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Issue 6052008: harfbuzz: check in harfbuzz-ng, add gyp define to use it (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src
Patch Set: fix Created 9 years, 11 months ago
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1 /*
2 * Copyright (C) 2007,2008,2009,2010 Red Hat, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Red Hat Author(s): Behdad Esfahbod
25 */
26
27 #ifndef HB_OPEN_TYPE_PRIVATE_HH
28 #define HB_OPEN_TYPE_PRIVATE_HH
29
30 #include "hb-private.h"
31
32 #include "hb-blob.h"
33
34 HB_BEGIN_DECLS
35 HB_END_DECLS
36
37
38 /*
39 * Casts
40 */
41
42 /* Cast to struct T, reference to reference */
43 template<typename Type, typename TObject>
44 inline const Type& CastR(const TObject &X)
45 { return reinterpret_cast<const Type&> (X); }
46 template<typename Type, typename TObject>
47 inline Type& CastR(TObject &X)
48 { return reinterpret_cast<Type&> (X); }
49
50 /* Cast to struct T, pointer to pointer */
51 template<typename Type, typename TObject>
52 inline const Type* CastP(const TObject *X)
53 { return reinterpret_cast<const Type*> (X); }
54 template<typename Type, typename TObject>
55 inline Type* CastP(TObject *X)
56 { return reinterpret_cast<Type*> (X); }
57
58 /* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory
59 * location pointed to by P plus Ofs bytes. */
60 template<typename Type>
61 inline const Type& StructAtOffset(const void *P, unsigned int offset)
62 { return * reinterpret_cast<const Type*> ((const char *) P + offset); }
63 template<typename Type>
64 inline Type& StructAtOffset(void *P, unsigned int offset)
65 { return * reinterpret_cast<Type*> ((char *) P + offset); }
66
67 /* StructAfter<T>(X) returns the struct T& that is placed after X.
68 * Works with X of variable size also. X must implement get_size() */
69 template<typename Type, typename TObject>
70 inline const Type& StructAfter(const TObject &X)
71 { return StructAtOffset<Type>(&X, X.get_size()); }
72 template<typename Type, typename TObject>
73 inline Type& StructAfter(TObject &X)
74 { return StructAtOffset<Type>(&X, X.get_size()); }
75
76
77
78 /*
79 * Size checking
80 */
81
82 /* Check _assertion in a method environment */
83 #define _DEFINE_SIZE_ASSERTION(_assertion) \
84 inline void _size_assertion (void) const \
85 { ASSERT_STATIC (_assertion); }
86 /* Check that _code compiles in a method environment */
87 #define _DEFINE_COMPILES_ASSERTION(_code) \
88 inline void _compiles_assertion (void) const \
89 { _code; }
90
91
92 #define DEFINE_SIZE_STATIC(size) \
93 _DEFINE_SIZE_ASSERTION (sizeof (*this) == (size)); \
94 static const unsigned int static_size = (size); \
95 static const unsigned int min_size = (size)
96
97 /* Size signifying variable-sized array */
98 #define VAR 1
99
100 #define DEFINE_SIZE_UNION(size, _member) \
101 _DEFINE_SIZE_ASSERTION (this->u._member.static_size == (size)); \
102 static const unsigned int min_size = (size)
103
104 #define DEFINE_SIZE_MIN(size) \
105 _DEFINE_SIZE_ASSERTION (sizeof (*this) >= (size)); \
106 static const unsigned int min_size = (size)
107
108 #define DEFINE_SIZE_ARRAY(size, array) \
109 _DEFINE_SIZE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \
110 _DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \
111 static const unsigned int min_size = (size)
112
113 #define DEFINE_SIZE_ARRAY2(size, array1, array2) \
114 _DEFINE_SIZE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \
115 _DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].sta tic_size) \
116 static const unsigned int min_size = (size)
117
118
119
120 /*
121 * Null objects
122 */
123
124 /* Global nul-content Null pool. Enlarge as necessary. */
125 static const void *_NullPool[64 / sizeof (void *)];
126
127 /* Generic nul-content Null objects. */
128 template <typename Type>
129 static inline const Type& Null (void) {
130 ASSERT_STATIC (Type::min_size <= sizeof (_NullPool));
131 return *CastP<Type> (_NullPool);
132 }
133
134 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
135 #define DEFINE_NULL_DATA(Type, data) \
136 static const char _Null##Type[Type::min_size + 1] = data; /* +1 is for nul-termi nation in data */ \
137 template <> \
138 inline const Type& Null<Type> (void) { \
139 return *CastP<Type> (_Null##Type); \
140 } /* The following line really exists such that we end in a place needing semico lon */ \
141 ASSERT_STATIC (Type::min_size + 1 <= sizeof (_Null##Type))
142
143 /* Accessor macro. */
144 #define Null(Type) Null<Type>()
145
146
147 /*
148 * Trace
149 */
150
151
152 template <int max_depth>
153 struct hb_trace_t {
154 explicit hb_trace_t (unsigned int *pdepth, const char *what, const char *funct ion, const void *obj) : pdepth(pdepth) {
155 (void) (*pdepth < max_depth &&
156 fprintf (stderr, "%s(%p) %-*d-> %s\n", what, obj, *pdepth, *pdepth, function));
157 if (max_depth) ++*pdepth;
158 }
159 ~hb_trace_t (void) { if (max_depth) --*pdepth; }
160
161 private:
162 unsigned int *pdepth;
163 };
164 template <> /* Optimize when tracing is disabled */
165 struct hb_trace_t<0> {
166 explicit hb_trace_t (unsigned int *pdepth HB_UNUSED, const char *what HB_UNUSE D, const char *function HB_UNUSED, const void *obj HB_UNUSED) {}
167 };
168
169
170
171 /*
172 * Sanitize
173 */
174
175 #ifndef HB_DEBUG_SANITIZE
176 #define HB_DEBUG_SANITIZE (HB_DEBUG+0)
177 #endif
178
179
180 #define TRACE_SANITIZE() \
181 hb_trace_t<HB_DEBUG_SANITIZE> trace (&c->debug_depth, "SANITIZE", HB_FUN C, this); \
182
183
184 struct hb_sanitize_context_t
185 {
186 inline void init (hb_blob_t *blob)
187 {
188 this->blob = hb_blob_reference (blob);
189 this->start = hb_blob_lock (blob);
190 this->end = this->start + hb_blob_get_length (blob);
191 this->writable = hb_blob_is_writable (blob);
192 this->edit_count = 0;
193 this->debug_depth = 0;
194
195 (void) (HB_DEBUG_SANITIZE &&
196 fprintf (stderr, "sanitize %p init [%p..%p] (%lu bytes)\n",
197 this->blob, this->start, this->end,
198 (unsigned long) (this->end - this->start)));
199 }
200
201 inline void finish (void)
202 {
203 (void) (HB_DEBUG_SANITIZE &&
204 fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n",
205 this->blob, this->start, this->end, this->edit_count));
206
207 hb_blob_unlock (this->blob);
208 hb_blob_destroy (this->blob);
209 this->blob = NULL;
210 this->start = this->end = NULL;
211 }
212
213 inline bool check_range (const void *base, unsigned int len) const
214 {
215 const char *p = (const char *) base;
216 bool ret = this->start <= p &&
217 p <= this->end &&
218 (unsigned int) (this->end - p) >= len;
219
220 (void) (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITI ZE &&
221 fprintf (stderr, "SANITIZE(%p) %-*d-> range [%p..%p] (%d bytes) in [%p..%p ] -> %s\n",
222 p,
223 this->debug_depth, this->debug_depth,
224 p, p + len, len,
225 this->start, this->end,
226 ret ? "pass" : "FAIL"));
227
228 return likely (ret);
229 }
230
231 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
232 {
233 const char *p = (const char *) base;
234 bool overflows = record_size > 0 && len >= ((unsigned int) -1) / record_size ;
235
236 (void) (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITI ZE &&
237 fprintf (stderr, "SANITIZE(%p) %-*d-> array [%p..%p] (%d*%d=%ld bytes) in [%p..%p] -> %s\n",
238 p,
239 this->debug_depth, this->debug_depth,
240 p, p + (record_size * len), record_size, len, (unsigned long) rec ord_size * len,
241 this->start, this->end,
242 !overflows ? "does not overflow" : "OVERFLOWS FAIL"));
243
244 return likely (!overflows && this->check_range (base, record_size * len));
245 }
246
247 template <typename Type>
248 inline bool check_struct (const Type *obj) const
249 {
250 return likely (this->check_range (obj, obj->min_size));
251 }
252
253 inline bool can_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED)
254 {
255 const char *p = (const char *) base;
256 this->edit_count++;
257
258 (void) (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITI ZE &&
259 fprintf (stderr, "SANITIZE(%p) %-*d-> edit(%u) [%p..%p] (%d bytes) in [%p. .%p] -> %s\n",
260 p,
261 this->debug_depth, this->debug_depth,
262 this->edit_count,
263 p, p + len, len,
264 this->start, this->end,
265 this->writable ? "granted" : "REJECTED"));
266
267 return this->writable;
268 }
269
270 unsigned int debug_depth;
271 const char *start, *end;
272 bool writable;
273 unsigned int edit_count;
274 hb_blob_t *blob;
275 };
276
277
278
279 /* Template to sanitize an object. */
280 template <typename Type>
281 struct Sanitizer
282 {
283 static hb_blob_t *sanitize (hb_blob_t *blob) {
284 hb_sanitize_context_t c[1] = {{0}};
285 bool sane;
286
287 /* TODO is_sane() stuff */
288
289 if (!blob)
290 return hb_blob_create_empty ();
291
292 retry:
293 (void) (HB_DEBUG_SANITIZE &&
294 fprintf (stderr, "Sanitizer %p start %s\n", blob, HB_FUNC));
295
296 c->init (blob);
297
298 if (unlikely (!c->start)) {
299 c->finish ();
300 return blob;
301 }
302
303 Type *t = CastP<Type> (const_cast<char *> (c->start));
304
305 sane = t->sanitize (c);
306 if (sane) {
307 if (c->edit_count) {
308 (void) (HB_DEBUG_SANITIZE &&
309 fprintf (stderr, "Sanitizer %p passed first round with %d edits; doing a second round %s\n",
310 blob, c->edit_count, HB_FUNC));
311
312 /* sanitize again to ensure no toe-stepping */
313 c->edit_count = 0;
314 sane = t->sanitize (c);
315 if (c->edit_count) {
316 (void) (HB_DEBUG_SANITIZE &&
317 fprintf (stderr, "Sanitizer %p requested %d edits in second round; F AILLING %s\n",
318 blob, c->edit_count, HB_FUNC));
319 sane = false;
320 }
321 }
322 c->finish ();
323 } else {
324 unsigned int edit_count = c->edit_count;
325 c->finish ();
326 if (edit_count && !hb_blob_is_writable (blob) && hb_blob_try_writable (blo b)) {
327 /* ok, we made it writable by relocating. try again */
328 (void) (HB_DEBUG_SANITIZE &&
329 fprintf (stderr, "Sanitizer %p retry %s\n", blob, HB_FUNC));
330 goto retry;
331 }
332 }
333
334 (void) (HB_DEBUG_SANITIZE &&
335 fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "FAILED", HB_FUNC));
336 if (sane)
337 return blob;
338 else {
339 hb_blob_destroy (blob);
340 return hb_blob_create_empty ();
341 }
342 }
343
344 static const Type* lock_instance (hb_blob_t *blob) {
345 const char *base = hb_blob_lock (blob);
346 return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
347 }
348 };
349
350
351
352
353 /*
354 *
355 * The OpenType Font File: Data Types
356 */
357
358
359 /* "The following data types are used in the OpenType font file.
360 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
361
362 /*
363 * Int types
364 */
365
366
367 template <typename Type, int Bytes> class BEInt;
368
369 /* LONGTERMTODO: On machines allowing unaligned access, we can make the
370 * following tighter by using byteswap instructions on ints directly. */
371 template <typename Type>
372 class BEInt<Type, 2>
373 {
374 public:
375 inline void set (Type i) { hb_be_uint16_put (v,i); }
376 inline operator Type (void) const { return hb_be_uint16_get (v); }
377 inline bool operator == (const BEInt<Type, 2>& o) const { return hb_be_uint16_ cmp (v, o.v); }
378 inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o) ; }
379 private: uint8_t v[2];
380 };
381 template <typename Type>
382 class BEInt<Type, 4>
383 {
384 public:
385 inline void set (Type i) { hb_be_uint32_put (v,i); }
386 inline operator Type (void) const { return hb_be_uint32_get (v); }
387 inline bool operator == (const BEInt<Type, 4>& o) const { return hb_be_uint32_ cmp (v, o.v); }
388 inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o) ; }
389 private: uint8_t v[4];
390 };
391
392 /* Integer types in big-endian order and no alignment requirement */
393 template <typename Type>
394 struct IntType
395 {
396 inline void set (Type i) { v.set (i); }
397 inline operator Type(void) const { return v; }
398 inline bool operator == (const IntType<Type> &o) const { return v == o.v; }
399 inline bool operator != (const IntType<Type> &o) const { return v != o.v; }
400 inline int cmp (Type a) const { Type b = v; return a < b ? -1 : a == b ? 0 : + 1; }
401 inline bool sanitize (hb_sanitize_context_t *c) {
402 TRACE_SANITIZE ();
403 return likely (c->check_struct (this));
404 }
405 protected:
406 BEInt<Type, sizeof (Type)> v;
407 public:
408 DEFINE_SIZE_STATIC (sizeof (Type));
409 };
410
411 typedef IntType<uint16_t> USHORT; /* 16-bit unsigned integer. */
412 typedef IntType<int16_t> SHORT; /* 16-bit signed integer. */
413 typedef IntType<uint32_t> ULONG; /* 32-bit unsigned integer. */
414 typedef IntType<int32_t> LONG; /* 32-bit signed integer. */
415
416 /* Date represented in number of seconds since 12:00 midnight, January 1,
417 * 1904. The value is represented as a signed 64-bit integer. */
418 struct LONGDATETIME
419 {
420 inline bool sanitize (hb_sanitize_context_t *c) {
421 TRACE_SANITIZE ();
422 return likely (c->check_struct (this));
423 }
424 private:
425 LONG major;
426 ULONG minor;
427 public:
428 DEFINE_SIZE_STATIC (8);
429 };
430
431 /* Array of four uint8s (length = 32 bits) used to identify a script, language
432 * system, feature, or baseline */
433 struct Tag : ULONG
434 {
435 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
436 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
437 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
438 public:
439 DEFINE_SIZE_STATIC (4);
440 };
441 DEFINE_NULL_DATA (Tag, " ");
442
443 /* Glyph index number, same as uint16 (length = 16 bits) */
444 typedef USHORT GlyphID;
445
446 /* Script/language-system/feature index */
447 struct Index : USHORT {
448 static const unsigned int NOT_FOUND_INDEX = 0xFFFF;
449 };
450 DEFINE_NULL_DATA (Index, "\xff\xff");
451
452 /* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
453 typedef USHORT Offset;
454
455 /* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x000 00000 */
456 typedef ULONG LongOffset;
457
458
459 /* CheckSum */
460 struct CheckSum : ULONG
461 {
462 static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length)
463 {
464 uint32_t Sum = 0L;
465 ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size;
466
467 while (Table < EndPtr)
468 Sum += *Table++;
469 return Sum;
470 }
471 public:
472 DEFINE_SIZE_STATIC (4);
473 };
474
475
476 /*
477 * Version Numbers
478 */
479
480 struct FixedVersion
481 {
482 inline operator uint32_t (void) const { return (major << 16) + minor; }
483
484 inline bool sanitize (hb_sanitize_context_t *c) {
485 TRACE_SANITIZE ();
486 return c->check_struct (this);
487 }
488
489 USHORT major;
490 USHORT minor;
491 public:
492 DEFINE_SIZE_STATIC (4);
493 };
494
495
496
497 /*
498 * Template subclasses of Offset and LongOffset that do the dereferencing.
499 * Use: (base+offset)
500 */
501
502 template <typename OffsetType, typename Type>
503 struct GenericOffsetTo : OffsetType
504 {
505 inline const Type& operator () (const void *base) const
506 {
507 unsigned int offset = *this;
508 if (unlikely (!offset)) return Null(Type);
509 return StructAtOffset<Type> (base, offset);
510 }
511
512 inline bool sanitize (hb_sanitize_context_t *c, void *base) {
513 TRACE_SANITIZE ();
514 if (unlikely (!c->check_struct (this))) return false;
515 unsigned int offset = *this;
516 if (unlikely (!offset)) return true;
517 Type &obj = StructAtOffset<Type> (base, offset);
518 return likely (obj.sanitize (c)) || neuter (c);
519 }
520 template <typename T>
521 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
522 TRACE_SANITIZE ();
523 if (unlikely (!c->check_struct (this))) return false;
524 unsigned int offset = *this;
525 if (unlikely (!offset)) return true;
526 Type &obj = StructAtOffset<Type> (base, offset);
527 return likely (obj.sanitize (c, user_data)) || neuter (c);
528 }
529
530 private:
531 /* Set the offset to Null */
532 inline bool neuter (hb_sanitize_context_t *c) {
533 if (c->can_edit (this, this->static_size)) {
534 this->set (0); /* 0 is Null offset */
535 return true;
536 }
537 return false;
538 }
539 };
540 template <typename Base, typename OffsetType, typename Type>
541 inline const Type& operator + (const Base &base, GenericOffsetTo<OffsetType, Typ e> offset) { return offset (base); }
542
543 template <typename Type>
544 struct OffsetTo : GenericOffsetTo<Offset, Type> {};
545
546 template <typename Type>
547 struct LongOffsetTo : GenericOffsetTo<LongOffset, Type> {};
548
549
550 /*
551 * Array Types
552 */
553
554 template <typename LenType, typename Type>
555 struct GenericArrayOf
556 {
557 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/O UT */) const
558 {
559 unsigned int count = len;
560 if (unlikely (start_offset > count))
561 count = 0;
562 else
563 count -= start_offset;
564 count = MIN (count, *pcount);
565 *pcount = count;
566 return array + start_offset;
567 }
568
569 inline const Type& operator [] (unsigned int i) const
570 {
571 if (unlikely (i >= len)) return Null(Type);
572 return array[i];
573 }
574 inline unsigned int get_size (void) const
575 { return len.static_size + len * Type::static_size; }
576
577 inline bool sanitize (hb_sanitize_context_t *c) {
578 TRACE_SANITIZE ();
579 if (unlikely (!sanitize_shallow (c))) return false;
580
581 /* Note: for structs that do not reference other structs,
582 * we do not need to call their sanitize() as we already did
583 * a bound check on the aggregate array size. We just include
584 * a small unreachable expression to make sure the structs
585 * pointed to do have a simple sanitize(), ie. they do not
586 * reference other structs via offsets.
587 */
588 (void) (false && array[0].sanitize (c));
589
590 return true;
591 }
592 inline bool sanitize (hb_sanitize_context_t *c, void *base) {
593 TRACE_SANITIZE ();
594 if (unlikely (!sanitize_shallow (c))) return false;
595 unsigned int count = len;
596 for (unsigned int i = 0; i < count; i++)
597 if (unlikely (!array[i].sanitize (c, base)))
598 return false;
599 return true;
600 }
601 template <typename T>
602 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
603 TRACE_SANITIZE ();
604 if (unlikely (!sanitize_shallow (c))) return false;
605 unsigned int count = len;
606 for (unsigned int i = 0; i < count; i++)
607 if (unlikely (!array[i].sanitize (c, base, user_data)))
608 return false;
609 return true;
610 }
611
612 private:
613 inline bool sanitize_shallow (hb_sanitize_context_t *c) {
614 TRACE_SANITIZE ();
615 return c->check_struct (this)
616 && c->check_array (this, Type::static_size, len);
617 }
618
619 public:
620 LenType len;
621 Type array[VAR];
622 public:
623 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
624 };
625
626 /* An array with a USHORT number of elements. */
627 template <typename Type>
628 struct ArrayOf : GenericArrayOf<USHORT, Type> {};
629
630 /* An array with a ULONG number of elements. */
631 template <typename Type>
632 struct LongArrayOf : GenericArrayOf<ULONG, Type> {};
633
634 /* Array of Offset's */
635 template <typename Type>
636 struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
637
638 /* Array of LongOffset's */
639 template <typename Type>
640 struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {};
641
642 /* LongArray of LongOffset's */
643 template <typename Type>
644 struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {};
645
646 /* Array of offsets relative to the beginning of the array itself. */
647 template <typename Type>
648 struct OffsetListOf : OffsetArrayOf<Type>
649 {
650 inline const Type& operator [] (unsigned int i) const
651 {
652 if (unlikely (i >= this->len)) return Null(Type);
653 return this+this->array[i];
654 }
655
656 inline bool sanitize (hb_sanitize_context_t *c) {
657 TRACE_SANITIZE ();
658 return OffsetArrayOf<Type>::sanitize (c, this);
659 }
660 template <typename T>
661 inline bool sanitize (hb_sanitize_context_t *c, T user_data) {
662 TRACE_SANITIZE ();
663 return OffsetArrayOf<Type>::sanitize (c, this, user_data);
664 }
665 };
666
667
668 /* An array with a USHORT number of elements,
669 * starting at second element. */
670 template <typename Type>
671 struct HeadlessArrayOf
672 {
673 inline const Type& operator [] (unsigned int i) const
674 {
675 if (unlikely (i >= len || !i)) return Null(Type);
676 return array[i-1];
677 }
678 inline unsigned int get_size (void) const
679 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
680
681 inline bool sanitize_shallow (hb_sanitize_context_t *c) {
682 return c->check_struct (this)
683 && c->check_array (this, Type::static_size, len);
684 }
685
686 inline bool sanitize (hb_sanitize_context_t *c) {
687 TRACE_SANITIZE ();
688 if (unlikely (!sanitize_shallow (c))) return false;
689
690 /* Note: for structs that do not reference other structs,
691 * we do not need to call their sanitize() as we already did
692 * a bound check on the aggregate array size. We just include
693 * a small unreachable expression to make sure the structs
694 * pointed to do have a simple sanitize(), ie. they do not
695 * reference other structs via offsets.
696 */
697 (void) (false && array[0].sanitize (c));
698
699 return true;
700 }
701
702 USHORT len;
703 Type array[VAR];
704 public:
705 DEFINE_SIZE_ARRAY (sizeof (USHORT), array);
706 };
707
708
709 /* An array with sorted elements. Supports binary searching. */
710 template <typename Type>
711 struct SortedArrayOf : ArrayOf<Type> {
712
713 template <typename SearchType>
714 inline int search (const SearchType &x) const {
715 class Cmp {
716 public: static int cmp (const SearchType *a, const Type *b) { return b->cm p (*a); }
717 };
718 const Type *p = (const Type *) bsearch (&x, this->array, this->len, sizeof ( this->array[0]), (hb_compare_func_t) Cmp::cmp);
719 return p ? p - this->array : -1;
720 }
721 };
722
723
724 HB_BEGIN_DECLS
725 HB_END_DECLS
726
727 #endif /* HB_OPEN_TYPE_PRIVATE_HH */
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