hb-open-type-private.hh revision 173fde7087c0db3e99409f1119530477c14072f5
1/* 2 * Copyright (C) 2007,2008,2009,2010 Red Hat, Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Red Hat Author(s): Behdad Esfahbod 25 */ 26 27#ifndef HB_OPEN_TYPES_PRIVATE_HH 28#define HB_OPEN_TYPES_PRIVATE_HH 29 30#include "hb-private.h" 31 32#include "hb-blob.h" 33 34 35/* Table/script/language-system/feature/... not found */ 36#define NO_INDEX ((unsigned int) 0xFFFF) 37 38 39 40/* 41 * Casts 42 */ 43 44/* Cast to "const char *" and "char *" */ 45template <typename Type> 46inline const char * CharP (const Type* X) 47{ return reinterpret_cast<const char *>(X); } 48template <typename Type> 49inline char * CharP (Type* X) 50{ return reinterpret_cast<char *>(X); } 51 52/* Cast to struct T, reference to reference */ 53template<typename Type, typename TObject> 54inline const Type& CastR(const TObject &X) 55{ return reinterpret_cast<const Type&> (X); } 56template<typename Type, typename TObject> 57inline Type& CastR(TObject &X) 58{ return reinterpret_cast<Type&> (X); } 59 60/* Cast to struct T, pointer to pointer */ 61template<typename Type, typename TObject> 62inline const Type* CastP(const TObject *X) 63{ return reinterpret_cast<const Type*> (X); } 64template<typename Type, typename TObject> 65inline Type* CastP(TObject *X) 66{ return reinterpret_cast<Type*> (X); } 67 68/* StructAtOffset<T>(X,Ofs) returns the struct T& that is placed at memory 69 * location of X plus Ofs bytes. */ 70template<typename Type, typename TObject> 71inline const Type& StructAtOffset(const TObject &X, unsigned int offset) 72{ return * reinterpret_cast<const Type*> (CharP(&X) + offset); } 73template<typename Type, typename TObject> 74inline Type& StructAtOffset(TObject &X, unsigned int offset) 75{ return * reinterpret_cast<Type*> (CharP(&X) + offset); } 76 77/* StructAfter<T>(X) returns the struct T& that is placed after X. 78 * Works with X of variable size also. X must implement get_size() */ 79template<typename Type, typename TObject> 80inline const Type& StructAfter(const TObject &X) 81{ return StructAtOffset<Type>(X, X.get_size()); } 82template<typename Type, typename TObject> 83inline Type& StructAfter(TObject &X) 84{ return StructAtOffset<Type>(X, X.get_size()); } 85 86 87 88/* 89 * Class features 90 */ 91 92 93/* Null objects */ 94 95/* Global nul-content Null pool. Enlarge as necessary. */ 96static const void *_NullPool[32 / sizeof (void *)]; 97 98/* Generic template for nul-content sizeof-sized Null objects. */ 99template <typename Type> 100static inline const Type& Null () { 101 ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool)); 102 return *CastP<Type> (_NullPool); 103} 104 105/* Specializaiton for arbitrary-content arbitrary-sized Null objects. */ 106#define DEFINE_NULL_DATA(Type, size, data) \ 107static const char _Null##Type[size + 1] = data; /* +1 is for nul-termination in data */ \ 108template <> \ 109inline const Type& Null<Type> () { \ 110 return *CastP<Type> (_Null##Type); \ 111} /* The following line really exists such that we end in a place needing semicolon */ \ 112ASSERT_STATIC (sizeof (Type) + 1 <= sizeof (_Null##Type)) 113 114/* Accessor macro. */ 115#define Null(Type) Null<Type>() 116 117 118 119/* 120 * Sanitize 121 */ 122 123#ifndef HB_DEBUG_SANITIZE 124#define HB_DEBUG_SANITIZE HB_DEBUG+0 125#endif 126 127#define TRACE_SANITIZE() \ 128 HB_STMT_START { \ 129 if (HB_DEBUG_SANITIZE) \ 130 _hb_trace ("SANITIZE", __PRETTY_FUNCTION__, this, sanitize_depth, HB_DEBUG_SANITIZE); \ 131 } HB_STMT_END 132 133 134#define SANITIZE_ARG_DEF \ 135 hb_sanitize_context_t *context, \ 136 unsigned int sanitize_depth HB_GNUC_UNUSED 137#define SANITIZE_ARG \ 138 context, \ 139 (HB_DEBUG_SANITIZE ? sanitize_depth + 1 : 0) 140 141 142typedef struct _hb_sanitize_context_t hb_sanitize_context_t; 143struct _hb_sanitize_context_t 144{ 145 const char *start, *end; 146 hb_bool_t writable; 147 unsigned int edit_count; 148}; 149 150static HB_GNUC_UNUSED void 151_hb_sanitize_init (hb_sanitize_context_t *context, 152 hb_blob_t *blob) 153{ 154 context->start = hb_blob_lock (blob); 155 context->end = context->start + hb_blob_get_length (blob); 156 context->writable = hb_blob_is_writable (blob); 157 context->edit_count = 0; 158 159#if HB_DEBUG_SANITIZE 160 fprintf (stderr, "sanitize %p init [%p..%p] (%u bytes)\n", 161 blob, context->start, context->end, context->end - context->start); 162#endif 163} 164 165static HB_GNUC_UNUSED void 166_hb_sanitize_fini (hb_sanitize_context_t *context HB_GNUC_UNUSED, 167 hb_blob_t *blob) 168{ 169#if HB_DEBUG_SANITIZE 170 fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n", 171 blob, context->start, context->end, context->edit_count); 172#endif 173 174 hb_blob_unlock (blob); 175} 176 177static HB_GNUC_UNUSED inline bool 178_hb_sanitize_check (SANITIZE_ARG_DEF, 179 const char *base, 180 unsigned int len) 181{ 182 bool ret = context->start <= base && 183 base <= context->end && 184 (unsigned int) (context->end - base) >= len; 185 186#if HB_DEBUG_SANITIZE 187 if (sanitize_depth < HB_DEBUG_SANITIZE) \ 188 fprintf (stderr, "SANITIZE(%p) %-*d-> check [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \ 189 base, 190 sanitize_depth, sanitize_depth, 191 base, base+len, len, 192 context->start, context->end, 193 ret ? "pass" : "FAIL"); 194#endif 195 return ret; 196} 197 198static HB_GNUC_UNUSED inline bool 199_hb_sanitize_array (SANITIZE_ARG_DEF, 200 const char *base, 201 unsigned int record_size, 202 unsigned int len) 203{ 204 bool overflows = len >= ((unsigned int) -1) / record_size; 205 206#if HB_DEBUG_SANITIZE 207 if (sanitize_depth < HB_DEBUG_SANITIZE) \ 208 fprintf (stderr, "SANITIZE(%p) %-*d-> array [%p..%p] (%d*%d=%ld bytes) in [%p..%p] -> %s\n", \ 209 base, 210 sanitize_depth, sanitize_depth, 211 base, base + (record_size * len), record_size, len, (unsigned long) record_size * len, 212 context->start, context->end, 213 !overflows ? "does not overflow" : "OVERFLOWS FAIL"); 214#endif 215 216 return HB_LIKELY (!overflows) && _hb_sanitize_check (SANITIZE_ARG, base, record_size * len); 217} 218 219static HB_GNUC_UNUSED inline bool 220_hb_sanitize_edit (SANITIZE_ARG_DEF, 221 const char *base HB_GNUC_UNUSED, 222 unsigned int len HB_GNUC_UNUSED) 223{ 224 context->edit_count++; 225 226#if HB_DEBUG_SANITIZE 227 fprintf (stderr, "SANITIZE(%p) %-*d-> edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \ 228 base, 229 sanitize_depth, sanitize_depth, 230 context->edit_count, 231 base, base+len, len, 232 context->start, context->end, 233 context->writable ? "granted" : "REJECTED"); 234#endif 235 236 return context->writable; 237} 238 239#define SANITIZE(X) HB_LIKELY ((X).sanitize (SANITIZE_ARG)) 240#define SANITIZE2(X,Y) (SANITIZE (X) && SANITIZE (Y)) 241 242#define SANITIZE_THIS(X) HB_LIKELY ((X).sanitize (SANITIZE_ARG, CharP(this))) 243#define SANITIZE_THIS2(X,Y) (SANITIZE_THIS (X) && SANITIZE_THIS (Y)) 244#define SANITIZE_THIS3(X,Y,Z) (SANITIZE_THIS (X) && SANITIZE_THIS (Y) && SANITIZE_THIS(Z)) 245 246#define SANITIZE_BASE(X,B) HB_LIKELY ((X).sanitize (SANITIZE_ARG, B)) 247#define SANITIZE_BASE2(X,Y,B) (SANITIZE_BASE (X,B) && SANITIZE_BASE (Y,B)) 248 249#define SANITIZE_SELF() SANITIZE_OBJ (*this) 250#define SANITIZE_OBJ(X) SANITIZE_MEM(&(X), sizeof (X)) 251 252#define SANITIZE_MEM(B,L) HB_LIKELY (_hb_sanitize_check (SANITIZE_ARG, CharP(B), (L))) 253 254#define SANITIZE_ARRAY(A,S,L) HB_LIKELY (_hb_sanitize_array (SANITIZE_ARG, CharP(A), S, L)) 255 256#define NEUTER(Obj, Val) \ 257 (SANITIZE_OBJ (Obj) && \ 258 _hb_sanitize_edit (SANITIZE_ARG, CharP(&(Obj)), (Obj).get_size ()) && \ 259 ((Obj).set (Val), true)) 260 261 262/* Template to sanitize an object. */ 263template <typename Type> 264struct Sanitizer 265{ 266 static hb_blob_t *sanitize (hb_blob_t *blob) { 267 hb_sanitize_context_t context[1]; 268 unsigned int sanitize_depth = 0; 269 bool sane; 270 271 /* TODO is_sane() stuff */ 272 273 retry: 274#if HB_DEBUG_SANITIZE 275 fprintf (stderr, "Sanitizer %p start %s\n", blob, __PRETTY_FUNCTION__); 276#endif 277 278 _hb_sanitize_init (context, blob); 279 280 /* Note: We drop const here */ 281 Type *t = CastP<Type> ((void *) context->start); 282 283 sane = t->sanitize (SANITIZE_ARG); 284 if (sane) { 285 if (context->edit_count) { 286#if HB_DEBUG_SANITIZE 287 fprintf (stderr, "Sanitizer %p passed first round with %d edits; doing a second round %s\n", 288 blob, context->edit_count, __PRETTY_FUNCTION__); 289#endif 290 /* sanitize again to ensure no toe-stepping */ 291 context->edit_count = 0; 292 sane = t->sanitize (SANITIZE_ARG); 293 if (context->edit_count) { 294#if HB_DEBUG_SANITIZE 295 fprintf (stderr, "Sanitizer %p requested %d edits in second round; FAILLING %s\n", 296 blob, context->edit_count, __PRETTY_FUNCTION__); 297#endif 298 sane = false; 299 } 300 } 301 _hb_sanitize_fini (context, blob); 302 } else { 303 unsigned int edit_count = context->edit_count; 304 _hb_sanitize_fini (context, blob); 305 if (edit_count && !hb_blob_is_writable (blob) && hb_blob_try_writable (blob)) { 306 /* ok, we made it writable by relocating. try again */ 307#if HB_DEBUG_SANITIZE 308 fprintf (stderr, "Sanitizer %p retry %s\n", blob, __PRETTY_FUNCTION__); 309#endif 310 goto retry; 311 } 312 } 313 314#if HB_DEBUG_SANITIZE 315 fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "FAILED", __PRETTY_FUNCTION__); 316#endif 317 if (sane) 318 return blob; 319 else { 320 hb_blob_destroy (blob); 321 return hb_blob_create_empty (); 322 } 323 } 324}; 325 326 327/* 328 * 329 * The OpenType Font File: Data Types 330 */ 331 332 333/* "The following data types are used in the OpenType font file. 334 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */ 335 336/* 337 * Int types 338 */ 339 340 341template <typename Type, int Bytes> class BEInt; 342 343/* LONGTERMTODO: On machines allowing unaligned access, we can make the 344 * following tighter by using byteswap instructions on ints directly. */ 345template <typename Type> 346class BEInt<Type, 2> 347{ 348 public: 349 inline class BEInt<Type,2>& operator = (Type i) { hb_be_uint16_put (v,i); return *this; } 350 inline operator Type () const { return hb_be_uint16_get (v); } 351 inline bool operator == (const BEInt<Type, 2>& o) const { return hb_be_uint16_cmp (v, o.v); } 352 inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); } 353 private: uint8_t v[2]; 354}; 355template <typename Type> 356class BEInt<Type, 4> 357{ 358 public: 359 inline class BEInt<Type,4>& operator = (Type i) { hb_be_uint32_put (v,i); return *this; } 360 inline operator Type () const { return hb_be_uint32_get (v); } 361 inline bool operator == (const BEInt<Type, 4>& o) const { return hb_be_uint32_cmp (v, o.v); } 362 inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); } 363 private: uint8_t v[4]; 364}; 365 366/* Integer types in big-endian order and no alignment requirement */ 367template <typename Type> 368struct IntType 369{ 370 static inline unsigned int get_size () { return sizeof (Type); } 371 inline void set (Type i) { v = i; } 372 inline operator Type(void) const { return v; } 373 inline bool operator == (const IntType<Type> &o) const { return v == o.v; } 374 inline bool operator != (const IntType<Type> &o) const { return v != o.v; } 375 inline bool sanitize (SANITIZE_ARG_DEF) { 376 TRACE_SANITIZE (); 377 return SANITIZE_SELF (); 378 } 379 private: BEInt<Type, sizeof (Type)> v; 380}; 381 382typedef IntType<uint16_t> USHORT; /* 16-bit unsigned integer. */ 383typedef IntType<int16_t> SHORT; /* 16-bit signed integer. */ 384typedef IntType<uint32_t> ULONG; /* 32-bit unsigned integer. */ 385typedef IntType<int32_t> LONG; /* 32-bit signed integer. */ 386 387ASSERT_SIZE (USHORT, 2); 388ASSERT_SIZE (SHORT, 2); 389ASSERT_SIZE (ULONG, 4); 390ASSERT_SIZE (LONG, 4); 391 392/* Array of four uint8s (length = 32 bits) used to identify a script, language 393 * system, feature, or baseline */ 394struct Tag : ULONG 395{ 396 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */ 397 inline operator const char* (void) const { return CharP(this); } 398 inline operator char* (void) { return CharP(this); } 399}; 400ASSERT_SIZE (Tag, 4); 401DEFINE_NULL_DATA (Tag, 4, " "); 402 403/* Glyph index number, same as uint16 (length = 16 bits) */ 404typedef USHORT GlyphID; 405 406/* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */ 407typedef USHORT Offset; 408 409/* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */ 410typedef ULONG LongOffset; 411 412 413/* CheckSum */ 414struct CheckSum : ULONG 415{ 416 static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length) 417 { 418 uint32_t Sum = 0L; 419 ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::get_size (); 420 421 while (Table < EndPtr) 422 Sum += *Table++; 423 return Sum; 424 } 425}; 426ASSERT_SIZE (CheckSum, 4); 427 428 429/* 430 * Version Numbers 431 */ 432 433struct FixedVersion 434{ 435 inline operator uint32_t (void) const { return (major << 16) + minor; } 436 437 inline bool sanitize (SANITIZE_ARG_DEF) { 438 TRACE_SANITIZE (); 439 return SANITIZE_SELF (); 440 } 441 442 USHORT major; 443 USHORT minor; 444}; 445ASSERT_SIZE (FixedVersion, 4); 446 447 448 449/* 450 * Template subclasses of Offset and LongOffset that do the dereferencing. 451 * Use: (this+memberName) 452 */ 453 454template <typename OffsetType, typename Type> 455struct GenericOffsetTo : OffsetType 456{ 457 inline const Type& operator () (const void *base) const 458 { 459 unsigned int offset = *this; 460 if (HB_UNLIKELY (!offset)) return Null(Type); 461 return StructAtOffset<Type> (*CharP(base), offset); 462 } 463 464 inline bool sanitize (SANITIZE_ARG_DEF, void *base) { 465 TRACE_SANITIZE (); 466 if (!SANITIZE_SELF ()) return false; 467 unsigned int offset = *this; 468 if (HB_UNLIKELY (!offset)) return true; 469 return SANITIZE (StructAtOffset<Type> (*CharP(base), offset)) || NEUTER (*this, 0); 470 } 471 inline bool sanitize (SANITIZE_ARG_DEF, void *base, void *base2) { 472 TRACE_SANITIZE (); 473 if (!SANITIZE_SELF ()) return false; 474 unsigned int offset = *this; 475 if (HB_UNLIKELY (!offset)) return true; 476 return SANITIZE_BASE (StructAtOffset<Type> (*CharP(base), offset), base2) || NEUTER (*this, 0); 477 } 478 inline bool sanitize (SANITIZE_ARG_DEF, void *base, unsigned int user_data) { 479 TRACE_SANITIZE (); 480 if (!SANITIZE_SELF ()) return false; 481 unsigned int offset = *this; 482 if (HB_UNLIKELY (!offset)) return true; 483 return SANITIZE_BASE (StructAtOffset<Type> (*CharP(base), offset), user_data) || NEUTER (*this, 0); 484 } 485}; 486template <typename Base, typename OffsetType, typename Type> 487inline const Type& operator + (const Base &base, GenericOffsetTo<OffsetType, Type> offset) { return offset (base); } 488 489template <typename Type> 490struct OffsetTo : GenericOffsetTo<Offset, Type> {}; 491 492template <typename Type> 493struct LongOffsetTo : GenericOffsetTo<LongOffset, Type> {}; 494 495 496/* 497 * Array Types 498 */ 499 500template <typename LenType, typename Type> 501struct GenericArrayOf 502{ 503 const Type *array(void) const { return &StructAfter<Type> (len); } 504 Type *array(void) { return &StructAfter<Type> (len); } 505 506 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const 507 { 508 unsigned int count = len; 509 if (HB_UNLIKELY (start_offset > count)) 510 count = 0; 511 else 512 count -= start_offset; 513 count = MIN (count, *pcount); 514 *pcount = count; 515 return array() + start_offset; 516 } 517 518 inline const Type& operator [] (unsigned int i) const 519 { 520 if (HB_UNLIKELY (i >= len)) return Null(Type); 521 return array()[i]; 522 } 523 inline unsigned int get_size () const 524 { return len.get_size () + len * Type::get_size (); } 525 526 inline bool sanitize_shallow (SANITIZE_ARG_DEF) { 527 TRACE_SANITIZE (); 528 return SANITIZE_SELF() && SANITIZE_ARRAY (this, Type::get_size (), len); 529 } 530 531 inline bool sanitize (SANITIZE_ARG_DEF) { 532 TRACE_SANITIZE (); 533 if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; 534 /* Note: for structs that do not reference other structs, 535 * we do not need to call their sanitize() as we already did 536 * a bound check on the aggregate array size, hence the return. 537 */ 538 return true; 539 /* We do keep this code though to make sure the structs pointed 540 * to do have a simple sanitize(), ie. they do not reference 541 * other structs. */ 542 unsigned int count = len; 543 for (unsigned int i = 0; i < count; i++) 544 if (!SANITIZE (array()[i])) 545 return false; 546 return true; 547 } 548 inline bool sanitize (SANITIZE_ARG_DEF, void *base) { 549 TRACE_SANITIZE (); 550 if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; 551 unsigned int count = len; 552 for (unsigned int i = 0; i < count; i++) 553 if (!array()[i].sanitize (SANITIZE_ARG, base)) 554 return false; 555 return true; 556 } 557 inline bool sanitize (SANITIZE_ARG_DEF, void *base, void *base2) { 558 TRACE_SANITIZE (); 559 if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; 560 unsigned int count = len; 561 for (unsigned int i = 0; i < count; i++) 562 if (!array()[i].sanitize (SANITIZE_ARG, base, base2)) 563 return false; 564 return true; 565 } 566 inline bool sanitize (SANITIZE_ARG_DEF, void *base, unsigned int user_data) { 567 TRACE_SANITIZE (); 568 if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; 569 unsigned int count = len; 570 for (unsigned int i = 0; i < count; i++) 571 if (!array()[i].sanitize (SANITIZE_ARG, base, user_data)) 572 return false; 573 return true; 574 } 575 576 LenType len; 577/*Type array[VAR];*/ 578}; 579 580/* An array with a USHORT number of elements. */ 581template <typename Type> 582struct ArrayOf : GenericArrayOf<USHORT, Type> {}; 583 584/* An array with a ULONG number of elements. */ 585template <typename Type> 586struct LongArrayOf : GenericArrayOf<ULONG, Type> {}; 587 588/* Array of Offset's */ 589template <typename Type> 590struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {}; 591 592/* Array of LongOffset's */ 593template <typename Type> 594struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {}; 595 596/* LongArray of LongOffset's */ 597template <typename Type> 598struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {}; 599 600/* Array of offsets relative to the beginning of the array itself. */ 601template <typename Type> 602struct OffsetListOf : OffsetArrayOf<Type> 603{ 604 inline const Type& operator [] (unsigned int i) const 605 { 606 if (HB_UNLIKELY (i >= this->len)) return Null(Type); 607 return this+this->array()[i]; 608 } 609 610 inline bool sanitize (SANITIZE_ARG_DEF) { 611 TRACE_SANITIZE (); 612 return OffsetArrayOf<Type>::sanitize (SANITIZE_ARG, CharP(this)); 613 } 614 inline bool sanitize (SANITIZE_ARG_DEF, unsigned int user_data) { 615 TRACE_SANITIZE (); 616 return OffsetArrayOf<Type>::sanitize (SANITIZE_ARG, CharP(this), user_data); 617 } 618}; 619 620 621/* An array with a USHORT number of elements, 622 * starting at second element. */ 623template <typename Type> 624struct HeadlessArrayOf 625{ 626 const Type *array(void) const { return &StructAfter<Type> (len); } 627 Type *array(void) { return &StructAfter<Type> (len); } 628 629 inline const Type& operator [] (unsigned int i) const 630 { 631 if (HB_UNLIKELY (i >= len || !i)) return Null(Type); 632 return array()[i-1]; 633 } 634 inline unsigned int get_size () const 635 { return len.get_size () + (len ? len - 1 : 0) * Type::get_size (); } 636 637 inline bool sanitize_shallow (SANITIZE_ARG_DEF) { 638 TRACE_SANITIZE (); 639 return SANITIZE_SELF() && SANITIZE_ARRAY (this, Type::get_size (), len); 640 } 641 642 inline bool sanitize (SANITIZE_ARG_DEF) { 643 TRACE_SANITIZE (); 644 if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; 645 /* Note: for structs that do not reference other structs, 646 * we do not need to call their sanitize() as we already did 647 * a bound check on the aggregate array size, hence the return. 648 */ 649 return true; 650 /* We do keep this code though to make sure the structs pointed 651 * to do have a simple sanitize(), ie. they do not reference 652 * other structs. */ 653 unsigned int count = len ? len - 1 : 0; 654 Type *a = array(); 655 for (unsigned int i = 0; i < count; i++) 656 if (!SANITIZE (a[i])) 657 return false; 658 return true; 659 } 660 661 USHORT len; 662/*Type array[VAR];*/ 663}; 664 665 666#endif /* HB_OPEN_TYPE_PRIVATE_HH */ 667