1 // Copyright 2006-2008 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_ARGUMENTS_H_ 29 #define V8_ARGUMENTS_H_ 30 31 #include "allocation.h" 32 33 namespace v8 { 34 namespace internal { 35 36 // Arguments provides access to runtime call parameters. 37 // 38 // It uses the fact that the instance fields of Arguments 39 // (length_, arguments_) are "overlayed" with the parameters 40 // (no. of parameters, and the parameter pointer) passed so 41 // that inside the C++ function, the parameters passed can 42 // be accessed conveniently: 43 // 44 // Object* Runtime_function(Arguments args) { 45 // ... use args[i] here ... 46 // } 47 48 class Arguments BASE_EMBEDDED { 49 public: Arguments(int length,Object ** arguments)50 Arguments(int length, Object** arguments) 51 : length_(length), arguments_(arguments) { } 52 53 Object*& operator[] (int index) { 54 ASSERT(0 <= index && index < length_); 55 return arguments_[-index]; 56 } 57 at(int index)58 template <class S> Handle<S> at(int index) { 59 Object** value = &((*this)[index]); 60 // This cast checks that the object we're accessing does indeed have the 61 // expected type. 62 S::cast(*value); 63 return Handle<S>(reinterpret_cast<S**>(value)); 64 } 65 smi_at(int index)66 int smi_at(int index) { 67 return Smi::cast((*this)[index])->value(); 68 } 69 number_at(int index)70 double number_at(int index) { 71 return (*this)[index]->Number(); 72 } 73 74 // Get the total number of arguments including the receiver. length()75 int length() const { return length_; } 76 arguments()77 Object** arguments() { return arguments_; } 78 79 private: 80 int length_; 81 Object** arguments_; 82 }; 83 84 85 // Custom arguments replicate a small segment of stack that can be 86 // accessed through an Arguments object the same way the actual stack 87 // can. 88 class CustomArguments : public Relocatable { 89 public: CustomArguments(Isolate * isolate,Object * data,Object * self,JSObject * holder)90 inline CustomArguments(Isolate* isolate, 91 Object* data, 92 Object* self, 93 JSObject* holder) : Relocatable(isolate) { 94 values_[2] = self; 95 values_[1] = holder; 96 values_[0] = data; 97 } 98 CustomArguments(Isolate * isolate)99 inline explicit CustomArguments(Isolate* isolate) : Relocatable(isolate) { 100 #ifdef DEBUG 101 for (size_t i = 0; i < ARRAY_SIZE(values_); i++) { 102 values_[i] = reinterpret_cast<Object*>(kZapValue); 103 } 104 #endif 105 } 106 107 void IterateInstance(ObjectVisitor* v); end()108 Object** end() { return values_ + ARRAY_SIZE(values_) - 1; } 109 private: 110 Object* values_[3]; 111 }; 112 113 114 #define DECLARE_RUNTIME_FUNCTION(Type, Name) \ 115 Type Name(Arguments args, Isolate* isolate) 116 117 118 #define RUNTIME_FUNCTION(Type, Name) \ 119 Type Name(Arguments args, Isolate* isolate) 120 121 122 #define RUNTIME_ARGUMENTS(isolate, args) args, isolate 123 124 125 } } // namespace v8::internal 126 127 #endif // V8_ARGUMENTS_H_ 128