABLED (WHAT, 0))

static inline void
_hb_print_func (const char *func)
{
  if (func)
  {
    unsigned int func_len = strlen (func);
    /* Skip "static" */
    if (0 == strncmp (func, "static ", 7))
      func += 7;
    /* Skip "typename" */
    if (0 == strncmp (func, "typename ", 9))
      func += 9;
    /* Skip return type */
    const char *space = strchr (func, ' ');
    if (space)
      func = space + 1;
    /* Skip parameter list */
    const char *paren = strchr (func, '(');
    if (paren)
      func_len = paren - func;
    fprintf (stderr, "%.*s", func_len, func);
  }
}

template <int max_level> static inline void
_hb_debug_msg_va (const char *what,
		  const void *obj,
		  const char *func,
		  bool indented,
		  unsigned int level,
		  int level_dir,
		  const char *message,
		  va_list ap) HB_PRINTF_FUNC(7, 0);
template <int max_level> static inline void
_hb_debug_msg_va (const char *what,
		  const void *obj,
		  const char *func,
		  bool indented,
		  unsigned int level,
		  int level_dir,
		  const char *message,
		  va_list ap)
{
  if (!_hb_debug (level, max_level))
    return;

  fprintf (stderr, "%-10s", what ? what : "");

  if (obj)
    fprintf (stderr, "(%0*lx) ", (unsigned int) (2 * sizeof (void *)), (unsigned long) obj);
  else
    fprintf (stderr, " %*s  ", (unsigned int) (2 * sizeof (void *)), "");

  if (indented) {
#define VBAR	"\342\224\202"	/* U+2502 BOX DRAWINGS LIGHT VERTICAL */
#define VRBAR	"\342\224\234"	/* U+251C BOX DRAWINGS LIGHT VERTICAL AND RIGHT */
#define DLBAR	"\342\225\256"	/* U+256E BOX DRAWINGS LIGHT ARC DOWN AND LEFT */
#define ULBAR	"\342\225\257"	/* U+256F BOX DRAWINGS LIGHT ARC UP AND LEFT */
#define LBAR	"\342\225\264"	/* U+2574 BOX DRAWINGS LIGHT LEFT */
    static const char bars[] =
      VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR
      VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR
      VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR
      VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR
      VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR VBAR;
    fprintf (stderr, "%2u %s" VRBAR "%s",
	     level,
	     bars + sizeof (bars) - 1 - MIN ((unsigned int) sizeof (bars) - 1, (unsigned int) (sizeof (VBAR) - 1) * level),
	     level_dir ? (level_dir > 0 ? DLBAR : ULBAR) : LBAR);
  } else
    fprintf (stderr, "   " VRBAR LBAR);

  _hb_print_func (func);

  if (message)
  {
    fprintf (stderr, ": ");
    vfprintf (stderr, message, ap);
  }

  fprintf (stderr, "\n");
}
template <> inline void
_hb_debug_msg_va<0> (const char *what HB_UNUSED,
		     const void *obj HB_UNUSED,
		     const char *func HB_UNUSED,
		     bool indented HB_UNUSED,
		     unsigned int level HB_UNUSED,
		     int level_dir HB_UNUSED,
		     const char *message HB_UNUSED,
		     va_list ap HB_UNUSED) {}

template <int max_level> static inline void
_hb_debug_msg (const char *what,
	       const void *obj,
	       const char *func,
	       bool indented,
	       unsigned int level,
	       int level_dir,
	       const char *message,
	       ...) HB_PRINTF_FUNC(7, 8);
template <int max_level> static inline void
_hb_debug_msg (const char *what,
	       const void *obj,
	       const char *func,
	       bool indented,
	       unsigned int level,
	       int level_dir,
	       const char *message,
	       ...)
{
  va_list ap;
  va_start (ap, message);
  _hb_debug_msg_va<max_level> (what, obj, func, indented, level, level_dir, message, ap);
  va_end (ap);
}
template <> inline void
_hb_debug_msg<0> (const char *what HB_UNUSED,
		  const void *obj HB_UNUSED,
		  const char *func HB_UNUSED,
		  bool indented HB_UNUSED,
		  unsigned int level HB_UNUSED,
		  int level_dir HB_UNUSED,
		  const char *message HB_UNUSED,
		  ...) HB_PRINTF_FUNC(7, 8);
template <> inline void
_hb_debug_msg<0> (const char *what HB_UNUSED,
		  const void *obj HB_UNUSED,
		  const char *func HB_UNUSED,
		  bool indented HB_UNUSED,
		  unsigned int level HB_UNUSED,
		  int level_dir HB_UNUSED,
		  const char *message HB_UNUSED,
		  ...) {}

#define DEBUG_MSG_LEVEL(WHAT, OBJ, LEVEL, LEVEL_DIR, ...)	_hb_debug_msg<HB_DEBUG_##WHAT> (#WHAT, (OBJ), nullptr,    true, (LEVEL), (LEVEL_DIR), __VA_ARGS__)
#define DEBUG_MSG(WHAT, OBJ, ...) 				_hb_debug_msg<HB_DEBUG_##WHAT> (#WHAT, (OBJ), nullptr,    false, 0, 0, __VA_ARGS__)
#define DEBUG_MSG_FUNC(WHAT, OBJ, ...)				_hb_debug_msg<HB_DEBUG_##WHAT> (#WHAT, (OBJ), HB_FUNC, false, 0, 0, __VA_ARGS__)


/*
 * Printer
 */

template <typename T>
struct hb_printer_t {
  const char *print (const T&) { return "something"; }
};

template <>
struct hb_printer_t<bool> {
  const char *print (bool v) { return v ? "true" : "false"; }
};

template <>
struct hb_printer_t<hb_void_t> {
  const char *print (hb_void_t) { return ""; }
};


/*
 * Trace
 */

template <typename T>
static inline void _hb_warn_no_return (bool returned)
{
  if (unlikely (!returned)) {
    fprintf (stderr, "OUCH, returned with no call to return_trace().  This is a bug, please report.\n");
  }
}
template <>
/*static*/ inline void _hb_warn_no_return<hb_void_t> (bool returned HB_UNUSED)
{}

template <int max_level, typename ret_t>
struct hb_auto_trace_t {
  explicit inline hb_auto_trace_t (unsigned int *plevel_,
				   const char *what_,
				   const void *obj_,
				   const char *func,
				   const char *message,
				   ...) : plevel (plevel_), what (what_), obj (obj_), returned (false)
  {
    if (plevel) ++*plevel;

    va_list ap;
    va_start (ap, message);
    _hb_debug_msg_va<max_level> (what, obj, func, true, plevel ? *plevel : 0, +1, message, ap);
    va_end (ap);
  }
  inline ~hb_auto_trace_t (void)
  {
    _hb_warn_no_return<ret_t> (returned);
    if (!returned) {
      _hb_debug_msg<max_level> (what, obj, nullptr, true, plevel ? *plevel : 1, -1, " ");
    }
    if (plevel) --*plevel;
  }

  inline ret_t ret (ret_t v, unsigned int line = 0)
  {
    if (unlikely (returned)) {
      fprintf (stderr, "OUCH, double calls to return_trace().  This is a bug, please report.\n");
      return v;
    }

    _hb_debug_msg<max_level> (what, obj, nullptr, true, plevel ? *plevel : 1, -1,
			      "return %s (line %d)",
			      hb_printer_t<ret_t>().print (v), line);
    if (plevel) --*plevel;
    plevel = nullptr;
    returned = true;
    return v;
  }

  private:
  unsigned int *plevel;
  const char *what;
  const void *obj;
  bool returned;
};
template <typename ret_t> /* Optimize when tracing is disabled */
struct hb_auto_trace_t<0, ret_t> {
  explicit inline hb_auto_trace_t (unsigned int *plevel_ HB_UNUSED,
				   const char *what HB_UNUSED,
				   const void *obj HB_UNUSED,
				   const char *func HB_UNUSED,
				   const char *message HB_UNUSED,
				   ...) {}

  inline ret_t ret (ret_t v, unsigned int line HB_UNUSED = 0) { return v; }
};

#define return_trace(RET) return trace.ret (RET, __LINE__)

/* Misc */

template <typename T> class hb_assert_unsigned_t;
template <> class hb_assert_unsigned_t<unsigned char> {};
template <> class hb_assert_unsigned_t<unsigned short> {};
template <> class hb_assert_unsigned_t<unsigned int> {};
template <> class hb_assert_unsigned_t<unsigned long> {};

template <typename T> static inline bool
hb_in_range (T u, T lo, T hi)
{
  /* The sizeof() is here to force template instantiation.
   * I'm sure there are better ways to do this but can't think of
   * one right now.  Declaring a variable won't work as HB_UNUSED
   * is unusable on some platforms and unused types are less likely
   * to generate a warning than unused variables. */
  static_assert ((sizeof (hb_assert_unsigned_t<T>) >= 0), "");

  /* The casts below are important as if T is smaller than int,
   * the subtract results will become a signed int! */
  return (T)(u - lo) <= (T)(hi - lo);
}

template <typename T> static inline bool
hb_in_ranges (T u, T lo1, T hi1, T lo2, T hi2)
{
  return hb_in_range (u, lo1, hi1) || hb_in_range (u, lo2, hi2);
}

template <typename T> static inline bool
hb_in_ranges (T u, T lo1, T hi1, T lo2, T hi2, T lo3, T hi3)
{
  return hb_in_range (u, lo1, hi1) || hb_in_range (u, lo2, hi2) || hb_in_range (u, lo3, hi3);
}


/* Enable bitwise ops on enums marked as flags_t */
/* To my surprise, looks like the function resolver is happy to silently cast
 * one enum to another...  So this doesn't provide the type-checking that I
 * originally had in mind... :(.
 *
 * For MSVC warnings, see: https://github.com/behdad/harfbuzz/pull/163
 */
#ifdef _MSC_VER
# pragma warning(disable:4200)
# pragma warning(disable:4800)
#endif
#define HB_MARK_AS_FLAG_T(T) \
	extern "C++" { \
	  static inline T operator | (T l, T r) { return T ((unsigned) l | (unsigned) r); } \
	  static inline T operator & (T l, T r) { return T ((unsigned) l & (unsigned) r); } \
	  static inline T operator ^ (T l, T r) { return T ((unsigned) l ^ (unsigned) r); } \
	  static inline T operator ~ (T r) { return T (~(unsigned int) r); } \
	  static inline T& operator |= (T &l, T r) { l = l | r; return l; } \
	  static inline T& operator &= (T& l, T r) { l = l & r; return l; } \
	  static inline T& operator ^= (T& l, T r) { l = l ^ r; return l; } \
	}


/* Useful for set-operations on small enums.
 * For example, for testing "x ∈ {x1, x2, x3}" use:
 * (FLAG_SAFE(x) & (FLAG(x1) | FLAG(x2) | FLAG(x3)))
 */
#define FLAG(x) (ASSERT_STATIC_EXPR_ZERO ((x) < 32) + (1U << (x)))
#define FLAG_SAFE(x) (1U << (x))
#define FLAG_UNSAFE(x) ((x) < 32 ? FLAG_SAFE(x) : 0)
#define FLAG_RANGE(x,y) (ASSERT_STATIC_EXPR_ZERO ((x) < (y)) + FLAG(y+1) - FLAG(x))


template <typename T, typename T2> static inline void
hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *), T2 *array2)
{
  for (unsigned int i = 1; i < len; i++)
  {
    unsigned int j = i;
    while (j && compar (&array[j - 1], &array[i]) > 0)
      j--;
    if (i == j)
      continue;
    /* Move item i to occupy place for item j, shift what's in between. */
    {
      T t = array[i];
      memmove (&array[j + 1], &array[j], (i - j) * sizeof (T));
      array[j] = t;
    }
    if (array2)
    {
      T2 t = array2[i];
      memmove (&array2[j + 1], &array2[j], (i - j) * sizeof (T2));
      array2[j] = t;
    }
  }
}

template <typename T> static inline void
hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *))
{
  hb_stable_sort (array, len, compar, (int *) nullptr);
}

static inline hb_bool_t
hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *out)
{
  /* Pain because we don't know whether s is nul-terminated. */
  char buf[64];
  len = MIN (ARRAY_LENGTH (buf) - 1, len);
  strncpy (buf, s, len);
  buf[len] = '\0';

  char *end;
  errno = 0;
  unsigned long v = strtoul (buf, &end, base);
  if (errno) return false;
  if (*end) return false;
  *out = v;
  return true;
}


/* Global runtime options. */

struct hb_options_t
{
  unsigned int initialized : 1;
  unsigned int uniscribe_bug_compatible : 1;
};

union hb_options_union_t {
  unsigned int i;
  hb_options_t opts;
};
static_assert ((sizeof (int) == sizeof (hb_options_union_t)), "");

HB_INTERNAL void
_hb_options_init (void);

extern HB_INTERNAL hb_options_union_t _hb_options;

static inline hb_options_t
hb_options (void)
{
  if (unlikely (!_hb_options.i))
    _hb_options_init ();

  return _hb_options.opts;
}

/* Size signifying variable-sized array */
#define VAR 1

#endif /* HB_PRIVATE_HH */