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
37namespace OT {
38
39
40
41/*
42 * Casts
43 */
44
45/* Cast to struct T, reference to reference */
46template<typename Type, typename TObject>
47static inline const Type& CastR(const TObject &X)
48{ return reinterpret_cast<const Type&> (X); }
49template<typename Type, typename TObject>
50static inline Type& CastR(TObject &X)
51{ return reinterpret_cast<Type&> (X); }
52
53/* Cast to struct T, pointer to pointer */
54template<typename Type, typename TObject>
55static inline const Type* CastP(const TObject *X)
56{ return reinterpret_cast<const Type*> (X); }
57template<typename Type, typename TObject>
58static 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. */
63template<typename Type>
64static inline const Type& StructAtOffset(const void *P, unsigned int offset)
65{ return * reinterpret_cast<const Type*> ((const char *) P + offset); }
66template<typename Type>
67static 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() */
72template<typename Type, typename TObject>
73static inline const Type& StructAfter(const TObject &X)
74{ return StructAtOffset<Type>(&X, X.get_size()); }
75template<typename Type, typename TObject>
76static 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
136static_assert (HB_NULL_POOL_SIZE % sizeof (void *) == 0, "Align HB_NULL_POOL_SIZE.");
137extern HB_INTERNAL const void * const _hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)];
138
139/* Generic nul-content Null objects. */
140template <typename Type>
141static 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) \
148static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \
149template <> \
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 */ \
153static_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
163template <typename Context, typename Return, unsigned int MaxDebugDepth>
164struct 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>
169 inline bool may_dispatch (const T *obj, const F *format) { return true; }
170 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
183struct hb_sanitize_context_t :
184 hb_dispatch_context_t<hb_sanitize_context_t, bool, HB_DEBUG_SANITIZE>
185{
186 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
192 inline const char *get_name (void) { return "SANITIZE"; }
193 template <typename T, typename F>
194 inline bool may_dispatch (const T *obj, const F *format)
195 { return format->sanitize (this); }
196 template <typename T>
197 inline return_t dispatch (const T &obj) { return obj.sanitize (this); }
198 static return_t default_return_value (void) { return true; }
199 static return_t no_dispatch_return_value (void) { return false; }
200 bool stop_sublookup_iteration (const return_t r) const { return !r; }
201
202 inline void init (hb_blob_t *b)
203 {
204 this->blob = hb_blob_reference (blob: b);
205 this->writable = false;
206 }
207
208 inline void start_processing (void)
209 {
210 this->start = hb_blob_get_data (blob: this->blob, length: nullptr);
211 this->end = this->start + hb_blob_get_length (blob: 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
222 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 (blob: this->blob);
229 this->blob = nullptr;
230 this->start = this->end = nullptr;
231 }
232
233 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
247 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 (count: len, size: record_size);
251 unsigned int array_size = record_size * len;
252 bool ok = !overflows && this->check_range (base, len: 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>
264 inline bool check_struct (const Type *obj) const
265 {
266 return likely (this->check_range (obj, obj->min_size));
267 }
268
269 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>
288 inline bool try_set (const Type *obj, const ValueType &v) {
289 if (this->may_edit (base: obj, len: 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. */
306template <typename Type>
307struct Sanitizer
308{
309 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 (b: 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, length: 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
368 static const Type* lock_instance (hb_blob_t *blob) {
369 hb_blob_make_immutable (blob);
370 const char *base = hb_blob_get_data (blob, length: nullptr);
371 return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
372 }
373};
374
375
376
377/*
378 * Serialize
379 */
380
381
382struct hb_serialize_context_t
383{
384 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>
395 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
405 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>
416 inline Type *copy (void)
417 {
418 assert (!this->ran_out_of_room);
419 unsigned int len = this->head - this->start;
420 void *p = malloc (size: len);
421 if (p)
422 memcpy (dest: p, src: this->start, n: len);
423 return reinterpret_cast<Type *> (p);
424 }
425
426 template <typename Type>
427 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 (s: this->head, c: 0, n: size);
434 char *ret = this->head;
435 this->head += size;
436 return reinterpret_cast<Type *> (ret);
437 }
438
439 template <typename Type>
440 inline Type *allocate_min (void)
441 {
442 return this->allocate_size<Type> (Type::min_size);
443 }
444
445 template <typename Type>
446 inline Type *start_embed (void)
447 {
448 Type *ret = reinterpret_cast<Type *> (this->head);
449 return ret;
450 }
451
452 template <typename Type>
453 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>
463 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>
472 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
480 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
491template <typename Type>
492struct Supplier
493{
494 inline Supplier (const Type *array, unsigned int len_)
495 {
496 head = array;
497 len = len_;
498 }
499 inline const Type operator [] (unsigned int i) const
500 {
501 if (unlikely (i >= len)) return Type ();
502 return head[i];
503 }
504
505 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
538template <typename Type, int Bytes> struct BEInt;
539
540template <typename Type>
541struct BEInt<Type, 1>
542{
543 public:
544 inline void set (Type V)
545 {
546 v = V;
547 }
548 inline operator Type (void) const
549 {
550 return v;
551 }
552 private: uint8_t v;
553};
554template <typename Type>
555struct BEInt<Type, 2>
556{
557 public:
558 inline void set (Type V)
559 {
560 v[0] = (V >> 8) & 0xFF;
561 v[1] = (V ) & 0xFF;
562 }
563 inline operator Type (void) const
564 {
565 return (v[0] << 8)
566 + (v[1] );
567 }
568 private: uint8_t v[2];
569};
570template <typename Type>
571struct BEInt<Type, 3>
572{
573 public:
574 inline void set (Type V)
575 {
576 v[0] = (V >> 16) & 0xFF;
577 v[1] = (V >> 8) & 0xFF;
578 v[2] = (V ) & 0xFF;
579 }
580 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};
588template <typename Type>
589struct BEInt<Type, 4>
590{
591 public:
592 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 }
599 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 */
610template <typename Type, unsigned int Size>
611struct IntType
612{
613 inline void set (Type i) { v.set (i); }
614 inline operator Type(void) const { return v; }
615 inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; }
616 inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); }
617 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); }
618 template <typename Type2>
619 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 }
627 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
638typedef IntType<uint8_t, 1> UINT8; /* 8-bit unsigned integer. */
639typedef IntType<int8_t, 1> INT8; /* 8-bit signed integer. */
640typedef IntType<uint16_t, 2> UINT16; /* 16-bit unsigned integer. */
641typedef IntType<int16_t, 2> INT16; /* 16-bit signed integer. */
642typedef IntType<uint32_t, 4> UINT32; /* 32-bit unsigned integer. */
643typedef IntType<int32_t, 4> INT32; /* 32-bit signed integer. */
644typedef IntType<uint32_t, 3> UINT24; /* 24-bit unsigned integer. */
645
646/* 16-bit signed integer (INT16) that describes a quantity in FUnits. */
647typedef INT16 FWORD;
648
649/* 16-bit unsigned integer (UINT16) that describes a quantity in FUnits. */
650typedef UINT16 UFWORD;
651
652/* 16-bit signed fixed number with the low 14 bits of fraction (2.14). */
653struct 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). */
662struct 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. */
672struct LONGDATETIME
673{
674 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 */
688struct Tag : UINT32
689{
690 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
691 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
692 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
693 public:
694 DEFINE_SIZE_STATIC (4);
695};
696DEFINE_NULL_DATA (Tag, " ");
697
698/* Glyph index number, same as uint16 (length = 16 bits) */
699typedef UINT16 GlyphID;
700
701/* Script/language-system/feature index */
702struct Index : UINT16 {
703 static const unsigned int NOT_FOUND_INDEX = 0xFFFFu;
704};
705DEFINE_NULL_DATA (Index, "\xff\xff");
706
707/* Offset, Null offset = 0 */
708template <typename Type>
709struct Offset : Type
710{
711 inline bool is_null (void) const { return 0 == *this; }
712 public:
713 DEFINE_SIZE_STATIC (sizeof(Type));
714};
715
716typedef Offset<UINT16> Offset16;
717typedef Offset<UINT32> Offset32;
718
719
720/* CheckSum */
721struct CheckSum : UINT32
722{
723 /* This is reference implementation from the spec. */
724 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. */
735 inline void set_for_data (const void *data, unsigned int length)
736 { set (CalcTableChecksum (Table: (const UINT32 *) data, Length: length)); }
737
738 public:
739 DEFINE_SIZE_STATIC (4);
740};
741
742
743/*
744 * Version Numbers
745 */
746
747template <typename FixedType=UINT16>
748struct FixedVersion
749{
750 inline uint32_t to_int (void) const { return (major << (sizeof(FixedType) * 8)) + minor; }
751
752 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
771template <typename Type, typename OffsetType=UINT16>
772struct OffsetTo : Offset<OffsetType>
773{
774 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
781 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
788 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>
799 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 */
811 inline bool neuter (hb_sanitize_context_t *c) const {
812 return c->try_set (this, 0);
813 }
814 DEFINE_SIZE_STATIC (sizeof(OffsetType));
815};
816template <typename Type> struct LOffsetTo : OffsetTo<Type, UINT32> {};
817template <typename Base, typename OffsetType, typename Type>
818static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); }
819template <typename Base, typename OffsetType, typename Type>
820static 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. */
828template <typename Type, typename LenType=UINT16>
829struct ArrayOf
830{
831 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 (a: count, b: *pcount);
839 *pcount = count;
840 return array + start_offset;
841 }
842
843 inline const Type& operator [] (unsigned int i) const
844 {
845 if (unlikely (i >= len)) return Null(Type);
846 return array[i];
847 }
848 inline Type& operator [] (unsigned int i)
849 {
850 return array[i];
851 }
852 inline unsigned int get_size (void) const
853 { return len.static_size + len * Type::static_size; }
854
855 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
865 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
877 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 }
893 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>
904 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>
916 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:
926 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};
938template <typename Type> struct LArrayOf : ArrayOf<Type, UINT32> {};
939
940/* Array of Offset's */
941template <typename Type, typename OffsetType=UINT16>
942struct OffsetArrayOf : ArrayOf<OffsetTo<Type, OffsetType> > {};
943
944/* Array of offsets relative to the beginning of the array itself. */
945template <typename Type>
946struct OffsetListOf : OffsetArrayOf<Type>
947{
948 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
954 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>
960 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. */
969template <typename Type, typename LenType=UINT16>
970struct HeadlessArrayOf
971{
972 inline const Type& operator [] (unsigned int i) const
973 {
974 if (unlikely (i >= len || !i)) return Null(Type);
975 return array[i-1];
976 }
977 inline unsigned int get_size (void) const
978 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
979
980 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
995 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:
1013 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 */
1031template <typename Type, typename LenType=UINT16>
1032struct SortedArrayOf : ArrayOf<Type, LenType>
1033{
1034 template <typename SearchType>
1035 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
1059struct BinSearchHeader
1060{
1061 inline operator uint32_t (void) const { return len; }
1062
1063 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
1079template <typename Type>
1080struct 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 */
1086template <typename T>
1087struct hb_lazy_loader_t
1088{
1089 inline void init (hb_face_t *face_)
1090 {
1091 face = face_;
1092 instance = nullptr;
1093 }
1094
1095 inline void fini (void)
1096 {
1097 if (instance && instance != &OT::Null(T))
1098 {
1099 instance->fini();
1100 free (instance);
1101 }
1102 }
1103
1104 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 (nmemb: 1, size: 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
1125 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 */
1136template <typename T>
1137struct hb_lazy_table_loader_t
1138{
1139 inline void init (hb_face_t *face_)
1140 {
1141 face = face_;
1142 instance = nullptr;
1143 blob = nullptr;
1144 }
1145
1146 inline void fini (void)
1147 {
1148 hb_blob_destroy (blob);
1149 }
1150
1151 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 (tag: 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: blob_);
1162 goto retry;
1163 }
1164 blob = blob_;
1165 }
1166 return p;
1167 }
1168
1169 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

source code of qtbase/src/3rdparty/harfbuzz-ng/src/hb-open-type-private.hh