1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 // This file is available under and governed by the GNU General Public
26 // License version 2 only, as published by the Free Software Foundation.
27 // However, the following notice accompanied the original version of this
28 // file:
29 //
30 /*
31 * Copyright © 2007,2008,2009,2010 Red Hat, Inc.
32 * Copyright © 2012 Google, Inc.
33 *
34 * This is part of HarfBuzz, a text shaping library.
35 *
36 * Permission is hereby granted, without written agreement and without
37 * license or royalty fees, to use, copy, modify, and distribute this
38 * software and its documentation for any purpose, provided that the
39 * above copyright notice and the following two paragraphs appear in
40 * all copies of this software.
41 *
42 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
43 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
44 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
45 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
46 * DAMAGE.
47 *
48 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
49 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
50 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
51 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
52 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
53 *
54 * Red Hat Author(s): Behdad Esfahbod
55 * Google Author(s): Behdad Esfahbod
56 */
57
58 #ifndef HB_OPEN_TYPE_PRIVATE_HH
59 #define HB_OPEN_TYPE_PRIVATE_HH
60
61 #include "hb-private.hh"
62
63
64 namespace OT {
65
66
67
68 /*
69 * Casts
70 */
71
72 /* Cast to struct T, reference to reference */
73 template<typename Type, typename TObject>
74 static inline const Type& CastR(const TObject &X)
75 { return reinterpret_cast<const Type&> (X); }
76 template<typename Type, typename TObject>
77 static inline Type& CastR(TObject &X)
78 { return reinterpret_cast<Type&> (X); }
79
80 /* Cast to struct T, pointer to pointer */
81 template<typename Type, typename TObject>
82 static inline const Type* CastP(const TObject *X)
83 { return reinterpret_cast<const Type*> (X); }
84 template<typename Type, typename TObject>
85 static inline Type* CastP(TObject *X)
86 { return reinterpret_cast<Type*> (X); }
87
88 /* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory
89 * location pointed to by P plus Ofs bytes. */
90 template<typename Type>
91 static inline const Type& StructAtOffset(const void *P, unsigned int offset)
92 { return * reinterpret_cast<const Type*> ((const char *) P + offset); }
93 template<typename Type>
94 static inline Type& StructAtOffset(void *P, unsigned int offset)
95 { return * reinterpret_cast<Type*> ((char *) P + offset); }
96
97 /* StructAfter<T>(X) returns the struct T& that is placed after X.
98 * Works with X of variable size also. X must implement get_size() */
99 template<typename Type, typename TObject>
100 static inline const Type& StructAfter(const TObject &X)
101 { return StructAtOffset<Type>(&X, X.get_size()); }
102 template<typename Type, typename TObject>
103 static inline Type& StructAfter(TObject &X)
104 { return StructAtOffset<Type>(&X, X.get_size()); }
105
106
107
108 /*
109 * Size checking
110 */
111
112 /* Check _assertion in a method environment */
113 #define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \
114 inline void _instance_assertion_on_line_##_line (void) const \
115 { \
116 ASSERT_STATIC (_assertion); \
117 ASSERT_INSTANCE_POD (*this); /* Make sure it's POD. */ \
118 }
119 # define _DEFINE_INSTANCE_ASSERTION0(_line, _assertion) _DEFINE_INSTANCE_ASSERTION1 (_line, _assertion)
120 # define DEFINE_INSTANCE_ASSERTION(_assertion) _DEFINE_INSTANCE_ASSERTION0 (__LINE__, _assertion)
121
122 /* Check that _code compiles in a method environment */
123 #define _DEFINE_COMPILES_ASSERTION1(_line, _code) \
124 inline void _compiles_assertion_on_line_##_line (void) const \
125 { _code; }
126 # define _DEFINE_COMPILES_ASSERTION0(_line, _code) _DEFINE_COMPILES_ASSERTION1 (_line, _code)
127 # define DEFINE_COMPILES_ASSERTION(_code) _DEFINE_COMPILES_ASSERTION0 (__LINE__, _code)
128
129
130 #define DEFINE_SIZE_STATIC(size) \
131 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size)); \
132 static const unsigned int static_size = (size); \
133 static const unsigned int min_size = (size)
134
135 /* Size signifying variable-sized array */
136 #define VAR 1
137
138 #define DEFINE_SIZE_UNION(size, _member) \
139 DEFINE_INSTANCE_ASSERTION (this->u._member.static_size == (size)); \
140 static const unsigned int min_size = (size)
141
142 #define DEFINE_SIZE_MIN(size) \
143 DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)); \
144 static const unsigned int min_size = (size)
145
146 #define DEFINE_SIZE_ARRAY(size, array) \
147 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \
148 DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \
149 static const unsigned int min_size = (size)
150
151 #define DEFINE_SIZE_ARRAY2(size, array1, array2) \
152 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \
153 DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].static_size) \
154 static const unsigned int min_size = (size)
155
156
157
158 /*
159 * Null objects
160 */
161
162 /* Global nul-content Null pool. Enlarge as necessary. */
163 /* TODO This really should be a extern HB_INTERNAL and defined somewhere... */
164 static const void *_NullPool[(256+8) / sizeof (void *)];
165
166 /* Generic nul-content Null objects. */
167 template <typename Type>
168 static inline const Type& Null (void) {
169 ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool));
170 return *CastP<Type> (_NullPool);
171 }
172
173 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
174 #define DEFINE_NULL_DATA(Type, data) \
175 static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \
176 template <> \
177 /*static*/ inline const Type& Null<Type> (void) { \
178 return *CastP<Type> (_Null##Type); \
179 } /* The following line really exists such that we end in a place needing semicolon */ \
180 ASSERT_STATIC (Type::min_size + 1 <= sizeof (_Null##Type))
181
182 /* Accessor macro. */
183 #define Null(Type) Null<Type>()
184
185
186 /*
187 * Dispatch
188 */
189
190 template <typename Context, typename Return, unsigned int MaxDebugDepth>
191 struct hb_dispatch_context_t
192 {
193 static const unsigned int max_debug_depth = MaxDebugDepth;
194 typedef Return return_t;
195 template <typename T, typename F>
196 inline bool may_dispatch (const T *obj, const F *format) { return true; }
197 static return_t no_dispatch_return_value (void) { return Context::default_return_value (); }
198 };
199
200
201 /*
202 * Sanitize
203 */
204
205 #ifndef HB_DEBUG_SANITIZE
206 #define HB_DEBUG_SANITIZE (HB_DEBUG+0)
207 #endif
208
209
210 #define TRACE_SANITIZE(this) \
211 hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace \
212 (&c->debug_depth, c->get_name (), this, HB_FUNC, \
213 "");
214
215 /* This limits sanitizing time on really broken fonts. */
216 #ifndef HB_SANITIZE_MAX_EDITS
217 #define HB_SANITIZE_MAX_EDITS 100
218 #endif
219
220 struct hb_sanitize_context_t :
221 hb_dispatch_context_t<hb_sanitize_context_t, bool, HB_DEBUG_SANITIZE>
222 {
223 inline hb_sanitize_context_t (void) :
224 debug_depth (0),
225 start (NULL), end (NULL),
226 writable (false), edit_count (0),
227 blob (NULL) {}
228
229 inline const char *get_name (void) { return "SANITIZE"; }
230 template <typename T, typename F>
231 inline bool may_dispatch (const T *obj, const F *format)
232 { return format->sanitize (this); }
233 template <typename T>
234 inline return_t dispatch (const T &obj) { return obj.sanitize (this); }
235 static return_t default_return_value (void) { return true; }
236 static return_t no_dispatch_return_value (void) { return false; }
237 bool stop_sublookup_iteration (const return_t r) const { return !r; }
238
239 inline void init (hb_blob_t *b)
240 {
241 this->blob = hb_blob_reference (b);
242 this->writable = false;
243 }
244
245 inline void start_processing (void)
246 {
247 this->start = hb_blob_get_data (this->blob, NULL);
248 this->end = this->start + hb_blob_get_length (this->blob);
249 assert (this->start <= this->end); /* Must not overflow. */
250 this->edit_count = 0;
251 this->debug_depth = 0;
252
253 DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1,
254 "start [%p..%p] (%lu bytes)",
255 this->start, this->end,
256 (unsigned long) (this->end - this->start));
257 }
258
259 inline void end_processing (void)
260 {
261 DEBUG_MSG_LEVEL (SANITIZE, this->start, 0, -1,
262 "end [%p..%p] %u edit requests",
263 this->start, this->end, this->edit_count);
264
265 hb_blob_destroy (this->blob);
266 this->blob = NULL;
267 this->start = this->end = NULL;
268 }
269
270 inline bool check_range (const void *base, unsigned int len) const
271 {
272 const char *p = (const char *) base;
273 bool ok = this->start <= p && p <= this->end && (unsigned int) (this->end - p) >= len;
274
275 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
276 "check_range [%p..%p] (%d bytes) in [%p..%p] -> %s",
277 p, p + len, len,
278 this->start, this->end,
279 ok ? "OK" : "OUT-OF-RANGE");
280
281 return likely (ok);
282 }
283
284 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
285 {
286 const char *p = (const char *) base;
287 bool overflows = _hb_unsigned_int_mul_overflows (len, record_size);
288 unsigned int array_size = record_size * len;
289 bool ok = !overflows && this->check_range (base, array_size);
290
291 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
292 "check_array [%p..%p] (%d*%d=%d bytes) in [%p..%p] -> %s",
293 p, p + (record_size * len), record_size, len, (unsigned int) array_size,
294 this->start, this->end,
295 overflows ? "OVERFLOWS" : ok ? "OK" : "OUT-OF-RANGE");
296
297 return likely (ok);
298 }
299
300 template <typename Type>
301 inline bool check_struct (const Type *obj) const
302 {
303 return likely (this->check_range (obj, obj->min_size));
304 }
305
306 inline bool may_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED)
307 {
308 if (this->edit_count >= HB_SANITIZE_MAX_EDITS)
309 return false;
310
311 const char *p = (const char *) base;
312 this->edit_count++;
313
314 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
315 "may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s",
316 this->edit_count,
317 p, p + len, len,
318 this->start, this->end,
319 this->writable ? "GRANTED" : "DENIED");
320
321 return this->writable;
322 }
323
324 template <typename Type, typename ValueType>
325 inline bool try_set (const Type *obj, const ValueType &v) {
326 if (this->may_edit (obj, obj->static_size)) {
327 const_cast<Type *> (obj)->set (v);
328 return true;
329 }
330 return false;
331 }
332
333 mutable unsigned int debug_depth;
334 const char *start, *end;
335 bool writable;
336 unsigned int edit_count;
337 hb_blob_t *blob;
338 };
339
340
341
342 /* Template to sanitize an object. */
343 template <typename Type>
344 struct Sanitizer
345 {
346 static hb_blob_t *sanitize (hb_blob_t *blob) {
347 hb_sanitize_context_t c[1];
348 bool sane;
349
350 /* TODO is_sane() stuff */
351
352 c->init (blob);
353
354 retry:
355 DEBUG_MSG_FUNC (SANITIZE, c->start, "start");
356
357 c->start_processing ();
358
359 if (unlikely (!c->start)) {
360 c->end_processing ();
361 return blob;
362 }
363
364 Type *t = CastP<Type> (const_cast<char *> (c->start));
365
366 sane = t->sanitize (c);
367 if (sane) {
368 if (c->edit_count) {
369 DEBUG_MSG_FUNC (SANITIZE, c->start, "passed first round with %d edits; going for second round", c->edit_count);
370
371 /* sanitize again to ensure no toe-stepping */
372 c->edit_count = 0;
373 sane = t->sanitize (c);
374 if (c->edit_count) {
375 DEBUG_MSG_FUNC (SANITIZE, c->start, "requested %d edits in second round; FAILLING", c->edit_count);
376 sane = false;
377 }
378 }
379 } else {
380 unsigned int edit_count = c->edit_count;
381 if (edit_count && !c->writable) {
382 c->start = hb_blob_get_data_writable (blob, NULL);
383 c->end = c->start + hb_blob_get_length (blob);
384
385 if (c->start) {
386 c->writable = true;
387 /* ok, we made it writable by relocating. try again */
388 DEBUG_MSG_FUNC (SANITIZE, c->start, "retry");
389 goto retry;
390 }
391 }
392 }
393
394 c->end_processing ();
395
396 DEBUG_MSG_FUNC (SANITIZE, c->start, sane ? "PASSED" : "FAILED");
397 if (sane)
398 return blob;
399 else {
400 hb_blob_destroy (blob);
401 return hb_blob_get_empty ();
402 }
403 }
404
405 static const Type* lock_instance (hb_blob_t *blob) {
406 hb_blob_make_immutable (blob);
407 const char *base = hb_blob_get_data (blob, NULL);
408 return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
409 }
410 };
411
412
413
414 /*
415 * Serialize
416 */
417
418 #ifndef HB_DEBUG_SERIALIZE
419 #define HB_DEBUG_SERIALIZE (HB_DEBUG+0)
420 #endif
421
422
423 #define TRACE_SERIALIZE(this) \
424 hb_auto_trace_t<HB_DEBUG_SERIALIZE, bool> trace \
425 (&c->debug_depth, "SERIALIZE", c, HB_FUNC, \
426 "");
427
428
429 struct hb_serialize_context_t
430 {
431 inline hb_serialize_context_t (void *start, unsigned int size)
432 {
433 this->start = (char *) start;
434 this->end = this->start + size;
435
436 this->ran_out_of_room = false;
437 this->head = this->start;
438 this->debug_depth = 0;
439 }
440
441 template <typename Type>
442 inline Type *start_serialize (void)
443 {
444 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1,
445 "start [%p..%p] (%lu bytes)",
446 this->start, this->end,
447 (unsigned long) (this->end - this->start));
448
449 return start_embed<Type> ();
450 }
451
452 inline void end_serialize (void)
453 {
454 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1,
455 "end [%p..%p] serialized %d bytes; %s",
456 this->start, this->end,
457 (int) (this->head - this->start),
458 this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room");
459
460 }
461
462 template <typename Type>
463 inline Type *copy (void)
464 {
465 assert (!this->ran_out_of_room);
466 unsigned int len = this->head - this->start;
467 void *p = malloc (len);
468 if (p)
469 memcpy (p, this->start, len);
470 return reinterpret_cast<Type *> (p);
471 }
472
473 template <typename Type>
474 inline Type *allocate_size (unsigned int size)
475 {
476 if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) {
477 this->ran_out_of_room = true;
478 return NULL;
479 }
480 memset (this->head, 0, size);
481 char *ret = this->head;
482 this->head += size;
483 return reinterpret_cast<Type *> (ret);
484 }
485
486 template <typename Type>
487 inline Type *allocate_min (void)
488 {
489 return this->allocate_size<Type> (Type::min_size);
490 }
491
492 template <typename Type>
493 inline Type *start_embed (void)
494 {
495 Type *ret = reinterpret_cast<Type *> (this->head);
496 return ret;
497 }
498
499 template <typename Type>
500 inline Type *embed (const Type &obj)
501 {
502 unsigned int size = obj.get_size ();
503 Type *ret = this->allocate_size<Type> (size);
504 if (unlikely (!ret)) return NULL;
505 memcpy (ret, obj, size);
506 return ret;
507 }
508
509 template <typename Type>
510 inline Type *extend_min (Type &obj)
511 {
512 unsigned int size = obj.min_size;
513 assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
514 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL;
515 return reinterpret_cast<Type *> (&obj);
516 }
517
518 template <typename Type>
519 inline Type *extend (Type &obj)
520 {
521 unsigned int size = obj.get_size ();
522 assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
523 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL;
524 return reinterpret_cast<Type *> (&obj);
525 }
526
527 inline void truncate (void *head)
528 {
529 assert (this->start < head && head <= this->head);
530 this->head = (char *) head;
531 }
532
533 unsigned int debug_depth;
534 char *start, *end, *head;
535 bool ran_out_of_room;
536 };
537
538 template <typename Type>
539 struct Supplier
540 {
541 inline Supplier (const Type *array, unsigned int len_)
542 {
543 head = array;
544 len = len_;
545 }
546 inline const Type operator [] (unsigned int i) const
547 {
548 if (unlikely (i >= len)) return Type ();
549 return head[i];
550 }
551
552 inline void advance (unsigned int count)
553 {
554 if (unlikely (count > len))
555 count = len;
556 len -= count;
557 head += count;
558 }
559
560 private:
561 inline Supplier (const Supplier<Type> &); /* Disallow copy */
562 inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */
563
564 unsigned int len;
565 const Type *head;
566 };
567
568
569
570
571 /*
572 *
573 * The OpenType Font File: Data Types
574 */
575
576
577 /* "The following data types are used in the OpenType font file.
578 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
579
580 /*
581 * Int types
582 */
583
584
585 template <typename Type, int Bytes> struct BEInt;
586
587 template <typename Type>
588 struct BEInt<Type, 1>
589 {
590 public:
591 inline void set (Type V)
592 {
593 v = V;
594 }
595 inline operator Type (void) const
596 {
597 return v;
598 }
599 private: uint8_t v;
600 };
601 template <typename Type>
602 struct BEInt<Type, 2>
603 {
604 public:
605 inline void set (Type V)
606 {
607 v[0] = (V >> 8) & 0xFF;
608 v[1] = (V ) & 0xFF;
609 }
610 inline operator Type (void) const
611 {
612 return (v[0] << 8)
613 + (v[1] );
614 }
615 private: uint8_t v[2];
616 };
617 template <typename Type>
618 struct BEInt<Type, 3>
619 {
620 public:
621 inline void set (Type V)
622 {
623 v[0] = (V >> 16) & 0xFF;
624 v[1] = (V >> 8) & 0xFF;
625 v[2] = (V ) & 0xFF;
626 }
627 inline operator Type (void) const
628 {
629 return (v[0] << 16)
630 + (v[1] << 8)
631 + (v[2] );
632 }
633 private: uint8_t v[3];
634 };
635 template <typename Type>
636 struct BEInt<Type, 4>
637 {
638 public:
639 inline void set (Type V)
640 {
641 v[0] = (V >> 24) & 0xFF;
642 v[1] = (V >> 16) & 0xFF;
643 v[2] = (V >> 8) & 0xFF;
644 v[3] = (V ) & 0xFF;
645 }
646 inline operator Type (void) const
647 {
648 return (v[0] << 24)
649 + (v[1] << 16)
650 + (v[2] << 8)
651 + (v[3] );
652 }
653 private: uint8_t v[4];
654 };
655
656 /* Integer types in big-endian order and no alignment requirement */
657 template <typename Type, unsigned int Size>
658 struct IntType
659 {
660 inline void set (Type i) { v.set (i); }
661 inline operator Type(void) const { return v; }
662 inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; }
663 inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); }
664 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); }
665 inline int cmp (Type a) const
666 {
667 Type b = v;
668 if (sizeof (Type) < sizeof (int))
669 return (int) a - (int) b;
670 else
671 return a < b ? -1 : a == b ? 0 : +1;
672 }
673 inline bool sanitize (hb_sanitize_context_t *c) const
674 {
675 TRACE_SANITIZE (this);
676 return_trace (likely (c->check_struct (this)));
677 }
678 protected:
679 BEInt<Type, Size> v;
680 public:
681 DEFINE_SIZE_STATIC (Size);
682 };
683
684 typedef IntType<uint8_t , 1> BYTE; /* 8-bit unsigned integer. */
685 typedef IntType<uint16_t, 2> USHORT; /* 16-bit unsigned integer. */
686 typedef IntType<int16_t, 2> SHORT; /* 16-bit signed integer. */
687 typedef IntType<uint32_t, 4> ULONG; /* 32-bit unsigned integer. */
688 typedef IntType<int32_t, 4> LONG; /* 32-bit signed integer. */
689 typedef IntType<uint32_t, 3> UINT24; /* 24-bit unsigned integer. */
690
691 /* 16-bit signed integer (SHORT) that describes a quantity in FUnits. */
692 typedef SHORT FWORD;
693
694 /* 16-bit unsigned integer (USHORT) that describes a quantity in FUnits. */
695 typedef USHORT UFWORD;
696
697 /* Date represented in number of seconds since 12:00 midnight, January 1,
698 * 1904. The value is represented as a signed 64-bit integer. */
699 struct LONGDATETIME
700 {
701 inline bool sanitize (hb_sanitize_context_t *c) const
702 {
703 TRACE_SANITIZE (this);
704 return_trace (likely (c->check_struct (this)));
705 }
706 protected:
707 LONG major;
708 ULONG minor;
709 public:
710 DEFINE_SIZE_STATIC (8);
711 };
712
713 /* Array of four uint8s (length = 32 bits) used to identify a script, language
714 * system, feature, or baseline */
715 struct Tag : ULONG
716 {
717 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
718 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
719 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
720 public:
721 DEFINE_SIZE_STATIC (4);
722 };
723 DEFINE_NULL_DATA (Tag, " ");
724
725 /* Glyph index number, same as uint16 (length = 16 bits) */
726 struct GlyphID : USHORT {
727 static inline int cmp (const GlyphID *a, const GlyphID *b) { return b->USHORT::cmp (*a); }
728 inline int cmp (hb_codepoint_t a) const { return (int) a - (int) *this; }
729 };
730
731 /* Script/language-system/feature index */
732 struct Index : USHORT {
733 static const unsigned int NOT_FOUND_INDEX = 0xFFFFu;
734 };
735 DEFINE_NULL_DATA (Index, "\xff\xff");
736
737 /* Offset, Null offset = 0 */
738 template <typename Type=USHORT>
739 struct Offset : Type
740 {
741 inline bool is_null (void) const { return 0 == *this; }
742 public:
743 DEFINE_SIZE_STATIC (sizeof(Type));
744 };
745
746
747 /* CheckSum */
748 struct CheckSum : ULONG
749 {
750 /* This is reference implementation from the spec. */
751 static inline uint32_t CalcTableChecksum (const ULONG *Table, uint32_t Length)
752 {
753 uint32_t Sum = 0L;
754 const ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size;
755
756 while (Table < EndPtr)
757 Sum += *Table++;
758 return Sum;
759 }
760
761 /* Note: data should be 4byte aligned and have 4byte padding at the end. */
762 inline void set_for_data (const void *data, unsigned int length)
763 { set (CalcTableChecksum ((const ULONG *) data, length)); }
764
765 public:
766 DEFINE_SIZE_STATIC (4);
767 };
768
769
770 /*
771 * Version Numbers
772 */
773
774 struct FixedVersion
775 {
776 inline uint32_t to_int (void) const { return (major << 16) + minor; }
777
778 inline bool sanitize (hb_sanitize_context_t *c) const
779 {
780 TRACE_SANITIZE (this);
781 return_trace (c->check_struct (this));
782 }
783
784 USHORT major;
785 USHORT minor;
786 public:
787 DEFINE_SIZE_STATIC (4);
788 };
789
790
791
792 /*
793 * Template subclasses of Offset that do the dereferencing.
794 * Use: (base+offset)
795 */
796
797 template <typename Type, typename OffsetType=USHORT>
798 struct OffsetTo : Offset<OffsetType>
799 {
800 inline const Type& operator () (const void *base) const
801 {
802 unsigned int offset = *this;
803 if (unlikely (!offset)) return Null(Type);
804 return StructAtOffset<Type> (base, offset);
805 }
806
807 inline Type& serialize (hb_serialize_context_t *c, const void *base)
808 {
809 Type *t = c->start_embed<Type> ();
810 this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */
811 return *t;
812 }
813
814 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
815 {
816 TRACE_SANITIZE (this);
817 if (unlikely (!c->check_struct (this))) return_trace (false);
818 unsigned int offset = *this;
819 if (unlikely (!offset)) return_trace (true);
820 const Type &obj = StructAtOffset<Type> (base, offset);
821 return_trace (likely (obj.sanitize (c)) || neuter (c));
822 }
823 template <typename T>
824 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
825 {
826 TRACE_SANITIZE (this);
827 if (unlikely (!c->check_struct (this))) return_trace (false);
828 unsigned int offset = *this;
829 if (unlikely (!offset)) return_trace (true);
830 const Type &obj = StructAtOffset<Type> (base, offset);
831 return_trace (likely (obj.sanitize (c, user_data)) || neuter (c));
832 }
833
834 /* Set the offset to Null */
835 inline bool neuter (hb_sanitize_context_t *c) const {
836 return c->try_set (this, 0);
837 }
838 DEFINE_SIZE_STATIC (sizeof(OffsetType));
839 };
840 template <typename Base, typename OffsetType, typename Type>
841 static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); }
842 template <typename Base, typename OffsetType, typename Type>
843 static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); }
844
845
846 /*
847 * Array Types
848 */
849
850 /* An array with a number of elements. */
851 template <typename Type, typename LenType=USHORT>
852 struct ArrayOf
853 {
854 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
855 {
856 unsigned int count = len;
857 if (unlikely (start_offset > count))
858 count = 0;
859 else
860 count -= start_offset;
861 count = MIN (count, *pcount);
862 *pcount = count;
863 return array + start_offset;
864 }
865
866 inline const Type& operator [] (unsigned int i) const
867 {
868 if (unlikely (i >= len)) return Null(Type);
869 return array[i];
870 }
871 inline Type& operator [] (unsigned int i)
872 {
873 return array[i];
874 }
875 inline unsigned int get_size (void) const
876 { return len.static_size + len * Type::static_size; }
877
878 inline bool serialize (hb_serialize_context_t *c,
879 unsigned int items_len)
880 {
881 TRACE_SERIALIZE (this);
882 if (unlikely (!c->extend_min (*this))) return_trace (false);
883 len.set (items_len); /* TODO(serialize) Overflow? */
884 if (unlikely (!c->extend (*this))) return_trace (false);
885 return_trace (true);
886 }
887
888 inline bool serialize (hb_serialize_context_t *c,
889 Supplier<Type> &items,
890 unsigned int items_len)
891 {
892 TRACE_SERIALIZE (this);
893 if (unlikely (!serialize (c, items_len))) return_trace (false);
894 for (unsigned int i = 0; i < items_len; i++)
895 array[i] = items[i];
896 items.advance (items_len);
897 return_trace (true);
898 }
899
900 inline bool sanitize (hb_sanitize_context_t *c) const
901 {
902 TRACE_SANITIZE (this);
903 if (unlikely (!sanitize_shallow (c))) return_trace (false);
904
905 /* Note: for structs that do not reference other structs,
906 * we do not need to call their sanitize() as we already did
907 * a bound check on the aggregate array size. We just include
908 * a small unreachable expression to make sure the structs
909 * pointed to do have a simple sanitize(), ie. they do not
910 * reference other structs via offsets.
911 */
912 (void) (false && array[0].sanitize (c));
913
914 return_trace (true);
915 }
916 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
917 {
918 TRACE_SANITIZE (this);
919 if (unlikely (!sanitize_shallow (c))) return_trace (false);
920 unsigned int count = len;
921 for (unsigned int i = 0; i < count; i++)
922 if (unlikely (!array[i].sanitize (c, base)))
923 return_trace (false);
924 return_trace (true);
925 }
926 template <typename T>
927 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
928 {
929 TRACE_SANITIZE (this);
930 if (unlikely (!sanitize_shallow (c))) return_trace (false);
931 unsigned int count = len;
932 for (unsigned int i = 0; i < count; i++)
933 if (unlikely (!array[i].sanitize (c, base, user_data)))
934 return_trace (false);
935 return_trace (true);
936 }
937
938 template <typename SearchType>
939 inline int lsearch (const SearchType &x) const
940 {
941 unsigned int count = len;
942 for (unsigned int i = 0; i < count; i++)
943 if (!this->array[i].cmp (x))
944 return i;
945 return -1;
946 }
947
948 private:
949 inline bool sanitize_shallow (hb_sanitize_context_t *c) const
950 {
951 TRACE_SANITIZE (this);
952 return_trace (c->check_struct (this) && c->check_array (array, Type::static_size, len));
953 }
954
955 public:
956 LenType len;
957 Type array[VAR];
958 public:
959 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
960 };
961
962 /* Array of Offset's */
963 template <typename Type>
964 struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
965
966 /* Array of offsets relative to the beginning of the array itself. */
967 template <typename Type>
968 struct OffsetListOf : OffsetArrayOf<Type>
969 {
970 inline const Type& operator [] (unsigned int i) const
971 {
972 if (unlikely (i >= this->len)) return Null(Type);
973 return this+this->array[i];
974 }
975
976 inline bool sanitize (hb_sanitize_context_t *c) const
977 {
978 TRACE_SANITIZE (this);
979 return_trace (OffsetArrayOf<Type>::sanitize (c, this));
980 }
981 template <typename T>
982 inline bool sanitize (hb_sanitize_context_t *c, T user_data) const
983 {
984 TRACE_SANITIZE (this);
985 return_trace (OffsetArrayOf<Type>::sanitize (c, this, user_data));
986 }
987 };
988
989
990 /* An array starting at second element. */
991 template <typename Type, typename LenType=USHORT>
992 struct HeadlessArrayOf
993 {
994 inline const Type& operator [] (unsigned int i) const
995 {
996 if (unlikely (i >= len || !i)) return Null(Type);
997 return array[i-1];
998 }
999 inline unsigned int get_size (void) const
1000 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
1001
1002 inline bool serialize (hb_serialize_context_t *c,
1003 Supplier<Type> &items,
1004 unsigned int items_len)
1005 {
1006 TRACE_SERIALIZE (this);
1007 if (unlikely (!c->extend_min (*this))) return_trace (false);
1008 len.set (items_len); /* TODO(serialize) Overflow? */
1009 if (unlikely (!items_len)) return_trace (true);
1010 if (unlikely (!c->extend (*this))) return_trace (false);
1011 for (unsigned int i = 0; i < items_len - 1; i++)
1012 array[i] = items[i];
1013 items.advance (items_len - 1);
1014 return_trace (true);
1015 }
1016
1017 inline bool sanitize_shallow (hb_sanitize_context_t *c) const
1018 {
1019 return c->check_struct (this)
1020 && c->check_array (this, Type::static_size, len);
1021 }
1022
1023 inline bool sanitize (hb_sanitize_context_t *c) const
1024 {
1025 TRACE_SANITIZE (this);
1026 if (unlikely (!sanitize_shallow (c))) return_trace (false);
1027
1028 /* Note: for structs that do not reference other structs,
1029 * we do not need to call their sanitize() as we already did
1030 * a bound check on the aggregate array size. We just include
1031 * a small unreachable expression to make sure the structs
1032 * pointed to do have a simple sanitize(), ie. they do not
1033 * reference other structs via offsets.
1034 */
1035 (void) (false && array[0].sanitize (c));
1036
1037 return_trace (true);
1038 }
1039
1040 LenType len;
1041 Type array[VAR];
1042 public:
1043 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
1044 };
1045
1046
1047 /* An array with sorted elements. Supports binary searching. */
1048 template <typename Type, typename LenType=USHORT>
1049 struct SortedArrayOf : ArrayOf<Type, LenType>
1050 {
1051 template <typename SearchType>
1052 inline int bsearch (const SearchType &x) const
1053 {
1054 /* Hand-coded bsearch here since this is in the hot inner loop. */
1055 int min = 0, max = (int) this->len - 1;
1056 while (min <= max)
1057 {
1058 int mid = (min + max) / 2;
1059 int c = this->array[mid].cmp (x);
1060 if (c < 0)
1061 max = mid - 1;
1062 else if (c > 0)
1063 min = mid + 1;
1064 else
1065 return mid;
1066 }
1067 return -1;
1068 }
1069 };
1070
1071
1072 } /* namespace OT */
1073
1074
1075 #endif /* HB_OPEN_TYPE_PRIVATE_HH */