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 34 35 namespace OT { 36 37 38 39 /* 40 * Casts 41 */ 42 43 /* Cast to struct T, reference to reference */ 44 template<typename Type, typename TObject> 45 static inline const Type& CastR(const TObject &X) 46 { return reinterpret_cast<const Type&> (X); } 47 template<typename Type, typename TObject> 48 static inline Type& CastR(TObject &X) 49 { return reinterpret_cast<Type&> (X); } 50 51 /* Cast to struct T, pointer to pointer */ 52 template<typename Type, typename TObject> 53 static inline const Type* CastP(const TObject *X) 54 { return reinterpret_cast<const Type*> (X); } 55 template<typename Type, typename TObject> 56 static inline Type* CastP(TObject *X) 57 { return reinterpret_cast<Type*> (X); } 58 59 /* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory 60 * location pointed to by P plus Ofs bytes. */ 61 template<typename Type> 62 static inline const Type& StructAtOffset(const void *P, unsigned int offset) 63 { return * reinterpret_cast<const Type*> ((const char *) P + offset); } 64 template<typename Type> 65 static inline Type& StructAtOffset(void *P, unsigned int offset) 66 { return * reinterpret_cast<Type*> ((char *) P + offset); } 67 68 /* StructAfter<T>(X) returns the struct T& that is placed after X. 69 * Works with X of variable size also. X must implement get_size() */ 70 template<typename Type, typename TObject> 71 static inline const Type& StructAfter(const TObject &X) 72 { return StructAtOffset<Type>(&X, X.get_size()); } 73 template<typename Type, typename TObject> 74 static inline Type& StructAfter(TObject &X) 75 { return StructAtOffset<Type>(&X, X.get_size()); } 76 77 78 79 /* 80 * Size checking 81 */ 82 83 /* Check _assertion in a method environment */ 84 #define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \ 85 inline void _instance_assertion_on_line_##_line (void) const \ 86 { \ 87 ASSERT_STATIC (_assertion); \ 88 ASSERT_INSTANCE_POD (*this); /* Make sure it's POD. */ \ 89 } 90 # define _DEFINE_INSTANCE_ASSERTION0(_line, _assertion) _DEFINE_INSTANCE_ASSERTION1 (_line, _assertion) 91 # define DEFINE_INSTANCE_ASSERTION(_assertion) _DEFINE_INSTANCE_ASSERTION0 (__LINE__, _assertion) 92 93 /* Check that _code compiles in a method environment */ 94 #define _DEFINE_COMPILES_ASSERTION1(_line, _code) \ 95 inline void _compiles_assertion_on_line_##_line (void) const \ 96 { _code; } 97 # define _DEFINE_COMPILES_ASSERTION0(_line, _code) _DEFINE_COMPILES_ASSERTION1 (_line, _code) 98 # define DEFINE_COMPILES_ASSERTION(_code) _DEFINE_COMPILES_ASSERTION0 (__LINE__, _code) 99 100 101 #define DEFINE_SIZE_STATIC(size) \ 102 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size)); \ 103 static const unsigned int static_size = (size); \ 104 static const unsigned int min_size = (size) 105 106 #define DEFINE_SIZE_UNION(size, _member) \ 107 DEFINE_INSTANCE_ASSERTION (this->u._member.static_size == (size)); \ 108 static const unsigned int min_size = (size) 109 110 #define DEFINE_SIZE_MIN(size) \ 111 DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)); \ 112 static const unsigned int min_size = (size) 113 114 #define DEFINE_SIZE_ARRAY(size, array) \ 115 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \ 116 DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \ 117 static const unsigned int min_size = (size) 118 119 #define DEFINE_SIZE_ARRAY2(size, array1, array2) \ 120 DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \ 121 DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].static_size) \ 122 static const unsigned int min_size = (size) 123 124 125 126 /* 127 * Null objects 128 */ 129 130 /* Global nul-content Null pool. Enlarge as necessary. */ 131 /* TODO This really should be a extern HB_INTERNAL and defined somewhere... */ 132 static const void *_NullPool[(256+8) / sizeof (void *)]; 133 134 /* Generic nul-content Null objects. */ 135 template <typename Type> 136 static inline const Type& Null (void) { 137 ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool)); 138 return *CastP<Type> (_NullPool); 139 } 140 141 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */ 142 #define DEFINE_NULL_DATA(Type, data) \ 143 static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \ 144 template <> \ 145 /*static*/ inline const Type& Null<Type> (void) { \ 146 return *CastP<Type> (_Null##Type); \ 147 } /* The following line really exists such that we end in a place needing semicolon */ \ 148 ASSERT_STATIC (Type::min_size + 1 <= sizeof (_Null##Type)) 149 150 /* Accessor macro. */ 151 #define Null(Type) Null<Type>() 152 153 154 /* 155 * Dispatch 156 */ 157 158 template <typename Context, typename Return, unsigned int MaxDebugDepth> 159 struct hb_dispatch_context_t 160 { 161 static const unsigned int max_debug_depth = MaxDebugDepth; 162 typedef Return return_t; 163 template <typename T, typename F> 164 inline bool may_dispatch (const T *obj, const F *format) { return true; } 165 static return_t no_dispatch_return_value (void) { return Context::default_return_value (); } 166 }; 167 168 169 /* 170 * Sanitize 171 */ 172 173 #ifndef HB_DEBUG_SANITIZE 174 #define HB_DEBUG_SANITIZE (HB_DEBUG+0) 175 #endif 176 177 178 #define TRACE_SANITIZE(this) \ 179 hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace \ 180 (&c->debug_depth, c->get_name (), this, HB_FUNC, \ 181 ""); 182 183 /* This limits sanitizing time on really broken fonts. */ 184 #ifndef HB_SANITIZE_MAX_EDITS 185 #define HB_SANITIZE_MAX_EDITS 32 186 #endif 187 188 struct hb_sanitize_context_t : 189 hb_dispatch_context_t<hb_sanitize_context_t, bool, HB_DEBUG_SANITIZE> 190 { 191 inline hb_sanitize_context_t (void) : 192 debug_depth (0), 193 start (NULL), end (NULL), 194 writable (false), edit_count (0), 195 blob (NULL) {} 196 197 inline const char *get_name (void) { return "SANITIZE"; } 198 template <typename T, typename F> 199 inline bool may_dispatch (const T *obj, const F *format) 200 { return format->sanitize (this); } 201 template <typename T> 202 inline return_t dispatch (const T &obj) { return obj.sanitize (this); } 203 static return_t default_return_value (void) { return true; } 204 static return_t no_dispatch_return_value (void) { return false; } 205 bool stop_sublookup_iteration (const return_t r) const { return !r; } 206 207 inline void init (hb_blob_t *b) 208 { 209 this->blob = hb_blob_reference (b); 210 this->writable = false; 211 } 212 213 inline void start_processing (void) 214 { 215 this->start = hb_blob_get_data (this->blob, NULL); 216 this->end = this->start + hb_blob_get_length (this->blob); 217 assert (this->start <= this->end); /* Must not overflow. */ 218 this->edit_count = 0; 219 this->debug_depth = 0; 220 221 DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1, 222 "start [%p..%p] (%lu bytes)", 223 this->start, this->end, 224 (unsigned long) (this->end - this->start)); 225 } 226 227 inline void end_processing (void) 228 { 229 DEBUG_MSG_LEVEL (SANITIZE, this->start, 0, -1, 230 "end [%p..%p] %u edit requests", 231 this->start, this->end, this->edit_count); 232 233 hb_blob_destroy (this->blob); 234 this->blob = NULL; 235 this->start = this->end = NULL; 236 } 237 238 inline bool check_range (const void *base, unsigned int len) const 239 { 240 const char *p = (const char *) base; 241 bool ok = this->start <= p && p <= this->end && (unsigned int) (this->end - p) >= len; 242 243 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0, 244 "check_range [%p..%p] (%d bytes) in [%p..%p] -> %s", 245 p, p + len, len, 246 this->start, this->end, 247 ok ? "OK" : "OUT-OF-RANGE"); 248 249 return likely (ok); 250 } 251 252 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const 253 { 254 const char *p = (const char *) base; 255 bool overflows = _hb_unsigned_int_mul_overflows (len, record_size); 256 unsigned int array_size = record_size * len; 257 bool ok = !overflows && this->check_range (base, array_size); 258 259 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0, 260 "check_array [%p..%p] (%d*%d=%d bytes) in [%p..%p] -> %s", 261 p, p + (record_size * len), record_size, len, (unsigned int) array_size, 262 this->start, this->end, 263 overflows ? "OVERFLOWS" : ok ? "OK" : "OUT-OF-RANGE"); 264 265 return likely (ok); 266 } 267 268 template <typename Type> 269 inline bool check_struct (const Type *obj) const 270 { 271 return likely (this->check_range (obj, obj->min_size)); 272 } 273 274 inline bool may_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED) 275 { 276 if (this->edit_count >= HB_SANITIZE_MAX_EDITS) 277 return false; 278 279 const char *p = (const char *) base; 280 this->edit_count++; 281 282 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0, 283 "may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s", 284 this->edit_count, 285 p, p + len, len, 286 this->start, this->end, 287 this->writable ? "GRANTED" : "DENIED"); 288 289 return this->writable; 290 } 291 292 template <typename Type, typename ValueType> 293 inline bool try_set (const Type *obj, const ValueType &v) { 294 if (this->may_edit (obj, obj->static_size)) { 295 const_cast<Type *> (obj)->set (v); 296 return true; 297 } 298 return false; 299 } 300 301 mutable unsigned int debug_depth; 302 const char *start, *end; 303 bool writable; 304 unsigned int edit_count; 305 hb_blob_t *blob; 306 }; 307 308 309 310 /* Template to sanitize an object. */ 311 template <typename Type> 312 struct Sanitizer 313 { 314 static hb_blob_t *sanitize (hb_blob_t *blob) { 315 hb_sanitize_context_t c[1]; 316 bool sane; 317 318 /* TODO is_sane() stuff */ 319 320 c->init (blob); 321 322 retry: 323 DEBUG_MSG_FUNC (SANITIZE, c->start, "start"); 324 325 c->start_processing (); 326 327 if (unlikely (!c->start)) { 328 c->end_processing (); 329 return blob; 330 } 331 332 Type *t = CastP<Type> (const_cast<char *> (c->start)); 333 334 sane = t->sanitize (c); 335 if (sane) { 336 if (c->edit_count) { 337 DEBUG_MSG_FUNC (SANITIZE, c->start, "passed first round with %d edits; going for second round", c->edit_count); 338 339 /* sanitize again to ensure no toe-stepping */ 340 c->edit_count = 0; 341 sane = t->sanitize (c); 342 if (c->edit_count) { 343 DEBUG_MSG_FUNC (SANITIZE, c->start, "requested %d edits in second round; FAILLING", c->edit_count); 344 sane = false; 345 } 346 } 347 } else { 348 unsigned int edit_count = c->edit_count; 349 if (edit_count && !c->writable) { 350 c->start = hb_blob_get_data_writable (blob, NULL); 351 c->end = c->start + hb_blob_get_length (blob); 352 353 if (c->start) { 354 c->writable = true; 355 /* ok, we made it writable by relocating. try again */ 356 DEBUG_MSG_FUNC (SANITIZE, c->start, "retry"); 357 goto retry; 358 } 359 } 360 } 361 362 c->end_processing (); 363 364 DEBUG_MSG_FUNC (SANITIZE, c->start, sane ? "PASSED" : "FAILED"); 365 if (sane) 366 return blob; 367 else { 368 hb_blob_destroy (blob); 369 return hb_blob_get_empty (); 370 } 371 } 372 373 static const Type* lock_instance (hb_blob_t *blob) { 374 hb_blob_make_immutable (blob); 375 const char *base = hb_blob_get_data (blob, NULL); 376 return unlikely (!base) ? &Null(Type) : CastP<Type> (base); 377 } 378 }; 379 380 381 382 /* 383 * Serialize 384 */ 385 386 #ifndef HB_DEBUG_SERIALIZE 387 #define HB_DEBUG_SERIALIZE (HB_DEBUG+0) 388 #endif 389 390 391 #define TRACE_SERIALIZE(this) \ 392 hb_auto_trace_t<HB_DEBUG_SERIALIZE, bool> trace \ 393 (&c->debug_depth, "SERIALIZE", c, HB_FUNC, \ 394 ""); 395 396 397 struct hb_serialize_context_t 398 { 399 inline hb_serialize_context_t (void *start_, unsigned int size) 400 { 401 this->start = (char *) start_; 402 this->end = this->start + size; 403 404 this->ran_out_of_room = false; 405 this->head = this->start; 406 this->debug_depth = 0; 407 } 408 409 template <typename Type> 410 inline Type *start_serialize (void) 411 { 412 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1, 413 "start [%p..%p] (%lu bytes)", 414 this->start, this->end, 415 (unsigned long) (this->end - this->start)); 416 417 return start_embed<Type> (); 418 } 419 420 inline void end_serialize (void) 421 { 422 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1, 423 "end [%p..%p] serialized %d bytes; %s", 424 this->start, this->end, 425 (int) (this->head - this->start), 426 this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room"); 427 428 } 429 430 template <typename Type> 431 inline Type *copy (void) 432 { 433 assert (!this->ran_out_of_room); 434 unsigned int len = this->head - this->start; 435 void *p = malloc (len); 436 if (p) 437 memcpy (p, this->start, len); 438 return reinterpret_cast<Type *> (p); 439 } 440 441 template <typename Type> 442 inline Type *allocate_size (unsigned int size) 443 { 444 if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) { 445 this->ran_out_of_room = true; 446 return NULL; 447 } 448 memset (this->head, 0, size); 449 char *ret = this->head; 450 this->head += size; 451 return reinterpret_cast<Type *> (ret); 452 } 453 454 template <typename Type> 455 inline Type *allocate_min (void) 456 { 457 return this->allocate_size<Type> (Type::min_size); 458 } 459 460 template <typename Type> 461 inline Type *start_embed (void) 462 { 463 Type *ret = reinterpret_cast<Type *> (this->head); 464 return ret; 465 } 466 467 template <typename Type> 468 inline Type *embed (const Type &obj) 469 { 470 unsigned int size = obj.get_size (); 471 Type *ret = this->allocate_size<Type> (size); 472 if (unlikely (!ret)) return NULL; 473 memcpy (ret, obj, size); 474 return ret; 475 } 476 477 template <typename Type> 478 inline Type *extend_min (Type &obj) 479 { 480 unsigned int size = obj.min_size; 481 assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head); 482 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL; 483 return reinterpret_cast<Type *> (&obj); 484 } 485 486 template <typename Type> 487 inline Type *extend (Type &obj) 488 { 489 unsigned int size = obj.get_size (); 490 assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head); 491 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL; 492 return reinterpret_cast<Type *> (&obj); 493 } 494 495 inline void truncate (void *new_head) 496 { 497 assert (this->start < new_head && new_head <= this->head); 498 this->head = (char *) new_head; 499 } 500 501 unsigned int debug_depth; 502 char *start, *end, *head; 503 bool ran_out_of_room; 504 }; 505 506 template <typename Type> 507 struct Supplier 508 { 509 inline Supplier (const Type *array, unsigned int len_) 510 { 511 head = array; 512 len = len_; 513 } 514 inline const Type operator [] (unsigned int i) const 515 { 516 if (unlikely (i >= len)) return Type (); 517 return head[i]; 518 } 519 520 inline void advance (unsigned int count) 521 { 522 if (unlikely (count > len)) 523 count = len; 524 len -= count; 525 head += count; 526 } 527 528 private: 529 inline Supplier (const Supplier<Type> &); /* Disallow copy */ 530 inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */ 531 532 unsigned int len; 533 const Type *head; 534 }; 535 536 537 538 539 /* 540 * 541 * The OpenType Font File: Data Types 542 */ 543 544 545 /* "The following data types are used in the OpenType font file. 546 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */ 547 548 /* 549 * Int types 550 */ 551 552 553 template <typename Type, int Bytes> struct BEInt; 554 555 template <typename Type> 556 struct BEInt<Type, 1> 557 { 558 public: 559 inline void set (Type V) 560 { 561 v = V; 562 } 563 inline operator Type (void) const 564 { 565 return v; 566 } 567 private: uint8_t v; 568 }; 569 template <typename Type> 570 struct BEInt<Type, 2> 571 { 572 public: 573 inline void set (Type V) 574 { 575 v[0] = (V >> 8) & 0xFF; 576 v[1] = (V ) & 0xFF; 577 } 578 inline operator Type (void) const 579 { 580 return (v[0] << 8) 581 + (v[1] ); 582 } 583 private: uint8_t v[2]; 584 }; 585 template <typename Type> 586 struct BEInt<Type, 3> 587 { 588 public: 589 inline void set (Type V) 590 { 591 v[0] = (V >> 16) & 0xFF; 592 v[1] = (V >> 8) & 0xFF; 593 v[2] = (V ) & 0xFF; 594 } 595 inline operator Type (void) const 596 { 597 return (v[0] << 16) 598 + (v[1] << 8) 599 + (v[2] ); 600 } 601 private: uint8_t v[3]; 602 }; 603 template <typename Type> 604 struct BEInt<Type, 4> 605 { 606 public: 607 inline void set (Type V) 608 { 609 v[0] = (V >> 24) & 0xFF; 610 v[1] = (V >> 16) & 0xFF; 611 v[2] = (V >> 8) & 0xFF; 612 v[3] = (V ) & 0xFF; 613 } 614 inline operator Type (void) const 615 { 616 return (v[0] << 24) 617 + (v[1] << 16) 618 + (v[2] << 8) 619 + (v[3] ); 620 } 621 private: uint8_t v[4]; 622 }; 623 624 /* Integer types in big-endian order and no alignment requirement */ 625 template <typename Type, unsigned int Size> 626 struct IntType 627 { 628 inline void set (Type i) { v.set (i); } 629 inline operator Type(void) const { return v; } 630 inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; } 631 inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); } 632 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); } 633 inline int cmp (Type a) const 634 { 635 Type b = v; 636 if (sizeof (Type) < sizeof (int)) 637 return (int) a - (int) b; 638 else 639 return a < b ? -1 : a == b ? 0 : +1; 640 } 641 inline bool sanitize (hb_sanitize_context_t *c) const 642 { 643 TRACE_SANITIZE (this); 644 return_trace (likely (c->check_struct (this))); 645 } 646 protected: 647 BEInt<Type, Size> v; 648 public: 649 DEFINE_SIZE_STATIC (Size); 650 }; 651 652 typedef IntType<uint8_t , 1> BYTE; /* 8-bit unsigned integer. */ 653 typedef IntType<uint16_t, 2> USHORT; /* 16-bit unsigned integer. */ 654 typedef IntType<int16_t, 2> SHORT; /* 16-bit signed integer. */ 655 typedef IntType<uint32_t, 4> ULONG; /* 32-bit unsigned integer. */ 656 typedef IntType<int32_t, 4> LONG; /* 32-bit signed integer. */ 657 typedef IntType<uint32_t, 3> UINT24; /* 24-bit unsigned integer. */ 658 659 /* 16-bit signed integer (SHORT) that describes a quantity in FUnits. */ 660 typedef SHORT FWORD; 661 662 /* 16-bit unsigned integer (USHORT) that describes a quantity in FUnits. */ 663 typedef USHORT UFWORD; 664 665 /* 16-bit signed fixed number with the low 14 bits of fraction (2.14). */ 666 struct F2DOT14 : SHORT 667 { 668 //inline float to_float (void) const { return ???; } 669 //inline void set_float (float f) { v.set (f * ???); } 670 public: 671 DEFINE_SIZE_STATIC (2); 672 }; 673 674 /* Date represented in number of seconds since 12:00 midnight, January 1, 675 * 1904. The value is represented as a signed 64-bit integer. */ 676 struct LONGDATETIME 677 { 678 inline bool sanitize (hb_sanitize_context_t *c) const 679 { 680 TRACE_SANITIZE (this); 681 return_trace (likely (c->check_struct (this))); 682 } 683 protected: 684 LONG major; 685 ULONG minor; 686 public: 687 DEFINE_SIZE_STATIC (8); 688 }; 689 690 /* Array of four uint8s (length = 32 bits) used to identify a script, language 691 * system, feature, or baseline */ 692 struct Tag : ULONG 693 { 694 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */ 695 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); } 696 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); } 697 public: 698 DEFINE_SIZE_STATIC (4); 699 }; 700 DEFINE_NULL_DATA (Tag, " "); 701 702 /* Glyph index number, same as uint16 (length = 16 bits) */ 703 struct GlyphID : USHORT { 704 static inline int cmp (const GlyphID *a, const GlyphID *b) { return b->USHORT::cmp (*a); } 705 inline int cmp (hb_codepoint_t a) const { return (int) a - (int) *this; } 706 }; 707 708 /* Script/language-system/feature index */ 709 struct Index : USHORT { 710 static const unsigned int NOT_FOUND_INDEX = 0xFFFFu; 711 }; 712 DEFINE_NULL_DATA (Index, "\xff\xff"); 713 714 /* Offset, Null offset = 0 */ 715 template <typename Type=USHORT> 716 struct Offset : Type 717 { 718 inline bool is_null (void) const { return 0 == *this; } 719 public: 720 DEFINE_SIZE_STATIC (sizeof(Type)); 721 }; 722 723 724 /* CheckSum */ 725 struct CheckSum : ULONG 726 { 727 /* This is reference implementation from the spec. */ 728 static inline uint32_t CalcTableChecksum (const ULONG *Table, uint32_t Length) 729 { 730 uint32_t Sum = 0L; 731 const ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size; 732 733 while (Table < EndPtr) 734 Sum += *Table++; 735 return Sum; 736 } 737 738 /* Note: data should be 4byte aligned and have 4byte padding at the end. */ 739 inline void set_for_data (const void *data, unsigned int length) 740 { set (CalcTableChecksum ((const ULONG *) data, length)); } 741 742 public: 743 DEFINE_SIZE_STATIC (4); 744 }; 745 746 747 /* 748 * Version Numbers 749 */ 750 751 template <typename FixedType=USHORT> 752 struct FixedVersion 753 { 754 inline uint32_t to_int (void) const { return (major << (sizeof(FixedType) * 8)) + minor; } 755 756 inline bool sanitize (hb_sanitize_context_t *c) const 757 { 758 TRACE_SANITIZE (this); 759 return_trace (c->check_struct (this)); 760 } 761 762 FixedType major; 763 FixedType minor; 764 public: 765 DEFINE_SIZE_STATIC (2 * sizeof(FixedType)); 766 }; 767 768 769 770 /* 771 * Template subclasses of Offset that do the dereferencing. 772 * Use: (base+offset) 773 */ 774 775 template <typename Type, typename OffsetType=USHORT> 776 struct OffsetTo : Offset<OffsetType> 777 { 778 inline const Type& operator () (const void *base) const 779 { 780 unsigned int offset = *this; 781 if (unlikely (!offset)) return Null(Type); 782 return StructAtOffset<Type> (base, offset); 783 } 784 785 inline Type& serialize (hb_serialize_context_t *c, const void *base) 786 { 787 Type *t = c->start_embed<Type> (); 788 this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */ 789 return *t; 790 } 791 792 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const 793 { 794 TRACE_SANITIZE (this); 795 if (unlikely (!c->check_struct (this))) return_trace (false); 796 unsigned int offset = *this; 797 if (unlikely (!offset)) return_trace (true); 798 const Type &obj = StructAtOffset<Type> (base, offset); 799 return_trace (likely (obj.sanitize (c)) || neuter (c)); 800 } 801 template <typename T> 802 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const 803 { 804 TRACE_SANITIZE (this); 805 if (unlikely (!c->check_struct (this))) return_trace (false); 806 unsigned int offset = *this; 807 if (unlikely (!offset)) return_trace (true); 808 const Type &obj = StructAtOffset<Type> (base, offset); 809 return_trace (likely (obj.sanitize (c, user_data)) || neuter (c)); 810 } 811 812 /* Set the offset to Null */ 813 inline bool neuter (hb_sanitize_context_t *c) const { 814 return c->try_set (this, 0); 815 } 816 DEFINE_SIZE_STATIC (sizeof(OffsetType)); 817 }; 818 template <typename Base, typename OffsetType, typename Type> 819 static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); } 820 template <typename Base, typename OffsetType, typename Type> 821 static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); } 822 823 824 /* 825 * Array Types 826 */ 827 828 /* An array with a number of elements. */ 829 template <typename Type, typename LenType=USHORT> 830 struct ArrayOf 831 { 832 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const 833 { 834 unsigned int count = len; 835 if (unlikely (start_offset > count)) 836 count = 0; 837 else 838 count -= start_offset; 839 count = MIN (count, *pcount); 840 *pcount = count; 841 return array + start_offset; 842 } 843 844 inline const Type& operator [] (unsigned int i) const 845 { 846 if (unlikely (i >= len)) return Null(Type); 847 return array[i]; 848 } 849 inline Type& operator [] (unsigned int i) 850 { 851 return array[i]; 852 } 853 inline unsigned int get_size (void) const 854 { return len.static_size + len * Type::static_size; } 855 856 inline bool serialize (hb_serialize_context_t *c, 857 unsigned int items_len) 858 { 859 TRACE_SERIALIZE (this); 860 if (unlikely (!c->extend_min (*this))) return_trace (false); 861 len.set (items_len); /* TODO(serialize) Overflow? */ 862 if (unlikely (!c->extend (*this))) return_trace (false); 863 return_trace (true); 864 } 865 866 inline bool serialize (hb_serialize_context_t *c, 867 Supplier<Type> &items, 868 unsigned int items_len) 869 { 870 TRACE_SERIALIZE (this); 871 if (unlikely (!serialize (c, items_len))) return_trace (false); 872 for (unsigned int i = 0; i < items_len; i++) 873 array[i] = items[i]; 874 items.advance (items_len); 875 return_trace (true); 876 } 877 878 inline bool sanitize (hb_sanitize_context_t *c) const 879 { 880 TRACE_SANITIZE (this); 881 if (unlikely (!sanitize_shallow (c))) return_trace (false); 882 883 /* Note: for structs that do not reference other structs, 884 * we do not need to call their sanitize() as we already did 885 * a bound check on the aggregate array size. We just include 886 * a small unreachable expression to make sure the structs 887 * pointed to do have a simple sanitize(), ie. they do not 888 * reference other structs via offsets. 889 */ 890 (void) (false && array[0].sanitize (c)); 891 892 return_trace (true); 893 } 894 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const 895 { 896 TRACE_SANITIZE (this); 897 if (unlikely (!sanitize_shallow (c))) return_trace (false); 898 unsigned int count = len; 899 for (unsigned int i = 0; i < count; i++) 900 if (unlikely (!array[i].sanitize (c, base))) 901 return_trace (false); 902 return_trace (true); 903 } 904 template <typename T> 905 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const 906 { 907 TRACE_SANITIZE (this); 908 if (unlikely (!sanitize_shallow (c))) return_trace (false); 909 unsigned int count = len; 910 for (unsigned int i = 0; i < count; i++) 911 if (unlikely (!array[i].sanitize (c, base, user_data))) 912 return_trace (false); 913 return_trace (true); 914 } 915 916 template <typename SearchType> 917 inline int lsearch (const SearchType &x) const 918 { 919 unsigned int count = len; 920 for (unsigned int i = 0; i < count; i++) 921 if (!this->array[i].cmp (x)) 922 return i; 923 return -1; 924 } 925 926 private: 927 inline bool sanitize_shallow (hb_sanitize_context_t *c) const 928 { 929 TRACE_SANITIZE (this); 930 return_trace (c->check_struct (this) && c->check_array (array, Type::static_size, len)); 931 } 932 933 public: 934 LenType len; 935 Type array[VAR]; 936 public: 937 DEFINE_SIZE_ARRAY (sizeof (LenType), array); 938 }; 939 940 /* Array of Offset's */ 941 template <typename Type> 942 struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {}; 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=USHORT> 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_shallow (hb_sanitize_context_t *c) const 996 { 997 return c->check_struct (this) 998 && c->check_array (this, Type::static_size, len); 999 } 1000 1001 inline bool sanitize (hb_sanitize_context_t *c) const 1002 { 1003 TRACE_SANITIZE (this); 1004 if (unlikely (!sanitize_shallow (c))) return_trace (false); 1005 1006 /* Note: for structs that do not reference other structs, 1007 * we do not need to call their sanitize() as we already did 1008 * a bound check on the aggregate array size. We just include 1009 * a small unreachable expression to make sure the structs 1010 * pointed to do have a simple sanitize(), ie. they do not 1011 * reference other structs via offsets. 1012 */ 1013 (void) (false && array[0].sanitize (c)); 1014 1015 return_trace (true); 1016 } 1017 1018 LenType len; 1019 Type array[VAR]; 1020 public: 1021 DEFINE_SIZE_ARRAY (sizeof (LenType), array); 1022 }; 1023 1024 1025 /* An array with sorted elements. Supports binary searching. */ 1026 template <typename Type, typename LenType=USHORT> 1027 struct SortedArrayOf : ArrayOf<Type, LenType> 1028 { 1029 template <typename SearchType> 1030 inline int bsearch (const SearchType &x) const 1031 { 1032 /* Hand-coded bsearch here since this is in the hot inner loop. */ 1033 int min = 0, max = (int) this->len - 1; 1034 while (min <= max) 1035 { 1036 int mid = (min + max) / 2; 1037 int c = this->array[mid].cmp (x); 1038 if (c < 0) 1039 max = mid - 1; 1040 else if (c > 0) 1041 min = mid + 1; 1042 else 1043 return mid; 1044 } 1045 return -1; 1046 } 1047 }; 1048 1049 1050 } /* namespace OT */ 1051 1052 1053 #endif /* HB_OPEN_TYPE_PRIVATE_HH */ 1054
