1 /* 2 * Copyright (C) 1999-2001 Harri Porten (porten (at) kde.org) 3 * Copyright (C) 2001 Peter Kelly (pmk (at) 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 "MacroAssemblerCodeRef.h" 28 #include "RegisterFile.h" 29 30 namespace JSC { 31 32 class Arguments; 33 class JSActivation; 34 class Interpreter; 35 class ScopeChainNode; 36 37 // Represents the current state of script execution. 38 // Passed as the first argument to most functions. 39 class ExecState : private Register { 40 public: 41 JSObject* callee() const { return this[RegisterFile::Callee].function(); } 42 CodeBlock* codeBlock() const { return this[RegisterFile::CodeBlock].Register::codeBlock(); } 43 ScopeChainNode* scopeChain() const 44 { 45 ASSERT(this[RegisterFile::ScopeChain].Register::scopeChain()); 46 return this[RegisterFile::ScopeChain].Register::scopeChain(); 47 } 48 49 // Global object in which execution began. 50 JSGlobalObject* dynamicGlobalObject(); 51 52 // Global object in which the currently executing code was defined. 53 // Differs from dynamicGlobalObject() during function calls across web browser frames. 54 inline JSGlobalObject* lexicalGlobalObject() const; 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. 58 inline JSObject* globalThisValue() const; 59 60 inline JSGlobalData& globalData() const; 61 62 // Convenience functions for access to global data. 63 // It takes a few memory references to get from a call frame to the global data 64 // pointer, so these are inefficient, and should be used sparingly in new code. 65 // But they're used in many places in legacy code, so they're not going away any time soon. 66 67 void clearException() { globalData().exception = JSValue(); } 68 JSValue exception() const { return globalData().exception; } 69 bool hadException() const { return globalData().exception; } 70 71 const CommonIdentifiers& propertyNames() const { return *globalData().propertyNames; } 72 const MarkedArgumentBuffer& emptyList() const { return *globalData().emptyList; } 73 Interpreter* interpreter() { return globalData().interpreter; } 74 Heap* heap() { return &globalData().heap; } 75 #ifndef NDEBUG 76 void dumpCaller(); 77 #endif 78 static const HashTable* arrayTable(CallFrame* callFrame) { return callFrame->globalData().arrayTable; } 79 static const HashTable* dateTable(CallFrame* callFrame) { return callFrame->globalData().dateTable; } 80 static const HashTable* jsonTable(CallFrame* callFrame) { return callFrame->globalData().jsonTable; } 81 static const HashTable* mathTable(CallFrame* callFrame) { return callFrame->globalData().mathTable; } 82 static const HashTable* numberTable(CallFrame* callFrame) { return callFrame->globalData().numberTable; } 83 static const HashTable* objectConstructorTable(CallFrame* callFrame) { return callFrame->globalData().objectConstructorTable; } 84 static const HashTable* regExpTable(CallFrame* callFrame) { return callFrame->globalData().regExpTable; } 85 static const HashTable* regExpConstructorTable(CallFrame* callFrame) { return callFrame->globalData().regExpConstructorTable; } 86 static const HashTable* stringTable(CallFrame* callFrame) { return callFrame->globalData().stringTable; } 87 88 static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); } 89 Register* registers() { return this; } 90 91 CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; } 92 93 CallFrame* callerFrame() const { return this[RegisterFile::CallerFrame].callFrame(); } 94 #if ENABLE(JIT) 95 ReturnAddressPtr returnPC() const { return ReturnAddressPtr(this[RegisterFile::ReturnPC].vPC()); } 96 #endif 97 #if ENABLE(INTERPRETER) 98 Instruction* returnVPC() const { return this[RegisterFile::ReturnPC].vPC(); } 99 #endif 100 101 void setCallerFrame(CallFrame* callerFrame) { static_cast<Register*>(this)[RegisterFile::CallerFrame] = callerFrame; } 102 void setScopeChain(ScopeChainNode* scopeChain) { static_cast<Register*>(this)[RegisterFile::ScopeChain] = scopeChain; } 103 104 ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC, ScopeChainNode* scopeChain, 105 CallFrame* callerFrame, int argc, JSObject* callee) 106 { 107 ASSERT(callerFrame); // Use noCaller() rather than 0 for the outer host call frame caller. 108 ASSERT(callerFrame == noCaller() || callerFrame->removeHostCallFrameFlag()->registerFile()->end() >= this); 109 110 setCodeBlock(codeBlock); 111 setScopeChain(scopeChain); 112 setCallerFrame(callerFrame); 113 setReturnPC(vPC); // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*. 114 setArgumentCountIncludingThis(argc); // original argument count (for the sake of the "arguments" object) 115 setCallee(callee); 116 } 117 118 // Read a register from the codeframe (or constant from the CodeBlock). 119 inline Register& r(int); 120 // Read a register for a non-constant 121 inline Register& uncheckedR(int); 122 123 // Access to arguments. 124 int hostThisRegister() { return -RegisterFile::CallFrameHeaderSize - argumentCountIncludingThis(); } 125 JSValue hostThisValue() { return this[hostThisRegister()].jsValue(); } 126 size_t argumentCount() const { return argumentCountIncludingThis() - 1; } 127 size_t argumentCountIncludingThis() const { return this[RegisterFile::ArgumentCount].i(); } 128 JSValue argument(int argumentNumber) 129 { 130 int argumentIndex = -RegisterFile::CallFrameHeaderSize - this[RegisterFile::ArgumentCount].i() + argumentNumber + 1; 131 if (argumentIndex >= -RegisterFile::CallFrameHeaderSize) 132 return jsUndefined(); 133 return this[argumentIndex].jsValue(); 134 } 135 136 static CallFrame* noCaller() { return reinterpret_cast<CallFrame*>(HostCallFrameFlag); } 137 138 bool hasHostCallFrameFlag() const { return reinterpret_cast<intptr_t>(this) & HostCallFrameFlag; } 139 CallFrame* addHostCallFrameFlag() const { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) | HostCallFrameFlag); } 140 CallFrame* removeHostCallFrameFlag() { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) & ~HostCallFrameFlag); } 141 142 void setArgumentCountIncludingThis(int count) { static_cast<Register*>(this)[RegisterFile::ArgumentCount] = Register::withInt(count); } 143 void setCallee(JSObject* callee) { static_cast<Register*>(this)[RegisterFile::Callee] = Register::withCallee(callee); } 144 void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[RegisterFile::CodeBlock] = codeBlock; } 145 void setReturnPC(void* value) { static_cast<Register*>(this)[RegisterFile::ReturnPC] = (Instruction*)value; } 146 147 private: 148 static const intptr_t HostCallFrameFlag = 1; 149 #ifndef NDEBUG 150 RegisterFile* registerFile(); 151 #endif 152 ExecState(); 153 ~ExecState(); 154 }; 155 156 } // namespace JSC 157 158 #endif // CallFrame_h 159
