1 /*

     2  * Copyright © 2007,2008,2009  Red Hat, Inc.

     3  * Copyright © 2011,2012  Google, Inc.

     4  *

     5  *  This is part of HarfBuzz, a text shaping library.

     6  *

     7  * Permission is hereby granted, without written agreement and without

     8  * license or royalty fees, to use, copy, modify, and distribute this

     9  * software and its documentation for any purpose, provided that the

    10  * above copyright notice and the following two paragraphs appear in

    11  * all copies of this software.

    12  *

    13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

    14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

    15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

    16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

    17  * DAMAGE.

    18  *

    19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

    20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

    21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

    22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

    23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

    24  *

    25  * Red Hat Author(s): Behdad Esfahbod

    26  * Google Author(s): Behdad Esfahbod

    27  */

    28 

    29 #ifndef HB_PRIVATE_HH

    30 #define HB_PRIVATE_HH

    31 

    32 #define _GNU_SOURCE 1

    33 

    34 #ifdef HAVE_CONFIG_H

    35 #include "config.h"

    36 #endif

    37 

    38 #include "hb.h"

    39 #define HB_H_IN

    40 #ifdef HAVE_OT

    41 #include "hb-ot.h"

    42 #define HB_OT_H_IN

    43 #endif

    44 

    45 #include <math.h>

    46 #include <stdlib.h>

    47 #include <stddef.h>

    48 #include <string.h>

    49 #include <assert.h>

    50 #include <errno.h>

    51 #include <stdio.h>

    52 #include <stdarg.h>

    53 

    54 #if (defined(_MSC_VER) && _MSC_VER >= 1500) || defined(__MINGW32__)

    55 #include <intrin.h>

    56 #endif

    57 

    58 #define HB_PASTE1(a,b) a##b

    59 #define HB_PASTE(a,b) HB_PASTE1(a,b)

    60 

    61 /* Compile-time custom allocator support. */

    62 

    63 #if defined(hb_malloc_impl) \

    64  && defined(hb_calloc_impl) \

    65  && defined(hb_realloc_impl) \

    66  && defined(hb_free_impl)

    67 extern "C" void* hb_malloc_impl(size_t size);

    68 extern "C" void* hb_calloc_impl(size_t nmemb, size_t size);

    69 extern "C" void* hb_realloc_impl(void *ptr, size_t size);

    70 extern "C" void  hb_free_impl(void *ptr);

    71 #define malloc hb_malloc_impl

    72 #define calloc hb_calloc_impl

    73 #define realloc hb_realloc_impl

    74 #define free hb_free_impl

    75 #endif

    76 

    77 

    78 /* Compiler attributes */

    79 

    80 

    81 #if __cplusplus < 201103L

    82 

    83 #ifndef nullptr

    84 #define nullptr NULL

    85 #endif

    86 

    87 // Static assertions

    88 #ifndef static_assert

    89 #define static_assert(e, msg) \

    90         HB_UNUSED typedef int HB_PASTE(static_assertion_failed_at_line_, __LINE__) [(e) ? 1 : -1]

    91 #endif // static_assert

    92 

    93 #ifdef __GNUC__

    94 #if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8))

    95 #define thread_local __thread

    96 #endif

    97 #else

    98 #define thread_local

    99 #endif

   100 

   101 #endif // __cplusplus < 201103L

   102 

   103 #if (defined(__GNUC__) || defined(__clang__)) && defined(__OPTIMIZE__)

   104 #define likely(expr) (__builtin_expect (!!(expr), 1))

   105 #define unlikely(expr) (__builtin_expect (!!(expr), 0))

   106 #else

   107 #define likely(expr) (expr)

   108 #define unlikely(expr) (expr)

   109 #endif

   110 

   111 #if !defined(__GNUC__) && !defined(__clang__)

   112 #undef __attribute__

   113 #define __attribute__(x)

   114 #endif

   115 

   116 #if __GNUC__ >= 3

   117 #define HB_PURE_FUNC    __attribute__((pure))

   118 #define HB_CONST_FUNC   __attribute__((const))

   119 #define HB_PRINTF_FUNC(format_idx, arg_idx) __attribute__((__format__ (__printf__, format_idx, arg_idx)))

   120 #else

   121 #define HB_PURE_FUNC

   122 #define HB_CONST_FUNC

   123 #define HB_PRINTF_FUNC(format_idx, arg_idx)

   124 #endif

   125 #if __GNUC__ >= 4

   126 #define HB_UNUSED       __attribute__((unused))

   127 #elif defined(_MSC_VER) /* https://github.com/harfbuzz/harfbuzz/issues/635 */

   128 #define HB_UNUSED __pragma(warning(suppress: 4100 4101))

   129 #else

   130 #define HB_UNUSED

   131 #endif

   132 

   133 #ifndef HB_INTERNAL

   134 # if !defined(HB_NO_VISIBILITY) && !defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_MSC_VER) && !defined(__SUNPRO_CC)

   135 #  define HB_INTERNAL __attribute__((__visibility__("hidden")))

   136 # else

   137 #  define HB_INTERNAL

   138 #  define HB_NO_VISIBILITY 1

   139 # endif

   140 #endif

   141 

   142 #if __GNUC__ >= 3

   143 #define HB_FUNC __PRETTY_FUNCTION__

   144 #elif defined(_MSC_VER)

   145 #define HB_FUNC __FUNCSIG__

   146 #else

   147 #define HB_FUNC __func__

   148 #endif

   149 

   150 #if defined(__SUNPRO_CC) && (__SUNPRO_CC < 0x5140)

   151 /* https://github.com/harfbuzz/harfbuzz/issues/630 */

   152 #define __restrict

   153 #endif

   154 

   155 /*

   156  * Borrowed from https://bugzilla.mozilla.org/show_bug.cgi?id=1215411

   157  * HB_FALLTHROUGH is an annotation to suppress compiler warnings about switch

   158  * cases that fall through without a break or return statement. HB_FALLTHROUGH

   159  * is only needed on cases that have code:

   160  *

   161  * switch (foo) {

   162  *   case 1: // These cases have no code. No fallthrough annotations are needed.

   163  *   case 2:

   164  *   case 3:

   165  *     foo = 4; // This case has code, so a fallthrough annotation is needed:

   166  *     HB_FALLTHROUGH;

   167  *   default:

   168  *     return foo;

   169  * }

   170  */

   171 #if defined(__clang__) && __cplusplus >= 201103L

   172    /* clang's fallthrough annotations are only available starting in C++11. */

   173 #  define HB_FALLTHROUGH [[clang::fallthrough]]

   174 #elif __GNUC__ >= 7

   175    /* GNU fallthrough attribute is available from GCC7 */

   176 #  define HB_FALLTHROUGH __attribute__((fallthrough))

   177 #elif defined(_MSC_VER)

   178    /*

   179     * MSVC's __fallthrough annotations are checked by /analyze (Code Analysis):

   180     * https://msdn.microsoft.com/en-us/library/ms235402%28VS.80%29.aspx

   181     */

   182 #  include <sal.h>

   183 #  define HB_FALLTHROUGH __fallthrough

   184 #else

   185 #  define HB_FALLTHROUGH /* FALLTHROUGH */

   186 #endif

   187 

   188 #if defined(_WIN32) || defined(__CYGWIN__)

   189    /* We need Windows Vista for both Uniscribe backend and for

   190     * MemoryBarrier.  We don't support compiling on Windows XP,

   191     * though we run on it fine. */

   192 #  if defined(_WIN32_WINNT) && _WIN32_WINNT < 0x0600

   193 #    undef _WIN32_WINNT

   194 #  endif

   195 #  ifndef _WIN32_WINNT

   196 #    define _WIN32_WINNT 0x0600

   197 #  endif

   198 #  ifndef WIN32_LEAN_AND_MEAN

   199 #    define WIN32_LEAN_AND_MEAN 1

   200 #  endif

   201 #  ifndef STRICT

   202 #    define STRICT 1

   203 #  endif

   204 

   205 #  if defined(_WIN32_WCE)

   206      /* Some things not defined on Windows CE. */

   207 #    define vsnprintf _vsnprintf

   208 #    define getenv(Name) nullptr

   209 #    if _WIN32_WCE < 0x800

   210 #      define setlocale(Category, Locale) "C"

   211 static int errno = 0; /* Use something better? */

   212 #    endif

   213 #  elif defined(WINAPI_FAMILY) && (WINAPI_FAMILY==WINAPI_FAMILY_PC_APP || WINAPI_FAMILY==WINAPI_FAMILY_PHONE_APP)

   214 #    define getenv(Name) nullptr

   215 #  endif

   216 #  if defined(_MSC_VER) && _MSC_VER < 1900

   217 #    define snprintf _snprintf

   218 #  endif

   219 #endif

   220 

   221 #if HAVE_ATEXIT

   222 /* atexit() is only safe to be called from shared libraries on certain

   223  * platforms.  Whitelist.

   224  * https://bugs.freedesktop.org/show_bug.cgi?id=82246 */

   225 #  if defined(__linux) && defined(__GLIBC_PREREQ)

   226 #    if __GLIBC_PREREQ(2,3)

   227 /* From atexit() manpage, it's safe with glibc 2.2.3 on Linux. */

   228 #      define HB_USE_ATEXIT 1

   229 #    endif

   230 #  elif defined(_MSC_VER) || defined(__MINGW32__)

   231 /* For MSVC:

   232  * https://msdn.microsoft.com/en-us/library/tze57ck3.aspx

   233  * https://msdn.microsoft.com/en-us/library/zk17ww08.aspx

   234  * mingw32 headers say atexit is safe to use in shared libraries.

   235  */

   236 #    define HB_USE_ATEXIT 1

   237 #  elif defined(__ANDROID__)

   238 /* This is available since Android NKD r8 or r8b:

   239  * https://issuetracker.google.com/code/p/android/issues/detail?id=6455

   240  */

   241 #    define HB_USE_ATEXIT 1

   242 #  elif defined(__APPLE__)

   243 /* For macOS and related platforms, the atexit man page indicates

   244  * that it will be invoked when the library is unloaded, not only

   245  * at application exit.

   246  */

   247 #    define HB_USE_ATEXIT 1

   248 #  endif

   249 #endif

   250 #ifdef HB_NO_ATEXIT

   251 #  undef HB_USE_ATEXIT

   252 #endif

   253 

   254 /* Basics */

   255 

   256 #undef MIN

   257 template <typename Type>

   258 static inline Type MIN (const Type &a, const Type &b) { return a < b ? a : b; }

   259 

   260 #undef MAX

   261 template <typename Type>

   262 static inline Type MAX (const Type &a, const Type &b) { return a > b ? a : b; }

   263 

   264 static inline unsigned int DIV_CEIL (const unsigned int a, unsigned int b)

   265 { return (a + (b - 1)) / b; }

   266 

   267 

   268 #undef  ARRAY_LENGTH

   269 template <typename Type, unsigned int n>

   270 static inline unsigned int ARRAY_LENGTH (const Type (&)[n]) { return n; }

   271 /* A const version, but does not detect erratically being called on pointers. */

   272 #define ARRAY_LENGTH_CONST(__array) ((signed int) (sizeof (__array) / sizeof (__array[0])))

   273 

   274 #define HB_STMT_START do

   275 #define HB_STMT_END   while (0)

   276 

   277 template <unsigned int cond> class hb_assert_constant_t;

   278 template <> class hb_assert_constant_t<1> {};

   279 

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

   281 

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

   283 

   284 static_assert ((sizeof (int8_t) == 1), "");

   285 static_assert ((sizeof (uint8_t) == 1), "");

   286 static_assert ((sizeof (int16_t) == 2), "");

   287 static_assert ((sizeof (uint16_t) == 2), "");

   288 static_assert ((sizeof (int32_t) == 4), "");

   289 static_assert ((sizeof (uint32_t) == 4), "");

   290 static_assert ((sizeof (int64_t) == 8), "");

   291 static_assert ((sizeof (uint64_t) == 8), "");

   292 

   293 static_assert ((sizeof (hb_codepoint_t) == 4), "");

   294 static_assert ((sizeof (hb_position_t) == 4), "");

   295 static_assert ((sizeof (hb_mask_t) == 4), "");

   296 static_assert ((sizeof (hb_var_int_t) == 4), "");

   297 

   298 

   299 /* We like our types POD */

   300 

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

   302 #define _ASSERT_TYPE_POD0(_line, _type) _ASSERT_TYPE_POD1 (_line, _type)

   303 #define ASSERT_TYPE_POD(_type)          _ASSERT_TYPE_POD0 (__LINE__, _type)

   304 

   305 #ifdef __GNUC__

   306 # define _ASSERT_INSTANCE_POD1(_line, _instance) \

   307         HB_STMT_START { \

   308                 typedef __typeof__(_instance) _type_##_line; \

   309                 _ASSERT_TYPE_POD1 (_line, _type_##_line); \

   310         } HB_STMT_END

   311 #else

   312 # define _ASSERT_INSTANCE_POD1(_line, _instance)        typedef int _assertion_on_line_##_line##_not_tested

   313 #endif

   314 # define _ASSERT_INSTANCE_POD0(_line, _instance)        _ASSERT_INSTANCE_POD1 (_line, _instance)

   315 # define ASSERT_INSTANCE_POD(_instance)                 _ASSERT_INSTANCE_POD0 (__LINE__, _instance)

   316 

   317 /* Check _assertion in a method environment */

   318 #define _ASSERT_POD1(_line) \

   319         HB_UNUSED inline void _static_assertion_on_line_##_line (void) const \

   320         { _ASSERT_INSTANCE_POD1 (_line, *this); /* Make sure it's POD. */ }

   321 # define _ASSERT_POD0(_line)    _ASSERT_POD1 (_line)

   322 # define ASSERT_POD()           _ASSERT_POD0 (__LINE__)

   323 

   324 

   325 

   326 /* Tiny functions */

   327 

   328 /*

   329  * Void!

   330  */

   331 typedef const struct _hb_void_t *hb_void_t;

   332 #define HB_VOID ((const _hb_void_t *) nullptr)

   333 

   334 /* Return the number of 1 bits in v. */

   335 template <typename T>

   336 static inline HB_CONST_FUNC unsigned int

   337 _hb_popcount (T v)

   338 {

   339 #if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) && defined(__OPTIMIZE__)

   340   if (sizeof (T) <= sizeof (unsigned int))

   341     return __builtin_popcount (v);

   342 

   343   if (sizeof (T) <= sizeof (unsigned long))

   344     return __builtin_popcountl (v);

   345 

   346   if (sizeof (T) <= sizeof (unsigned long long))

   347     return __builtin_popcountll (v);

   348 #endif

   349 

   350   if (sizeof (T) <= 4)

   351   {

   352     /* "HACKMEM 169" */

   353     uint32_t y;

   354     y = (v >> 1) &033333333333;

   355     y = v - y - ((y >>1) & 033333333333);

   356     return (((y + (y >> 3)) & 030707070707) % 077);

   357   }

   358 

   359   if (sizeof (T) == 8)

   360   {

   361     unsigned int shift = 32;

   362     return _hb_popcount<uint32_t> ((uint32_t) v) + _hb_popcount ((uint32_t) (v >> shift));

   363   }

   364 

   365   if (sizeof (T) == 16)

   366   {

   367     unsigned int shift = 64;

   368     return _hb_popcount<uint64_t> ((uint64_t) v) + _hb_popcount ((uint64_t) (v >> shift));

   369   }

   370 

   371   assert (0);

   372   return 0; /* Shut up stupid compiler. */

   373 }

   374 

   375 /* Returns the number of bits needed to store number */

   376 template <typename T>

   377 static inline HB_CONST_FUNC unsigned int

   378 _hb_bit_storage (T v)

   379 {

   380   if (unlikely (!v)) return 0;

   381 

   382 #if defined(__GNUC__) && (__GNUC__ >= 4) && defined(__OPTIMIZE__)

   383   if (sizeof (T) <= sizeof (unsigned int))

   384     return sizeof (unsigned int) * 8 - __builtin_clz (v);

   385 

   386   if (sizeof (T) <= sizeof (unsigned long))

   387     return sizeof (unsigned long) * 8 - __builtin_clzl (v);

   388 

   389   if (sizeof (T) <= sizeof (unsigned long long))

   390     return sizeof (unsigned long long) * 8 - __builtin_clzll (v);

   391 #endif

   392 

   393 #if (defined(_MSC_VER) && _MSC_VER >= 1500) || defined(__MINGW32__)

   394   if (sizeof (T) <= sizeof (unsigned int))

   395   {

   396     unsigned long where;

   397     _BitScanReverse (&where, v);

   398     return 1 + where;

   399   }

   400 # if _WIN64

   401   if (sizeof (T) <= 8)

   402   {

   403     unsigned long where;

   404     _BitScanReverse64 (&where, v);

   405     return 1 + where;

   406   }

   407 # endif

   408 #endif

   409 

   410   if (sizeof (T) <= 4)

   411   {

   412     /* "bithacks" */

   413     const unsigned int b[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000};

   414     const unsigned int S[] = {1, 2, 4, 8, 16};

   415     unsigned int r = 0;

   416     for (int i = 4; i >= 0; i--)

   417       if (v & b[i])

   418       {

   419         v >>= S[i];

   420         r |= S[i];

   421       }

   422     return r + 1;

   423   }

   424   if (sizeof (T) <= 8)

   425   {

   426     /* "bithacks" */

   427     const uint64_t b[] = {0x2ULL, 0xCULL, 0xF0ULL, 0xFF00ULL, 0xFFFF0000ULL, 0xFFFFFFFF00000000ULL};

   428     const unsigned int S[] = {1, 2, 4, 8, 16, 32};

   429     unsigned int r = 0;

   430     for (int i = 5; i >= 0; i--)

   431       if (v & b[i])

   432       {

   433         v >>= S[i];

   434         r |= S[i];

   435       }

   436     return r + 1;

   437   }

   438   if (sizeof (T) == 16)

   439   {

   440     unsigned int shift = 64;

   441     return (v >> shift) ? _hb_bit_storage<uint64_t> ((uint64_t) (v >> shift)) + shift :

   442                           _hb_bit_storage<uint64_t> ((uint64_t) v);

   443   }

   444 

   445   assert (0);

   446   return 0; /* Shut up stupid compiler. */

   447 }

   448 

   449 /* Returns the number of zero bits in the least significant side of v */

   450 template <typename T>

   451 static inline HB_CONST_FUNC unsigned int

   452 _hb_ctz (T v)

   453 {

   454   if (unlikely (!v)) return 0;

   455 

   456 #if defined(__GNUC__) && (__GNUC__ >= 4) && defined(__OPTIMIZE__)

   457   if (sizeof (T) <= sizeof (unsigned int))

   458     return __builtin_ctz (v);

   459 

   460   if (sizeof (T) <= sizeof (unsigned long))

   461     return __builtin_ctzl (v);

   462 

   463   if (sizeof (T) <= sizeof (unsigned long long))

   464     return __builtin_ctzll (v);

   465 #endif

   466 

   467 #if (defined(_MSC_VER) && _MSC_VER >= 1500) || defined(__MINGW32__)

   468   if (sizeof (T) <= sizeof (unsigned int))

   469   {

   470     unsigned long where;

   471     _BitScanForward (&where, v);

   472     return where;

   473   }

   474 # if _WIN64

   475   if (sizeof (T) <= 8)

   476   {

   477     unsigned long where;

   478     _BitScanForward64 (&where, v);

   479     return where;

   480   }

   481 # endif

   482 #endif

   483 

   484   if (sizeof (T) <= 4)

   485   {

   486     /* "bithacks" */

   487     unsigned int c = 32;

   488     v &= - (int32_t) v;

   489     if (v) c--;

   490     if (v & 0x0000FFFF) c -= 16;

   491     if (v & 0x00FF00FF) c -= 8;

   492     if (v & 0x0F0F0F0F) c -= 4;

   493     if (v & 0x33333333) c -= 2;

   494     if (v & 0x55555555) c -= 1;

   495     return c;

   496   }

   497   if (sizeof (T) <= 8)

   498   {

   499     /* "bithacks" */

   500     unsigned int c = 64;

   501     v &= - (int64_t) (v);

   502     if (v) c--;

   503     if (v & 0x00000000FFFFFFFFULL) c -= 32;

   504     if (v & 0x0000FFFF0000FFFFULL) c -= 16;

   505     if (v & 0x00FF00FF00FF00FFULL) c -= 8;

   506     if (v & 0x0F0F0F0F0F0F0F0FULL) c -= 4;

   507     if (v & 0x3333333333333333ULL) c -= 2;

   508     if (v & 0x5555555555555555ULL) c -= 1;

   509     return c;

   510   }

   511   if (sizeof (T) == 16)

   512   {

   513     unsigned int shift = 64;

   514     return (uint64_t) v ? _hb_bit_storage<uint64_t> ((uint64_t) v) :

   515                           _hb_bit_storage<uint64_t> ((uint64_t) v >> shift) + shift;

   516   }

   517 

   518   assert (0);

   519   return 0; /* Shut up stupid compiler. */

   520 }

   521 

   522 static inline bool

   523 _hb_unsigned_int_mul_overflows (unsigned int count, unsigned int size)

   524 {

   525   return (size > 0) && (count >= ((unsigned int) -1) / size);

   526 }

   527 

   528 static inline unsigned int

   529 _hb_ceil_to_4 (unsigned int v)

   530 {

   531   return ((v - 1) | 3) + 1;

   532 }

   533 

   534 

   535 

   536 /*

   537  *

   538  * Utility types

   539  *

   540  */

   541 

   542 #define HB_DISALLOW_COPY_AND_ASSIGN(TypeName) \

   543   TypeName(const TypeName&); \

   544   void operator=(const TypeName&)

   545 

   546 /*

   547  * Static pools

   548  */

   549 

   550 /* Global nul-content Null pool.  Enlarge as necessary. */

   551 

   552 #define HB_NULL_POOL_SIZE 264

   553 static_assert (HB_NULL_POOL_SIZE % sizeof (void *) == 0, "Align HB_NULL_POOL_SIZE.");

   554 

   555 #ifdef HB_NO_VISIBILITY

   556 static

   557 #else

   558 extern HB_INTERNAL

   559 #endif

   560 void * const _hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)]

   561 #ifdef HB_NO_VISIBILITY

   562 = {}

   563 #endif

   564 ;

   565 /* Generic nul-content Null objects. */

   566 template <typename Type>

   567 static inline Type const & Null (void) {

   568   static_assert (sizeof (Type) <= HB_NULL_POOL_SIZE, "Increase HB_NULL_POOL_SIZE.");

   569   return *reinterpret_cast<Type const *> (_hb_NullPool);

   570 }

   571 #define Null(Type) Null<Type>()

   572 

   573 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */

   574 #define DEFINE_NULL_DATA(Namespace, Type, data) \

   575 } /* Close namespace. */ \

   576 static const char _Null##Type[sizeof (Namespace::Type) + 1] = data; /* +1 is for nul-termination in data */ \

   577 template <> \

   578 /*static*/ inline const Namespace::Type& Null<Namespace::Type> (void) { \

   579   return *reinterpret_cast<const Namespace::Type *> (_Null##Type); \

   580 } \

   581 namespace Namespace { \

   582 /* The following line really exists such that we end in a place needing semicolon */ \

   583 static_assert (Namespace::Type::min_size + 1 <= sizeof (_Null##Type), "Null pool too small.  Enlarge.")

   584 

   585 

   586 /* Global writable pool.  Enlarge as necessary. */

   587 

   588 /* To be fully correct, CrapPool must be thread_local. However, we do not rely on CrapPool

   589  * for correct operation. It only exist to catch and divert program logic bugs instead of

   590  * causing bad memory access. So, races there are not actually introducing incorrectness

   591  * in the code. Has ~12kb binary size overhead to have it, also clang build fails with it. */

   592 #ifdef HB_NO_VISIBILITY

   593 static

   594 #else

   595 extern HB_INTERNAL

   596 #endif

   597 /*thread_local*/ void * _hb_CrapPool[HB_NULL_POOL_SIZE / sizeof (void *)]

   598 #ifdef HB_NO_VISIBILITY

   599 = {}

   600 #endif

   601 ;

   602 /* CRAP pool: Common Region for Access Protection. */

   603 template <typename Type>

   604 static inline Type& Crap (void) {

   605   static_assert (sizeof (Type) <= HB_NULL_POOL_SIZE, "Increase HB_NULL_POOL_SIZE.");

   606   Type *obj = reinterpret_cast<Type *> (_hb_CrapPool);

   607   *obj = Null(Type);

   608   return *obj;

   609 }

   610 #define Crap(Type) Crap<Type>()

   611 

   612 template <typename Type>

   613 struct CrapOrNull {

   614   static inline Type & get (void) { return Crap(Type); }

   615 };

   616 template <typename Type>

   617 struct CrapOrNull<const Type> {

   618   static inline Type const & get (void) { return Null(Type); }

   619 };

   620 #define CrapOrNull(Type) CrapOrNull<Type>::get ()

   621 

   622 

   623 

   624 /* arrays and maps */

   625 

   626 

   627 #define HB_PREALLOCED_ARRAY_INIT {0, 0, nullptr}

   628 template <typename Type, unsigned int StaticSize=8>

   629 struct hb_vector_t

   630 {

   631   unsigned int len;

   632   unsigned int allocated;

   633   bool successful;

   634   Type *arrayZ;

   635   Type static_array[StaticSize];

   636 

   637   void init (void)

   638   {

   639     len = 0;

   640     allocated = ARRAY_LENGTH (static_array);

   641     successful = true;

   642     arrayZ = static_array;

   643   }

   644 

   645   inline Type& operator [] (unsigned int i)

   646   {

   647     if (unlikely (i >= len))

   648       return Crap (Type);

   649     return arrayZ[i];

   650   }

   651   inline const Type& operator [] (unsigned int i) const

   652   {

   653     if (unlikely (i >= len))

   654       return Null(Type);

   655     return arrayZ[i];

   656   }

   657 

   658   inline Type *push (void)

   659   {

   660     if (unlikely (!resize (len + 1)))

   661       return &Crap(Type);

   662     return &arrayZ[len - 1];

   663   }

   664   inline Type *push (const Type& v)

   665   {

   666     Type *p = push ();

   667     *p = v;

   668     return p;

   669   }

   670 

   671   /* Allocate for size but don't adjust len. */

   672   inline bool alloc (unsigned int size)

   673   {

   674     if (unlikely (!successful))

   675       return false;

   676 

   677     if (likely (size <= allocated))

   678       return true;

   679 

   680     /* Reallocate */

   681 

   682     unsigned int new_allocated = allocated;

   683     while (size >= new_allocated)

   684       new_allocated += (new_allocated >> 1) + 8;

   685 

   686     Type *new_array = nullptr;

   687 

   688     if (arrayZ == static_array)

   689     {

   690       new_array = (Type *) calloc (new_allocated, sizeof (Type));

   691       if (new_array)

   692         memcpy (new_array, arrayZ, len * sizeof (Type));

   693     }

   694     else

   695     {

   696       bool overflows = (new_allocated < allocated) || _hb_unsigned_int_mul_overflows (new_allocated, sizeof (Type));

   697       if (likely (!overflows))

   698         new_array = (Type *) realloc (arrayZ, new_allocated * sizeof (Type));

   699     }

   700 

   701     if (unlikely (!new_array))

   702     {

   703       successful = false;

   704       return false;

   705     }

   706 

   707     arrayZ = new_array;

   708     allocated = new_allocated;

   709 

   710     return true;

   711   }

   712 

   713   inline bool resize (int size_)

   714   {

   715     unsigned int size = size_ < 0 ? 0u : (unsigned int) size_;

   716     if (!alloc (size))

   717       return false;

   718 

   719     if (size > len)

   720       memset (arrayZ + len, 0, (size - len) * sizeof (*arrayZ));

   721 

   722     len = size;

   723     return true;

   724   }

   725 

   726   inline void pop (void)

   727   {

   728     if (!len) return;

   729     len--;

   730   }

   731 

   732   inline void remove (unsigned int i)

   733   {

   734      if (unlikely (i >= len))

   735        return;

   736      memmove (static_cast<void *> (&arrayZ[i]),

   737               static_cast<void *> (&arrayZ[i + 1]),

   738               (len - i - 1) * sizeof (Type));

   739      len--;

   740   }

   741 

   742   inline void shrink (int size_)

   743   {

   744     unsigned int size = size_ < 0 ? 0u : (unsigned int) size_;

   745      if (size < len)

   746        len = size;

   747   }

   748 

   749   template <typename T>

   750   inline Type *find (T v) {

   751     for (unsigned int i = 0; i < len; i++)

   752       if (arrayZ[i] == v)

   753         return &arrayZ[i];

   754     return nullptr;

   755   }

   756   template <typename T>

   757   inline const Type *find (T v) const {

   758     for (unsigned int i = 0; i < len; i++)

   759       if (arrayZ[i] == v)

   760         return &arrayZ[i];

   761     return nullptr;

   762   }

   763 

   764   inline void qsort (int (*cmp)(const void*, const void*))

   765   {

   766     ::qsort (arrayZ, len, sizeof (Type), cmp);

   767   }

   768 

   769   inline void qsort (void)

   770   {

   771     ::qsort (arrayZ, len, sizeof (Type), Type::cmp);

   772   }

   773 

   774   inline void qsort (unsigned int start, unsigned int end)

   775   {

   776     ::qsort (arrayZ + start, end - start, sizeof (Type), Type::cmp);

   777   }

   778 

   779   template <typename T>

   780   inline Type *lsearch (const T &x)

   781   {

   782     for (unsigned int i = 0; i < len; i++)

   783       if (0 == this->arrayZ[i].cmp (&x))

   784         return &arrayZ[i];

   785     return nullptr;

   786   }

   787 

   788   template <typename T>

   789   inline Type *bsearch (const T &x)

   790   {

   791     unsigned int i;

   792     return bfind (x, &i) ? &arrayZ[i] : nullptr;

   793   }

   794   template <typename T>

   795   inline const Type *bsearch (const T &x) const

   796   {

   797     unsigned int i;

   798     return bfind (x, &i) ? &arrayZ[i] : nullptr;

   799   }

   800   template <typename T>

   801   inline bool bfind (const T &x, unsigned int *i) const

   802   {

   803     int min = 0, max = (int) this->len - 1;

   804     while (min <= max)

   805     {

   806       int mid = (min + max) / 2;

   807       int c = this->arrayZ[mid].cmp (&x);

   808       if (c < 0)

   809         max = mid - 1;

   810       else if (c > 0)

   811         min = mid + 1;

   812       else

   813       {

   814         *i = mid;

   815         return true;

   816       }

   817     }

   818     if (max < 0 || (max < (int) this->len && this->arrayZ[max].cmp (&x) > 0))

   819       max++;

   820     *i = max;

   821     return false;

   822   }

   823 

   824   inline void fini (void)

   825   {

   826     if (arrayZ != static_array)

   827       free (arrayZ);

   828     arrayZ = nullptr;

   829     allocated = len = 0;

   830   }

   831 };

   832 

   833 template <typename Type>

   834 struct hb_auto_t : Type

   835 {

   836   hb_auto_t (void) { Type::init (); }

   837   ~hb_auto_t (void) { Type::fini (); }

   838   private: /* Hide */

   839   void init (void) {}

   840   void fini (void) {}

   841 };

   842 template <typename Type>

   843 struct hb_auto_array_t : hb_auto_t <hb_vector_t <Type> > {};

   844 

   845 

   846 #define HB_LOCKABLE_SET_INIT {HB_PREALLOCED_ARRAY_INIT}

   847 template <typename item_t, typename lock_t>

   848 struct hb_lockable_set_t

   849 {

   850   hb_vector_t <item_t, 1> items;

   851 

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

   853 

   854   template <typename T>

   855   inline item_t *replace_or_insert (T v, lock_t &l, bool replace)

   856   {

   857     l.lock ();

   858     item_t *item = items.find (v);

   859     if (item) {

   860       if (replace) {

   861         item_t old = *item;

   862         *item = v;

   863         l.unlock ();

   864         old.fini ();

   865       }

   866       else {

   867         item = nullptr;

   868         l.unlock ();

   869       }

   870     } else {

   871       item = items.push (v);

   872       l.unlock ();

   873     }

   874     return item;

   875   }

   876 

   877   template <typename T>

   878   inline void remove (T v, lock_t &l)

   879   {

   880     l.lock ();

   881     item_t *item = items.find (v);

   882     if (item) {

   883       item_t old = *item;

   884       *item = items[items.len - 1];

   885       items.pop ();

   886       l.unlock ();

   887       old.fini ();

   888     } else {

   889       l.unlock ();

   890     }

   891   }

   892 

   893   template <typename T>

   894   inline bool find (T v, item_t *i, lock_t &l)

   895   {

   896     l.lock ();

   897     item_t *item = items.find (v);

   898     if (item)

   899       *i = *item;

   900     l.unlock ();

   901     return !!item;

   902   }

   903 

   904   template <typename T>

   905   inline item_t *find_or_insert (T v, lock_t &l)

   906   {

   907     l.lock ();

   908     item_t *item = items.find (v);

   909     if (!item) {

   910       item = items.push (v);

   911     }

   912     l.unlock ();

   913     return item;

   914   }

   915 

   916   inline void fini (lock_t &l)

   917   {

   918     if (!items.len) {

   919       /* No need for locking. */

   920       items.fini ();

   921       return;

   922     }

   923     l.lock ();

   924     while (items.len) {

   925       item_t old = items[items.len - 1];

   926         items.pop ();

   927         l.unlock ();

   928         old.fini ();

   929         l.lock ();

   930     }

   931     items.fini ();

   932     l.unlock ();

   933   }

   934 

   935 };

   936 

   937 

   938 /* ASCII tag/character handling */

   939 

   940 static inline bool ISALPHA (unsigned char c)

   941 { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); }

   942 static inline bool ISALNUM (unsigned char c)

   943 { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'); }

   944 static inline bool ISSPACE (unsigned char c)

   945 { return c == ' ' || c =='\f'|| c =='\n'|| c =='\r'|| c =='\t'|| c =='\v'; }

   946 static inline unsigned char TOUPPER (unsigned char c)

   947 { return (c >= 'a' && c <= 'z') ? c - 'a' + 'A' : c; }

   948 static inline unsigned char TOLOWER (unsigned char c)

   949 { return (c >= 'A' && c <= 'Z') ? c - 'A' + 'a' : c; }

   950 

   951 

   952 /* HB_NDEBUG disables some sanity checks that are very safe to disable and

   953  * should be disabled in production systems.  If NDEBUG is defined, enable

   954  * HB_NDEBUG; but if it's desirable that normal assert()s (which are very

   955  * light-weight) to be enabled, then HB_DEBUG can be defined to disable

   956  * the costlier checks. */

   957 #ifdef NDEBUG

   958 #define HB_NDEBUG 1

   959 #endif

   960 

   961 

   962 /* Misc */

   963 

   964 template <typename T> class hb_assert_unsigned_t;

   965 template <> class hb_assert_unsigned_t<unsigned char> {};

   966 template <> class hb_assert_unsigned_t<unsigned short> {};

   967 template <> class hb_assert_unsigned_t<unsigned int> {};

   968 template <> class hb_assert_unsigned_t<unsigned long> {};

   969 

   970 template <typename T> static inline bool

   971 hb_in_range (T u, T lo, T hi)

   972 {

   973   /* The sizeof() is here to force template instantiation.

   974    * I'm sure there are better ways to do this but can't think of

   975    * one right now.  Declaring a variable won't work as HB_UNUSED

   976    * is unusable on some platforms and unused types are less likely

   977    * to generate a warning than unused variables. */

   978   static_assert ((sizeof (hb_assert_unsigned_t<T>) >= 0), "");

   979 

   980   /* The casts below are important as if T is smaller than int,

   981    * the subtract results will become a signed int! */

   982   return (T)(u - lo) <= (T)(hi - lo);

   983 }

   984 

   985 template <typename T> static inline bool

   986 hb_in_ranges (T u, T lo1, T hi1, T lo2, T hi2)

   987 {

   988   return hb_in_range (u, lo1, hi1) || hb_in_range (u, lo2, hi2);

   989 }

   990 

   991 template <typename T> static inline bool

   992 hb_in_ranges (T u, T lo1, T hi1, T lo2, T hi2, T lo3, T hi3)

   993 {

   994   return hb_in_range (u, lo1, hi1) || hb_in_range (u, lo2, hi2) || hb_in_range (u, lo3, hi3);

   995 }

   996 

   997 

   998 /* Enable bitwise ops on enums marked as flags_t */

   999 /* To my surprise, looks like the function resolver is happy to silently cast

  1000  * one enum to another...  So this doesn't provide the type-checking that I

  1001  * originally had in mind... :(.

  1002  *

  1003  * For MSVC warnings, see: https://github.com/harfbuzz/harfbuzz/pull/163

  1004  */

  1005 #ifdef _MSC_VER

  1006 # pragma warning(disable:4200)

  1007 # pragma warning(disable:4800)

  1008 #endif

  1009 #define HB_MARK_AS_FLAG_T(T) \

  1010         extern "C++" { \

  1011           static inline T operator | (T l, T r) { return T ((unsigned) l | (unsigned) r); } \

  1012           static inline T operator & (T l, T r) { return T ((unsigned) l & (unsigned) r); } \

  1013           static inline T operator ^ (T l, T r) { return T ((unsigned) l ^ (unsigned) r); } \

  1014           static inline T operator ~ (T r) { return T (~(unsigned int) r); } \

  1015           static inline T& operator |= (T &l, T r) { l = l | r; return l; } \

  1016           static inline T& operator &= (T& l, T r) { l = l & r; return l; } \

  1017           static inline T& operator ^= (T& l, T r) { l = l ^ r; return l; } \

  1018         }

  1019 

  1020 

  1021 /* Useful for set-operations on small enums.

  1022  * For example, for testing "x ∈ {x1, x2, x3}" use:

  1023  * (FLAG_UNSAFE(x) & (FLAG(x1) | FLAG(x2) | FLAG(x3)))

  1024  */

  1025 #define FLAG(x) (ASSERT_STATIC_EXPR_ZERO ((unsigned int)(x) < 32) + (1U << (unsigned int)(x)))

  1026 #define FLAG_UNSAFE(x) ((unsigned int)(x) < 32 ? (1U << (unsigned int)(x)) : 0)

  1027 #define FLAG_RANGE(x,y) (ASSERT_STATIC_EXPR_ZERO ((x) < (y)) + FLAG(y+1) - FLAG(x))

  1028 

  1029 

  1030 template <typename T, typename T2> static inline void

  1031 hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *), T2 *array2)

  1032 {

  1033   for (unsigned int i = 1; i < len; i++)

  1034   {

  1035     unsigned int j = i;

  1036     while (j && compar (&array[j - 1], &array[i]) > 0)

  1037       j--;

  1038     if (i == j)

  1039       continue;

  1040     /* Move item i to occupy place for item j, shift what's in between. */

  1041     {

  1042       T t = array[i];

  1043       memmove (&array[j + 1], &array[j], (i - j) * sizeof (T));

  1044       array[j] = t;

  1045     }

  1046     if (array2)

  1047     {

  1048       T2 t = array2[i];

  1049       memmove (&array2[j + 1], &array2[j], (i - j) * sizeof (T2));

  1050       array2[j] = t;

  1051     }

  1052   }

  1053 }

  1054 

  1055 template <typename T> static inline void

  1056 hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *))

  1057 {

  1058   hb_stable_sort (array, len, compar, (int *) nullptr);

  1059 }

  1060 

  1061 static inline hb_bool_t

  1062 hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *out)

  1063 {

  1064   /* Pain because we don't know whether s is nul-terminated. */

  1065   char buf[64];

  1066   len = MIN (ARRAY_LENGTH (buf) - 1, len);

  1067   strncpy (buf, s, len);

  1068   buf[len] = '\0';

  1069 

  1070   char *end;

  1071   errno = 0;

  1072   unsigned long v = strtoul (buf, &end, base);

  1073   if (errno) return false;

  1074   if (*end) return false;

  1075   *out = v;

  1076   return true;

  1077 }

  1078 

  1079 

  1080 /* Vectorization */

  1081 

  1082 struct HbOpOr

  1083 {

  1084   static const bool passthru_left = true;

  1085   static const bool passthru_right = true;

  1086   template <typename T> static void process (T &o, const T &a, const T &b) { o = a | b; }

  1087 };

  1088 struct HbOpAnd

  1089 {

  1090   static const bool passthru_left = false;

  1091   static const bool passthru_right = false;

  1092   template <typename T> static void process (T &o, const T &a, const T &b) { o = a & b; }

  1093 };

  1094 struct HbOpMinus

  1095 {

  1096   static const bool passthru_left = true;

  1097   static const bool passthru_right = false;

  1098   template <typename T> static void process (T &o, const T &a, const T &b) { o = a & ~b; }

  1099 };

  1100 struct HbOpXor

  1101 {

  1102   static const bool passthru_left = true;

  1103   static const bool passthru_right = true;

  1104   template <typename T> static void process (T &o, const T &a, const T &b) { o = a ^ b; }

  1105 };

  1106 

  1107 

  1108 /* Compiler-assisted vectorization. */

  1109 

  1110 /* The `vector_size' attribute was introduced in gcc 3.1. */

  1111 #if defined( __GNUC__ ) && ( __GNUC__ >= 4 )

  1112 #define HB_VECTOR_SIZE 128

  1113 #elif !defined(HB_VECTOR_SIZE)

  1114 #define HB_VECTOR_SIZE 0

  1115 #endif

  1116 

  1117 /* Type behaving similar to vectorized vars defined using __attribute__((vector_size(...))). */

  1118 template <typename elt_t, unsigned int byte_size>

  1119 struct hb_vector_size_t

  1120 {

  1121   elt_t& operator [] (unsigned int i) { return u.v[i]; }

  1122   const elt_t& operator [] (unsigned int i) const { return u.v[i]; }

  1123 

  1124   template <class Op>

  1125   inline hb_vector_size_t process (const hb_vector_size_t &o) const

  1126   {

  1127     hb_vector_size_t r;

  1128 #if HB_VECTOR_SIZE

  1129     if (HB_VECTOR_SIZE && 0 == (byte_size * 8) % HB_VECTOR_SIZE)

  1130       for (unsigned int i = 0; i < ARRAY_LENGTH (u.vec); i++)

  1131         Op::process (r.u.vec[i], u.vec[i], o.u.vec[i]);

  1132     else

  1133 #endif

  1134       for (unsigned int i = 0; i < ARRAY_LENGTH (u.v); i++)

  1135         Op::process (r.u.v[i], u.v[i], o.u.v[i]);