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/*
* Copyright (C) 2007,2008,2009,2010 Red Hat, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
*/
#ifndef HB_OPEN_TYPES_PRIVATE_HH
#define HB_OPEN_TYPES_PRIVATE_HH
#include "hb-private.h"
#include "hb-blob.h"
/* Table/script/language-system/feature/... not found */
#define NO_INDEX ((unsigned int) 0xFFFF)
/*
* Casts
*/
/* Cast to "const char *" and "char *" */
template <typename Type> inline const char * CharP (const Type* X) { return reinterpret_cast<const char *>(X); }
template <typename Type> inline char * CharP (Type* X) { return reinterpret_cast<char *>(X); }
#define CONST_CAST(T,X,Ofs) (*(reinterpret_cast<const T *>(CharP(&(X)) + Ofs)))
#define DECONST_CAST(T,X,Ofs) (*(reinterpret_cast<T *>((char *)CharP(&(X)) + Ofs)))
#define CAST(T,X,Ofs) (*(reinterpret_cast<T *>(CharP(&(X)) + Ofs)))
/* StructAfter<T>(X) returns the struct T& that is placed after X.
* Works with X of variable size also. X must implement get_size() */
template<typename Type, typename TObject>
inline const Type& StructAfter(const TObject &X)
{
return * reinterpret_cast<const Type*> (CharP (&X) + X.get_size());
}
template<typename Type, typename TObject>
inline Type& StructAfter(TObject &X)
{
return * reinterpret_cast<Type*> (CharP (&X) + X.get_size());
}
/*
* Class features
*/
/* Null objects */
/* Global nul-content Null pool. Enlarge as necessary. */
static const void *_NullPool[32 / sizeof (void *)];
/* Generic template for nul-content sizeof-sized Null objects. */
template <typename Type>
static inline const Type& Null () {
ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool));
return CONST_CAST (Type, *_NullPool, 0);
}
/* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
#define DEFINE_NULL_DATA(Type, size, data) \
static const char _Null##Type[size + 1] = data; \
template <> \
inline const Type& Null<Type> () { \
return CONST_CAST (Type, *_Null##Type, 0); \
}
/* Accessor macro. */
#define Null(Type) Null<Type>()
/* get_for_data() is a static class method returning a reference to an
* instance of Type located at the input data location. It's just a
* fancy, NULL-safe, cast! */
#define STATIC_DEFINE_GET_FOR_DATA(Type) \
static inline const Type& get_for_data (const char *data) \
{ \
if (HB_UNLIKELY (data == NULL)) return Null(Type); \
return CONST_CAST (Type, *data, 0); \
}
/* Like get_for_data(), but checks major version first. */
#define STATIC_DEFINE_GET_FOR_DATA_CHECK_MAJOR_VERSION(Type, MajorMin, MajorMax) \
static inline const Type& get_for_data (const char *data) \
{ \
if (HB_UNLIKELY (data == NULL)) return Null(Type); \
const Type& t = CONST_CAST (Type, *data, 0); \
if (HB_UNLIKELY (t.version.major < MajorMin || t.version.major > MajorMax)) return Null(Type); \
return t; \
}
/*
* Sanitize
*/
#ifndef HB_DEBUG_SANITIZE
#define HB_DEBUG_SANITIZE HB_DEBUG
#endif
#if HB_DEBUG_SANITIZE
#include <stdio.h>
#define TRACE_SANITIZE_ARG_DEF , unsigned int sanitize_depth HB_GNUC_UNUSED
#define TRACE_SANITIZE_ARG , sanitize_depth + 1
#define TRACE_SANITIZE_ARG_INIT , 1
#define TRACE_SANITIZE() \
HB_STMT_START { \
if (sanitize_depth < HB_DEBUG_SANITIZE) \
fprintf (stderr, "SANITIZE(%p) %-*d-> %s\n", \
(CharP (this) == CharP (&NullPool)) ? 0 : this, \
sanitize_depth, sanitize_depth, \
__PRETTY_FUNCTION__); \
} HB_STMT_END
#else
#define TRACE_SANITIZE_ARG_DEF
#define TRACE_SANITIZE_ARG
#define TRACE_SANITIZE_ARG_INIT
#define TRACE_SANITIZE() HB_STMT_START {} HB_STMT_END
#endif
#define SANITIZE_ARG_DEF \
hb_sanitize_context_t *context TRACE_SANITIZE_ARG_DEF
#define SANITIZE_ARG \
context TRACE_SANITIZE_ARG
#define SANITIZE_ARG_INIT \
&context TRACE_SANITIZE_ARG_INIT
typedef struct _hb_sanitize_context_t hb_sanitize_context_t;
struct _hb_sanitize_context_t
{
const char *start, *end;
int edit_count;
hb_blob_t *blob;
};
static HB_GNUC_UNUSED void
_hb_sanitize_init (hb_sanitize_context_t *context,
hb_blob_t *blob)
{
context->blob = blob;
context->start = hb_blob_lock (blob);
context->end = context->start + hb_blob_get_length (blob);
context->edit_count = 0;
#if HB_DEBUG_SANITIZE
fprintf (stderr, "sanitize %p init [%p..%p] (%u bytes)\n",
context->blob, context->start, context->end, context->end - context->start);
#endif
}
static HB_GNUC_UNUSED void
_hb_sanitize_fini (hb_sanitize_context_t *context,
bool unlock)
{
#if HB_DEBUG_SANITIZE
fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n",
context->blob, context->start, context->end, context->edit_count);
#endif
if (unlock)
hb_blob_unlock (context->blob);
}
static HB_GNUC_UNUSED inline bool
_hb_sanitize_check (SANITIZE_ARG_DEF,
const char *base,
unsigned int len)
{
bool ret = context->start <= base &&
base <= context->end &&
(unsigned int) (context->end - base) >= len;
#if HB_DEBUG_SANITIZE
if (sanitize_depth < HB_DEBUG_SANITIZE) \
fprintf (stderr, "SANITIZE(%p) %-*d-> check [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \
base,
sanitize_depth, sanitize_depth,
base, base+len, len,
context->start, context->end,
ret ? "pass" : "FAIL");
#endif
return ret;
}
static HB_GNUC_UNUSED inline bool
_hb_sanitize_array (SANITIZE_ARG_DEF,
const char *base,
unsigned int record_size,
unsigned int len)
{
bool overflows = len >= ((unsigned int) -1) / record_size;
#if HB_DEBUG_SANITIZE
if (sanitize_depth < HB_DEBUG_SANITIZE) \
fprintf (stderr, "SANITIZE(%p) %-*d-> array [%p..%p] (%d*%d=%ld bytes) in [%p..%p] -> %s\n", \
base,
sanitize_depth, sanitize_depth,
base, base + (record_size * len), record_size, len, (unsigned long) record_size * len,
context->start, context->end,
!overflows ? "does not overflow" : "OVERFLOWS FAIL");
#endif
return HB_LIKELY (!overflows) && _hb_sanitize_check (SANITIZE_ARG, base, record_size * len);
}
static HB_GNUC_UNUSED inline bool
_hb_sanitize_edit (SANITIZE_ARG_DEF,
const char *base HB_GNUC_UNUSED,
unsigned int len HB_GNUC_UNUSED)
{
bool perm = hb_blob_try_writable_inplace (context->blob);
context->edit_count++;
#if HB_DEBUG_SANITIZE
fprintf (stderr, "SANITIZE(%p) %-*d-> edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \
base,
sanitize_depth, sanitize_depth,
context->edit_count,
base, base+len, len,
context->start, context->end,
perm ? "granted" : "REJECTED");
#endif
return perm;
}
#define SANITIZE(X) HB_LIKELY ((X).sanitize (SANITIZE_ARG))
#define SANITIZE2(X,Y) (SANITIZE (X) && SANITIZE (Y))
#define SANITIZE_THIS(X) HB_LIKELY ((X).sanitize (SANITIZE_ARG, CharP(this)))
#define SANITIZE_THIS2(X,Y) (SANITIZE_THIS (X) && SANITIZE_THIS (Y))
#define SANITIZE_THIS3(X,Y,Z) (SANITIZE_THIS (X) && SANITIZE_THIS (Y) && SANITIZE_THIS(Z))
#define SANITIZE_BASE(X,B) HB_LIKELY ((X).sanitize (SANITIZE_ARG, B))
#define SANITIZE_BASE2(X,Y,B) (SANITIZE_BASE (X,B) && SANITIZE_BASE (Y,B))
#define SANITIZE_SELF() SANITIZE_OBJ (*this)
#define SANITIZE_OBJ(X) SANITIZE_MEM(&(X), sizeof (X))
#define SANITIZE_GET_SIZE() SANITIZE_SELF() && SANITIZE_MEM (this, this->get_size ())
#define SANITIZE_MEM(B,L) HB_LIKELY (_hb_sanitize_check (SANITIZE_ARG, CharP(B), (L)))
#define SANITIZE_ARRAY(A,S,L) HB_LIKELY (_hb_sanitize_array (SANITIZE_ARG, CharP(A), S, L))
#define NEUTER(Var, Val) \
(SANITIZE_OBJ (Var) && \
_hb_sanitize_edit (SANITIZE_ARG, CharP(&(Var)), sizeof (Var)) && \
((Var).set (Val), true))
/* Template to sanitize an object. */
template <typename Type>
struct Sanitizer
{
static hb_blob_t *sanitize (hb_blob_t *blob) {
hb_sanitize_context_t context;
bool sane;
/* TODO is_sane() stuff */
retry:
#if HB_DEBUG_SANITIZE
fprintf (stderr, "Sanitizer %p start %s\n", blob, __PRETTY_FUNCTION__);
#endif
_hb_sanitize_init (&context, blob);
Type *t = &CAST (Type, * (char *) CharP(context.start), 0);
sane = t->sanitize (SANITIZE_ARG_INIT);
if (sane) {
if (context.edit_count) {
#if HB_DEBUG_SANITIZE
fprintf (stderr, "Sanitizer %p passed first round with %d edits; going a second round %s\n",
blob, context.edit_count, __PRETTY_FUNCTION__);
#endif
/* sanitize again to ensure no toe-stepping */
context.edit_count = 0;
sane = t->sanitize (SANITIZE_ARG_INIT);
if (context.edit_count) {
#if HB_DEBUG_SANITIZE
fprintf (stderr, "Sanitizer %p requested %d edits in second round; FAILLING %s\n",
blob, context.edit_count, __PRETTY_FUNCTION__);
#endif
sane = false;
}
}
_hb_sanitize_fini (&context, true);
} else {
unsigned int edit_count = context.edit_count;
_hb_sanitize_fini (&context, true);
if (edit_count && !hb_blob_is_writable (blob) && hb_blob_try_writable (blob)) {
/* ok, we made it writable by relocating. try again */
#if HB_DEBUG_SANITIZE
fprintf (stderr, "Sanitizer %p retry %s\n", blob, __PRETTY_FUNCTION__);
#endif
goto retry;
}
}
#if HB_DEBUG_SANITIZE
fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "FAILED", __PRETTY_FUNCTION__);
#endif
if (sane)
return blob;
else {
hb_blob_destroy (blob);
return hb_blob_create_empty ();
}
}
static const Type& lock_instance (hb_blob_t *blob) {
return Type::get_for_data (hb_blob_lock (blob));
}
};
/*
*
* The OpenType Font File: Data Types
*/
/* "The following data types are used in the OpenType font file.
* All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
/*
* Int types
*/
template <typename Type, int Bytes> class BEInt;
template <typename Type>
class BEInt<Type, 2>
{
public:
inline class BEInt<Type,2>& operator = (Type i) { hb_be_uint16_put (v,i); return *this; }
inline operator Type () const { return hb_be_uint16_get (v); }
inline bool operator == (const BEInt<Type, 2>& o) const { return hb_be_uint16_cmp (v, o.v); }
inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); }
private: uint8_t v[2];
};
template <typename Type>
class BEInt<Type, 4>
{
public:
inline class BEInt<Type,4>& operator = (Type i) { hb_be_uint32_put (v,i); return *this; }
inline operator Type () const { return hb_be_uint32_get (v); }
inline bool operator == (const BEInt<Type, 4>& o) const { return hb_be_uint32_cmp (v, o.v); }
inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); }
private: uint8_t v[4];
};
/* Integer types in big-endian order and no alignment requirement */
template <typename Type>
struct IntType
{
static inline unsigned int get_size () { return sizeof (Type); }
inline void set (Type i) { v = i; }
inline operator Type(void) const { return v; }
inline bool operator == (const IntType<Type> &o) const { return v == o.v; }
inline bool operator != (const IntType<Type> &o) const { return v != o.v; }
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
return SANITIZE_SELF ();
}
private: BEInt<Type, sizeof (Type)> v;
};
typedef IntType<uint16_t> USHORT; /* 16-bit unsigned integer. */
typedef IntType<int16_t> SHORT; /* 16-bit signed integer. */
typedef IntType<uint32_t> ULONG; /* 32-bit unsigned integer. */
typedef IntType<int32_t> LONG; /* 32-bit signed integer. */
ASSERT_SIZE (USHORT, 2);
ASSERT_SIZE (SHORT, 2);
ASSERT_SIZE (ULONG, 4);
ASSERT_SIZE (LONG, 4);
/* Array of four uint8s (length = 32 bits) used to identify a script, language
* system, feature, or baseline */
struct Tag : ULONG
{
/* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
inline operator const char* (void) const { return CharP(this); }
inline operator char* (void) { return CharP(this); }
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
/* Note: Only accept ASCII-visible tags (mind DEL)
* This is one of the few places (only place?) that we check
* for data integrity, as opposed to just boundary checks.
*/
return SANITIZE_SELF () && (((uint32_t) *this) & 0x80808080) == 0;
}
};
ASSERT_SIZE (Tag, 4);
DEFINE_NULL_DATA (Tag, 4, " ");
/* Glyph index number, same as uint16 (length = 16 bits) */
typedef USHORT GlyphID;
/* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
typedef USHORT Offset;
/* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */
typedef ULONG LongOffset;
/* CheckSum */
struct CheckSum : ULONG
{
static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length)
{
uint32_t Sum = 0L;
ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::get_size ();
while (Table < EndPtr)
Sum += *Table++;
return Sum;
}
};
ASSERT_SIZE (CheckSum, 4);
/*
* Version Numbers
*/
struct FixedVersion
{
inline operator uint32_t (void) const { return (major << 16) + minor; }
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
return SANITIZE_SELF ();
}
USHORT major;
USHORT minor;
};
ASSERT_SIZE (FixedVersion, 4);
/*
* Template subclasses of Offset and LongOffset that do the dereferencing.
* Use: (this+memberName)
*/
template <typename OffsetType, typename Type>
struct GenericOffsetTo : OffsetType
{
inline const Type& operator () (const void *base) const
{
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return Null(Type);
return CONST_CAST(Type, *CharP(base), offset);
}
inline bool sanitize (SANITIZE_ARG_DEF, void *base) {
TRACE_SANITIZE ();
if (!SANITIZE_SELF ()) return false;
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return true;
return SANITIZE (CAST(Type, *CharP(base), offset)) || NEUTER (CAST(OffsetType,*this,0), 0);
}
inline bool sanitize (SANITIZE_ARG_DEF, void *base, void *base2) {
TRACE_SANITIZE ();
if (!SANITIZE_SELF ()) return false;
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return true;
return SANITIZE_BASE (CAST(Type, *CharP(base), offset), base2) || NEUTER (CAST(OffsetType,*this,0), 0);
}
inline bool sanitize (SANITIZE_ARG_DEF, void *base, unsigned int user_data) {
TRACE_SANITIZE ();
if (!SANITIZE_SELF ()) return false;
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return true;
return SANITIZE_BASE (CAST(Type, *CharP(base), offset), user_data) || NEUTER (CAST(OffsetType,*this,0), 0);
}
};
template <typename Base, typename OffsetType, typename Type>
inline const Type& operator + (const Base &base, GenericOffsetTo<OffsetType, Type> offset) { return offset (base); }
template <typename Type>
struct OffsetTo : GenericOffsetTo<Offset, Type> {};
template <typename Type>
struct LongOffsetTo : GenericOffsetTo<LongOffset, Type> {};
/*
* Array Types
*/
template <typename LenType, typename Type>
struct GenericArrayOf
{
const Type *array(void) const { return &StructAfter<Type> (len); }
Type *array(void) { return &StructAfter<Type> (len); }
const Type *const_sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
{
unsigned int count = len;
if (HB_UNLIKELY (start_offset > count))
count = 0;
else
count -= start_offset;
count = MIN (count, *pcount);
*pcount = count;
return array() + start_offset;
}
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= len)) return Null(Type);
return array()[i];
}
inline unsigned int get_size () const
{ return len.get_size () + len * Type::get_size (); }
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
if (!SANITIZE_GET_SIZE()) return false;
/* Note: for structs that do not reference other structs,
* we do not need to call their sanitize() as we already did
* a bound check on the aggregate array size, hence the return.
*/
return true;
/* We do keep this code though to make sure the structs pointed
* to do have a simple sanitize(), ie. they do not reference
* other structs. */
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
if (!SANITIZE (array()[i]))
return false;
return true;
}
inline bool sanitize (SANITIZE_ARG_DEF, void *base) {
TRACE_SANITIZE ();
if (!SANITIZE_GET_SIZE()) return false;
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
if (!array()[i].sanitize (SANITIZE_ARG, base))
return false;
return true;
}
inline bool sanitize (SANITIZE_ARG_DEF, void *base, void *base2) {
TRACE_SANITIZE ();
if (!SANITIZE_GET_SIZE()) return false;
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
if (!array()[i].sanitize (SANITIZE_ARG, base, base2))
return false;
return true;
}
inline bool sanitize (SANITIZE_ARG_DEF, void *base, unsigned int user_data) {
TRACE_SANITIZE ();
if (!SANITIZE_GET_SIZE()) return false;
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
if (!array()[i].sanitize (SANITIZE_ARG, base, user_data))
return false;
return true;
}
LenType len;
/*Type array[VAR];*/
};
/* An array with a USHORT number of elements. */
template <typename Type>
struct ArrayOf : GenericArrayOf<USHORT, Type> {};
/* An array with a ULONG number of elements. */
template <typename Type>
struct LongArrayOf : GenericArrayOf<ULONG, Type> {};
/* Array of Offset's */
template <typename Type>
struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
/* Array of LongOffset's */
template <typename Type>
struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {};
/* LongArray of LongOffset's */
template <typename Type>
struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {};
/* Array of offsets relative to the beginning of the array itself. */
template <typename Type>
struct OffsetListOf : OffsetArrayOf<Type>
{
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= this->len)) return Null(Type);
return this+this->array()[i];
}
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
return OffsetArrayOf<Type>::sanitize (SANITIZE_ARG, CharP(this));
}
inline bool sanitize (SANITIZE_ARG_DEF, unsigned int user_data) {
TRACE_SANITIZE ();
return OffsetArrayOf<Type>::sanitize (SANITIZE_ARG, CharP(this), user_data);
}
};
/* An array with a USHORT number of elements,
* starting at second element. */
template <typename Type>
struct HeadlessArrayOf
{
const Type *array(void) const { return &StructAfter<Type> (len); }
Type *array(void) { return &StructAfter<Type> (len); }
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= len || !i)) return Null(Type);
return array()[i-1];
}
inline unsigned int get_size () const
{ return len.get_size () + (len ? len - 1 : 0) * Type::get_size (); }
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
if (!SANITIZE_GET_SIZE()) return false;
/* Note: for structs that do not reference other structs,
* we do not need to call their sanitize() as we already did
* a bound check on the aggregate array size, hence the return.
*/
return true;
/* We do keep this code though to make sure the structs pointed
* to do have a simple sanitize(), ie. they do not reference
* other structs. */
unsigned int count = len ? len - 1 : 0;
Type *a = array();
for (unsigned int i = 0; i < count; i++)
if (!SANITIZE (a[i]))
return false;
return true;
}
USHORT len;
/*Type array[VAR];*/
};
#endif /* HB_OPEN_TYPE_PRIVATE_HH */
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