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 /* 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... */ 135 static const void *_NullPool[(256+8) / sizeof (void *)]; 136 137 /* Generic nul-content Null objects. */ 138 template <typename Type> 139 static 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) \ 146 static const char _Null##Type[sizeof (Type) + 1] = data; /* +1 is for nul-termination in data */ \ 147 template <> \ 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 */ \ 151 ASSERT_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 176 177 struct 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 this->edit_count = 0; 198 this->debug_depth = 0; 199 200 DEBUG_MSG_LEVEL (SANITIZE, this->blob, 0, +1, 201 "start [%p..%p] (%lu bytes)", 202 this->start, this->end, 203 (unsigned long) (this->end - this->start)); 204 } 205 206 inline void end_processing (void) 207 { 208 DEBUG_MSG_LEVEL (SANITIZE, this->blob, 0, -1, 209 "end [%p..%p] %u edit requests", 210 this->start, this->end, this->edit_count); 211 212 hb_blob_destroy (this->blob); 213 this->blob = NULL; 214 this->start = this->end = NULL; 215 } 216 217 inline bool check_range (const void *base, unsigned int len) const 218 { 219 const char *p = (const char *) base; 220 221 hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace 222 (&this->debug_depth, "SANITIZE", this->blob, NULL, 223 "check_range [%p..%p] (%d bytes) in [%p..%p]", 224 p, p + len, len, 225 this->start, this->end); 226 227 return TRACE_RETURN (likely (this->start <= p && p <= this->end && (unsigned int) (this->end - p) >= len)); 228 } 229 230 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const 231 { 232 const char *p = (const char *) base; 233 bool overflows = _hb_unsigned_int_mul_overflows (len, record_size); 234 235 hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace 236 (&this->debug_depth, "SANITIZE", this->blob, NULL, 237 "check_array [%p..%p] (%d*%d=%ld bytes) in [%p..%p]", 238 p, p + (record_size * len), record_size, len, (unsigned long) record_size * len, 239 this->start, this->end); 240 241 return TRACE_RETURN (likely (!overflows && this->check_range (base, record_size * len))); 242 } 243 244 template <typename Type> 245 inline bool check_struct (const Type *obj) const 246 { 247 return likely (this->check_range (obj, obj->min_size)); 248 } 249 250 inline bool may_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED) 251 { 252 if (this->edit_count >= HB_SANITIZE_MAX_EDITS) 253 return false; 254 255 const char *p = (const char *) base; 256 this->edit_count++; 257 258 hb_auto_trace_t<HB_DEBUG_SANITIZE, bool> trace 259 (&this->debug_depth, "SANITIZE", this->blob, NULL, 260 "may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s", 261 this->edit_count, 262 p, p + len, len, 263 this->start, this->end, 264 this->writable ? "GRANTED" : "DENIED"); 265 266 return TRACE_RETURN (this->writable); 267 } 268 269 template <typename Type, typename ValueType> 270 inline bool try_set (Type *obj, const ValueType &v) { 271 if (this->may_edit (obj, obj->static_size)) { 272 obj->set (v); 273 return true; 274 } 275 return false; 276 } 277 278 mutable unsigned int debug_depth; 279 const char *start, *end; 280 bool writable; 281 unsigned int edit_count; 282 hb_blob_t *blob; 283 }; 284 285 286 287 /* Template to sanitize an object. */ 288 template <typename Type> 289 struct Sanitizer 290 { 291 static hb_blob_t *sanitize (hb_blob_t *blob) { 292 hb_sanitize_context_t c[1] = {{0, NULL, NULL, false, 0, NULL}}; 293 bool sane; 294 295 /* TODO is_sane() stuff */ 296 297 c->init (blob); 298 299 retry: 300 DEBUG_MSG_FUNC (SANITIZE, blob, "start"); 301 302 c->start_processing (); 303 304 if (unlikely (!c->start)) { 305 c->end_processing (); 306 return blob; 307 } 308 309 Type *t = CastP<Type> (const_cast<char *> (c->start)); 310 311 sane = t->sanitize (c); 312 if (sane) { 313 if (c->edit_count) { 314 DEBUG_MSG_FUNC (SANITIZE, blob, "passed first round with %d edits; going for second round", c->edit_count); 315 316 /* sanitize again to ensure no toe-stepping */ 317 c->edit_count = 0; 318 sane = t->sanitize (c); 319 if (c->edit_count) { 320 DEBUG_MSG_FUNC (SANITIZE, blob, "requested %d edits in second round; FAILLING", c->edit_count); 321 sane = false; 322 } 323 } 324 } else { 325 unsigned int edit_count = c->edit_count; 326 if (edit_count && !c->writable) { 327 c->start = hb_blob_get_data_writable (blob, NULL); 328 c->end = c->start + hb_blob_get_length (blob); 329 330 if (c->start) { 331 c->writable = true; 332 /* ok, we made it writable by relocating. try again */ 333 DEBUG_MSG_FUNC (SANITIZE, blob, "retry"); 334 goto retry; 335 } 336 } 337 } 338 339 c->end_processing (); 340 341 DEBUG_MSG_FUNC (SANITIZE, blob, sane ? "PASSED" : "FAILED"); 342 if (sane) 343 return blob; 344 else { 345 hb_blob_destroy (blob); 346 return hb_blob_get_empty (); 347 } 348 } 349 350 static const Type* lock_instance (hb_blob_t *blob) { 351 hb_blob_make_immutable (blob); 352 const char *base = hb_blob_get_data (blob, NULL); 353 return unlikely (!base) ? &Null(Type) : CastP<Type> (base); 354 } 355 }; 356 357 358 359 /* 360 * Serialize 361 */ 362 363 #ifndef HB_DEBUG_SERIALIZE 364 #define HB_DEBUG_SERIALIZE (HB_DEBUG+0) 365 #endif 366 367 368 #define TRACE_SERIALIZE(this) \ 369 hb_auto_trace_t<HB_DEBUG_SERIALIZE, bool> trace \ 370 (&c->debug_depth, "SERIALIZE", c, HB_FUNC, \ 371 ""); 372 373 374 struct hb_serialize_context_t 375 { 376 inline hb_serialize_context_t (void *start, unsigned int size) 377 { 378 this->start = (char *) start; 379 this->end = this->start + size; 380 381 this->ran_out_of_room = false; 382 this->head = this->start; 383 this->debug_depth = 0; 384 } 385 386 template <typename Type> 387 inline Type *start_serialize (void) 388 { 389 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1, 390 "start [%p..%p] (%lu bytes)", 391 this->start, this->end, 392 (unsigned long) (this->end - this->start)); 393 394 return start_embed<Type> (); 395 } 396 397 inline void end_serialize (void) 398 { 399 DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1, 400 "end [%p..%p] serialized %d bytes; %s", 401 this->start, this->end, 402 (int) (this->head - this->start), 403 this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room"); 404 405 } 406 407 template <typename Type> 408 inline Type *copy (void) 409 { 410 assert (!this->ran_out_of_room); 411 unsigned int len = this->head - this->start; 412 void *p = malloc (len); 413 if (p) 414 memcpy (p, this->start, len); 415 return reinterpret_cast<Type *> (p); 416 } 417 418 template <typename Type> 419 inline Type *allocate_size (unsigned int size) 420 { 421 if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) { 422 this->ran_out_of_room = true; 423 return NULL; 424 } 425 memset (this->head, 0, size); 426 char *ret = this->head; 427 this->head += size; 428 return reinterpret_cast<Type *> (ret); 429 } 430 431 template <typename Type> 432 inline Type *allocate_min (void) 433 { 434 return this->allocate_size<Type> (Type::min_size); 435 } 436 437 template <typename Type> 438 inline Type *start_embed (void) 439 { 440 Type *ret = reinterpret_cast<Type *> (this->head); 441 return ret; 442 } 443 444 template <typename Type> 445 inline Type *embed (const Type &obj) 446 { 447 unsigned int size = obj.get_size (); 448 Type *ret = this->allocate_size<Type> (size); 449 if (unlikely (!ret)) return NULL; 450 memcpy (ret, obj, size); 451 return ret; 452 } 453 454 template <typename Type> 455 inline Type *extend_min (Type &obj) 456 { 457 unsigned int size = obj.min_size; 458 assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head); 459 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL; 460 return reinterpret_cast<Type *> (&obj); 461 } 462 463 template <typename Type> 464 inline Type *extend (Type &obj) 465 { 466 unsigned int size = obj.get_size (); 467 assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head); 468 if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return NULL; 469 return reinterpret_cast<Type *> (&obj); 470 } 471 472 inline void truncate (void *head) 473 { 474 assert (this->start < head && head <= this->head); 475 this->head = (char *) head; 476 } 477 478 unsigned int debug_depth; 479 char *start, *end, *head; 480 bool ran_out_of_room; 481 }; 482 483 template <typename Type> 484 struct Supplier 485 { 486 inline Supplier (const Type *array, unsigned int len_) 487 { 488 head = array; 489 len = len_; 490 } 491 inline const Type operator [] (unsigned int i) const 492 { 493 if (unlikely (i >= len)) return Type (); 494 return head[i]; 495 } 496 497 inline void advance (unsigned int count) 498 { 499 if (unlikely (count > len)) 500 count = len; 501 len -= count; 502 head += count; 503 } 504 505 private: 506 inline Supplier (const Supplier<Type> &); /* Disallow copy */ 507 inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */ 508 509 unsigned int len; 510 const Type *head; 511 }; 512 513 514 515 516 /* 517 * 518 * The OpenType Font File: Data Types 519 */ 520 521 522 /* "The following data types are used in the OpenType font file. 523 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */ 524 525 /* 526 * Int types 527 */ 528 529 530 template <typename Type, int Bytes> struct BEInt; 531 532 template <typename Type> 533 struct BEInt<Type, 2> 534 { 535 public: 536 inline void set (Type i) { hb_be_uint16_put (v,i); } 537 inline operator Type (void) const { return hb_be_uint16_get (v); } 538 inline bool operator == (const BEInt<Type, 2>& o) const { return hb_be_uint16_eq (v, o.v); } 539 inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); } 540 private: uint8_t v[2]; 541 }; 542 template <typename Type> 543 struct BEInt<Type, 4> 544 { 545 public: 546 inline void set (Type i) { hb_be_uint32_put (v,i); } 547 inline operator Type (void) const { return hb_be_uint32_get (v); } 548 inline bool operator == (const BEInt<Type, 4>& o) const { return hb_be_uint32_eq (v, o.v); } 549 inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); } 550 private: uint8_t v[4]; 551 }; 552 template <typename Type> 553 struct BEInt<Type, 3> 554 { 555 public: 556 inline void set (Type i) { hb_be_uint24_put (v,i); } 557 inline operator Type (void) const { return hb_be_uint24_get (v); } 558 inline bool operator == (const BEInt<Type, 3>& o) const { return hb_be_uint24_eq (v, o.v); } 559 inline bool operator != (const BEInt<Type, 3>& o) const { return !(*this == o); } 560 private: uint8_t v[3]; 561 }; 562 563 /* Integer types in big-endian order and no alignment requirement */ 564 template <typename Type, unsigned int Size> 565 struct IntType 566 { 567 inline void set (Type i) { v.set (i); } 568 inline operator Type(void) const { return v; } 569 inline bool operator == (const IntType<Type,Size> &o) const { return v == o.v; } 570 inline bool operator != (const IntType<Type,Size> &o) const { return v != o.v; } 571 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); } 572 inline int cmp (IntType<Type,Size> va) const { Type a = va; Type b = v; return a < b ? -1 : a == b ? 0 : +1; } 573 inline int cmp (Type a) const { Type b = v; return a < b ? -1 : a == b ? 0 : +1; } 574 inline bool sanitize (hb_sanitize_context_t *c) { 575 TRACE_SANITIZE (this); 576 return TRACE_RETURN (likely (c->check_struct (this))); 577 } 578 protected: 579 BEInt<Type, Size> v; 580 public: 581 DEFINE_SIZE_STATIC (Size); 582 }; 583 584 typedef uint8_t BYTE; /* 8-bit unsigned integer. */ 585 typedef IntType<uint16_t, 2> USHORT; /* 16-bit unsigned integer. */ 586 typedef IntType<int16_t, 2> SHORT; /* 16-bit signed integer. */ 587 typedef IntType<uint32_t, 4> ULONG; /* 32-bit unsigned integer. */ 588 typedef IntType<int32_t, 4> LONG; /* 32-bit signed integer. */ 589 typedef IntType<uint32_t, 3> UINT24; /* 24-bit unsigned integer. */ 590 591 /* 16-bit signed integer (SHORT) that describes a quantity in FUnits. */ 592 typedef SHORT FWORD; 593 594 /* 16-bit unsigned integer (USHORT) that describes a quantity in FUnits. */ 595 typedef USHORT UFWORD; 596 597 /* Date represented in number of seconds since 12:00 midnight, January 1, 598 * 1904. The value is represented as a signed 64-bit integer. */ 599 struct LONGDATETIME 600 { 601 inline bool sanitize (hb_sanitize_context_t *c) { 602 TRACE_SANITIZE (this); 603 return TRACE_RETURN (likely (c->check_struct (this))); 604 } 605 protected: 606 LONG major; 607 ULONG minor; 608 public: 609 DEFINE_SIZE_STATIC (8); 610 }; 611 612 /* Array of four uint8s (length = 32 bits) used to identify a script, language 613 * system, feature, or baseline */ 614 struct Tag : ULONG 615 { 616 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */ 617 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); } 618 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); } 619 public: 620 DEFINE_SIZE_STATIC (4); 621 }; 622 DEFINE_NULL_DATA (Tag, " "); 623 624 /* Glyph index number, same as uint16 (length = 16 bits) */ 625 typedef USHORT GlyphID; 626 627 /* Script/language-system/feature index */ 628 struct Index : USHORT { 629 static const unsigned int NOT_FOUND_INDEX = 0xFFFFu; 630 }; 631 DEFINE_NULL_DATA (Index, "\xff\xff"); 632 633 /* Offset, Null offset = 0 */ 634 template <typename Type=USHORT> 635 struct Offset : Type 636 { 637 inline bool is_null (void) const { return 0 == *this; } 638 public: 639 DEFINE_SIZE_STATIC (sizeof(Type)); 640 }; 641 642 643 /* CheckSum */ 644 struct CheckSum : ULONG 645 { 646 /* This is reference implementation from the spec. */ 647 static inline uint32_t CalcTableChecksum (const ULONG *Table, uint32_t Length) 648 { 649 uint32_t Sum = 0L; 650 const ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size; 651 652 while (Table < EndPtr) 653 Sum += *Table++; 654 return Sum; 655 } 656 657 /* Note: data should be 4byte aligned and have 4byte padding at the end. */ 658 inline void set_for_data (const void *data, unsigned int length) 659 { set (CalcTableChecksum ((const ULONG *) data, length)); } 660 661 public: 662 DEFINE_SIZE_STATIC (4); 663 }; 664 665 666 /* 667 * Version Numbers 668 */ 669 670 struct FixedVersion 671 { 672 inline uint32_t to_int (void) const { return (major << 16) + minor; } 673 674 inline bool sanitize (hb_sanitize_context_t *c) { 675 TRACE_SANITIZE (this); 676 return TRACE_RETURN (c->check_struct (this)); 677 } 678 679 USHORT major; 680 USHORT minor; 681 public: 682 DEFINE_SIZE_STATIC (4); 683 }; 684 685 686 687 /* 688 * Template subclasses of Offset that do the dereferencing. 689 * Use: (base+offset) 690 */ 691 692 template <typename Type, typename OffsetType=USHORT> 693 struct OffsetTo : Offset<OffsetType> 694 { 695 inline const Type& operator () (const void *base) const 696 { 697 unsigned int offset = *this; 698 if (unlikely (!offset)) return Null(Type); 699 return StructAtOffset<Type> (base, offset); 700 } 701 702 inline Type& serialize (hb_serialize_context_t *c, void *base) 703 { 704 Type *t = c->start_embed<Type> (); 705 this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */ 706 return *t; 707 } 708 709 inline bool sanitize (hb_sanitize_context_t *c, void *base) { 710 TRACE_SANITIZE (this); 711 if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false); 712 unsigned int offset = *this; 713 if (unlikely (!offset)) return TRACE_RETURN (true); 714 Type &obj = StructAtOffset<Type> (base, offset); 715 return TRACE_RETURN (likely (obj.sanitize (c)) || neuter (c)); 716 } 717 template <typename T> 718 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) { 719 TRACE_SANITIZE (this); 720 if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false); 721 unsigned int offset = *this; 722 if (unlikely (!offset)) return TRACE_RETURN (true); 723 Type &obj = StructAtOffset<Type> (base, offset); 724 return TRACE_RETURN (likely (obj.sanitize (c, user_data)) || neuter (c)); 725 } 726 727 /* Set the offset to Null */ 728 inline bool neuter (hb_sanitize_context_t *c) { 729 return c->try_set (this, 0); 730 } 731 DEFINE_SIZE_STATIC (sizeof(OffsetType)); 732 }; 733 template <typename Base, typename OffsetType, typename Type> 734 static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); } 735 template <typename Base, typename OffsetType, typename Type> 736 static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); } 737 738 739 /* 740 * Array Types 741 */ 742 743 /* An array with a number of elements. */ 744 template <typename Type, typename LenType=USHORT> 745 struct ArrayOf 746 { 747 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const 748 { 749 unsigned int count = len; 750 if (unlikely (start_offset > count)) 751 count = 0; 752 else 753 count -= start_offset; 754 count = MIN (count, *pcount); 755 *pcount = count; 756 return array + start_offset; 757 } 758 759 inline const Type& operator [] (unsigned int i) const 760 { 761 if (unlikely (i >= len)) return Null(Type); 762 return array[i]; 763 } 764 inline Type& operator [] (unsigned int i) 765 { 766 return array[i]; 767 } 768 inline unsigned int get_size (void) const 769 { return len.static_size + len * Type::static_size; } 770 771 inline bool serialize (hb_serialize_context_t *c, 772 unsigned int items_len) 773 { 774 TRACE_SERIALIZE (this); 775 if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false); 776 len.set (items_len); /* TODO(serialize) Overflow? */ 777 if (unlikely (!c->extend (*this))) return TRACE_RETURN (false); 778 return TRACE_RETURN (true); 779 } 780 781 inline bool serialize (hb_serialize_context_t *c, 782 Supplier<Type> &items, 783 unsigned int items_len) 784 { 785 TRACE_SERIALIZE (this); 786 if (unlikely (!serialize (c, items_len))) return TRACE_RETURN (false); 787 for (unsigned int i = 0; i < items_len; i++) 788 array[i] = items[i]; 789 items.advance (items_len); 790 return TRACE_RETURN (true); 791 } 792 793 inline bool sanitize (hb_sanitize_context_t *c) { 794 TRACE_SANITIZE (this); 795 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 796 797 /* Note: for structs that do not reference other structs, 798 * we do not need to call their sanitize() as we already did 799 * a bound check on the aggregate array size. We just include 800 * a small unreachable expression to make sure the structs 801 * pointed to do have a simple sanitize(), ie. they do not 802 * reference other structs via offsets. 803 */ 804 (void) (false && array[0].sanitize (c)); 805 806 return TRACE_RETURN (true); 807 } 808 inline bool sanitize (hb_sanitize_context_t *c, void *base) { 809 TRACE_SANITIZE (this); 810 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 811 unsigned int count = len; 812 for (unsigned int i = 0; i < count; i++) 813 if (unlikely (!array[i].sanitize (c, base))) 814 return TRACE_RETURN (false); 815 return TRACE_RETURN (true); 816 } 817 template <typename T> 818 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) { 819 TRACE_SANITIZE (this); 820 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 821 unsigned int count = len; 822 for (unsigned int i = 0; i < count; i++) 823 if (unlikely (!array[i].sanitize (c, base, user_data))) 824 return TRACE_RETURN (false); 825 return TRACE_RETURN (true); 826 } 827 828 template <typename SearchType> 829 inline int lsearch (const SearchType &x) const 830 { 831 unsigned int count = len; 832 for (unsigned int i = 0; i < count; i++) 833 if (!this->array[i].cmp (x)) 834 return i; 835 return -1; 836 } 837 838 private: 839 inline bool sanitize_shallow (hb_sanitize_context_t *c) { 840 TRACE_SANITIZE (this); 841 return TRACE_RETURN (c->check_struct (this) && c->check_array (this, Type::static_size, len)); 842 } 843 844 public: 845 LenType len; 846 Type array[VAR]; 847 public: 848 DEFINE_SIZE_ARRAY (sizeof (LenType), array); 849 }; 850 851 /* Array of Offset's */ 852 template <typename Type> 853 struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {}; 854 855 /* Array of offsets relative to the beginning of the array itself. */ 856 template <typename Type> 857 struct OffsetListOf : OffsetArrayOf<Type> 858 { 859 inline const Type& operator [] (unsigned int i) const 860 { 861 if (unlikely (i >= this->len)) return Null(Type); 862 return this+this->array[i]; 863 } 864 865 inline bool sanitize (hb_sanitize_context_t *c) { 866 TRACE_SANITIZE (this); 867 return TRACE_RETURN (OffsetArrayOf<Type>::sanitize (c, this)); 868 } 869 template <typename T> 870 inline bool sanitize (hb_sanitize_context_t *c, T user_data) { 871 TRACE_SANITIZE (this); 872 return TRACE_RETURN (OffsetArrayOf<Type>::sanitize (c, this, user_data)); 873 } 874 }; 875 876 877 /* An array starting at second element. */ 878 template <typename Type, typename LenType=USHORT> 879 struct HeadlessArrayOf 880 { 881 inline const Type& operator [] (unsigned int i) const 882 { 883 if (unlikely (i >= len || !i)) return Null(Type); 884 return array[i-1]; 885 } 886 inline unsigned int get_size (void) const 887 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; } 888 889 inline bool serialize (hb_serialize_context_t *c, 890 Supplier<Type> &items, 891 unsigned int items_len) 892 { 893 TRACE_SERIALIZE (this); 894 if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false); 895 len.set (items_len); /* TODO(serialize) Overflow? */ 896 if (unlikely (!items_len)) return TRACE_RETURN (true); 897 if (unlikely (!c->extend (*this))) return TRACE_RETURN (false); 898 for (unsigned int i = 0; i < items_len - 1; i++) 899 array[i] = items[i]; 900 items.advance (items_len - 1); 901 return TRACE_RETURN (true); 902 } 903 904 inline bool sanitize_shallow (hb_sanitize_context_t *c) { 905 return c->check_struct (this) 906 && c->check_array (this, Type::static_size, len); 907 } 908 909 inline bool sanitize (hb_sanitize_context_t *c) { 910 TRACE_SANITIZE (this); 911 if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false); 912 913 /* Note: for structs that do not reference other structs, 914 * we do not need to call their sanitize() as we already did 915 * a bound check on the aggregate array size. We just include 916 * a small unreachable expression to make sure the structs 917 * pointed to do have a simple sanitize(), ie. they do not 918 * reference other structs via offsets. 919 */ 920 (void) (false && array[0].sanitize (c)); 921 922 return TRACE_RETURN (true); 923 } 924 925 LenType len; 926 Type array[VAR]; 927 public: 928 DEFINE_SIZE_ARRAY (sizeof (LenType), array); 929 }; 930 931 932 /* An array with sorted elements. Supports binary searching. */ 933 template <typename Type, typename LenType=USHORT> 934 struct SortedArrayOf : ArrayOf<Type, LenType> 935 { 936 template <typename SearchType> 937 inline int bsearch (const SearchType &x) const 938 { 939 /* Hand-coded bsearch here since this is in the hot inner loop. */ 940 int min = 0, max = (int) this->len - 1; 941 while (min <= max) 942 { 943 int mid = (min + max) / 2; 944 int c = this->array[mid].cmp (x); 945 if (c < 0) 946 max = mid - 1; 947 else if (c > 0) 948 min = mid + 1; 949 else 950 return mid; 951 } 952 return -1; 953 } 954 }; 955 956 957 } /* namespace OT */ 958 959 960 #endif /* HB_OPEN_TYPE_PRIVATE_HH */ 961
