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      1 // Copyright 2008 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #ifndef V8_API_H_
     29 #define V8_API_H_
     30 
     31 #include "apiutils.h"
     32 #include "factory.h"
     33 
     34 namespace v8 {
     35 
     36 // Constants used in the implementation of the API.  The most natural thing
     37 // would usually be to place these with the classes that use them, but
     38 // we want to keep them out of v8.h because it is an externally
     39 // visible file.
     40 class Consts {
     41  public:
     42   enum TemplateType {
     43     FUNCTION_TEMPLATE = 0,
     44     OBJECT_TEMPLATE = 1
     45   };
     46 };
     47 
     48 
     49 // Utilities for working with neander-objects, primitive
     50 // env-independent JSObjects used by the api.
     51 class NeanderObject {
     52  public:
     53   explicit NeanderObject(int size);
     54   inline NeanderObject(v8::internal::Handle<v8::internal::Object> obj);
     55   inline NeanderObject(v8::internal::Object* obj);
     56   inline v8::internal::Object* get(int index);
     57   inline void set(int index, v8::internal::Object* value);
     58   inline v8::internal::Handle<v8::internal::JSObject> value() { return value_; }
     59   int size();
     60  private:
     61   v8::internal::Handle<v8::internal::JSObject> value_;
     62 };
     63 
     64 
     65 // Utilities for working with neander-arrays, a simple extensible
     66 // array abstraction built on neander-objects.
     67 class NeanderArray {
     68  public:
     69   NeanderArray();
     70   inline NeanderArray(v8::internal::Handle<v8::internal::Object> obj);
     71   inline v8::internal::Handle<v8::internal::JSObject> value() {
     72     return obj_.value();
     73   }
     74 
     75   void add(v8::internal::Handle<v8::internal::Object> value);
     76 
     77   int length();
     78 
     79   v8::internal::Object* get(int index);
     80   // Change the value at an index to undefined value. If the index is
     81   // out of bounds, the request is ignored. Returns the old value.
     82   void set(int index, v8::internal::Object* value);
     83  private:
     84   NeanderObject obj_;
     85 };
     86 
     87 
     88 NeanderObject::NeanderObject(v8::internal::Handle<v8::internal::Object> obj)
     89     : value_(v8::internal::Handle<v8::internal::JSObject>::cast(obj)) { }
     90 
     91 
     92 NeanderObject::NeanderObject(v8::internal::Object* obj)
     93     : value_(v8::internal::Handle<v8::internal::JSObject>(
     94         v8::internal::JSObject::cast(obj))) { }
     95 
     96 
     97 NeanderArray::NeanderArray(v8::internal::Handle<v8::internal::Object> obj)
     98     : obj_(obj) { }
     99 
    100 
    101 v8::internal::Object* NeanderObject::get(int offset) {
    102   ASSERT(value()->HasFastElements());
    103   return v8::internal::FixedArray::cast(value()->elements())->get(offset);
    104 }
    105 
    106 
    107 void NeanderObject::set(int offset, v8::internal::Object* value) {
    108   ASSERT(value_->HasFastElements());
    109   v8::internal::FixedArray::cast(value_->elements())->set(offset, value);
    110 }
    111 
    112 
    113 template <typename T> static inline T ToCData(v8::internal::Object* obj) {
    114   STATIC_ASSERT(sizeof(T) == sizeof(v8::internal::Address));
    115   return reinterpret_cast<T>(
    116       reinterpret_cast<intptr_t>(v8::internal::Proxy::cast(obj)->proxy()));
    117 }
    118 
    119 
    120 template <typename T>
    121 static inline v8::internal::Handle<v8::internal::Object> FromCData(T obj) {
    122   STATIC_ASSERT(sizeof(T) == sizeof(v8::internal::Address));
    123   return v8::internal::Factory::NewProxy(
    124       reinterpret_cast<v8::internal::Address>(reinterpret_cast<intptr_t>(obj)));
    125 }
    126 
    127 
    128 class ApiFunction {
    129  public:
    130   explicit ApiFunction(v8::internal::Address addr) : addr_(addr) { }
    131   v8::internal::Address address() { return addr_; }
    132  private:
    133   v8::internal::Address addr_;
    134 };
    135 
    136 
    137 v8::Arguments::Arguments(v8::Local<v8::Value> data,
    138                          v8::Local<v8::Object> holder,
    139                          v8::Local<v8::Function> callee,
    140                          bool is_construct_call,
    141                          void** values, int length)
    142     : data_(data), holder_(holder), callee_(callee),
    143       is_construct_call_(is_construct_call),
    144       values_(values), length_(length) { }
    145 
    146 
    147 enum ExtensionTraversalState {
    148   UNVISITED, VISITED, INSTALLED
    149 };
    150 
    151 
    152 class RegisteredExtension {
    153  public:
    154   explicit RegisteredExtension(Extension* extension);
    155   static void Register(RegisteredExtension* that);
    156   Extension* extension() { return extension_; }
    157   RegisteredExtension* next() { return next_; }
    158   RegisteredExtension* next_auto() { return next_auto_; }
    159   ExtensionTraversalState state() { return state_; }
    160   void set_state(ExtensionTraversalState value) { state_ = value; }
    161   static RegisteredExtension* first_extension() { return first_extension_; }
    162  private:
    163   Extension* extension_;
    164   RegisteredExtension* next_;
    165   RegisteredExtension* next_auto_;
    166   ExtensionTraversalState state_;
    167   static RegisteredExtension* first_extension_;
    168   static RegisteredExtension* first_auto_extension_;
    169 };
    170 
    171 
    172 class Utils {
    173  public:
    174   static bool ReportApiFailure(const char* location, const char* message);
    175 
    176   static Local<FunctionTemplate> ToFunctionTemplate(NeanderObject obj);
    177   static Local<ObjectTemplate> ToObjectTemplate(NeanderObject obj);
    178 
    179   static inline Local<Context> ToLocal(
    180       v8::internal::Handle<v8::internal::Context> obj);
    181   static inline Local<Value> ToLocal(
    182       v8::internal::Handle<v8::internal::Object> obj);
    183   static inline Local<Function> ToLocal(
    184       v8::internal::Handle<v8::internal::JSFunction> obj);
    185   static inline Local<String> ToLocal(
    186       v8::internal::Handle<v8::internal::String> obj);
    187   static inline Local<Object> ToLocal(
    188       v8::internal::Handle<v8::internal::JSObject> obj);
    189   static inline Local<Array> ToLocal(
    190       v8::internal::Handle<v8::internal::JSArray> obj);
    191   static inline Local<External> ToLocal(
    192       v8::internal::Handle<v8::internal::Proxy> obj);
    193   static inline Local<Message> MessageToLocal(
    194       v8::internal::Handle<v8::internal::Object> obj);
    195   static inline Local<Number> NumberToLocal(
    196       v8::internal::Handle<v8::internal::Object> obj);
    197   static inline Local<Integer> IntegerToLocal(
    198       v8::internal::Handle<v8::internal::Object> obj);
    199   static inline Local<Uint32> Uint32ToLocal(
    200       v8::internal::Handle<v8::internal::Object> obj);
    201   static inline Local<FunctionTemplate> ToLocal(
    202       v8::internal::Handle<v8::internal::FunctionTemplateInfo> obj);
    203   static inline Local<ObjectTemplate> ToLocal(
    204       v8::internal::Handle<v8::internal::ObjectTemplateInfo> obj);
    205   static inline Local<Signature> ToLocal(
    206       v8::internal::Handle<v8::internal::SignatureInfo> obj);
    207   static inline Local<TypeSwitch> ToLocal(
    208       v8::internal::Handle<v8::internal::TypeSwitchInfo> obj);
    209 
    210   static inline v8::internal::Handle<v8::internal::TemplateInfo>
    211       OpenHandle(const Template* that);
    212   static inline v8::internal::Handle<v8::internal::FunctionTemplateInfo>
    213       OpenHandle(const FunctionTemplate* that);
    214   static inline v8::internal::Handle<v8::internal::ObjectTemplateInfo>
    215       OpenHandle(const ObjectTemplate* that);
    216   static inline v8::internal::Handle<v8::internal::Object>
    217       OpenHandle(const Data* data);
    218   static inline v8::internal::Handle<v8::internal::JSObject>
    219       OpenHandle(const v8::Object* data);
    220   static inline v8::internal::Handle<v8::internal::JSArray>
    221       OpenHandle(const v8::Array* data);
    222   static inline v8::internal::Handle<v8::internal::String>
    223       OpenHandle(const String* data);
    224   static inline v8::internal::Handle<v8::internal::JSFunction>
    225       OpenHandle(const Script* data);
    226   static inline v8::internal::Handle<v8::internal::JSFunction>
    227       OpenHandle(const Function* data);
    228   static inline v8::internal::Handle<v8::internal::JSObject>
    229       OpenHandle(const Message* message);
    230   static inline v8::internal::Handle<v8::internal::Context>
    231       OpenHandle(const v8::Context* context);
    232   static inline v8::internal::Handle<v8::internal::SignatureInfo>
    233       OpenHandle(const v8::Signature* sig);
    234   static inline v8::internal::Handle<v8::internal::TypeSwitchInfo>
    235       OpenHandle(const v8::TypeSwitch* that);
    236   static inline v8::internal::Handle<v8::internal::Proxy>
    237       OpenHandle(const v8::External* that);
    238 };
    239 
    240 
    241 template <class T>
    242 static inline T* ToApi(v8::internal::Handle<v8::internal::Object> obj) {
    243   return reinterpret_cast<T*>(obj.location());
    244 }
    245 
    246 
    247 template <class T>
    248 v8::internal::Handle<T> v8::internal::Handle<T>::EscapeFrom(
    249     v8::HandleScope* scope) {
    250   return Utils::OpenHandle(*scope->Close(Utils::ToLocal(*this)));
    251 }
    252 
    253 
    254 // Implementations of ToLocal
    255 
    256 #define MAKE_TO_LOCAL(Name, From, To)                                       \
    257   Local<v8::To> Utils::Name(v8::internal::Handle<v8::internal::From> obj) { \
    258     ASSERT(!obj->IsTheHole());                                              \
    259     return Local<To>(reinterpret_cast<To*>(obj.location()));                \
    260   }
    261 
    262 MAKE_TO_LOCAL(ToLocal, Context, Context)
    263 MAKE_TO_LOCAL(ToLocal, Object, Value)
    264 MAKE_TO_LOCAL(ToLocal, JSFunction, Function)
    265 MAKE_TO_LOCAL(ToLocal, String, String)
    266 MAKE_TO_LOCAL(ToLocal, JSObject, Object)
    267 MAKE_TO_LOCAL(ToLocal, JSArray, Array)
    268 MAKE_TO_LOCAL(ToLocal, Proxy, External)
    269 MAKE_TO_LOCAL(ToLocal, FunctionTemplateInfo, FunctionTemplate)
    270 MAKE_TO_LOCAL(ToLocal, ObjectTemplateInfo, ObjectTemplate)
    271 MAKE_TO_LOCAL(ToLocal, SignatureInfo, Signature)
    272 MAKE_TO_LOCAL(ToLocal, TypeSwitchInfo, TypeSwitch)
    273 MAKE_TO_LOCAL(MessageToLocal, Object, Message)
    274 MAKE_TO_LOCAL(NumberToLocal, Object, Number)
    275 MAKE_TO_LOCAL(IntegerToLocal, Object, Integer)
    276 MAKE_TO_LOCAL(Uint32ToLocal, Object, Uint32)
    277 
    278 #undef MAKE_TO_LOCAL
    279 
    280 
    281 // Implementations of OpenHandle
    282 
    283 #define MAKE_OPEN_HANDLE(From, To) \
    284   v8::internal::Handle<v8::internal::To> Utils::OpenHandle(\
    285     const v8::From* that) { \
    286     return v8::internal::Handle<v8::internal::To>( \
    287         reinterpret_cast<v8::internal::To**>(const_cast<v8::From*>(that))); \
    288   }
    289 
    290 MAKE_OPEN_HANDLE(Template, TemplateInfo)
    291 MAKE_OPEN_HANDLE(FunctionTemplate, FunctionTemplateInfo)
    292 MAKE_OPEN_HANDLE(ObjectTemplate, ObjectTemplateInfo)
    293 MAKE_OPEN_HANDLE(Signature, SignatureInfo)
    294 MAKE_OPEN_HANDLE(TypeSwitch, TypeSwitchInfo)
    295 MAKE_OPEN_HANDLE(Data, Object)
    296 MAKE_OPEN_HANDLE(Object, JSObject)
    297 MAKE_OPEN_HANDLE(Array, JSArray)
    298 MAKE_OPEN_HANDLE(String, String)
    299 MAKE_OPEN_HANDLE(Script, JSFunction)
    300 MAKE_OPEN_HANDLE(Function, JSFunction)
    301 MAKE_OPEN_HANDLE(Message, JSObject)
    302 MAKE_OPEN_HANDLE(Context, Context)
    303 MAKE_OPEN_HANDLE(External, Proxy)
    304 
    305 #undef MAKE_OPEN_HANDLE
    306 
    307 
    308 namespace internal {
    309 
    310 // This class is here in order to be able to declare it a friend of
    311 // HandleScope.  Moving these methods to be members of HandleScope would be
    312 // neat in some ways, but it would expose external implementation details in
    313 // our public header file, which is undesirable.
    314 //
    315 // There is a singleton instance of this class to hold the per-thread data.
    316 // For multithreaded V8 programs this data is copied in and out of storage
    317 // so that the currently executing thread always has its own copy of this
    318 // data.
    319 class HandleScopeImplementer {
    320  public:
    321 
    322   HandleScopeImplementer()
    323       : blocks_(0),
    324         entered_contexts_(0),
    325         saved_contexts_(0),
    326         spare_(NULL),
    327         ignore_out_of_memory_(false),
    328         call_depth_(0) { }
    329 
    330   static HandleScopeImplementer* instance();
    331 
    332   // Threading support for handle data.
    333   static int ArchiveSpacePerThread();
    334   static char* RestoreThread(char* from);
    335   static char* ArchiveThread(char* to);
    336   static void FreeThreadResources();
    337 
    338   // Garbage collection support.
    339   static void Iterate(v8::internal::ObjectVisitor* v);
    340   static char* Iterate(v8::internal::ObjectVisitor* v, char* data);
    341 
    342 
    343   inline internal::Object** GetSpareOrNewBlock();
    344   inline void DeleteExtensions(int extensions);
    345 
    346   inline void IncrementCallDepth() {call_depth_++;}
    347   inline void DecrementCallDepth() {call_depth_--;}
    348   inline bool CallDepthIsZero() { return call_depth_ == 0; }
    349 
    350   inline void EnterContext(Handle<Object> context);
    351   inline bool LeaveLastContext();
    352 
    353   // Returns the last entered context or an empty handle if no
    354   // contexts have been entered.
    355   inline Handle<Object> LastEnteredContext();
    356 
    357   inline void SaveContext(Context* context);
    358   inline Context* RestoreContext();
    359   inline bool HasSavedContexts();
    360 
    361   inline List<internal::Object**>* blocks() { return &blocks_; }
    362   inline bool ignore_out_of_memory() { return ignore_out_of_memory_; }
    363   inline void set_ignore_out_of_memory(bool value) {
    364     ignore_out_of_memory_ = value;
    365   }
    366 
    367  private:
    368   void ResetAfterArchive() {
    369     blocks_.Initialize(0);
    370     entered_contexts_.Initialize(0);
    371     saved_contexts_.Initialize(0);
    372     spare_ = NULL;
    373     ignore_out_of_memory_ = false;
    374     call_depth_ = 0;
    375   }
    376 
    377   void Free() {
    378     ASSERT(blocks_.length() == 0);
    379     ASSERT(entered_contexts_.length() == 0);
    380     ASSERT(saved_contexts_.length() == 0);
    381     blocks_.Free();
    382     entered_contexts_.Free();
    383     saved_contexts_.Free();
    384     if (spare_ != NULL) {
    385       DeleteArray(spare_);
    386       spare_ = NULL;
    387     }
    388     ASSERT(call_depth_ == 0);
    389   }
    390 
    391   List<internal::Object**> blocks_;
    392   // Used as a stack to keep track of entered contexts.
    393   List<Handle<Object> > entered_contexts_;
    394   // Used as a stack to keep track of saved contexts.
    395   List<Context*> saved_contexts_;
    396   Object** spare_;
    397   bool ignore_out_of_memory_;
    398   int call_depth_;
    399   // This is only used for threading support.
    400   v8::ImplementationUtilities::HandleScopeData handle_scope_data_;
    401 
    402   void IterateThis(ObjectVisitor* v);
    403   char* RestoreThreadHelper(char* from);
    404   char* ArchiveThreadHelper(char* to);
    405 
    406   DISALLOW_COPY_AND_ASSIGN(HandleScopeImplementer);
    407 };
    408 
    409 
    410 static const int kHandleBlockSize = v8::internal::KB - 2;  // fit in one page
    411 
    412 
    413 void HandleScopeImplementer::SaveContext(Context* context) {
    414   saved_contexts_.Add(context);
    415 }
    416 
    417 
    418 Context* HandleScopeImplementer::RestoreContext() {
    419   return saved_contexts_.RemoveLast();
    420 }
    421 
    422 
    423 bool HandleScopeImplementer::HasSavedContexts() {
    424   return !saved_contexts_.is_empty();
    425 }
    426 
    427 
    428 void HandleScopeImplementer::EnterContext(Handle<Object> context) {
    429   entered_contexts_.Add(context);
    430 }
    431 
    432 
    433 bool HandleScopeImplementer::LeaveLastContext() {
    434   if (entered_contexts_.is_empty()) return false;
    435   entered_contexts_.RemoveLast();
    436   return true;
    437 }
    438 
    439 
    440 Handle<Object> HandleScopeImplementer::LastEnteredContext() {
    441   if (entered_contexts_.is_empty()) return Handle<Object>::null();
    442   return entered_contexts_.last();
    443 }
    444 
    445 
    446 // If there's a spare block, use it for growing the current scope.
    447 internal::Object** HandleScopeImplementer::GetSpareOrNewBlock() {
    448   internal::Object** block = (spare_ != NULL) ?
    449       spare_ :
    450       NewArray<internal::Object*>(kHandleBlockSize);
    451   spare_ = NULL;
    452   return block;
    453 }
    454 
    455 
    456 void HandleScopeImplementer::DeleteExtensions(int extensions) {
    457   if (spare_ != NULL) {
    458     DeleteArray(spare_);
    459     spare_ = NULL;
    460   }
    461   for (int i = extensions; i > 1; --i) {
    462     internal::Object** block = blocks_.RemoveLast();
    463 #ifdef DEBUG
    464     v8::ImplementationUtilities::ZapHandleRange(block,
    465                                                 &block[kHandleBlockSize]);
    466 #endif
    467     DeleteArray(block);
    468   }
    469   spare_ = blocks_.RemoveLast();
    470 #ifdef DEBUG
    471   v8::ImplementationUtilities::ZapHandleRange(
    472       spare_,
    473       &spare_[kHandleBlockSize]);
    474 #endif
    475 }
    476 
    477 } }  // namespace v8::internal
    478 
    479 #endif  // V8_API_H_
    480