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 "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: 40 JSFunction* callee() const { return this[RegisterFile::Callee].function(); } 41 CodeBlock* codeBlock() const { return this[RegisterFile::CodeBlock].Register::codeBlock(); } 42 ScopeChainNode* scopeChain() const 43 { 44 ASSERT(this[RegisterFile::ScopeChain].Register::scopeChain()); 45 return this[RegisterFile::ScopeChain].Register::scopeChain(); 46 } 47 int argumentCount() const { return this[RegisterFile::ArgumentCount].i(); } 48 49 JSValue thisValue(); 50 51 // Global object in which execution began. 52 JSGlobalObject* dynamicGlobalObject(); 53 54 // Global object in which the currently executing code was defined. 55 // Differs from dynamicGlobalObject() during function calls across web browser frames. 56 JSGlobalObject* lexicalGlobalObject() const 57 { 58 return scopeChain()->globalObject; 59 } 60 61 // Differs from lexicalGlobalObject because this will have DOM window shell rather than 62 // the actual DOM window, which can't be "this" for security reasons. 63 JSObject* globalThisValue() const 64 { 65 return scopeChain()->globalThis; 66 } 67 68 // FIXME: Elsewhere, we use JSGlobalData* rather than JSGlobalData&. 69 // We should make this more uniform and either use a reference everywhere 70 // or a pointer everywhere. 71 JSGlobalData& globalData() const 72 { 73 ASSERT(scopeChain()->globalData); 74 return *scopeChain()->globalData; 75 } 76 77 // Convenience functions for access to global data. 78 // It takes a few memory references to get from a call frame to the global data 79 // pointer, so these are inefficient, and should be used sparingly in new code. 80 // But they're used in many places in legacy code, so they're not going away any time soon. 81 82 void setException(JSValue exception) { globalData().exception = exception; } 83 void clearException() { globalData().exception = JSValue(); } 84 JSValue exception() const { return globalData().exception; } 85 JSValue* exceptionSlot() { return &globalData().exception; } 86 bool hadException() const { return globalData().exception; } 87 88 const CommonIdentifiers& propertyNames() const { return *globalData().propertyNames; } 89 const MarkedArgumentBuffer& emptyList() const { return *globalData().emptyList; } 90 Interpreter* interpreter() { return globalData().interpreter; } 91 Heap* heap() { return &globalData().heap; } 92 #ifndef NDEBUG 93 void dumpCaller(); 94 #endif 95 static const HashTable* arrayTable(CallFrame* callFrame) { return callFrame->globalData().arrayTable; } 96 static const HashTable* dateTable(CallFrame* callFrame) { return callFrame->globalData().dateTable; } 97 static const HashTable* jsonTable(CallFrame* callFrame) { return callFrame->globalData().jsonTable; } 98 static const HashTable* mathTable(CallFrame* callFrame) { return callFrame->globalData().mathTable; } 99 static const HashTable* numberTable(CallFrame* callFrame) { return callFrame->globalData().numberTable; } 100 static const HashTable* regExpTable(CallFrame* callFrame) { return callFrame->globalData().regExpTable; } 101 static const HashTable* regExpConstructorTable(CallFrame* callFrame) { return callFrame->globalData().regExpConstructorTable; } 102 static const HashTable* stringTable(CallFrame* callFrame) { return callFrame->globalData().stringTable; } 103 104 static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); } 105 Register* registers() { return this; } 106 107 CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; } 108 109 CallFrame* callerFrame() const { return this[RegisterFile::CallerFrame].callFrame(); } 110 Arguments* optionalCalleeArguments() const { return this[RegisterFile::OptionalCalleeArguments].arguments(); } 111 Instruction* returnPC() const { return this[RegisterFile::ReturnPC].vPC(); } 112 113 void setCalleeArguments(JSValue arguments) { static_cast<Register*>(this)[RegisterFile::OptionalCalleeArguments] = arguments; } 114 void setCallerFrame(CallFrame* callerFrame) { static_cast<Register*>(this)[RegisterFile::CallerFrame] = callerFrame; } 115 void setScopeChain(ScopeChainNode* scopeChain) { static_cast<Register*>(this)[RegisterFile::ScopeChain] = scopeChain; } 116 117 ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC, ScopeChainNode* scopeChain, 118 CallFrame* callerFrame, int returnValueRegister, int argc, JSFunction* function) 119 { 120 ASSERT(callerFrame); // Use noCaller() rather than 0 for the outer host call frame caller. 121 122 setCodeBlock(codeBlock); 123 setScopeChain(scopeChain); 124 setCallerFrame(callerFrame); 125 static_cast<Register*>(this)[RegisterFile::ReturnPC] = vPC; // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*. 126 static_cast<Register*>(this)[RegisterFile::ReturnValueRegister] = Register::withInt(returnValueRegister); 127 setArgumentCount(argc); // original argument count (for the sake of the "arguments" object) 128 setCallee(function); 129 setCalleeArguments(JSValue()); 130 } 131 132 // Read a register from the codeframe (or constant from the CodeBlock). 133 inline Register& r(int); 134 135 static CallFrame* noCaller() { return reinterpret_cast<CallFrame*>(HostCallFrameFlag); } 136 int returnValueRegister() const { return this[RegisterFile::ReturnValueRegister].i(); } 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 private: 143 void setArgumentCount(int count) { static_cast<Register*>(this)[RegisterFile::ArgumentCount] = Register::withInt(count); } 144 void setCallee(JSFunction* callee) { static_cast<Register*>(this)[RegisterFile::Callee] = callee; } 145 void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[RegisterFile::CodeBlock] = codeBlock; } 146 147 static const intptr_t HostCallFrameFlag = 1; 148 149 ExecState(); 150 ~ExecState(); 151 }; 152 153 } // namespace JSC 154 155 #endif // CallFrame_h 156
