1 /*
2 * Copyright © 2007,2008,2009,2010 Red Hat, Inc.
3 * Copyright © 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_OPEN_TYPE_PRIVATE_HH
30 #define HB_OPEN_TYPE_PRIVATE_HH
31
32 #include "hb-private.hh"
33 #include "hb-debug.hh"
34 #include "hb-face-private.hh"
35
36
37 namespace OT {
38
39
40
41 /*
42 * Casts
43 */
44
45 /* Cast to struct T, reference to reference */
46 template<typename Type, typename TObject>
CastR(const TObject & X)47 static inline const Type& CastR(const TObject &X)
48 { return reinterpret_cast<const Type&> (X); }
49 template<typename Type, typename TObject>
CastR(TObject & X)50 static inline Type& CastR(TObject &X)
51 { return reinterpret_cast<Type&> (X); }
52
53 /* Cast to struct T, pointer to pointer */
54 template<typename Type, typename TObject>
CastP(const TObject * X)55 static inline const Type* CastP(const TObject *X)
56 { return reinterpret_cast<const Type*> (X); }
57 template<typename Type, typename TObject>
CastP(TObject * X)58 static inline Type* CastP(TObject *X)
59 { return reinterpret_cast<Type*> (X); }
60
61 /* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory
62 * location pointed to by P plus Ofs bytes. */
63 template<typename Type>
StructAtOffset(const void * P,unsigned int offset)64 static inline const Type& StructAtOffset(const void *P, unsigned int offset)
65 { return * reinterpret_cast<const Type*> ((const char *) P + offset); }
66 template<typename Type>
StructAtOffset(void * P,unsigned int offset)67 static inline Type& StructAtOffset(void *P, unsigned int offset)
68 { return * reinterpret_cast<Type*> ((char *) P + offset); }
69
70 /* StructAfter<T>(X) returns the struct T& that is placed after X.
71 * Works with X of variable size also. X must implement get_size() */
72 template<typename Type, typename TObject>
StructAfter(const TObject & X)73 static inline const Type& StructAfter(const TObject &X)
74 { return StructAtOffset<Type>(&X, X.get_size()); }
75 template<typename Type, typename TObject>
StructAfter(TObject & X)76 static inline Type& StructAfter(TObject &X)
77 { return StructAtOffset<Type>(&X, X.get_size()); }
78
79
80
81 /*
82 * Size checking
83 */
84
85 /* Check _assertion in a method environment */
86 #define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \
87 inline void _instance_assertion_on_line_##_line (void) const \
88 { \
89 static_assert ((_assertion), ""); \
90 ASSERT_INSTANCE_POD (*this); /* Make sure it's POD. */ \
91 }
92 # define _DEFINE_INSTANCE_ASSERTION0(_line, _assertion) _DEFINE_INSTANCE_ASSERTION1 (_line, _assertion)
93 # define DEFINE_INSTANCE_ASSERTION(_assertion) _DEFINE_INSTANCE_ASSERTION0 (__LINE__, _assertion)
94
95 /* Check that _code compiles in a method environment */
96 #define _DEFINE_COMPILES_ASSERTION1(_line, _code) \
97 inline void _compiles_assertion_on_line_##_line (void) const \
98 { _code; }
99 # define _DEFINE_COMPILES_ASSERTION0(_line, _code) _DEFINE_COMPILES_ASSERTION1 (_line, _code)
100 # define DEFINE_COMPILES_ASSERTION(_code) _DEFINE_COMPILES_ASSERTION0 (__LINE__, _code)
101
102
103 #define DEFINE_SIZE_STATIC(size) \
104 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size)); \
105 static const unsigned int static_size = (size); \
106 static const unsigned int min_size = (size); \
107 inline unsigned int get_size (void) const { return (size); }
108
109 #define DEFINE_SIZE_UNION(size, _member) \
110 DEFINE_INSTANCE_ASSERTION (0*sizeof(this->u._member.static_size) + sizeof(this->u._member) == (size)); \
111 static const unsigned int min_size = (size)
112
113 #define DEFINE_SIZE_MIN(size) \
114 DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)); \
115 static const unsigned int min_size = (size)
116
117 #define DEFINE_SIZE_ARRAY(size, array) \
118 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \
119 DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \
120 static const unsigned int min_size = (size)
121
122 #define DEFINE_SIZE_ARRAY2(size, array1, array2) \
123 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \
124 DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].static_size) \
125 static const unsigned int min_size = (size)
126
127
128
129 /*
130 * Null objects
131 */
132
133 /* Global nul-content Null pool. Enlarge as necessary. */
134
135 #define HB_NULL_POOL_SIZE 264
136 static_assert (HB_NULL_POOL_SIZE % sizeof (void *) == 0, "Align HB_NULL_POOL_SIZE.");
137 extern HB_INTERNAL const void * const _hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)];
138
139 /* Generic nul-content Null objects. */
140 template <typename Type>
Null(void)141 static inline const Type& Null (void) {
142 static_assert (sizeof (Type) <= HB_NULL_POOL_SIZE, "Increase HB_NULL_POOL_SIZE.");
143 return *CastP<Type> (_hb_NullPool);
144 }
145
146 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
147 #define DEFINE_NULL_DATA(Type, data) \
148 static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \
149 template <> \
150 /*static*/ inline const Type& Null<Type> (void) { \
151 return *CastP<Type> (_Null##Type); \
152 } /* The following line really exists such that we end in a place needing semicolon */ \
153 static_assert (Type::min_size + 1 <= sizeof (_Null##Type), "Null pool too small. Enlarge.")
154
155 /* Accessor macro. */
156 #define Null(Type) Null<Type>()
157
158
159 /*
160 * Dispatch
161 */
162
163 template <typename Context, typename Return, unsigned int MaxDebugDepth>
164 struct hb_dispatch_context_t
165 {
166 static const unsigned int max_debug_depth = MaxDebugDepth;
167 typedef Return return_t;
168 template <typename T, typename F>
may_dispatchOT::hb_dispatch_context_t169 inline bool may_dispatch (const T *obj, const F *format) { return true; }
no_dispatch_return_valueOT::hb_dispatch_context_t170 static return_t no_dispatch_return_value (void) { return Context::default_return_value (); }
171 };
172
173
174 /*
175 * Sanitize
176 */
177
178 /* This limits sanitizing time on really broken fonts. */
179 #ifndef HB_SANITIZE_MAX_EDITS
180 #define HB_SANITIZE_MAX_EDITS 32
181 #endif
182
183 struct hb_sanitize_context_t :
184 hb_dispatch_context_t<hb_sanitize_context_t, bool, HB_DEBUG_SANITIZE>
185 {
hb_sanitize_context_tOT::hb_sanitize_context_t186 inline hb_sanitize_context_t (void) :
187 debug_depth (0),
188 start (nullptr), end (nullptr),
189 writable (false), edit_count (0),
190 blob (nullptr) {}
191
get_nameOT::hb_sanitize_context_t192 inline const char *get_name (void) { return "SANITIZE"; }
193 template <typename T, typename F>
may_dispatchOT::hb_sanitize_context_t194 inline bool may_dispatch (const T *obj, const F *format)
195 { return format->sanitize (this); }
196 template <typename T>
dispatchOT::hb_sanitize_context_t197 inline return_t dispatch (const T &obj) { return obj.sanitize (this); }
default_return_valueOT::hb_sanitize_context_t198 static return_t default_return_value (void) { return true; }
no_dispatch_return_valueOT::hb_sanitize_context_t199 static return_t no_dispatch_return_value (void) { return false; }
stop_sublookup_iterationOT::hb_sanitize_context_t200 bool stop_sublookup_iteration (const return_t r) const { return !r; }
201
initOT::hb_sanitize_context_t202 inline void init (hb_blob_t *b)
203 {
204 this->blob = hb_blob_reference (b);
205 this->writable = false;
206 }
207
start_processingOT::hb_sanitize_context_t208 inline void start_processing (void)
209 {
210 this->start = hb_blob_get_data (this->blob, nullptr);
211 this->end = this->start + hb_blob_get_length (this->blob);
212 assert (this->start <= this->end); /* Must not overflow. */
213 this->edit_count = 0;
214 this->debug_depth = 0;
215
216 DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1,
217 "start [%p..%p] (%lu bytes)",
218 this->start, this->end,
219 (unsigned long) (this->end - this->start));
220 }
221
end_processingOT::hb_sanitize_context_t222 inline void end_processing (void)
223 {
224 DEBUG_MSG_LEVEL (SANITIZE, this->start, 0, -1,
225 "end [%p..%p] %u edit requests",
226 this->start, this->end, this->edit_count);
227
228 hb_blob_destroy (this->blob);
229 this->blob = nullptr;
230 this->start = this->end = nullptr;
231 }
232
check_rangeOT::hb_sanitize_context_t233 inline bool check_range (const void *base, unsigned int len) const
234 {
235 const char *p = (const char *) base;
236 bool ok = this->start <= p && p <= this->end && (unsigned int) (this->end - p) >= len;
237
238 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
239 "check_range [%p..%p] (%d bytes) in [%p..%p] -> %s",
240 p, p + len, len,
241 this->start, this->end,
242 ok ? "OK" : "OUT-OF-RANGE");
243
244 return likely (ok);
245 }
246
check_arrayOT::hb_sanitize_context_t247 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
248 {
249 const char *p = (const char *) base;
250 bool overflows = _hb_unsigned_int_mul_overflows (len, record_size);
251 unsigned int array_size = record_size * len;
252 bool ok = !overflows && this->check_range (base, array_size);
253
254 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
255 "check_array [%p..%p] (%d*%d=%d bytes) in [%p..%p] -> %s",
256 p, p + (record_size * len), record_size, len, (unsigned int) array_size,
257 this->start, this->end,
258 overflows ? "OVERFLOWS" : ok ? "OK" : "OUT-OF-RANGE");
259
260 return likely (ok);
261 }
262
263 template <typename Type>
check_structOT::hb_sanitize_context_t264 inline bool check_struct (const Type *obj) const
265 {
266 return likely (this->check_range (obj, obj->min_size));
267 }
268
may_editOT::hb_sanitize_context_t269 inline bool may_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED)
270 {
271 if (this->edit_count >= HB_SANITIZE_MAX_EDITS)
272 return false;
273
274 const char *p = (const char *) base;
275 this->edit_count++;
276
277 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
278 "may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s",
279 this->edit_count,
280 p, p + len, len,
281 this->start, this->end,
282 this->writable ? "GRANTED" : "DENIED");
283
284 return this->writable;
285 }
286
287 template <typename Type, typename ValueType>
try_setOT::hb_sanitize_context_t288 inline bool try_set (const Type *obj, const ValueType &v) {
289 if (this->may_edit (obj, obj->static_size)) {
290 const_cast<Type *> (obj)->set (v);
291 return true;
292 }
293 return false;
294 }
295
296 mutable unsigned int debug_depth;
297 const char *start, *end;
298 bool writable;
299 unsigned int edit_count;
300 hb_blob_t *blob;
301 };
302
303
304
305 /* Template to sanitize an object. */
306 template <typename Type>
307 struct Sanitizer
308 {
sanitizeOT::Sanitizer309 static hb_blob_t *sanitize (hb_blob_t *blob) {
310 hb_sanitize_context_t c[1];
311 bool sane;
312
313 /* TODO is_sane() stuff */
314
315 c->init (blob);
316
317 retry:
318 DEBUG_MSG_FUNC (SANITIZE, c->start, "start");
319
320 c->start_processing ();
321
322 if (unlikely (!c->start)) {
323 c->end_processing ();
324 return blob;
325 }
326
327 Type *t = CastP<Type> (const_cast<char *> (c->start));
328
329 sane = t->sanitize (c);
330 if (sane) {
331 if (c->edit_count) {
332 DEBUG_MSG_FUNC (SANITIZE, c->start, "passed first round with %d edits; going for second round", c->edit_count);
333
334 /* sanitize again to ensure no toe-stepping */
335 c->edit_count = 0;
336 sane = t->sanitize (c);
337 if (c->edit_count) {
338 DEBUG_MSG_FUNC (SANITIZE, c->start, "requested %d edits in second round; FAILLING", c->edit_count);
339 sane = false;
340 }
341 }
342 } else {
343 unsigned int edit_count = c->edit_count;
344 if (edit_count && !c->writable) {
345 c->start = hb_blob_get_data_writable (blob, nullptr);
346 c->end = c->start + hb_blob_get_length (blob);
347
348 if (c->start) {
349 c->writable = true;
350 /* ok, we made it writable by relocating. try again */
351 DEBUG_MSG_FUNC (SANITIZE, c->start, "retry");
352 goto retry;
353 }
354 }
355 }
356
357 c->end_processing ();
358
359 DEBUG_MSG_FUNC (SANITIZE, c->start, sane ? "PASSED" : "FAILED");
360 if (sane)
361 return blob;
362 else {
363 hb_blob_destroy (blob);
364 return hb_blob_get_empty ();
365 }
366 }
367
lock_instanceOT::Sanitizer368 static const Type* lock_instance (hb_blob_t *blob) {
369 hb_blob_make_immutable (blob);
370 const char *base = hb_blob_get_data (blob, nullptr);
371 return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
372 }
373 };
374
375
376
377 /*
378 * Serialize
379 */
380
381
382 struct hb_serialize_context_t
383 {
hb_serialize_context_tOT::hb_serialize_context_t384 inline hb_serialize_context_t (void *start_, unsigned int size)
385 {
386 this->start = (char *) start_;
387 this->end = this->start + size;
388
389 this->ran_out_of_room = false;
390 this->head = this->start;
391 this->debug_depth = 0;
392 }
393
394 template <typename Type>
start_serializeOT::hb_serialize_context_t395 inline Type *start_serialize (void)
396 {
397 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1,
398 "start [%p..%p] (%lu bytes)",
399 this->start, this->end,
400 (unsigned long) (this->end - this->start));
401
402 return start_embed<Type> ();
403 }
404
end_serializeOT::hb_serialize_context_t405 inline void end_serialize (void)
406 {
407 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1,
408 "end [%p..%p] serialized %d bytes; %s",
409 this->start, this->end,
410 (int) (this->head - this->start),
411 this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room");
412
413 }
414
415 template <typename Type>
copyOT::hb_serialize_context_t416 inline Type *copy (void)
417 {
418 assert (!this->ran_out_of_room);
419 unsigned int len = this->head - this->start;
420 void *p = malloc (len);
421 if (p)
422 memcpy (p, this->start, len);
423 return reinterpret_cast<Type *> (p);
424 }
425
426 template <typename Type>
allocate_sizeOT::hb_serialize_context_t427 inline Type *allocate_size (unsigned int size)
428 {
429 if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) {
430 this->ran_out_of_room = true;
431 return nullptr;
432 }
433 memset (this->head, 0, size);
434 char *ret = this->head;
435 this->head += size;
436 return reinterpret_cast<Type *> (ret);
437 }
438
439 template <typename Type>
allocate_minOT::hb_serialize_context_t440 inline Type *allocate_min (void)
441 {
442 return this->allocate_size<Type> (Type::min_size);
443 }
444
445 template <typename Type>
start_embedOT::hb_serialize_context_t446 inline Type *start_embed (void)
447 {
448 Type *ret = reinterpret_cast<Type *> (this->head);
449 return ret;
450 }
451
452 template <typename Type>
embedOT::hb_serialize_context_t453 inline Type *embed (const Type &obj)
454 {
455 unsigned int size = obj.get_size ();
456 Type *ret = this->allocate_size<Type> (size);
457 if (unlikely (!ret)) return nullptr;
458 memcpy (ret, obj, size);
459 return ret;
460 }
461
462 template <typename Type>
extend_minOT::hb_serialize_context_t463 inline Type *extend_min (Type &obj)
464 {
465 unsigned int size = obj.min_size;
466 assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
467 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return nullptr;
468 return reinterpret_cast<Type *> (&obj);
469 }
470
471 template <typename Type>
extendOT::hb_serialize_context_t472 inline Type *extend (Type &obj)
473 {
474 unsigned int size = obj.get_size ();
475 assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
476 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return nullptr;
477 return reinterpret_cast<Type *> (&obj);
478 }
479
truncateOT::hb_serialize_context_t480 inline void truncate (void *new_head)
481 {
482 assert (this->start < new_head && new_head <= this->head);
483 this->head = (char *) new_head;
484 }
485
486 unsigned int debug_depth;
487 char *start, *end, *head;
488 bool ran_out_of_room;
489 };
490
491 template <typename Type>
492 struct Supplier
493 {
SupplierOT::Supplier494 inline Supplier (const Type *array, unsigned int len_)
495 {
496 head = array;
497 len = len_;
498 }
operator []OT::Supplier499 inline const Type operator [] (unsigned int i) const
500 {
501 if (unlikely (i >= len)) return Type ();
502 return head[i];
503 }
504
advanceOT::Supplier505 inline void advance (unsigned int count)
506 {
507 if (unlikely (count > len))
508 count = len;
509 len -= count;
510 head += count;
511 }
512
513 private:
514 inline Supplier (const Supplier<Type> &); /* Disallow copy */
515 inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */
516
517 unsigned int len;
518 const Type *head;
519 };
520
521
522
523
524 /*
525 *
526 * The OpenType Font File: Data Types
527 */
528
529
530 /* "The following data types are used in the OpenType font file.
531 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
532
533 /*
534 * Int types
535 */
536
537
538 template <typename Type, int Bytes> struct BEInt;
539
540 template <typename Type>
541 struct BEInt<Type, 1>
542 {
543 public:
setOT::BEInt544 inline void set (Type V)
545 {
546 v = V;
547 }
operator TypeOT::BEInt548 inline operator Type (void) const
549 {
550 return v;
551 }
552 private: uint8_t v;
553 };
554 template <typename Type>
555 struct BEInt<Type, 2>
556 {
557 public:
setOT::BEInt558 inline void set (Type V)
559 {
560 v[0] = (V >> 8) & 0xFF;
561 v[1] = (V ) & 0xFF;
562 }
operator TypeOT::BEInt563 inline operator Type (void) const
564 {
565 return (v[0] << 8)
566 + (v[1] );
567 }
568 private: uint8_t v[2];
569 };
570 template <typename Type>
571 struct BEInt<Type, 3>
572 {
573 public:
setOT::BEInt574 inline void set (Type V)
575 {
576 v[0] = (V >> 16) & 0xFF;
577 v[1] = (V >> 8) & 0xFF;
578 v[2] = (V ) & 0xFF;
579 }
operator TypeOT::BEInt580 inline operator Type (void) const
581 {
582 return (v[0] << 16)
583 + (v[1] << 8)
584 + (v[2] );
585 }
586 private: uint8_t v[3];
587 };
588 template <typename Type>
589 struct BEInt<Type, 4>
590 {
591 public:
setOT::BEInt592 inline void set (Type V)
593 {
594 v[0] = (V >> 24) & 0xFF;
595 v[1] = (V >> 16) & 0xFF;
596 v[2] = (V >> 8) & 0xFF;
597 v[3] = (V ) & 0xFF;
598 }
operator TypeOT::BEInt599 inline operator Type (void) const
600 {
601 return (v[0] << 24)
602 + (v[1] << 16)
603 + (v[2] << 8)
604 + (v[3] );
605 }
606 private: uint8_t v[4];
607 };
608
609 /* Integer types in big-endian order and no alignment requirement */
610 template <typename Type, unsigned int Size>
611 struct IntType
612 {
setOT::IntType613 inline void set (Type i) { v.set (i); }
operator TypeOT::IntType614 inline operator Type(void) const { return v; }
operator ==OT::IntType615 inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; }
operator !=OT::IntType616 inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); }
cmpOT::IntType617 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); }
618 template <typename Type2>
cmpOT::IntType619 inline int cmp (Type2 a) const
620 {
621 Type b = v;
622 if (sizeof (Type) < sizeof (int) && sizeof (Type2) < sizeof (int))
623 return (int) a - (int) b;
624 else
625 return a < b ? -1 : a == b ? 0 : +1;
626 }
sanitizeOT::IntType627 inline bool sanitize (hb_sanitize_context_t *c) const
628 {
629 TRACE_SANITIZE (this);
630 return_trace (likely (c->check_struct (this)));
631 }
632 protected:
633 BEInt<Type, Size> v;
634 public:
635 DEFINE_SIZE_STATIC (Size);
636 };
637
638 typedef IntType<uint8_t, 1> UINT8; /* 8-bit unsigned integer. */
639 typedef IntType<int8_t, 1> INT8; /* 8-bit signed integer. */
640 typedef IntType<uint16_t, 2> UINT16; /* 16-bit unsigned integer. */
641 typedef IntType<int16_t, 2> INT16; /* 16-bit signed integer. */
642 typedef IntType<uint32_t, 4> UINT32; /* 32-bit unsigned integer. */
643 typedef IntType<int32_t, 4> INT32; /* 32-bit signed integer. */
644 typedef IntType<uint32_t, 3> UINT24; /* 24-bit unsigned integer. */
645
646 /* 16-bit signed integer (INT16) that describes a quantity in FUnits. */
647 typedef INT16 FWORD;
648
649 /* 16-bit unsigned integer (UINT16) that describes a quantity in FUnits. */
650 typedef UINT16 UFWORD;
651
652 /* 16-bit signed fixed number with the low 14 bits of fraction (2.14). */
653 struct F2DOT14 : INT16
654 {
655 //inline float to_float (void) const { return ???; }
656 //inline void set_float (float f) { v.set (f * ???); }
657 public:
658 DEFINE_SIZE_STATIC (2);
659 };
660
661 /* 32-bit signed fixed-point number (16.16). */
662 struct Fixed: INT32
663 {
664 //inline float to_float (void) const { return ???; }
665 //inline void set_float (float f) { v.set (f * ???); }
666 public:
667 DEFINE_SIZE_STATIC (4);
668 };
669
670 /* Date represented in number of seconds since 12:00 midnight, January 1,
671 * 1904. The value is represented as a signed 64-bit integer. */
672 struct LONGDATETIME
673 {
sanitizeOT::LONGDATETIME674 inline bool sanitize (hb_sanitize_context_t *c) const
675 {
676 TRACE_SANITIZE (this);
677 return_trace (likely (c->check_struct (this)));
678 }
679 protected:
680 INT32 major;
681 UINT32 minor;
682 public:
683 DEFINE_SIZE_STATIC (8);
684 };
685
686 /* Array of four uint8s (length = 32 bits) used to identify a script, language
687 * system, feature, or baseline */
688 struct Tag : UINT32
689 {
690 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
operator const char*OT::Tag691 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
operator char*OT::Tag692 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
693 public:
694 DEFINE_SIZE_STATIC (4);
695 };
696 DEFINE_NULL_DATA (Tag, " ");
697
698 /* Glyph index number, same as uint16 (length = 16 bits) */
699 typedef UINT16 GlyphID;
700
701 /* Script/language-system/feature index */
702 struct Index : UINT16 {
703 static const unsigned int NOT_FOUND_INDEX = 0xFFFFu;
704 };
705 DEFINE_NULL_DATA (Index, "\xff\xff");
706
707 /* Offset, Null offset = 0 */
708 template <typename Type>
709 struct Offset : Type
710 {
is_nullOT::Offset711 inline bool is_null (void) const { return 0 == *this; }
712 public:
713 DEFINE_SIZE_STATIC (sizeof(Type));
714 };
715
716 typedef Offset<UINT16> Offset16;
717 typedef Offset<UINT32> Offset32;
718
719
720 /* CheckSum */
721 struct CheckSum : UINT32
722 {
723 /* This is reference implementation from the spec. */
CalcTableChecksumOT::CheckSum724 static inline uint32_t CalcTableChecksum (const UINT32 *Table, uint32_t Length)
725 {
726 uint32_t Sum = 0L;
727 const UINT32 *EndPtr = Table+((Length+3) & ~3) / UINT32::static_size;
728
729 while (Table < EndPtr)
730 Sum += *Table++;
731 return Sum;
732 }
733
734 /* Note: data should be 4byte aligned and have 4byte padding at the end. */
set_for_dataOT::CheckSum735 inline void set_for_data (const void *data, unsigned int length)
736 { set (CalcTableChecksum ((const UINT32 *) data, length)); }
737
738 public:
739 DEFINE_SIZE_STATIC (4);
740 };
741
742
743 /*
744 * Version Numbers
745 */
746
747 template <typename FixedType=UINT16>
748 struct FixedVersion
749 {
to_intOT::FixedVersion750 inline uint32_t to_int (void) const { return (major << (sizeof(FixedType) * 8)) + minor; }
751
sanitizeOT::FixedVersion752 inline bool sanitize (hb_sanitize_context_t *c) const
753 {
754 TRACE_SANITIZE (this);
755 return_trace (c->check_struct (this));
756 }
757
758 FixedType major;
759 FixedType minor;
760 public:
761 DEFINE_SIZE_STATIC (2 * sizeof(FixedType));
762 };
763
764
765
766 /*
767 * Template subclasses of Offset that do the dereferencing.
768 * Use: (base+offset)
769 */
770
771 template <typename Type, typename OffsetType=UINT16>
772 struct OffsetTo : Offset<OffsetType>
773 {
operator ()OT::OffsetTo774 inline const Type& operator () (const void *base) const
775 {
776 unsigned int offset = *this;
777 if (unlikely (!offset)) return Null(Type);
778 return StructAtOffset<Type> (base, offset);
779 }
780
serializeOT::OffsetTo781 inline Type& serialize (hb_serialize_context_t *c, const void *base)
782 {
783 Type *t = c->start_embed<Type> ();
784 this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */
785 return *t;
786 }
787
sanitizeOT::OffsetTo788 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
789 {
790 TRACE_SANITIZE (this);
791 if (unlikely (!c->check_struct (this))) return_trace (false);
792 unsigned int offset = *this;
793 if (unlikely (!offset)) return_trace (true);
794 if (unlikely (!c->check_range (base, offset))) return_trace (false);
795 const Type &obj = StructAtOffset<Type> (base, offset);
796 return_trace (likely (obj.sanitize (c)) || neuter (c));
797 }
798 template <typename T>
sanitizeOT::OffsetTo799 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
800 {
801 TRACE_SANITIZE (this);
802 if (unlikely (!c->check_struct (this))) return_trace (false);
803 unsigned int offset = *this;
804 if (unlikely (!offset)) return_trace (true);
805 if (unlikely (!c->check_range (base, offset))) return_trace (false);
806 const Type &obj = StructAtOffset<Type> (base, offset);
807 return_trace (likely (obj.sanitize (c, user_data)) || neuter (c));
808 }
809
810 /* Set the offset to Null */
neuterOT::OffsetTo811 inline bool neuter (hb_sanitize_context_t *c) const {
812 return c->try_set (this, 0);
813 }
814 DEFINE_SIZE_STATIC (sizeof(OffsetType));
815 };
816 template <typename Type> struct LOffsetTo : OffsetTo<Type, UINT32> {};
817 template <typename Base, typename OffsetType, typename Type>
operator +(const Base & base,const OffsetTo<Type,OffsetType> & offset)818 static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); }
819 template <typename Base, typename OffsetType, typename Type>
operator +(Base & base,OffsetTo<Type,OffsetType> & offset)820 static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); }
821
822
823 /*
824 * Array Types
825 */
826
827 /* An array with a number of elements. */
828 template <typename Type, typename LenType=UINT16>
829 struct ArrayOf
830 {
sub_arrayOT::ArrayOf831 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
832 {
833 unsigned int count = len;
834 if (unlikely (start_offset > count))
835 count = 0;
836 else
837 count -= start_offset;
838 count = MIN (count, *pcount);
839 *pcount = count;
840 return array + start_offset;
841 }
842
operator []OT::ArrayOf843 inline const Type& operator [] (unsigned int i) const
844 {
845 if (unlikely (i >= len)) return Null(Type);
846 return array[i];
847 }
operator []OT::ArrayOf848 inline Type& operator [] (unsigned int i)
849 {
850 return array[i];
851 }
get_sizeOT::ArrayOf852 inline unsigned int get_size (void) const
853 { return len.static_size + len * Type::static_size; }
854
serializeOT::ArrayOf855 inline bool serialize (hb_serialize_context_t *c,
856 unsigned int items_len)
857 {
858 TRACE_SERIALIZE (this);
859 if (unlikely (!c->extend_min (*this))) return_trace (false);
860 len.set (items_len); /* TODO(serialize) Overflow? */
861 if (unlikely (!c->extend (*this))) return_trace (false);
862 return_trace (true);
863 }
864
serializeOT::ArrayOf865 inline bool serialize (hb_serialize_context_t *c,
866 Supplier<Type> &items,
867 unsigned int items_len)
868 {
869 TRACE_SERIALIZE (this);
870 if (unlikely (!serialize (c, items_len))) return_trace (false);
871 for (unsigned int i = 0; i < items_len; i++)
872 array[i] = items[i];
873 items.advance (items_len);
874 return_trace (true);
875 }
876
sanitizeOT::ArrayOf877 inline bool sanitize (hb_sanitize_context_t *c) const
878 {
879 TRACE_SANITIZE (this);
880 if (unlikely (!sanitize_shallow (c))) return_trace (false);
881
882 /* Note: for structs that do not reference other structs,
883 * we do not need to call their sanitize() as we already did
884 * a bound check on the aggregate array size. We just include
885 * a small unreachable expression to make sure the structs
886 * pointed to do have a simple sanitize(), ie. they do not
887 * reference other structs via offsets.
888 */
889 (void) (false && array[0].sanitize (c));
890
891 return_trace (true);
892 }
sanitizeOT::ArrayOf893 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
894 {
895 TRACE_SANITIZE (this);
896 if (unlikely (!sanitize_shallow (c))) return_trace (false);
897 unsigned int count = len;
898 for (unsigned int i = 0; i < count; i++)
899 if (unlikely (!array[i].sanitize (c, base)))
900 return_trace (false);
901 return_trace (true);
902 }
903 template <typename T>
sanitizeOT::ArrayOf904 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
905 {
906 TRACE_SANITIZE (this);
907 if (unlikely (!sanitize_shallow (c))) return_trace (false);
908 unsigned int count = len;
909 for (unsigned int i = 0; i < count; i++)
910 if (unlikely (!array[i].sanitize (c, base, user_data)))
911 return_trace (false);
912 return_trace (true);
913 }
914
915 template <typename SearchType>
lsearchOT::ArrayOf916 inline int lsearch (const SearchType &x) const
917 {
918 unsigned int count = len;
919 for (unsigned int i = 0; i < count; i++)
920 if (!this->array[i].cmp (x))
921 return i;
922 return -1;
923 }
924
925 private:
sanitize_shallowOT::ArrayOf926 inline bool sanitize_shallow (hb_sanitize_context_t *c) const
927 {
928 TRACE_SANITIZE (this);
929 return_trace (len.sanitize (c) && c->check_array (array, Type::static_size, len));
930 }
931
932 public:
933 LenType len;
934 Type array[VAR];
935 public:
936 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
937 };
938 template <typename Type> struct LArrayOf : ArrayOf<Type, UINT32> {};
939
940 /* Array of Offset's */
941 template <typename Type, typename OffsetType=UINT16>
942 struct OffsetArrayOf : ArrayOf<OffsetTo<Type, OffsetType> > {};
943
944 /* Array of offsets relative to the beginning of the array itself. */
945 template <typename Type>
946 struct OffsetListOf : OffsetArrayOf<Type>
947 {
operator []OT::OffsetListOf948 inline const Type& operator [] (unsigned int i) const
949 {
950 if (unlikely (i >= this->len)) return Null(Type);
951 return this+this->array[i];
952 }
953
sanitizeOT::OffsetListOf954 inline bool sanitize (hb_sanitize_context_t *c) const
955 {
956 TRACE_SANITIZE (this);
957 return_trace (OffsetArrayOf<Type>::sanitize (c, this));
958 }
959 template <typename T>
sanitizeOT::OffsetListOf960 inline bool sanitize (hb_sanitize_context_t *c, T user_data) const
961 {
962 TRACE_SANITIZE (this);
963 return_trace (OffsetArrayOf<Type>::sanitize (c, this, user_data));
964 }
965 };
966
967
968 /* An array starting at second element. */
969 template <typename Type, typename LenType=UINT16>
970 struct HeadlessArrayOf
971 {
operator []OT::HeadlessArrayOf972 inline const Type& operator [] (unsigned int i) const
973 {
974 if (unlikely (i >= len || !i)) return Null(Type);
975 return array[i-1];
976 }
get_sizeOT::HeadlessArrayOf977 inline unsigned int get_size (void) const
978 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
979
serializeOT::HeadlessArrayOf980 inline bool serialize (hb_serialize_context_t *c,
981 Supplier<Type> &items,
982 unsigned int items_len)
983 {
984 TRACE_SERIALIZE (this);
985 if (unlikely (!c->extend_min (*this))) return_trace (false);
986 len.set (items_len); /* TODO(serialize) Overflow? */
987 if (unlikely (!items_len)) return_trace (true);
988 if (unlikely (!c->extend (*this))) return_trace (false);
989 for (unsigned int i = 0; i < items_len - 1; i++)
990 array[i] = items[i];
991 items.advance (items_len - 1);
992 return_trace (true);
993 }
994
sanitizeOT::HeadlessArrayOf995 inline bool sanitize (hb_sanitize_context_t *c) const
996 {
997 TRACE_SANITIZE (this);
998 if (unlikely (!sanitize_shallow (c))) return_trace (false);
999
1000 /* Note: for structs that do not reference other structs,
1001 * we do not need to call their sanitize() as we already did
1002 * a bound check on the aggregate array size. We just include
1003 * a small unreachable expression to make sure the structs
1004 * pointed to do have a simple sanitize(), ie. they do not
1005 * reference other structs via offsets.
1006 */
1007 (void) (false && array[0].sanitize (c));
1008
1009 return_trace (true);
1010 }
1011
1012 private:
sanitize_shallowOT::HeadlessArrayOf1013 inline bool sanitize_shallow (hb_sanitize_context_t *c) const
1014 {
1015 TRACE_SANITIZE (this);
1016 return_trace (len.sanitize (c) &&
1017 (!len || c->check_array (array, Type::static_size, len - 1)));
1018 }
1019
1020 public:
1021 LenType len;
1022 Type array[VAR];
1023 public:
1024 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
1025 };
1026
1027
1028 /*
1029 * An array with sorted elements. Supports binary searching.
1030 */
1031 template <typename Type, typename LenType=UINT16>
1032 struct SortedArrayOf : ArrayOf<Type, LenType>
1033 {
1034 template <typename SearchType>
bsearchOT::SortedArrayOf1035 inline int bsearch (const SearchType &x) const
1036 {
1037 /* Hand-coded bsearch here since this is in the hot inner loop. */
1038 const Type *array = this->array;
1039 int min = 0, max = (int) this->len - 1;
1040 while (min <= max)
1041 {
1042 int mid = (min + max) / 2;
1043 int c = array[mid].cmp (x);
1044 if (c < 0)
1045 max = mid - 1;
1046 else if (c > 0)
1047 min = mid + 1;
1048 else
1049 return mid;
1050 }
1051 return -1;
1052 }
1053 };
1054
1055 /*
1056 * Binary-search arrays
1057 */
1058
1059 struct BinSearchHeader
1060 {
operator uint32_tOT::BinSearchHeader1061 inline operator uint32_t (void) const { return len; }
1062
sanitizeOT::BinSearchHeader1063 inline bool sanitize (hb_sanitize_context_t *c) const
1064 {
1065 TRACE_SANITIZE (this);
1066 return_trace (c->check_struct (this));
1067 }
1068
1069 protected:
1070 UINT16 len;
1071 UINT16 searchRangeZ;
1072 UINT16 entrySelectorZ;
1073 UINT16 rangeShiftZ;
1074
1075 public:
1076 DEFINE_SIZE_STATIC (8);
1077 };
1078
1079 template <typename Type>
1080 struct BinSearchArrayOf : SortedArrayOf<Type, BinSearchHeader> {};
1081
1082
1083 /* Lazy struct and blob loaders. */
1084
1085 /* Logic is shared between hb_lazy_loader_t and hb_lazy_table_loader_t */
1086 template <typename T>
1087 struct hb_lazy_loader_t
1088 {
initOT::hb_lazy_loader_t1089 inline void init (hb_face_t *face_)
1090 {
1091 face = face_;
1092 instance = nullptr;
1093 }
1094
finiOT::hb_lazy_loader_t1095 inline void fini (void)
1096 {
1097 if (instance && instance != &OT::Null(T))
1098 {
1099 instance->fini();
1100 free (instance);
1101 }
1102 }
1103
getOT::hb_lazy_loader_t1104 inline const T* get (void) const
1105 {
1106 retry:
1107 T *p = (T *) hb_atomic_ptr_get (&instance);
1108 if (unlikely (!p))
1109 {
1110 p = (T *) calloc (1, sizeof (T));
1111 if (unlikely (!p))
1112 p = const_cast<T *> (&OT::Null(T));
1113 else
1114 p->init (face);
1115 if (unlikely (!hb_atomic_ptr_cmpexch (const_cast<T **>(&instance), nullptr, p)))
1116 {
1117 if (p != &OT::Null(T))
1118 p->fini ();
1119 goto retry;
1120 }
1121 }
1122 return p;
1123 }
1124
operator ->OT::hb_lazy_loader_t1125 inline const T* operator-> (void) const
1126 {
1127 return get ();
1128 }
1129
1130 private:
1131 hb_face_t *face;
1132 T *instance;
1133 };
1134
1135 /* Logic is shared between hb_lazy_loader_t and hb_lazy_table_loader_t */
1136 template <typename T>
1137 struct hb_lazy_table_loader_t
1138 {
initOT::hb_lazy_table_loader_t1139 inline void init (hb_face_t *face_)
1140 {
1141 face = face_;
1142 instance = nullptr;
1143 blob = nullptr;
1144 }
1145
finiOT::hb_lazy_table_loader_t1146 inline void fini (void)
1147 {
1148 hb_blob_destroy (blob);
1149 }
1150
getOT::hb_lazy_table_loader_t1151 inline const T* get (void) const
1152 {
1153 retry:
1154 T *p = (T *) hb_atomic_ptr_get (&instance);
1155 if (unlikely (!p))
1156 {
1157 hb_blob_t *blob_ = OT::Sanitizer<T>::sanitize (face->reference_table (T::tableTag));
1158 p = const_cast<T *>(OT::Sanitizer<T>::lock_instance (blob_));
1159 if (!hb_atomic_ptr_cmpexch (const_cast<T **>(&instance), nullptr, p))
1160 {
1161 hb_blob_destroy (blob_);
1162 goto retry;
1163 }
1164 blob = blob_;
1165 }
1166 return p;
1167 }
1168
operator ->OT::hb_lazy_table_loader_t1169 inline const T* operator-> (void) const
1170 {
1171 return get();
1172 }
1173
1174 private:
1175 hb_face_t *face;
1176 T *instance;
1177 mutable hb_blob_t *blob;
1178 };
1179
1180
1181 } /* namespace OT */
1182
1183
1184 #endif /* HB_OPEN_TYPE_PRIVATE_HH */
1185