1 /* 2 * Copyright (C) 1999-2001 Harri Porten (porten@kde.org) 3 * Copyright (C) 2001 Peter Kelly (pmk@post.com) 4 * Copyright (C) 2003, 2007, 2008 Apple Inc. All rights reserved. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Library General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Library General Public License for more details. 15 * 16 * You should have received a copy of the GNU Library General Public License 17 * along with this library; see the file COPYING.LIB. If not, write to 18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA. 20 * 21 */ 22 23 #ifndef CallFrame_h 24 #define CallFrame_h 25 26 #include "JSGlobalData.h" 27 #include "RegisterFile.h" 28 #include "ScopeChain.h" 29 30 namespace JSC { 31 32 class Arguments; 33 class JSActivation; 34 class Interpreter; 35 36 // Represents the current state of script execution. 37 // Passed as the first argument to most functions. 38 class ExecState : private Register { 39 public: callee()40 JSFunction* callee() const { return this[RegisterFile::Callee].function(); } codeBlock()41 CodeBlock* codeBlock() const { return this[RegisterFile::CodeBlock].Register::codeBlock(); } scopeChain()42 ScopeChainNode* scopeChain() const { return this[RegisterFile::ScopeChain].Register::scopeChain(); } 43 44 JSValuePtr thisValue(); 45 46 // Global object in which execution began. 47 JSGlobalObject* dynamicGlobalObject(); 48 49 // Global object in which the currently executing code was defined. 50 // Differs from dynamicGlobalObject() during function calls across web browser frames. lexicalGlobalObject()51 JSGlobalObject* lexicalGlobalObject() const 52 { 53 return scopeChain()->globalObject(); 54 } 55 56 // Differs from lexicalGlobalObject because this will have DOM window shell rather than 57 // the actual DOM window, which can't be "this" for security reasons. globalThisValue()58 JSObject* globalThisValue() const 59 { 60 return scopeChain()->globalThisObject(); 61 } 62 63 // FIXME: Elsewhere, we use JSGlobalData* rather than JSGlobalData&. 64 // We should make this more uniform and either use a reference everywhere 65 // or a pointer everywhere. globalData()66 JSGlobalData& globalData() const 67 { 68 return *scopeChain()->globalData; 69 } 70 71 // Convenience functions for access to global data. 72 // It takes a few memory references to get from a call frame to the global data 73 // pointer, so these are inefficient, and should be used sparingly in new code. 74 // But they're used in many places in legacy code, so they're not going away any time soon. 75 setException(JSValuePtr exception)76 void setException(JSValuePtr exception) { globalData().exception = exception; } clearException()77 void clearException() { globalData().exception = noValue(); } exception()78 JSValuePtr exception() const { return globalData().exception; } exceptionSlot()79 JSValuePtr* exceptionSlot() { return &globalData().exception; } hadException()80 bool hadException() const { return globalData().exception; } 81 propertyNames()82 const CommonIdentifiers& propertyNames() const { return *globalData().propertyNames; } emptyList()83 const ArgList& emptyList() const { return *globalData().emptyList; } interpreter()84 Interpreter* interpreter() { return globalData().interpreter; } heap()85 Heap* heap() { return &globalData().heap; } 86 arrayTable(CallFrame * callFrame)87 static const HashTable* arrayTable(CallFrame* callFrame) { return callFrame->globalData().arrayTable; } dateTable(CallFrame * callFrame)88 static const HashTable* dateTable(CallFrame* callFrame) { return callFrame->globalData().dateTable; } mathTable(CallFrame * callFrame)89 static const HashTable* mathTable(CallFrame* callFrame) { return callFrame->globalData().mathTable; } numberTable(CallFrame * callFrame)90 static const HashTable* numberTable(CallFrame* callFrame) { return callFrame->globalData().numberTable; } regExpTable(CallFrame * callFrame)91 static const HashTable* regExpTable(CallFrame* callFrame) { return callFrame->globalData().regExpTable; } regExpConstructorTable(CallFrame * callFrame)92 static const HashTable* regExpConstructorTable(CallFrame* callFrame) { return callFrame->globalData().regExpConstructorTable; } stringTable(CallFrame * callFrame)93 static const HashTable* stringTable(CallFrame* callFrame) { return callFrame->globalData().stringTable; } 94 95 private: 96 friend class Arguments; 97 friend class JSActivation; 98 friend class JSGlobalObject; 99 friend class Interpreter; 100 create(Register * callFrameBase)101 static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); } registers()102 Register* registers() { return this; } 103 104 CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; } 105 argumentCount()106 int argumentCount() const { return this[RegisterFile::ArgumentCount].i(); } callerFrame()107 CallFrame* callerFrame() const { return this[RegisterFile::CallerFrame].callFrame(); } optionalCalleeArguments()108 Arguments* optionalCalleeArguments() const { return this[RegisterFile::OptionalCalleeArguments].arguments(); } returnPC()109 Instruction* returnPC() const { return this[RegisterFile::ReturnPC].vPC(); } returnValueRegister()110 int returnValueRegister() const { return this[RegisterFile::ReturnValueRegister].i(); } 111 setArgumentCount(int count)112 void setArgumentCount(int count) { this[RegisterFile::ArgumentCount] = count; } setCallee(JSFunction * callee)113 void setCallee(JSFunction* callee) { this[RegisterFile::Callee] = callee; } setCalleeArguments(Arguments * arguments)114 void setCalleeArguments(Arguments* arguments) { this[RegisterFile::OptionalCalleeArguments] = arguments; } setCallerFrame(CallFrame * callerFrame)115 void setCallerFrame(CallFrame* callerFrame) { this[RegisterFile::CallerFrame] = callerFrame; } setCodeBlock(CodeBlock * codeBlock)116 void setCodeBlock(CodeBlock* codeBlock) { this[RegisterFile::CodeBlock] = codeBlock; } setScopeChain(ScopeChainNode * scopeChain)117 void setScopeChain(ScopeChainNode* scopeChain) { this[RegisterFile::ScopeChain] = scopeChain; } 118 init(CodeBlock * codeBlock,Instruction * vPC,ScopeChainNode * scopeChain,CallFrame * callerFrame,int returnValueRegister,int argc,JSFunction * function)119 ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC, ScopeChainNode* scopeChain, 120 CallFrame* callerFrame, int returnValueRegister, int argc, JSFunction* function) 121 { 122 ASSERT(callerFrame); // Use noCaller() rather than 0 for the outer host call frame caller. 123 124 setCodeBlock(codeBlock); 125 setScopeChain(scopeChain); 126 setCallerFrame(callerFrame); 127 this[RegisterFile::ReturnPC] = vPC; // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*. 128 this[RegisterFile::ReturnValueRegister] = returnValueRegister; 129 setArgumentCount(argc); // original argument count (for the sake of the "arguments" object) 130 setCallee(function); 131 setCalleeArguments(0); 132 } 133 134 static const intptr_t HostCallFrameFlag = 1; 135 noCaller()136 static CallFrame* noCaller() { return reinterpret_cast<CallFrame*>(HostCallFrameFlag); } hasHostCallFrameFlag()137 bool hasHostCallFrameFlag() const { return reinterpret_cast<intptr_t>(this) & HostCallFrameFlag; } addHostCallFrameFlag()138 CallFrame* addHostCallFrameFlag() const { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) | HostCallFrameFlag); } removeHostCallFrameFlag()139 CallFrame* removeHostCallFrameFlag() { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) & ~HostCallFrameFlag); } 140 141 ExecState(); 142 ~ExecState(); 143 }; 144 145 } // namespace JSC 146 147 #endif // CallFrame_h 148