2 * Copyright (C) 2007,2008,2009,2010 Red Hat, Inc.
4 * This is part of HarfBuzz, a text shaping library.
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.
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
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.
24 * Red Hat Author(s): Behdad Esfahbod
27 #ifndef HB_OPEN_TYPE_PRIVATE_HH
28 #define HB_OPEN_TYPE_PRIVATE_HH
30 #include "hb-private.h"
40 /* Cast to struct T, reference to reference */
41 template<typename Type, typename TObject>
42 inline const Type& CastR(const TObject &X)
43 { return reinterpret_cast<const Type&> (X); }
44 template<typename Type, typename TObject>
45 inline Type& CastR(TObject &X)
46 { return reinterpret_cast<Type&> (X); }
48 /* Cast to struct T, pointer to pointer */
49 template<typename Type, typename TObject>
50 inline const Type* CastP(const TObject *X)
51 { return reinterpret_cast<const Type*> (X); }
52 template<typename Type, typename TObject>
53 inline Type* CastP(TObject *X)
54 { return reinterpret_cast<Type*> (X); }
56 /* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory
57 * location pointed to by P plus Ofs bytes. */
58 template<typename Type>
59 inline const Type& StructAtOffset(const void *P, unsigned int offset)
60 { return * reinterpret_cast<const Type*> ((const char *) P + offset); }
61 template<typename Type>
62 inline Type& StructAtOffset(void *P, unsigned int offset)
63 { return * reinterpret_cast<Type*> ((char *) P + offset); }
65 /* StructAfter<T>(X) returns the struct T& that is placed after X.
66 * Works with X of variable size also. X must implement get_size() */
67 template<typename Type, typename TObject>
68 inline const Type& StructAfter(const TObject &X)
69 { return StructAtOffset<Type>(&X, X.get_size()); }
70 template<typename Type, typename TObject>
71 inline Type& StructAfter(TObject &X)
72 { return StructAtOffset<Type>(&X, X.get_size()); }
80 /* Check _assertion in a method environment */
81 #define _DEFINE_SIZE_ASSERTION(_assertion) \
82 inline void _size_assertion (void) const \
83 { ASSERT_STATIC (_assertion); }
84 /* Check that _code compiles in a method environment */
85 #define _DEFINE_COMPILES_ASSERTION(_code) \
86 inline void _compiles_assertion (void) const \
90 #define DEFINE_SIZE_STATIC(size) \
91 _DEFINE_SIZE_ASSERTION (sizeof (*this) == (size)); \
92 static const unsigned int static_size = (size); \
93 static const unsigned int min_size = (size)
95 /* Size signifying variable-sized array */
98 #define DEFINE_SIZE_UNION(size, _member) \
99 _DEFINE_SIZE_ASSERTION (this->u._member.static_size == (size)); \
100 static const unsigned int min_size = (size)
102 #define DEFINE_SIZE_MIN(size) \
103 _DEFINE_SIZE_ASSERTION (sizeof (*this) >= (size)); \
104 static const unsigned int min_size = (size)
106 #define DEFINE_SIZE_ARRAY(size, array) \
107 _DEFINE_SIZE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \
108 _DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \
109 static const unsigned int min_size = (size)
111 #define DEFINE_SIZE_ARRAY2(size, array1, array2) \
112 _DEFINE_SIZE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \
113 _DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].static_size) \
114 static const unsigned int min_size = (size)
122 /* Global nul-content Null pool. Enlarge as necessary. */
123 static const void *_NullPool[64 / sizeof (void *)];
125 /* Generic nul-content Null objects. */
126 template <typename Type>
127 static inline const Type& Null () {
128 ASSERT_STATIC (Type::min_size <= sizeof (_NullPool));
129 return *CastP<Type> (_NullPool);
132 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
133 #define DEFINE_NULL_DATA(Type, data) \
134 static const char _Null##Type[Type::min_size + 1] = data; /* +1 is for nul-termination in data */ \
136 inline const Type& Null<Type> () { \
137 return *CastP<Type> (_Null##Type); \
138 } /* The following line really exists such that we end in a place needing semicolon */ \
139 ASSERT_STATIC (Type::min_size + 1 <= sizeof (_Null##Type))
141 /* Accessor macro. */
142 #define Null(Type) Null<Type>()
150 template <int max_depth>
152 explicit hb_trace_t (unsigned int *pdepth, const char *what, const char *function, const void *obj) : pdepth(pdepth) {
153 if (*pdepth < max_depth)
154 fprintf (stderr, "%s(%p) %-*d-> %s\n", what, obj, *pdepth, *pdepth, function);
155 if (max_depth) ++*pdepth;
157 ~hb_trace_t (void) { if (max_depth) --*pdepth; }
160 unsigned int *pdepth;
162 template <> /* Optimize when tracing is disabled */
163 struct hb_trace_t<0> {
164 explicit hb_trace_t (unsigned int *pdepth HB_UNUSED, const char *what HB_UNUSED, const char *function HB_UNUSED, const void *obj HB_UNUSED) {}
173 #ifndef HB_DEBUG_SANITIZE
174 #define HB_DEBUG_SANITIZE HB_DEBUG+0
178 #define TRACE_SANITIZE() \
179 hb_trace_t<HB_DEBUG_SANITIZE> trace (&c->debug_depth, "SANITIZE", HB_FUNC, this); \
182 struct hb_sanitize_context_t
184 inline void init (hb_blob_t *blob)
186 this->blob = hb_blob_reference (blob);
187 this->start = hb_blob_lock (blob);
188 this->end = this->start + hb_blob_get_length (blob);
189 this->writable = hb_blob_is_writable (blob);
190 this->edit_count = 0;
191 this->debug_depth = 0;
193 if (HB_DEBUG_SANITIZE)
194 fprintf (stderr, "sanitize %p init [%p..%p] (%lu bytes)\n",
195 this->blob, this->start, this->end,
196 (unsigned long) (this->end - this->start));
199 inline void finish (void)
201 if (HB_DEBUG_SANITIZE)
202 fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n",
203 this->blob, this->start, this->end, this->edit_count);
205 hb_blob_unlock (this->blob);
206 hb_blob_destroy (this->blob);
208 this->start = this->end = NULL;
211 inline bool check_range (const void *base, unsigned int len) const
213 const char *p = (const char *) base;
214 bool ret = this->start <= p &&
216 (unsigned int) (this->end - p) >= len;
218 if (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITIZE) \
219 fprintf (stderr, "SANITIZE(%p) %-*d-> range [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \
221 this->debug_depth, this->debug_depth,
223 this->start, this->end,
224 ret ? "pass" : "FAIL");
229 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
231 const char *p = (const char *) base;
232 bool overflows = len >= ((unsigned int) -1) / record_size;
234 if (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITIZE)
235 fprintf (stderr, "SANITIZE(%p) %-*d-> array [%p..%p] (%d*%d=%ld bytes) in [%p..%p] -> %s\n", \
237 this->debug_depth, this->debug_depth,
238 p, p + (record_size * len), record_size, len, (unsigned long) record_size * len,
239 this->start, this->end,
240 !overflows ? "does not overflow" : "OVERFLOWS FAIL");
242 return likely (!overflows && this->check_range (base, record_size * len));
245 template <typename Type>
246 inline bool check_struct (const Type *obj) const
248 return likely (this->check_range (obj, obj->min_size));
251 inline bool can_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED)
253 const char *p = (const char *) base;
256 if (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITIZE)
257 fprintf (stderr, "SANITIZE(%p) %-*d-> edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \
259 this->debug_depth, this->debug_depth,
262 this->start, this->end,
263 this->writable ? "granted" : "REJECTED");
265 return this->writable;
268 unsigned int debug_depth;
269 const char *start, *end;
271 unsigned int edit_count;
277 /* Template to sanitize an object. */
278 template <typename Type>
281 static hb_blob_t *sanitize (hb_blob_t *blob) {
282 hb_sanitize_context_t c[1] = {{0}};
285 /* TODO is_sane() stuff */
288 return hb_blob_create_empty ();
291 if (HB_DEBUG_SANITIZE)
292 fprintf (stderr, "Sanitizer %p start %s\n", blob, HB_FUNC);
296 if (unlikely (!c->start)) {
301 Type *t = CastP<Type> (const_cast<char *> (c->start));
303 sane = t->sanitize (c);
306 if (HB_DEBUG_SANITIZE)
307 fprintf (stderr, "Sanitizer %p passed first round with %d edits; doing a second round %s\n",
308 blob, c->edit_count, HB_FUNC);
310 /* sanitize again to ensure no toe-stepping */
312 sane = t->sanitize (c);
314 if (HB_DEBUG_SANITIZE)
315 fprintf (stderr, "Sanitizer %p requested %d edits in second round; FAILLING %s\n",
316 blob, c->edit_count, HB_FUNC);
322 unsigned int edit_count = c->edit_count;
324 if (edit_count && !hb_blob_is_writable (blob) && hb_blob_try_writable (blob)) {
325 /* ok, we made it writable by relocating. try again */
326 if (HB_DEBUG_SANITIZE)
327 fprintf (stderr, "Sanitizer %p retry %s\n", blob, HB_FUNC);
332 if (HB_DEBUG_SANITIZE)
333 fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "FAILED", HB_FUNC);
337 hb_blob_destroy (blob);
338 return hb_blob_create_empty ();
342 static const Type* lock_instance (hb_blob_t *blob) {
343 const char *base = hb_blob_lock (blob);
344 return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
353 * The OpenType Font File: Data Types
357 /* "The following data types are used in the OpenType font file.
358 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
365 template <typename Type, int Bytes> class BEInt;
367 /* LONGTERMTODO: On machines allowing unaligned access, we can make the
368 * following tighter by using byteswap instructions on ints directly. */
369 template <typename Type>
373 inline class BEInt<Type,2>& operator = (Type i) { hb_be_uint16_put (v,i); return *this; }
374 inline operator Type () const { return hb_be_uint16_get (v); }
375 inline bool operator == (const BEInt<Type, 2>& o) const { return hb_be_uint16_cmp (v, o.v); }
376 inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); }
377 private: uint8_t v[2];
379 template <typename Type>
383 inline class BEInt<Type,4>& operator = (Type i) { hb_be_uint32_put (v,i); return *this; }
384 inline operator Type () const { return hb_be_uint32_get (v); }
385 inline bool operator == (const BEInt<Type, 4>& o) const { return hb_be_uint32_cmp (v, o.v); }
386 inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); }
387 private: uint8_t v[4];
390 /* Integer types in big-endian order and no alignment requirement */
391 template <typename Type>
394 inline void set (Type i) { v = i; }
395 inline operator Type(void) const { return v; }
396 inline bool operator == (const IntType<Type> &o) const { return v == o.v; }
397 inline bool operator != (const IntType<Type> &o) const { return v != o.v; }
398 inline int cmp (Type b) const { Type a = v; return b < a ? -1 : b == a ? 0 : +1; }
399 inline bool sanitize (hb_sanitize_context_t *c) {
401 return likely (c->check_struct (this));
404 BEInt<Type, sizeof (Type)> v;
406 DEFINE_SIZE_STATIC (sizeof (Type));
409 typedef IntType<uint16_t> USHORT; /* 16-bit unsigned integer. */
410 typedef IntType<int16_t> SHORT; /* 16-bit signed integer. */
411 typedef IntType<uint32_t> ULONG; /* 32-bit unsigned integer. */
412 typedef IntType<int32_t> LONG; /* 32-bit signed integer. */
414 /* Date represented in number of seconds since 12:00 midnight, January 1,
415 * 1904. The value is represented as a signed 64-bit integer. */
418 inline bool sanitize (hb_sanitize_context_t *c) {
420 return likely (c->check_struct (this));
426 DEFINE_SIZE_STATIC (8);
429 /* Array of four uint8s (length = 32 bits) used to identify a script, language
430 * system, feature, or baseline */
433 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
434 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
435 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
437 DEFINE_SIZE_STATIC (4);
439 DEFINE_NULL_DATA (Tag, " ");
441 /* Glyph index number, same as uint16 (length = 16 bits) */
442 typedef USHORT GlyphID;
444 /* Script/language-system/feature index */
445 struct Index : USHORT {
446 static const unsigned int NOT_FOUND_INDEX = 0xFFFF;
448 DEFINE_NULL_DATA (Index, "\xff\xff");
450 /* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
451 typedef USHORT Offset;
453 /* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */
454 typedef ULONG LongOffset;
458 struct CheckSum : ULONG
460 static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length)
463 ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size;
465 while (Table < EndPtr)
470 DEFINE_SIZE_STATIC (4);
480 inline operator uint32_t (void) const { return (major << 16) + minor; }
482 inline bool sanitize (hb_sanitize_context_t *c) {
484 return c->check_struct (this);
490 DEFINE_SIZE_STATIC (4);
496 * Template subclasses of Offset and LongOffset that do the dereferencing.
500 template <typename OffsetType, typename Type>
501 struct GenericOffsetTo : OffsetType
503 inline const Type& operator () (const void *base) const
505 unsigned int offset = *this;
506 if (unlikely (!offset)) return Null(Type);
507 return StructAtOffset<Type> (base, offset);
510 inline bool sanitize (hb_sanitize_context_t *c, void *base) {
512 if (unlikely (!c->check_struct (this))) return false;
513 unsigned int offset = *this;
514 if (unlikely (!offset)) return true;
515 Type &obj = StructAtOffset<Type> (base, offset);
516 return likely (obj.sanitize (c)) || neuter (c);
518 template <typename T>
519 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
521 if (unlikely (!c->check_struct (this))) return false;
522 unsigned int offset = *this;
523 if (unlikely (!offset)) return true;
524 Type &obj = StructAtOffset<Type> (base, offset);
525 return likely (obj.sanitize (c, user_data)) || neuter (c);
529 /* Set the offset to Null */
530 inline bool neuter (hb_sanitize_context_t *c) {
531 if (c->can_edit (this, this->static_size)) {
532 this->set (0); /* 0 is Null offset */
538 template <typename Base, typename OffsetType, typename Type>
539 inline const Type& operator + (const Base &base, GenericOffsetTo<OffsetType, Type> offset) { return offset (base); }
541 template <typename Type>
542 struct OffsetTo : GenericOffsetTo<Offset, Type> {};
544 template <typename Type>
545 struct LongOffsetTo : GenericOffsetTo<LongOffset, Type> {};
552 template <typename LenType, typename Type>
553 struct GenericArrayOf
555 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
557 unsigned int count = len;
558 if (unlikely (start_offset > count))
561 count -= start_offset;
562 count = MIN (count, *pcount);
564 return array + start_offset;
567 inline const Type& operator [] (unsigned int i) const
569 if (unlikely (i >= len)) return Null(Type);
572 inline unsigned int get_size () const
573 { return len.static_size + len * Type::static_size; }
575 inline bool sanitize (hb_sanitize_context_t *c) {
577 if (unlikely (!sanitize_shallow (c))) return false;
578 /* Note: for structs that do not reference other structs,
579 * we do not need to call their sanitize() as we already did
580 * a bound check on the aggregate array size, hence the return.
583 /* We do keep this code though to make sure the structs pointed
584 * to do have a simple sanitize(), ie. they do not reference
586 unsigned int count = len;
587 for (unsigned int i = 0; i < count; i++)
588 if (array[i].sanitize (c))
592 inline bool sanitize (hb_sanitize_context_t *c, void *base) {
594 if (unlikely (!sanitize_shallow (c))) return false;
595 unsigned int count = len;
596 for (unsigned int i = 0; i < count; i++)
597 if (unlikely (!array[i].sanitize (c, base)))
601 template <typename T>
602 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
604 if (unlikely (!sanitize_shallow (c))) return false;
605 unsigned int count = len;
606 for (unsigned int i = 0; i < count; i++)
607 if (unlikely (!array[i].sanitize (c, base, user_data)))
613 inline bool sanitize_shallow (hb_sanitize_context_t *c) {
615 return c->check_struct (this)
616 && c->check_array (this, Type::static_size, len);
623 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
626 /* An array with a USHORT number of elements. */
627 template <typename Type>
628 struct ArrayOf : GenericArrayOf<USHORT, Type> {};
630 /* An array with a ULONG number of elements. */
631 template <typename Type>
632 struct LongArrayOf : GenericArrayOf<ULONG, Type> {};
634 /* Array of Offset's */
635 template <typename Type>
636 struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
638 /* Array of LongOffset's */
639 template <typename Type>
640 struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {};
642 /* LongArray of LongOffset's */
643 template <typename Type>
644 struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {};
646 /* Array of offsets relative to the beginning of the array itself. */
647 template <typename Type>
648 struct OffsetListOf : OffsetArrayOf<Type>
650 inline const Type& operator [] (unsigned int i) const
652 if (unlikely (i >= this->len)) return Null(Type);
653 return this+this->array[i];
656 inline bool sanitize (hb_sanitize_context_t *c) {
658 return OffsetArrayOf<Type>::sanitize (c, this);
660 template <typename T>
661 inline bool sanitize (hb_sanitize_context_t *c, T user_data) {
663 return OffsetArrayOf<Type>::sanitize (c, this, user_data);
668 /* An array with a USHORT number of elements,
669 * starting at second element. */
670 template <typename Type>
671 struct HeadlessArrayOf
673 inline const Type& operator [] (unsigned int i) const
675 if (unlikely (i >= len || !i)) return Null(Type);
678 inline unsigned int get_size () const
679 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
681 inline bool sanitize_shallow (hb_sanitize_context_t *c) {
682 return c->check_struct (this)
683 && c->check_array (this, Type::static_size, len);
686 inline bool sanitize (hb_sanitize_context_t *c) {
688 if (unlikely (!sanitize_shallow (c))) return false;
689 /* Note: for structs that do not reference other structs,
690 * we do not need to call their sanitize() as we already did
691 * a bound check on the aggregate array size, hence the return.
694 /* We do keep this code though to make sure the structs pointed
695 * to do have a simple sanitize(), ie. they do not reference
697 unsigned int count = len ? len - 1 : 0;
699 for (unsigned int i = 0; i < count; i++)
700 if (unlikely (!a[i].sanitize (c)))
708 DEFINE_SIZE_ARRAY (sizeof (USHORT), array);
712 /* An array with sorted elements. Supports binary searching. */
713 template <typename Type>
714 struct SortedArrayOf : ArrayOf<Type> {
716 template <typename SearchType>
717 inline int search (const SearchType &x) const {
719 public: static int cmp (const void *p1, const void *p2) {
720 const SearchType *a = (const SearchType *) p1;
721 const Type *b = (const Type *) p2;
725 const Type *p = (const Type *) bsearch (&x, this->array, this->len, sizeof (this->array[0]), Cmp::cmp);
726 return p ? p - this->array : -1;
731 #endif /* HB_OPEN_TYPE_PRIVATE_HH */