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/*
* Copyright © 2007,2008,2009,2010 Red Hat, Inc.
* Copyright © 2012,2018 Google, 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
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_MACHINERY_PRIVATE_HH
#define HB_MACHINERY_PRIVATE_HH
#include "hb-private.hh"
#include "hb-blob-private.hh"
#include "hb-iter-private.hh"
/*
* Casts
*/
/* Cast to struct T, reference to reference */
template<typename Type, typename TObject>
static inline const Type& CastR(const TObject &X)
{ return reinterpret_cast<const Type&> (X); }
template<typename Type, typename TObject>
static inline Type& CastR(TObject &X)
{ return reinterpret_cast<Type&> (X); }
/* Cast to struct T, pointer to pointer */
template<typename Type, typename TObject>
static inline const Type* CastP(const TObject *X)
{ return reinterpret_cast<const Type*> (X); }
template<typename Type, typename TObject>
static inline Type* CastP(TObject *X)
{ return reinterpret_cast<Type*> (X); }
/* StructAtOffset<T>(P,Ofs) returns the struct T& that is placed at memory
* location pointed to by P plus Ofs bytes. */
template<typename Type>
static inline const Type& StructAtOffset(const void *P, unsigned int offset)
{ return * reinterpret_cast<const Type*> ((const char *) P + offset); }
template<typename Type>
static inline Type& StructAtOffset(void *P, unsigned int offset)
{ return * reinterpret_cast<Type*> ((char *) P + offset); }
/* 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>
static inline const Type& StructAfter(const TObject &X)
{ return StructAtOffset<Type>(&X, X.get_size()); }
template<typename Type, typename TObject>
static inline Type& StructAfter(TObject &X)
{ return StructAtOffset<Type>(&X, X.get_size()); }
/*
* Size checking
*/
/* Check _assertion in a method environment */
#define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \
inline void _instance_assertion_on_line_##_line (void) const \
{ \
static_assert ((_assertion), ""); \
ASSERT_INSTANCE_POD (*this); /* Make sure it's POD. */ \
}
# define _DEFINE_INSTANCE_ASSERTION0(_line, _assertion) _DEFINE_INSTANCE_ASSERTION1 (_line, _assertion)
# define DEFINE_INSTANCE_ASSERTION(_assertion) _DEFINE_INSTANCE_ASSERTION0 (__LINE__, _assertion)
/* Check that _code compiles in a method environment */
#define _DEFINE_COMPILES_ASSERTION1(_line, _code) \
inline void _compiles_assertion_on_line_##_line (void) const \
{ _code; }
# define _DEFINE_COMPILES_ASSERTION0(_line, _code) _DEFINE_COMPILES_ASSERTION1 (_line, _code)
# define DEFINE_COMPILES_ASSERTION(_code) _DEFINE_COMPILES_ASSERTION0 (__LINE__, _code)
#define DEFINE_SIZE_STATIC(size) \
DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size)); \
static const unsigned int static_size = (size); \
static const unsigned int min_size = (size); \
inline unsigned int get_size (void) const { return (size); }
#define DEFINE_SIZE_UNION(size, _member) \
DEFINE_INSTANCE_ASSERTION (0*sizeof(this->u._member.static_size) + sizeof(this->u._member) == (size)); \
static const unsigned int min_size = (size)
#define DEFINE_SIZE_MIN(size) \
DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)); \
static const unsigned int min_size = (size)
#define DEFINE_SIZE_ARRAY(size, array) \
DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (array[0])); \
DEFINE_COMPILES_ASSERTION ((void) array[0].static_size) \
static const unsigned int min_size = (size)
#define DEFINE_SIZE_ARRAY2(size, array1, array2) \
DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + sizeof (this->array1[0]) + sizeof (this->array2[0])); \
DEFINE_COMPILES_ASSERTION ((void) array1[0].static_size; (void) array2[0].static_size) \
static const unsigned int min_size = (size)
/*
* Dispatch
*/
template <typename Context, typename Return, unsigned int MaxDebugDepth>
struct hb_dispatch_context_t
{
static const unsigned int max_debug_depth = MaxDebugDepth;
typedef Return return_t;
template <typename T, typename F>
inline bool may_dispatch (const T *obj, const F *format) { return true; }
static return_t no_dispatch_return_value (void) { return Context::default_return_value (); }
};
/*
* Sanitize
*/
/* This limits sanitizing time on really broken fonts. */
#ifndef HB_SANITIZE_MAX_EDITS
#define HB_SANITIZE_MAX_EDITS 32
#endif
#ifndef HB_SANITIZE_MAX_OPS_FACTOR
#define HB_SANITIZE_MAX_OPS_FACTOR 8
#endif
#ifndef HB_SANITIZE_MAX_OPS_MIN
#define HB_SANITIZE_MAX_OPS_MIN 16384
#endif
struct hb_sanitize_context_t :
hb_dispatch_context_t<hb_sanitize_context_t, bool, HB_DEBUG_SANITIZE>
{
inline hb_sanitize_context_t (void) :
debug_depth (0),
start (nullptr), end (nullptr),
writable (false), edit_count (0), max_ops (0),
blob (nullptr),
num_glyphs (65536),
num_glyphs_set (false) {}
inline const char *get_name (void) { return "SANITIZE"; }
template <typename T, typename F>
inline bool may_dispatch (const T *obj, const F *format)
{ return format->sanitize (this); }
template <typename T>
inline return_t dispatch (const T &obj) { return obj.sanitize (this); }
static return_t default_return_value (void) { return true; }
static return_t no_dispatch_return_value (void) { return false; }
bool stop_sublookup_iteration (const return_t r) const { return !r; }
inline void init (hb_blob_t *b)
{
this->blob = hb_blob_reference (b);
this->writable = false;
}
inline void set_num_glyphs (unsigned int num_glyphs_)
{
num_glyphs = num_glyphs_;
num_glyphs_set = true;
}
inline unsigned int get_num_glyphs (void) { return num_glyphs; }
inline void start_processing (void)
{
this->start = this->blob->data;
this->end = this->start + this->blob->length;
assert (this->start <= this->end); /* Must not overflow. */
this->max_ops = MAX ((unsigned int) (this->end - this->start) * HB_SANITIZE_MAX_OPS_FACTOR,
(unsigned) HB_SANITIZE_MAX_OPS_MIN);
this->edit_count = 0;
this->debug_depth = 0;
DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1,
"start [%p..%p] (%lu bytes)",
this->start, this->end,
(unsigned long) (this->end - this->start));
}
inline void end_processing (void)
{
DEBUG_MSG_LEVEL (SANITIZE, this->start, 0, -1,
"end [%p..%p] %u edit requests",
this->start, this->end, this->edit_count);
hb_blob_destroy (this->blob);
this->blob = nullptr;
this->start = this->end = nullptr;
}
inline bool check_range (const void *base, unsigned int len) const
{
const char *p = (const char *) base;
bool ok = this->max_ops-- > 0 &&
this->start <= p &&
p <= this->end &&
(unsigned int) (this->end - p) >= len;
DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
"check_range [%p..%p] (%d bytes) in [%p..%p] -> %s",
p, p + len, len,
this->start, this->end,
ok ? "OK" : "OUT-OF-RANGE");
return likely (ok);
}
inline bool check_array (const void *base, unsigned int record_size, unsigned int len) const
{
const char *p = (const char *) base;
bool overflows = hb_unsigned_mul_overflows (len, record_size);
unsigned int array_size = record_size * len;
bool ok = !overflows && this->check_range (base, array_size);
DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
"check_array [%p..%p] (%d*%d=%d bytes) in [%p..%p] -> %s",
p, p + (record_size * len), record_size, len, (unsigned int) array_size,
this->start, this->end,
overflows ? "OVERFLOWS" : ok ? "OK" : "OUT-OF-RANGE");
return likely (ok);
}
template <typename Type>
inline bool check_struct (const Type *obj) const
{
return likely (this->check_range (obj, obj->min_size));
}
inline bool may_edit (const void *base, unsigned int len)
{
if (this->edit_count >= HB_SANITIZE_MAX_EDITS)
return false;
const char *p = (const char *) base;
this->edit_count++;
DEBUG_MSG_LEVEL (SANITIZE, p, this->debug_depth+1, 0,
"may_edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s",
this->edit_count,
p, p + len, len,
this->start, this->end,
this->writable ? "GRANTED" : "DENIED");
return this->writable;
}
template <typename Type, typename ValueType>
inline bool try_set (const Type *obj, const ValueType &v) {
if (this->may_edit (obj, obj->static_size)) {
const_cast<Type *> (obj)->set (v);
return true;
}
return false;
}
template <typename Type>
inline hb_blob_t *sanitize_blob (hb_blob_t *blob)
{
bool sane;
init (blob);
retry:
DEBUG_MSG_FUNC (SANITIZE, start, "start");
start_processing ();
if (unlikely (!start))
{
end_processing ();
return blob;
}
Type *t = CastP<Type> (const_cast<char *> (start));
sane = t->sanitize (this);
if (sane)
{
if (edit_count)
{
DEBUG_MSG_FUNC (SANITIZE, start, "passed first round with %d edits; going for second round", edit_count);
/* sanitize again to ensure no toe-stepping */
edit_count = 0;
sane = t->sanitize (this);
if (edit_count) {
DEBUG_MSG_FUNC (SANITIZE, start, "requested %d edits in second round; FAILLING", edit_count);
sane = false;
}
}
}
else
{
if (edit_count && !writable) {
start = hb_blob_get_data_writable (blob, nullptr);
end = start + blob->length;
if (start)
{
writable = true;
/* ok, we made it writable by relocating. try again */
DEBUG_MSG_FUNC (SANITIZE, start, "retry");
goto retry;
}
}
}
end_processing ();
DEBUG_MSG_FUNC (SANITIZE, start, sane ? "PASSED" : "FAILED");
if (sane)
{
hb_blob_make_immutable (blob);
return blob;
}
else
{
hb_blob_destroy (blob);
return hb_blob_get_empty ();
}
}
template <typename Type>
inline hb_blob_t *reference_table (const hb_face_t *face, hb_tag_t tableTag = Type::tableTag)
{
if (!num_glyphs_set)
set_num_glyphs (hb_face_get_glyph_count (face));
return sanitize_blob<Type> (hb_face_reference_table (face, tableTag));
}
mutable unsigned int debug_depth;
const char *start, *end;
private:
bool writable;
unsigned int edit_count;
mutable int max_ops;
hb_blob_t *blob;
unsigned int num_glyphs;
bool num_glyphs_set;
};
/*
* Serialize
*/
struct hb_serialize_context_t
{
inline hb_serialize_context_t (void *start_, unsigned int size)
{
this->start = (char *) start_;
this->end = this->start + size;
this->ran_out_of_room = false;
this->head = this->start;
this->debug_depth = 0;
}
template <typename Type>
inline Type *start_serialize (void)
{
DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, +1,
"start [%p..%p] (%lu bytes)",
this->start, this->end,
(unsigned long) (this->end - this->start));
return start_embed<Type> ();
}
inline void end_serialize (void)
{
DEBUG_MSG_LEVEL (SERIALIZE, this->start, 0, -1,
"end [%p..%p] serialized %d bytes; %s",
this->start, this->end,
(int) (this->head - this->start),
this->ran_out_of_room ? "RAN OUT OF ROOM" : "did not ran out of room");
}
template <typename Type>
inline Type *copy (void)
{
assert (!this->ran_out_of_room);
unsigned int len = this->head - this->start;
void *p = malloc (len);
if (p)
memcpy (p, this->start, len);
return reinterpret_cast<Type *> (p);
}
template <typename Type>
inline Type *allocate_size (unsigned int size)
{
if (unlikely (this->ran_out_of_room || this->end - this->head < ptrdiff_t (size))) {
this->ran_out_of_room = true;
return nullptr;
}
memset (this->head, 0, size);
char *ret = this->head;
this->head += size;
return reinterpret_cast<Type *> (ret);
}
template <typename Type>
inline Type *allocate_min (void)
{
return this->allocate_size<Type> (Type::min_size);
}
template <typename Type>
inline Type *start_embed (void)
{
Type *ret = reinterpret_cast<Type *> (this->head);
return ret;
}
template <typename Type>
inline Type *embed (const Type &obj)
{
unsigned int size = obj.get_size ();
Type *ret = this->allocate_size<Type> (size);
if (unlikely (!ret)) return nullptr;
memcpy (ret, obj, size);
return ret;
}
template <typename Type>
inline Type *extend_min (Type &obj)
{
unsigned int size = obj.min_size;
assert (this->start <= (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return nullptr;
return reinterpret_cast<Type *> (&obj);
}
template <typename Type>
inline Type *extend (Type &obj)
{
unsigned int size = obj.get_size ();
assert (this->start < (char *) &obj && (char *) &obj <= this->head && (char *) &obj + size >= this->head);
if (unlikely (!this->allocate_size<Type> (((char *) &obj) + size - this->head))) return nullptr;
return reinterpret_cast<Type *> (&obj);
}
unsigned int debug_depth;
char *start, *end, *head;
bool ran_out_of_room;
};
/*
* Supplier
*/
template <typename Type>
struct Supplier
{
inline Supplier (const Type *array, unsigned int len_, unsigned int stride_=sizeof(Type))
{
head = array;
len = len_;
stride = stride_;
}
inline const Type operator [] (unsigned int i) const
{
if (unlikely (i >= len)) return Type ();
return * (const Type *) (const void *) ((const char *) head + stride * i);
}
inline Supplier<Type> & operator += (unsigned int count)
{
if (unlikely (count > len))
count = len;
len -= count;
head = (const Type *) (const void *) ((const char *) head + stride * count);
return *this;
}
private:
inline Supplier (const Supplier<Type> &); /* Disallow copy */
inline Supplier<Type>& operator= (const Supplier<Type> &); /* Disallow copy */
unsigned int len;
unsigned int stride;
const Type *head;
};
/*
* Big-endian integers.
*/
template <typename Type, int Bytes> struct BEInt;
template <typename Type>
struct BEInt<Type, 1>
{
public:
inline void set (Type V)
{
v = V;
}
inline operator Type (void) const
{
return v;
}
private: uint8_t v;
};
template <typename Type>
struct BEInt<Type, 2>
{
public:
inline void set (Type V)
{
v[0] = (V >> 8) & 0xFF;
v[1] = (V ) & 0xFF;
}
inline operator Type (void) const
{
return (v[0] << 8)
+ (v[1] );
}
private: uint8_t v[2];
};
template <typename Type>
struct BEInt<Type, 3>
{
public:
inline void set (Type V)
{
v[0] = (V >> 16) & 0xFF;
v[1] = (V >> 8) & 0xFF;
v[2] = (V ) & 0xFF;
}
inline operator Type (void) const
{
return (v[0] << 16)
+ (v[1] << 8)
+ (v[2] );
}
private: uint8_t v[3];
};
template <typename Type>
struct BEInt<Type, 4>
{
public:
inline void set (Type V)
{
v[0] = (V >> 24) & 0xFF;
v[1] = (V >> 16) & 0xFF;
v[2] = (V >> 8) & 0xFF;
v[3] = (V ) & 0xFF;
}
inline operator Type (void) const
{
return (v[0] << 24)
+ (v[1] << 16)
+ (v[2] << 8)
+ (v[3] );
}
private: uint8_t v[4];
};
/*
* Lazy loaders.
*/
template <typename Data, unsigned int WheresData>
struct hb_data_wrapper_t
{
static_assert (WheresData > 0, "");
inline Data * get_data (void) const
{
return *(((Data **) this) - WheresData);
}
template <typename Stored, typename Subclass>
inline Stored * call_create (void) const
{
Data *data = this->get_data ();
return likely (data) ? Subclass::create (data) : nullptr;
}
};
template <>
struct hb_data_wrapper_t<void, 0>
{
template <typename Stored, typename Subclass>
inline Stored * call_create (void) const
{
return Subclass::create ();
}
};
template <typename Subclass,
typename Data,
unsigned int WheresData,
typename Returned,
typename Stored = Returned>
struct hb_lazy_loader_t : hb_data_wrapper_t<Data, WheresData>
{
inline void init0 (void) {} /* Init, when memory is already set to 0. No-op for us. */
inline void init (void) { instance.set_relaxed (nullptr); }
inline void fini (void)
{
retry:
Stored *p = instance.get ();
if (unlikely (p && !this->instance.cmpexch (p, nullptr)))
goto retry;
do_destroy (p);
}
inline Stored * do_create (void) const
{
Stored *p = this->template call_create<Stored, Subclass> ();
if (unlikely (!p))
p = const_cast<Stored *> (Subclass::get_null ());
return p;
}
static inline void do_destroy (Stored *p)
{
if (p && p != Subclass::get_null ())
Subclass::destroy (p);
}
inline const Returned * operator -> (void) const { return get (); }
inline const Returned & operator * (void) const { return *get (); }
inline Data * get_data (void) const
{
return *(((Data **) this) - WheresData);
}
inline Stored * get_stored (void) const
{
retry:
Stored *p = this->instance.get ();
if (unlikely (!p))
{
p = do_create ();
assert (p);
if (unlikely (!this->instance.cmpexch (nullptr, p)))
{
do_destroy (p);
goto retry;
}
}
return p;
}
inline void set_stored (Stored *instance_)
{
/* This *must* be called when there are no other threads accessing.
* However, to make TSan, etc, happy, we using cmpexch. */
retry:
Stored *p = this->instance.get ();
if (unlikely (!this->instance.cmpexch (p, instance_)))
goto retry;
do_destroy (p);
}
inline const Returned * get (void) const { return Subclass::convert (get_stored ()); }
/* To be possibly overloaded by subclasses. */
static inline const Returned* convert (const Stored *p) { return p; }
static inline Returned* convert (Stored *p) { return p; }
static inline const Stored* get_null (void) { return &Null(Stored); }
private:
/* Must only have one pointer. */
hb_atomic_ptr_t<Stored *> instance;
};
/* Specializations. */
template <unsigned int WheresFace, typename T>
struct hb_object_lazy_loader_t : hb_lazy_loader_t<hb_object_lazy_loader_t<WheresFace, T>,
hb_face_t, WheresFace,
T>
{
static inline T *create (hb_face_t *face)
{
T *p = (T *) calloc (1, sizeof (T));
if (likely (p))
p->init (face);
return p;
}
static inline void destroy (T *p)
{
p->fini ();
free (p);
}
static inline const T *get_null (void)
{
return &Null(T);
}
};
template <typename T, unsigned int WheresFace>
struct hb_table_lazy_loader_t : hb_lazy_loader_t<hb_table_lazy_loader_t<T, WheresFace>,
hb_face_t, WheresFace,
T, hb_blob_t>
{
static inline hb_blob_t *create (hb_face_t *face)
{
return hb_sanitize_context_t ().reference_table<T> (face);
}
static inline void destroy (hb_blob_t *p)
{
hb_blob_destroy (p);
}
static inline const hb_blob_t *get_null (void)
{
return hb_blob_get_empty ();
}
static inline const T* convert (const hb_blob_t *blob)
{
return blob->as<T> ();
}
inline hb_blob_t* get_blob (void) const
{
return this->get_stored ();
}
};
template <typename Subclass>
struct hb_font_funcs_lazy_loader_t : hb_lazy_loader_t<Subclass,
void, 0,
hb_font_funcs_t>
{
static inline void destroy (hb_font_funcs_t *p)
{
hb_font_funcs_destroy (p);
}
static inline const hb_font_funcs_t *get_null (void)
{
return hb_font_funcs_get_empty ();
}
};
template <typename Subclass>
struct hb_unicode_funcs_lazy_loader_t : hb_lazy_loader_t<Subclass,
void, 0,
hb_unicode_funcs_t>
{
static inline void destroy (hb_unicode_funcs_t *p)
{
hb_unicode_funcs_destroy (p);
}
static inline const hb_unicode_funcs_t *get_null (void)
{
return hb_unicode_funcs_get_empty ();
}
};
#endif /* HB_MACHINERY_PRIVATE_HH */
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