| /* |
| * 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_HH |
| #define HB_MACHINERY_HH |
| |
| #include "hb.hh" |
| #include "hb-blob.hh" |
| |
| #include "hb-dispatch.hh" |
| #include "hb-sanitize.hh" |
| #include "hb-serialize.hh" |
| |
| |
| /* |
| * Casts |
| */ |
| |
| /* 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); } |
| template<typename Type> |
| static inline const Type& StructAtOffsetUnaligned(const void *P, unsigned int offset) |
| { |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wcast-align" |
| return * reinterpret_cast<const Type*> ((const char *) P + offset); |
| #pragma GCC diagnostic pop |
| } |
| template<typename Type> |
| static inline Type& StructAtOffsetUnaligned(void *P, unsigned int offset) |
| { |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wcast-align" |
| return * reinterpret_cast<Type*> ((char *) P + offset); |
| #pragma GCC diagnostic pop |
| } |
| |
| /* 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 |
| */ |
| |
| /* Size signifying variable-sized array */ |
| #ifndef HB_VAR_ARRAY |
| #define HB_VAR_ARRAY 1 |
| #endif |
| |
| /* Check _assertion in a method environment */ |
| #define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \ |
| void _instance_assertion_on_line_##_line () const \ |
| { static_assert ((_assertion), ""); } |
| # 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) \ |
| void _compiles_assertion_on_line_##_line () 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)) \ |
| unsigned int get_size () const { return (size); } \ |
| static constexpr unsigned null_size = (size); \ |
| static constexpr unsigned min_size = (size); \ |
| static constexpr unsigned static_size = (size) |
| |
| #define DEFINE_SIZE_UNION(size, _member) \ |
| DEFINE_COMPILES_ASSERTION ((void) this->u._member.static_size) \ |
| DEFINE_INSTANCE_ASSERTION (sizeof(this->u._member) == (size)) \ |
| static constexpr unsigned null_size = (size); \ |
| static constexpr unsigned min_size = (size) |
| |
| #define DEFINE_SIZE_MIN(size) \ |
| DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)) \ |
| static constexpr unsigned null_size = (size); \ |
| static constexpr unsigned min_size = (size) |
| |
| #define DEFINE_SIZE_UNBOUNDED(size) \ |
| DEFINE_INSTANCE_ASSERTION (sizeof (*this) >= (size)) \ |
| static constexpr unsigned min_size = (size) |
| |
| #define DEFINE_SIZE_ARRAY(size, array) \ |
| DEFINE_COMPILES_ASSERTION ((void) (array)[0].static_size) \ |
| DEFINE_INSTANCE_ASSERTION (sizeof (*this) == (size) + (HB_VAR_ARRAY+0) * sizeof ((array)[0])) \ |
| static constexpr unsigned null_size = (size); \ |
| static constexpr unsigned min_size = (size) |
| |
| #define DEFINE_SIZE_ARRAY_SIZED(size, array) \ |
| unsigned int get_size () const { return (size - (array).min_size + (array).get_size ()); } \ |
| DEFINE_SIZE_ARRAY(size, array) |
| |
| |
| |
| /* |
| * Lazy loaders. |
| */ |
| |
| template <typename Data, unsigned int WheresData> |
| struct hb_data_wrapper_t |
| { |
| static_assert (WheresData > 0, ""); |
| |
| Data * get_data () const |
| { return *(((Data **) (void *) this) - WheresData); } |
| |
| bool is_inert () const { return !get_data (); } |
| |
| template <typename Stored, typename Subclass> |
| Stored * call_create () const { return Subclass::create (get_data ()); } |
| }; |
| template <> |
| struct hb_data_wrapper_t<void, 0> |
| { |
| bool is_inert () const { return false; } |
| |
| template <typename Stored, typename Funcs> |
| Stored * call_create () const { return Funcs::create (); } |
| }; |
| |
| template <typename T1, typename T2> struct hb_non_void_t { typedef T1 value; }; |
| template <typename T2> struct hb_non_void_t<void, T2> { typedef T2 value; }; |
| |
| template <typename Returned, |
| typename Subclass = void, |
| typename Data = void, |
| unsigned int WheresData = 0, |
| typename Stored = Returned> |
| struct hb_lazy_loader_t : hb_data_wrapper_t<Data, WheresData> |
| { |
| typedef typename hb_non_void_t<Subclass, |
| hb_lazy_loader_t<Returned,Subclass,Data,WheresData,Stored> |
| >::value Funcs; |
| |
| void init0 () {} /* Init, when memory is already set to 0. No-op for us. */ |
| void init () { instance.set_relaxed (nullptr); } |
| void fini () { do_destroy (instance.get ()); init (); } |
| |
| void free_instance () |
| { |
| retry: |
| Stored *p = instance.get (); |
| if (unlikely (p && !cmpexch (p, nullptr))) |
| goto retry; |
| do_destroy (p); |
| } |
| |
| static void do_destroy (Stored *p) |
| { |
| if (p && p != const_cast<Stored *> (Funcs::get_null ())) |
| Funcs::destroy (p); |
| } |
| |
| const Returned * operator -> () const { return get (); } |
| template <typename U = Returned, hb_enable_if (!hb_is_same (U, void))> |
| const U & operator * () const { return *get (); } |
| explicit operator bool () const |
| { return get_stored () != Funcs::get_null (); } |
| template <typename C> operator const C * () const { return get (); } |
| |
| Stored * get_stored () const |
| { |
| retry: |
| Stored *p = this->instance.get (); |
| if (unlikely (!p)) |
| { |
| if (unlikely (this->is_inert ())) |
| return const_cast<Stored *> (Funcs::get_null ()); |
| |
| p = this->template call_create<Stored, Funcs> (); |
| if (unlikely (!p)) |
| p = const_cast<Stored *> (Funcs::get_null ()); |
| |
| if (unlikely (!cmpexch (nullptr, p))) |
| { |
| do_destroy (p); |
| goto retry; |
| } |
| } |
| return p; |
| } |
| Stored * get_stored_relaxed () const |
| { |
| return this->instance.get_relaxed (); |
| } |
| |
| bool cmpexch (Stored *current, Stored *value) const |
| { |
| /* This *must* be called when there are no other threads accessing. */ |
| return this->instance.cmpexch (current, value); |
| } |
| |
| const Returned * get () const { return Funcs::convert (get_stored ()); } |
| const Returned * get_relaxed () const { return Funcs::convert (get_stored_relaxed ()); } |
| Returned * get_unconst () const { return const_cast<Returned *> (Funcs::convert (get_stored ())); } |
| |
| /* To be possibly overloaded by subclasses. */ |
| static Returned* convert (Stored *p) { return p; } |
| |
| /* By default null/init/fini the object. */ |
| static const Stored* get_null () { return &Null (Stored); } |
| static Stored *create (Data *data) |
| { |
| Stored *p = (Stored *) hb_calloc (1, sizeof (Stored)); |
| if (likely (p)) |
| p = new (p) Stored (data); |
| return p; |
| } |
| static Stored *create () |
| { |
| Stored *p = (Stored *) hb_calloc (1, sizeof (Stored)); |
| if (likely (p)) |
| p = new (p) Stored (); |
| return p; |
| } |
| static void destroy (Stored *p) |
| { |
| p->~Stored (); |
| hb_free (p); |
| } |
| |
| // private: |
| /* Must only have one pointer. */ |
| hb_atomic_ptr_t<Stored *> instance; |
| }; |
| |
| /* Specializations. */ |
| |
| template <typename T, unsigned int WheresFace> |
| struct hb_face_lazy_loader_t : hb_lazy_loader_t<T, |
| hb_face_lazy_loader_t<T, WheresFace>, |
| hb_face_t, WheresFace> {}; |
| |
| template <typename T, unsigned int WheresFace, bool core=false> |
| struct hb_table_lazy_loader_t : hb_lazy_loader_t<T, |
| hb_table_lazy_loader_t<T, WheresFace, core>, |
| hb_face_t, WheresFace, |
| hb_blob_t> |
| { |
| static hb_blob_t *create (hb_face_t *face) |
| { |
| auto c = hb_sanitize_context_t (); |
| if (core) |
| c.set_num_glyphs (0); // So we don't recurse ad infinitum... |
| return c.reference_table<T> (face); |
| } |
| static void destroy (hb_blob_t *p) { hb_blob_destroy (p); } |
| |
| static const hb_blob_t *get_null () |
| { return hb_blob_get_empty (); } |
| |
| static const T* convert (const hb_blob_t *blob) |
| { return blob->as<T> (); } |
| |
| hb_blob_t* get_blob () const { return this->get_stored (); } |
| }; |
| |
| template <typename Subclass> |
| struct hb_font_funcs_lazy_loader_t : hb_lazy_loader_t<hb_font_funcs_t, Subclass> |
| { |
| static void destroy (hb_font_funcs_t *p) |
| { hb_font_funcs_destroy (p); } |
| static const hb_font_funcs_t *get_null () |
| { return hb_font_funcs_get_empty (); } |
| }; |
| template <typename Subclass> |
| struct hb_unicode_funcs_lazy_loader_t : hb_lazy_loader_t<hb_unicode_funcs_t, Subclass> |
| { |
| static void destroy (hb_unicode_funcs_t *p) |
| { hb_unicode_funcs_destroy (p); } |
| static const hb_unicode_funcs_t *get_null () |
| { return hb_unicode_funcs_get_empty (); } |
| }; |
| |
| |
| #endif /* HB_MACHINERY_HH */ |