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_TYPES_PRIVATE_HH
28 #define HB_OPEN_TYPES_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] (%u bytes)\n",
195 this->blob, this->start, this->end, this->end - this->start);
198 inline void finish (void)
200 if (HB_DEBUG_SANITIZE)
201 fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n",
202 this->blob, this->start, this->end, this->edit_count);
204 hb_blob_unlock (this->blob);
205 hb_blob_destroy (this->blob);
207 this->start = this->end = NULL;
210 inline bool check_range (const void *base, unsigned int len) const
212 const char *p = (const char *) base;
213 bool ret = this->start <= p &&
215 (unsigned int) (this->end - p) >= len;
217 if (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITIZE) \
218 fprintf (stderr, "SANITIZE(%p) %-*d-> range [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \
220 this->debug_depth, this->debug_depth,
222 this->start, this->end,
223 ret ? "pass" : "FAIL");
228 inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
230 const char *p = (const char *) base;
231 bool overflows = len >= ((unsigned int) -1) / record_size;
233 if (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITIZE)
234 fprintf (stderr, "SANITIZE(%p) %-*d-> array [%p..%p] (%d*%d=%ld bytes) in [%p..%p] -> %s\n", \
236 this->debug_depth, this->debug_depth,
237 p, p + (record_size * len), record_size, len, (unsigned long) record_size * len,
238 this->start, this->end,
239 !overflows ? "does not overflow" : "OVERFLOWS FAIL");
241 return likely (!overflows && this->check_range (base, record_size * len));
244 template <typename Type>
245 inline bool check_struct (const Type *obj) const
247 return likely (this->check_range (obj, obj->min_size));
250 inline bool can_edit (const void *base HB_UNUSED, unsigned int len HB_UNUSED)
252 const char *p = (const char *) base;
255 if (HB_DEBUG_SANITIZE && (int) this->debug_depth < (int) HB_DEBUG_SANITIZE)
256 fprintf (stderr, "SANITIZE(%p) %-*d-> edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \
258 this->debug_depth, this->debug_depth,
261 this->start, this->end,
262 this->writable ? "granted" : "REJECTED");
264 return this->writable;
267 unsigned int debug_depth;
268 const char *start, *end;
270 unsigned int edit_count;
276 /* Template to sanitize an object. */
277 template <typename Type>
280 static hb_blob_t *sanitize (hb_blob_t *blob) {
281 hb_sanitize_context_t c[1] = {{0}};
284 /* TODO is_sane() stuff */
287 if (HB_DEBUG_SANITIZE)
288 fprintf (stderr, "Sanitizer %p start %s\n", blob, HB_FUNC);
292 if (unlikely (!c->start)) {
297 Type *t = CastP<Type> (const_cast<char *> (c->start));
299 sane = t->sanitize (c);
302 if (HB_DEBUG_SANITIZE)
303 fprintf (stderr, "Sanitizer %p passed first round with %d edits; doing a second round %s\n",
304 blob, c->edit_count, HB_FUNC);
306 /* sanitize again to ensure no toe-stepping */
308 sane = t->sanitize (c);
310 if (HB_DEBUG_SANITIZE)
311 fprintf (stderr, "Sanitizer %p requested %d edits in second round; FAILLING %s\n",
312 blob, c->edit_count, HB_FUNC);
318 unsigned int edit_count = c->edit_count;
320 if (edit_count && !hb_blob_is_writable (blob) && hb_blob_try_writable (blob)) {
321 /* ok, we made it writable by relocating. try again */
322 if (HB_DEBUG_SANITIZE)
323 fprintf (stderr, "Sanitizer %p retry %s\n", blob, HB_FUNC);
328 if (HB_DEBUG_SANITIZE)
329 fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "FAILED", HB_FUNC);
333 hb_blob_destroy (blob);
334 return hb_blob_create_empty ();
338 static const Type* lock_instance (hb_blob_t *blob) {
339 const char *base = hb_blob_lock (blob);
340 return unlikely (!base) ? &Null(Type) : CastP<Type> (base);
349 * The OpenType Font File: Data Types
353 /* "The following data types are used in the OpenType font file.
354 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
361 template <typename Type, int Bytes> class BEInt;
363 /* LONGTERMTODO: On machines allowing unaligned access, we can make the
364 * following tighter by using byteswap instructions on ints directly. */
365 template <typename Type>
369 inline class BEInt<Type,2>& operator = (Type i) { hb_be_uint16_put (v,i); return *this; }
370 inline operator Type () const { return hb_be_uint16_get (v); }
371 inline bool operator == (const BEInt<Type, 2>& o) const { return hb_be_uint16_cmp (v, o.v); }
372 inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); }
373 private: uint8_t v[2];
375 template <typename Type>
379 inline class BEInt<Type,4>& operator = (Type i) { hb_be_uint32_put (v,i); return *this; }
380 inline operator Type () const { return hb_be_uint32_get (v); }
381 inline bool operator == (const BEInt<Type, 4>& o) const { return hb_be_uint32_cmp (v, o.v); }
382 inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); }
383 private: uint8_t v[4];
386 /* Integer types in big-endian order and no alignment requirement */
387 template <typename Type>
390 inline void set (Type i) { v = i; }
391 inline operator Type(void) const { return v; }
392 inline bool operator == (const IntType<Type> &o) const { return v == o.v; }
393 inline bool operator != (const IntType<Type> &o) const { return v != o.v; }
394 inline bool sanitize (hb_sanitize_context_t *c) {
396 return likely (c->check_struct (this));
399 BEInt<Type, sizeof (Type)> v;
401 DEFINE_SIZE_STATIC (sizeof (Type));
404 typedef IntType<uint16_t> USHORT; /* 16-bit unsigned integer. */
405 typedef IntType<int16_t> SHORT; /* 16-bit signed integer. */
406 typedef IntType<uint32_t> ULONG; /* 32-bit unsigned integer. */
407 typedef IntType<int32_t> LONG; /* 32-bit signed integer. */
409 /* Date represented in number of seconds since 12:00 midnight, January 1,
410 * 1904. The value is represented as a signed 64-bit integer. */
413 inline bool sanitize (hb_sanitize_context_t *c) {
415 return likely (c->check_struct (this));
421 DEFINE_SIZE_STATIC (8);
424 /* Array of four uint8s (length = 32 bits) used to identify a script, language
425 * system, feature, or baseline */
428 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
429 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
430 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
432 DEFINE_SIZE_STATIC (4);
434 DEFINE_NULL_DATA (Tag, " ");
436 /* Glyph index number, same as uint16 (length = 16 bits) */
437 typedef USHORT GlyphID;
439 /* Script/language-system/feature index */
440 struct Index : USHORT {
441 static const unsigned int NOT_FOUND_INDEX = 0xFFFF;
443 DEFINE_NULL_DATA (Index, "\xff\xff");
445 /* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
446 typedef USHORT Offset;
448 /* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */
449 typedef ULONG LongOffset;
453 struct CheckSum : ULONG
455 static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length)
458 ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::static_size;
460 while (Table < EndPtr)
465 DEFINE_SIZE_STATIC (4);
475 inline operator uint32_t (void) const { return (major << 16) + minor; }
477 inline bool sanitize (hb_sanitize_context_t *c) {
479 return c->check_struct (this);
485 DEFINE_SIZE_STATIC (4);
491 * Template subclasses of Offset and LongOffset that do the dereferencing.
495 template <typename OffsetType, typename Type>
496 struct GenericOffsetTo : OffsetType
498 inline const Type& operator () (const void *base) const
500 unsigned int offset = *this;
501 if (unlikely (!offset)) return Null(Type);
502 return StructAtOffset<Type> (base, offset);
505 inline bool sanitize (hb_sanitize_context_t *c, void *base) {
507 if (unlikely (!c->check_struct (this))) return false;
508 unsigned int offset = *this;
509 if (unlikely (!offset)) return true;
510 Type &obj = StructAtOffset<Type> (base, offset);
511 return likely (obj.sanitize (c)) || neuter (c);
513 template <typename T>
514 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
516 if (unlikely (!c->check_struct (this))) return false;
517 unsigned int offset = *this;
518 if (unlikely (!offset)) return true;
519 Type &obj = StructAtOffset<Type> (base, offset);
520 return likely (obj.sanitize (c, user_data)) || neuter (c);
524 /* Set the offset to Null */
525 inline bool neuter (hb_sanitize_context_t *c) {
526 if (c->can_edit (this, this->static_size)) {
527 this->set (0); /* 0 is Null offset */
533 template <typename Base, typename OffsetType, typename Type>
534 inline const Type& operator + (const Base &base, GenericOffsetTo<OffsetType, Type> offset) { return offset (base); }
536 template <typename Type>
537 struct OffsetTo : GenericOffsetTo<Offset, Type> {};
539 template <typename Type>
540 struct LongOffsetTo : GenericOffsetTo<LongOffset, Type> {};
547 template <typename LenType, typename Type>
548 struct GenericArrayOf
550 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
552 unsigned int count = len;
553 if (unlikely (start_offset > count))
556 count -= start_offset;
557 count = MIN (count, *pcount);
559 return array + start_offset;
562 inline const Type& operator [] (unsigned int i) const
564 if (unlikely (i >= len)) return Null(Type);
567 inline unsigned int get_size () const
568 { return len.static_size + len * Type::static_size; }
570 inline bool sanitize (hb_sanitize_context_t *c) {
572 if (unlikely (!sanitize_shallow (c))) return false;
573 /* Note: for structs that do not reference other structs,
574 * we do not need to call their sanitize() as we already did
575 * a bound check on the aggregate array size, hence the return.
578 /* We do keep this code though to make sure the structs pointed
579 * to do have a simple sanitize(), ie. they do not reference
581 unsigned int count = len;
582 for (unsigned int i = 0; i < count; i++)
583 if (array[i].sanitize (c))
587 inline bool sanitize (hb_sanitize_context_t *c, void *base) {
589 if (unlikely (!sanitize_shallow (c))) return false;
590 unsigned int count = len;
591 for (unsigned int i = 0; i < count; i++)
592 if (unlikely (!array[i].sanitize (c, base)))
596 template <typename T>
597 inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
599 if (unlikely (!sanitize_shallow (c))) return false;
600 unsigned int count = len;
601 for (unsigned int i = 0; i < count; i++)
602 if (unlikely (!array[i].sanitize (c, base, user_data)))
608 inline bool sanitize_shallow (hb_sanitize_context_t *c) {
610 return c->check_struct (this)
611 && c->check_array (this, Type::static_size, len);
618 DEFINE_SIZE_ARRAY (sizeof (LenType), array);
621 /* An array with a USHORT number of elements. */
622 template <typename Type>
623 struct ArrayOf : GenericArrayOf<USHORT, Type> {};
625 /* An array with a ULONG number of elements. */
626 template <typename Type>
627 struct LongArrayOf : GenericArrayOf<ULONG, Type> {};
629 /* Array of Offset's */
630 template <typename Type>
631 struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
633 /* Array of LongOffset's */
634 template <typename Type>
635 struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {};
637 /* LongArray of LongOffset's */
638 template <typename Type>
639 struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {};
641 /* Array of offsets relative to the beginning of the array itself. */
642 template <typename Type>
643 struct OffsetListOf : OffsetArrayOf<Type>
645 inline const Type& operator [] (unsigned int i) const
647 if (unlikely (i >= this->len)) return Null(Type);
648 return this+this->array[i];
651 inline bool sanitize (hb_sanitize_context_t *c) {
653 return OffsetArrayOf<Type>::sanitize (c, this);
655 template <typename T>
656 inline bool sanitize (hb_sanitize_context_t *c, T user_data) {
658 return OffsetArrayOf<Type>::sanitize (c, this, user_data);
663 /* An array with a USHORT number of elements,
664 * starting at second element. */
665 template <typename Type>
666 struct HeadlessArrayOf
668 inline const Type& operator [] (unsigned int i) const
670 if (unlikely (i >= len || !i)) return Null(Type);
673 inline unsigned int get_size () const
674 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
676 inline bool sanitize_shallow (hb_sanitize_context_t *c) {
677 return c->check_struct (this)
678 && c->check_array (this, Type::static_size, len);
681 inline bool sanitize (hb_sanitize_context_t *c) {
683 if (unlikely (!sanitize_shallow (c))) return false;
684 /* Note: for structs that do not reference other structs,
685 * we do not need to call their sanitize() as we already did
686 * a bound check on the aggregate array size, hence the return.
689 /* We do keep this code though to make sure the structs pointed
690 * to do have a simple sanitize(), ie. they do not reference
692 unsigned int count = len ? len - 1 : 0;
694 for (unsigned int i = 0; i < count; i++)
695 if (unlikely (!a[i].sanitize (c)))
703 DEFINE_SIZE_ARRAY (sizeof (USHORT), array);
707 #endif /* HB_OPEN_TYPE_PRIVATE_HH */