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 35namespace OT { 36 37 38 39/* 40 * Casts 41 */ 42 43/* Cast to struct T, reference to reference */ 44template<typename Type, typename TObject> 45static inline const Type& CastR(const TObject &X) 46{ return reinterpret_cast<const Type&> (X); } 47template<typename Type, typename TObject> 48static inline Type& CastR(TObject &X) 49{ return reinterpret_cast<Type&> (X); } 50 51/* Cast to struct T, pointer to pointer */ 52template<typename Type, typename TObject> 53static inline const Type* CastP(const TObject *X) 54{ return reinterpret_cast<const Type*> (X); } 55template<typename Type, typename TObject> 56static 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. */ 61template<typename Type> 62static inline const Type& StructAtOffset(const void *P, unsigned int offset) 63{ return * reinterpret_cast<const Type*> ((const char *) P + offset); } 64template<typename Type> 65static 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() */ 70template<typename Type, typename TObject> 71static inline const Type& StructAfter(const TObject &X) 72{ return StructAtOffset<Type>(&X, X.get_size()); } 73template<typename Type, typename TObject> 74static 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/* Size signifying variable-sized array */ 107#define VAR 1 108 109#define DEFINE_SIZE_UNION(size, _member) \ 110 DEFINE_INSTANCE_ASSERTION (this->u._member.static_size == (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/* TODO This really should be a extern HB_INTERNAL and defined somewhere... */ 135static const void *_NullPool[(256+8) / sizeof (void *)]; 136 137/* Generic nul-content Null objects. */ 138template <typename Type> 139static inline const Type& Null (void) { 140 ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool)); 141 return *CastP<Type> (_NullPool); 142} 143 144/* Specializaiton for arbitrary-content arbitrary-sized Null objects. */ 145#define DEFINE_NULL_DATA(Type, data) \ 146static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \ 147template <> \ 148/*static*/ inline const Type& Null<Type> (void) { \ 149 return *CastP<Type> (_Null##Type); \ 150} /* The following line really exists such that we end in a place needing semicolon */ \ 151ASSERT_STATIC (Type::min_size + 1 <= sizeof (_Null##Type)) 152 153/* Accessor macro. */ 154#define Null(Type) Null<Type>() 155 156 157 158/* 159 * Sanitize 160 */ 161 162#ifndef HB_DEBUG_SANITIZE 163#define HB_DEBUG_SANITIZE (HB_DEBUG+0) 164#endif 165 166 167#define TRACE_SANITIZE(this) \ 168 hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace \ 169 (&c->debug_depth, c->get_name (), this, HB_FUNC, \ 170 ""); 171 172/* This limits sanitizing time on really broken fonts. */ 173#ifndef HB_SANITIZE_MAX_EDITS 174#define HB_SANITIZE_MAX_EDITS 100 175#endif 176 177struct hb_sanitize_context_t 178{ 179 inline const char *get_name (void) { return "SANITIZE"; } 180 static const unsigned int max_debug_depth = HB_DEBUG_SANITIZE; 181 typedef bool return_t; 182 template <typename T> 183 inline return_t dispatch (const T &obj) { return obj.sanitize (this); } 184 static return_t default_return_value (void) { return true; } 185 bool stop_sublookup_iteration (const return_t r HB_UNUSED) const { return false; } 186 187 inline void init (hb_blob_t *b) 188 { 189 this->blob = hb_blob_reference (b); 190 this->writable = false; 191 } 192 193 inline void start_processing (void) 194 { 195 this->start = hb_blob_get_data (this->blob, NULL); 196 this->end = this->start + hb_blob_get_length (this->blob); 197 assert (this->start <= this->end); /* Must not overflow. */ 198 this->edit_count = 0; 199 this->debug_depth = 0; 200 201 DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1, 202 "start [%p..%p] (%lu bytes)", 203 this->start, this->end, 204 (unsigned long) (this->end - this->start)); 205 } 206 207 inline void end_processing (void) 208 { 209 DEBUG_MSG_LEVEL (SANITIZE, this->start, 0, -1, 210 "end [%p..%p] %u edit requests", 211 this->start, this->end, this->edit_count); 212 213 hb_blob_destroy (this->blob); 214 this->blob = NULL; 215 this->start = this->end = NULL; 216 } 217 218 inline bool check_range (const void *base, unsigned int len) const 219 { 220 const char *p = (const char *) base; 221 bool ok = this->start <= p && p <= this->end && (unsigned int) (this->end - p) >= len; 222 223 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0, 224 "check_range [%p..%p] (%d bytes) in [%p..%p] -> %s", 225 p, p + len, len, 226 this->start, this->end, 227 ok ? "OK" : "OUT-OF-RANGE"); 228 229 return likely (ok); 230 } 231 232 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const 233 { 234 const char *p = (const char *) base; 235 bool overflows = _hb_unsigned_int_mul_overflows (len, record_size); 236 unsigned int array_size = record_size * len; 237 bool ok = !overflows && this->check_range (base, array_size); 238 239 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0, 240 "check_array [%p..%p] (%d*%d=%d bytes) in [%p..%p] -> %s", 241 p, p + (record_size * len), record_size, len, (unsigned int) array_size, 242 this->start, this->end, 243 overflows ? "OVERFLOWS" : ok ? "OK" : "OUT-OF-RANGE"); 244 245 return likely (ok); 246 } 247 248 template <typename Type> 249 inline bool check_struct (const Type *obj) const 250 { 251 return likely (this->check_range (obj, obj->min_size)); 252 } 253 254 inline bool may_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED) 255 { 256 if (this->edit_count >= HB_SANITIZE_MAX_EDITS) 257 return false; 258 259 const char *p = (const char *) base; 260 this->edit_count++; 261 262 DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0, 263 "may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s", 264 this->edit_count, 265 p, p + len, len, 266 this->start, this->end, 267 this->writable ? "GRANTED" : "DENIED"); 268 269 return this->writable; 270 } 271 272 template <typename Type, typename ValueType> 273 inline bool try_set (Type *obj, const ValueType &v) { 274 if (this->may_edit (obj, obj->static_size)) { 275 obj->set (v); 276 return true; 277 } 278 return false; 279 } 280 281 mutable unsigned int debug_depth; 282 const char *start, *end; 283 bool writable; 284 unsigned int edit_count; 285 hb_blob_t *blob; 286}; 287 288 289 290/* Template to sanitize an object. */ 291template <typename Type> 292struct Sanitizer 293{ 294 static hb_blob_t *sanitize (hb_blob_t *blob) { 295 hb_sanitize_context_t c[1] = {{0, NULL, NULL, false, 0, NULL}}; 296 bool sane; 297 298 /* TODO is_sane() stuff */ 299 300 c->init (blob); 301 302 retry: 303 DEBUG_MSG_FUNC (SANITIZE, c->start, "start"); 304 305 c->start_processing (); 306 307 if (unlikely (!c->start)) { 308 c->end_processing (); 309 return blob; 310 } 311 312 Type *t = CastP<Type> (const_cast<char *> (c->start)); 313 314 sane = t->sanitize (c); 315 if (sane) { 316 if (c->edit_count) { 317 DEBUG_MSG_FUNC (SANITIZE, c->start, "passed first round with %d edits; going for second round", c->edit_count); 318 319 /* sanitize again to ensure no toe-stepping */ 320 c->edit_count = 0; 321 sane = t->sanitize (c); 322 if (c->edit_count) { 323 DEBUG_MSG_FUNC (SANITIZE, c->start, "requested %d edits in second round; FAILLING", c->edit_count); 324 sane = false; 325 } 326 } 327 } else { 328 unsigned int edit_count = c->edit_count; 329 if (edit_count && !c->writable) { 330 c->start = hb_blob_get_data_writable (blob, NULL); 331 c->end = c->start + hb_blob_get_length (blob); 332 333 if (c->start) { 334 c->writable = true; 335 /* ok, we made it writable by relocating. try again */ 336 DEBUG_MSG_FUNC (SANITIZE, c->start, "retry"); 337 goto retry; 338 } 339 } 340 } 341 342 c->end_processing (); 343 344 DEBUG_MSG_FUNC (SANITIZE, c->start, sane ? "PASSED" : "FAILED"); 345 if (sane) 346 return blob; 347 else { 348 hb_blob_destroy (blob); 349 return hb_blob_get_empty (); 350 } 351 } 352 353 static const Type* lock_instance (hb_blob_t *blob) { 354 hb_blob_make_immutable (blob); 355 const char *base = hb_blob_get_data (blob, NULL); 356 return unlikely (!base) ? &Null(Type) : CastP<Type> (base); 357 } 358}; 359 360 361 362/* 363 * Serialize 364 */ 365 366#ifndef HB_DEBUG_SERIALIZE 367#define HB_DEBUG_SERIALIZE (HB_DEBUG+0) 368#endif 369 370 371#define TRACE_SERIALIZE(this) \ 372 hb_auto_trace_t<HB_DEBUG_SERIALIZE, bool> trace \ 373 (&c->debug_depth, "SERIALIZE", c, HB_FUNC, \ 374 ""); 375 376 377struct hb_serialize_context_t 378{ 379 inline hb_serialize_context_t (void *start, unsigned int size) 380 { 381 this->start = (char *) start; 382 this->end = this->start + size; 383 384 this->ran_out_of_room = false; 385 this->head = this->start; 386 this->debug_depth = 0; 387 } 388 389 template <typename Type> 390 inline Type *start_serialize (void) 391 { 392 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1, 393 "start [%p..%p] (%lu bytes)", 394 this->start, this->end, 395 (unsigned long) (this->end - this->start)); 396 397 return start_embed<Type> (); 398 } 399 400 inline void end_serialize (void) 401 { 402 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1, 403 "end [%p..%p] serialized %d bytes; %s", 404 this->start, this->end, 405 (int) (this->head - this->start), 406 this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room"); 407 408 } 409 410 template <typename Type> 411 inline Type *copy (void) 412 { 413 assert (!this->ran_out_of_room); 414 unsigned int len = this->head - this->start; 415 void *p = malloc (len); 416 if (p) 417 memcpy (p, this->start, len); 418 return reinterpret_cast<Type *> (p); 419 } 420 421 template <typename Type> 422 inline Type *allocate_size (unsigned int size) 423 { 424 if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) { 425 this->ran_out_of_room = true; 426 return NULL; 427 } 428 memset (this->head, 0, size); 429 char *ret = this->head; 430 this->head += size; 431 return reinterpret_cast<Type *> (ret); 432 } 433 434 template <typename Type> 435 inline Type *allocate_min (void) 436 { 437 return this->allocate_size<Type> (Type::min_size); 438 } 439 440 template <typename Type> 441 inline Type *start_embed (void) 442 { 443 Type *ret = reinterpret_cast<Type *> (this->head); 444 return ret; 445 } 446 447 template <typename Type> 448 inline Type *embed (const Type &obj) 449 { 450 unsigned int size = obj.get_size (); 451 Type *ret = this->allocate_size<Type> (size); 452 if (unlikely (!ret)) return NULL; 453 memcpy (ret, obj, size); 454 return ret; 455 } 456 457 template <typename Type> 458 inline Type *extend_min (Type &obj) 459 { 460 unsigned int size = obj.min_size; 461 assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head); 462 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL; 463 return reinterpret_cast<Type *> (&obj); 464 } 465 466 template <typename Type> 467 inline Type *extend (Type &obj) 468 { 469 unsigned int size = obj.get_size (); 470 assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head); 471 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL; 472 return reinterpret_cast<Type *> (&obj); 473 } 474 475 inline void truncate (void *head) 476 { 477 assert (this->start < head && head <= this->head); 478 this->head = (char *) head; 479 } 480 481 unsigned int debug_depth; 482 char *start, *end, *head; 483 bool ran_out_of_room; 484}; 485 486template <typename Type> 487struct Supplier 488{ 489 inline Supplier (const Type *array, unsigned int len_) 490 { 491 head = array; 492 len = len_; 493 } 494 inline const Type operator [] (unsigned int i) const 495 { 496 if (unlikely (i >= len)) return Type (); 497 return head[i]; 498 } 499 500 inline void advance (unsigned int count) 501 { 502 if (unlikely (count > len)) 503 count = len; 504 len -= count; 505 head += count; 506 } 507 508 private: 509 inline Supplier (const Supplier<Type> &); /* Disallow copy */ 510 inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */ 511 512 unsigned int len; 513 const Type *head; 514}; 515 516 517 518 519/* 520 * 521 * The OpenType Font File: Data Types 522 */ 523 524 525/* "The following data types are used in the OpenType font file. 526 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */ 527 528/* 529 * Int types 530 */ 531 532 533template <typename Type, int Bytes> struct BEInt; 534 535template <typename Type> 536struct BEInt<Type, 2> 537{ 538 public: 539 inline void set (Type V) 540 { 541 v[0] = (V >> 8) & 0xFF; 542 v[1] = (V ) & 0xFF; 543 } 544 inline operator Type (void) const 545 { 546 return (v[0] << 8) 547 + (v[1] ); 548 } 549 inline bool operator == (const BEInt<Type, 2>& o) const 550 { 551 return v[0] == o.v[0] 552 && v[1] == o.v[1]; 553 } 554 inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); } 555 private: uint8_t v[2]; 556}; 557template <typename Type> 558struct BEInt<Type, 3> 559{ 560 public: 561 inline void set (Type V) 562 { 563 v[0] = (V >> 16) & 0xFF; 564 v[1] = (V >> 8) & 0xFF; 565 v[2] = (V ) & 0xFF; 566 } 567 inline operator Type (void) const 568 { 569 return (v[0] << 16) 570 + (v[1] << 8) 571 + (v[2] ); 572 } 573 inline bool operator == (const BEInt<Type, 3>& o) const 574 { 575 return v[0] == o.v[0] 576 && v[1] == o.v[1] 577 && v[2] == o.v[2]; 578 } 579 inline bool operator != (const BEInt<Type, 3>& o) const { return !(*this == o); } 580 private: uint8_t v[3]; 581}; 582template <typename Type> 583struct BEInt<Type, 4> 584{ 585 public: 586 inline void set (Type V) 587 { 588 v[0] = (V >> 24) & 0xFF; 589 v[1] = (V >> 16) & 0xFF; 590 v[2] = (V >> 8) & 0xFF; 591 v[3] = (V ) & 0xFF; 592 } 593 inline operator Type (void) const 594 { 595 return (v[0] << 24) 596 + (v[1] << 16) 597 + (v[2] << 8) 598 + (v[3] ); 599 } 600 inline bool operator == (const BEInt<Type, 4>& o) const 601 { 602 return v[0] == o.v[0] 603 && v[1] == o.v[1] 604 && v[2] == o.v[2] 605 && v[3] == o.v[3]; 606 } 607 inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); } 608 private: uint8_t v[4]; 609}; 610 611/* Integer types in big-endian order and no alignment requirement */ 612template <typename Type, unsigned int Size> 613struct IntType 614{ 615 inline void set (Type i) { v.set (i); } 616 inline operator Type(void) const { return v; } 617 inline bool operator == (const IntType<Type,Size> &o) const { return v == o.v; } 618 inline bool operator != (const IntType<Type,Size> &o) const { return v != o.v; } 619 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); } 620 inline int cmp (IntType<Type,Size> va) const { Type a = va; Type b = v; return a < b ? -1 : a == b ? 0 : +1; } 621 inline int cmp (Type a) const { Type b = v; return a < b ? -1 : a == b ? 0 : +1; } 622 inline bool sanitize (hb_sanitize_context_t *c) { 623 TRACE_SANITIZE (this); 624 return TRACE_RETURN (likely (c->check_struct (this))); 625 } 626 protected: 627 BEInt<Type, Size> v; 628 public: 629 DEFINE_SIZE_STATIC (Size); 630}; 631 632typedef uint8_t BYTE; /* 8-bit unsigned integer. */ 633typedef IntType<uint16_t, 2> USHORT; /* 16-bit unsigned integer. */ 634typedef IntType<int16_t, 2> SHORT; /* 16-bit signed integer. */ 635typedef IntType<uint32_t, 4> ULONG; /* 32-bit unsigned integer. */ 636typedef IntType<int32_t, 4> LONG; /* 32-bit signed integer. */ 637typedef IntType<uint32_t, 3> UINT24; /* 24-bit unsigned integer. */ 638 639/* 16-bit signed integer (SHORT) that describes a quantity in FUnits. */ 640typedef SHORT FWORD; 641 642/* 16-bit unsigned integer (USHORT) that describes a quantity in FUnits. */ 643typedef USHORT UFWORD; 644 645/* Date represented in number of seconds since 12:00 midnight, January 1, 646 * 1904. The value is represented as a signed 64-bit integer. */ 647struct LONGDATETIME 648{ 649 inline bool sanitize (hb_sanitize_context_t *c) { 650 TRACE_SANITIZE (this); 651 return TRACE_RETURN (likely (c->check_struct (this))); 652 } 653 protected: 654 LONG major; 655 ULONG minor; 656 public: 657 DEFINE_SIZE_STATIC (8); 658}; 659 660/* Array of four uint8s (length = 32 bits) used to identify a script, language 661 * system, feature, or baseline */ 662struct Tag : ULONG 663{ 664 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */ 665 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); } 666 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); } 667 public: 668 DEFINE_SIZE_STATIC (4); 669}; 670DEFINE_NULL_DATA (Tag, " "); 671 672/* Glyph index number, same as uint16 (length = 16 bits) */ 673typedef USHORT GlyphID; 674 675/* Script/language-system/feature index */ 676struct Index : USHORT { 677 static const unsigned int NOT_FOUND_INDEX = 0xFFFFu; 678}; 679DEFINE_NULL_DATA (Index, "\xff\xff"); 680 681/* Offset, Null offset = 0 */ 682template <typename Type=USHORT> 683struct Offset : Type 684{ 685 inline bool is_null (void) const { return 0 == *this; } 686 public: 687 DEFINE_SIZE_STATIC (sizeof(Type)); 688}; 689 690 691/* CheckSum */ 692struct CheckSum : ULONG 693{ 694 /* This is reference implementation from the spec. */ 695 static inline uint32_t CalcTableChecksum (const ULONG *Table, uint32_t Length) 696 { 697 uint32_t Sum = 0L; 698 const ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size; 699 700 while (Table < EndPtr) 701 Sum += *Table++; 702 return Sum; 703 } 704 705 /* Note: data should be 4byte aligned and have 4byte padding at the end. */ 706 inline void set_for_data (const void *data, unsigned int length) 707 { set (CalcTableChecksum ((const ULONG *) data, length)); } 708 709 public: 710 DEFINE_SIZE_STATIC (4); 711}; 712 713 714/* 715 * Version Numbers 716 */ 717 718struct FixedVersion 719{ 720 inline uint32_t to_int (void) const { return (major << 16) + minor; } 721 722 inline bool sanitize (hb_sanitize_context_t *c) { 723 TRACE_SANITIZE (this); 724 return TRACE_RETURN (c->check_struct (this)); 725 } 726 727 USHORT major; 728 USHORT minor; 729 public: 730 DEFINE_SIZE_STATIC (4); 731}; 732 733 734 735/* 736 * Template subclasses of Offset that do the dereferencing. 737 * Use: (base+offset) 738 */ 739 740template <typename Type, typename OffsetType=USHORT> 741struct OffsetTo : Offset<OffsetType> 742{ 743 inline const Type& operator () (const void *base) const 744 { 745 unsigned int offset = *this; 746 if (unlikely (!offset)) return Null(Type); 747 return StructAtOffset<Type> (base, offset); 748 } 749 750 inline Type& serialize (hb_serialize_context_t *c, void *base) 751 { 752 Type *t = c->start_embed<Type> (); 753 this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */ 754 return *t; 755 } 756 757 inline bool sanitize (hb_sanitize_context_t *c, void *base) { 758 TRACE_SANITIZE (this); 759 if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false); 760 unsigned int offset = *this; 761 if (unlikely (!offset)) return TRACE_RETURN (true); 762 Type &obj = StructAtOffset<Type> (base, offset); 763 return TRACE_RETURN (likely (obj.sanitize (c)) || neuter (c)); 764 } 765 template <typename T> 766 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) { 767 TRACE_SANITIZE (this); 768 if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false); 769 unsigned int offset = *this; 770 if (unlikely (!offset)) return TRACE_RETURN (true); 771 Type &obj = StructAtOffset<Type> (base, offset); 772 return TRACE_RETURN (likely (obj.sanitize (c, user_data)) || neuter (c)); 773 } 774 775 /* Set the offset to Null */ 776 inline bool neuter (hb_sanitize_context_t *c) { 777 return c->try_set (this, 0); 778 } 779 DEFINE_SIZE_STATIC (sizeof(OffsetType)); 780}; 781template <typename Base, typename OffsetType, typename Type> 782static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); } 783template <typename Base, typename OffsetType, typename Type> 784static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); } 785 786 787/* 788 * Array Types 789 */ 790 791/* An array with a number of elements. */ 792template <typename Type, typename LenType=USHORT> 793struct ArrayOf 794{ 795 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const 796 { 797 unsigned int count = len; 798 if (unlikely (start_offset > count)) 799 count = 0; 800 else 801 count -= start_offset; 802 count = MIN (count, *pcount); 803 *pcount = count; 804 return array + start_offset; 805 } 806 807 inline const Type& operator [] (unsigned int i) const 808 { 809 if (unlikely (i >= len)) return Null(Type); 810 return array[i]; 811 } 812 inline Type& operator [] (unsigned int i) 813 { 814 return array[i]; 815 } 816 inline unsigned int get_size (void) const 817 { return len.static_size + len * Type::static_size; } 818 819 inline bool serialize (hb_serialize_context_t *c, 820 unsigned int items_len) 821 { 822 TRACE_SERIALIZE (this); 823 if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false); 824 len.set (items_len); /* TODO(serialize) Overflow? */ 825 if (unlikely (!c->extend (*this))) return TRACE_RETURN (false); 826 return TRACE_RETURN (true); 827 } 828 829 inline bool serialize (hb_serialize_context_t *c, 830 Supplier<Type> &items, 831 unsigned int items_len) 832 { 833 TRACE_SERIALIZE (this); 834 if (unlikely (!serialize (c, items_len))) return TRACE_RETURN (false); 835 for (unsigned int i = 0; i < items_len; i++) 836 array[i] = items[i]; 837 items.advance (items_len); 838 return TRACE_RETURN (true); 839 } 840 841 inline bool sanitize (hb_sanitize_context_t *c) { 842 TRACE_SANITIZE (this); 843 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 844 845 /* Note: for structs that do not reference other structs, 846 * we do not need to call their sanitize() as we already did 847 * a bound check on the aggregate array size. We just include 848 * a small unreachable expression to make sure the structs 849 * pointed to do have a simple sanitize(), ie. they do not 850 * reference other structs via offsets. 851 */ 852 (void) (false && array[0].sanitize (c)); 853 854 return TRACE_RETURN (true); 855 } 856 inline bool sanitize (hb_sanitize_context_t *c, void *base) { 857 TRACE_SANITIZE (this); 858 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 859 unsigned int count = len; 860 for (unsigned int i = 0; i < count; i++) 861 if (unlikely (!array[i].sanitize (c, base))) 862 return TRACE_RETURN (false); 863 return TRACE_RETURN (true); 864 } 865 template <typename T> 866 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) { 867 TRACE_SANITIZE (this); 868 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 869 unsigned int count = len; 870 for (unsigned int i = 0; i < count; i++) 871 if (unlikely (!array[i].sanitize (c, base, user_data))) 872 return TRACE_RETURN (false); 873 return TRACE_RETURN (true); 874 } 875 876 template <typename SearchType> 877 inline int lsearch (const SearchType &x) const 878 { 879 unsigned int count = len; 880 for (unsigned int i = 0; i < count; i++) 881 if (!this->array[i].cmp (x)) 882 return i; 883 return -1; 884 } 885 886 private: 887 inline bool sanitize_shallow (hb_sanitize_context_t *c) { 888 TRACE_SANITIZE (this); 889 return TRACE_RETURN (c->check_struct (this) && c->check_array (this, Type::static_size, len)); 890 } 891 892 public: 893 LenType len; 894 Type array[VAR]; 895 public: 896 DEFINE_SIZE_ARRAY (sizeof (LenType), array); 897}; 898 899/* Array of Offset's */ 900template <typename Type> 901struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {}; 902 903/* Array of offsets relative to the beginning of the array itself. */ 904template <typename Type> 905struct OffsetListOf : OffsetArrayOf<Type> 906{ 907 inline const Type& operator [] (unsigned int i) const 908 { 909 if (unlikely (i >= this->len)) return Null(Type); 910 return this+this->array[i]; 911 } 912 913 inline bool sanitize (hb_sanitize_context_t *c) { 914 TRACE_SANITIZE (this); 915 return TRACE_RETURN (OffsetArrayOf<Type>::sanitize (c, this)); 916 } 917 template <typename T> 918 inline bool sanitize (hb_sanitize_context_t *c, T user_data) { 919 TRACE_SANITIZE (this); 920 return TRACE_RETURN (OffsetArrayOf<Type>::sanitize (c, this, user_data)); 921 } 922}; 923 924 925/* An array starting at second element. */ 926template <typename Type, typename LenType=USHORT> 927struct HeadlessArrayOf 928{ 929 inline const Type& operator [] (unsigned int i) const 930 { 931 if (unlikely (i >= len || !i)) return Null(Type); 932 return array[i-1]; 933 } 934 inline unsigned int get_size (void) const 935 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; } 936 937 inline bool serialize (hb_serialize_context_t *c, 938 Supplier<Type> &items, 939 unsigned int items_len) 940 { 941 TRACE_SERIALIZE (this); 942 if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false); 943 len.set (items_len); /* TODO(serialize) Overflow? */ 944 if (unlikely (!items_len)) return TRACE_RETURN (true); 945 if (unlikely (!c->extend (*this))) return TRACE_RETURN (false); 946 for (unsigned int i = 0; i < items_len - 1; i++) 947 array[i] = items[i]; 948 items.advance (items_len - 1); 949 return TRACE_RETURN (true); 950 } 951 952 inline bool sanitize_shallow (hb_sanitize_context_t *c) { 953 return c->check_struct (this) 954 && c->check_array (this, Type::static_size, len); 955 } 956 957 inline bool sanitize (hb_sanitize_context_t *c) { 958 TRACE_SANITIZE (this); 959 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 960 961 /* Note: for structs that do not reference other structs, 962 * we do not need to call their sanitize() as we already did 963 * a bound check on the aggregate array size. We just include 964 * a small unreachable expression to make sure the structs 965 * pointed to do have a simple sanitize(), ie. they do not 966 * reference other structs via offsets. 967 */ 968 (void) (false && array[0].sanitize (c)); 969 970 return TRACE_RETURN (true); 971 } 972 973 LenType len; 974 Type array[VAR]; 975 public: 976 DEFINE_SIZE_ARRAY (sizeof (LenType), array); 977}; 978 979 980/* An array with sorted elements. Supports binary searching. */ 981template <typename Type, typename LenType=USHORT> 982struct SortedArrayOf : ArrayOf<Type, LenType> 983{ 984 template <typename SearchType> 985 inline int bsearch (const SearchType &x) const 986 { 987 /* Hand-coded bsearch here since this is in the hot inner loop. */ 988 int min = 0, max = (int) this->len - 1; 989 while (min <= max) 990 { 991 int mid = (min + max) / 2; 992 int c = this->array[mid].cmp (x); 993 if (c < 0) 994 max = mid - 1; 995 else if (c > 0) 996 min = mid + 1; 997 else 998 return mid; 999 } 1000 return -1; 1001 } 1002}; 1003 1004 1005} /* namespace OT */ 1006 1007 1008#endif /* HB_OPEN_TYPE_PRIVATE_HH */ 1009