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> 47 static inline const Type& CastR(const TObject &X) 48 { return reinterpret_cast<const Type&> (X); } 49 template<typename Type, typename TObject> 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> 55 static inline const Type* CastP(const TObject *X) 56 { return reinterpret_cast<const Type*> (X); } 57 template<typename Type, typename TObject> 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> 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> 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> 73 static inline const Type& StructAfter(const TObject &X) 74 { return StructAtOffset<Type>(&X, X.get_size()); } 75 template<typename Type, typename TObject> 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> 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> 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 182 183 struct 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 (b); 205 this->writable = false; 206 } 207 208 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 } 221 222 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 (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 (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> 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 (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 { 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 (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 } 367 368 static const Type* lock_instance (hb_blob_t *blob) { 369 hb_blob_make_immutable (blob); 370 const char *base = hb_blob_get_data (blob, 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 { 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 (len); 421 if (p) 422 memcpy (p, this->start, 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 (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> 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 }; 490 491 template <typename Type> 492 struct 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 */ 536 537 538 template <typename Type, int Bytes> struct BEInt; 539 540 template <typename Type> 541 struct 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 }; 554 template <typename Type> 555 struct 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 }; 570 template <typename Type> 571 struct 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 }; 588 template <typename Type> 589 struct 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 */ 610 template <typename Type, unsigned int Size> 611 struct 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 }; 637 638 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 { 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 */ 688 struct 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 }; 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 { 711 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. */ 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 ((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 { 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 */ 770 771 template <typename Type, typename OffsetType=UINT16> 772 struct 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 }; 816 template <typename Type> struct LOffsetTo : OffsetTo<Type, UINT32> {}; 817 template <typename Base, typename OffsetType, typename Type> 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> 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 { 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 (count, *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 }; 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 { 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. */ 969 template <typename Type, typename LenType=UINT16> 970 struct 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 */ 1031 template <typename Type, typename LenType=UINT16> 1032 struct 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 1059 struct 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 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 { 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 (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 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 */ 1136 template <typename T> 1137 struct 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 (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 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