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.
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.
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.
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.
26 #include "JSGlobalData.h"
27 #include "MacroAssemblerCodeRef.h"
28 #include "RegisterFile.h"
29 #include "ScopeChain.h"
37 // Represents the current state of script execution.
38 // Passed as the first argument to most functions.
39 class ExecState : private Register {
41 JSObject* callee() const { return this[RegisterFile::Callee].function(); }
42 CodeBlock* codeBlock() const { return this[RegisterFile::CodeBlock].Register::codeBlock(); }
43 ScopeChainNode* scopeChain() const
45 ASSERT(this[RegisterFile::ScopeChain].Register::scopeChain());
46 return this[RegisterFile::ScopeChain].Register::scopeChain();
49 // Global object in which execution began.
50 JSGlobalObject* dynamicGlobalObject();
52 // Global object in which the currently executing code was defined.
53 // Differs from dynamicGlobalObject() during function calls across web browser frames.
54 JSGlobalObject* lexicalGlobalObject() const
56 return scopeChain()->globalObject;
59 // Differs from lexicalGlobalObject because this will have DOM window shell rather than
60 // the actual DOM window, which can't be "this" for security reasons.
61 JSObject* globalThisValue() const
63 return scopeChain()->globalThis;
66 JSGlobalData& globalData() const
68 ASSERT(scopeChain()->globalData);
69 return *scopeChain()->globalData;
72 // Convenience functions for access to global data.
73 // It takes a few memory references to get from a call frame to the global data
74 // pointer, so these are inefficient, and should be used sparingly in new code.
75 // But they're used in many places in legacy code, so they're not going away any time soon.
77 void clearException() { globalData().exception = JSValue(); }
78 JSValue exception() const { return globalData().exception.get(); }
79 bool hadException() const { return globalData().exception; }
81 const CommonIdentifiers& propertyNames() const { return *globalData().propertyNames; }
82 const MarkedArgumentBuffer& emptyList() const { return *globalData().emptyList; }
83 Interpreter* interpreter() { return globalData().interpreter; }
84 Heap* heap() { return &globalData().heap; }
88 static const HashTable* arrayTable(CallFrame* callFrame) { return callFrame->globalData().arrayTable; }
89 static const HashTable* dateTable(CallFrame* callFrame) { return callFrame->globalData().dateTable; }
90 static const HashTable* jsonTable(CallFrame* callFrame) { return callFrame->globalData().jsonTable; }
91 static const HashTable* mathTable(CallFrame* callFrame) { return callFrame->globalData().mathTable; }
92 static const HashTable* numberTable(CallFrame* callFrame) { return callFrame->globalData().numberTable; }
93 static const HashTable* regExpTable(CallFrame* callFrame) { return callFrame->globalData().regExpTable; }
94 static const HashTable* regExpConstructorTable(CallFrame* callFrame) { return callFrame->globalData().regExpConstructorTable; }
95 static const HashTable* stringTable(CallFrame* callFrame) { return callFrame->globalData().stringTable; }
97 static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); }
98 Register* registers() { return this; }
100 CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; }
102 CallFrame* callerFrame() const { return this[RegisterFile::CallerFrame].callFrame(); }
104 ReturnAddressPtr returnPC() const { return ReturnAddressPtr(this[RegisterFile::ReturnPC].vPC()); }
106 #if ENABLE(INTERPRETER)
107 Instruction* returnVPC() const { return this[RegisterFile::ReturnPC].vPC(); }
110 void setCallerFrame(CallFrame* callerFrame) { static_cast<Register*>(this)[RegisterFile::CallerFrame] = callerFrame; }
111 void setScopeChain(ScopeChainNode* scopeChain) { static_cast<Register*>(this)[RegisterFile::ScopeChain] = scopeChain; }
113 ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC, ScopeChainNode* scopeChain,
114 CallFrame* callerFrame, int argc, JSObject* callee)
116 ASSERT(callerFrame); // Use noCaller() rather than 0 for the outer host call frame caller.
117 ASSERT(callerFrame == noCaller() || callerFrame->removeHostCallFrameFlag()->registerFile()->end() >= this);
119 setCodeBlock(codeBlock);
120 setScopeChain(scopeChain);
121 setCallerFrame(callerFrame);
122 setReturnPC(vPC); // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*.
123 setArgumentCountIncludingThis(argc); // original argument count (for the sake of the "arguments" object)
127 // Read a register from the codeframe (or constant from the CodeBlock).
128 inline Register& r(int);
129 // Read a register for a non-constant
130 inline Register& uncheckedR(int);
132 // Access to arguments.
133 int hostThisRegister() { return -RegisterFile::CallFrameHeaderSize - argumentCountIncludingThis(); }
134 JSValue hostThisValue() { return this[hostThisRegister()].jsValue(); }
135 size_t argumentCount() const { return argumentCountIncludingThis() - 1; }
136 size_t argumentCountIncludingThis() const { return this[RegisterFile::ArgumentCount].i(); }
137 JSValue argument(int argumentNumber)
139 int argumentIndex = -RegisterFile::CallFrameHeaderSize - this[RegisterFile::ArgumentCount].i() + argumentNumber + 1;
140 if (argumentIndex >= -RegisterFile::CallFrameHeaderSize)
141 return jsUndefined();
142 return this[argumentIndex].jsValue();
145 static CallFrame* noCaller() { return reinterpret_cast<CallFrame*>(HostCallFrameFlag); }
147 bool hasHostCallFrameFlag() const { return reinterpret_cast<intptr_t>(this) & HostCallFrameFlag; }
148 CallFrame* addHostCallFrameFlag() const { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) | HostCallFrameFlag); }
149 CallFrame* removeHostCallFrameFlag() { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) & ~HostCallFrameFlag); }
151 void setArgumentCountIncludingThis(int count) { static_cast<Register*>(this)[RegisterFile::ArgumentCount] = Register::withInt(count); }
152 void setCallee(JSObject* callee) { static_cast<Register*>(this)[RegisterFile::Callee] = Register::withCallee(callee); }
153 void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[RegisterFile::CodeBlock] = codeBlock; }
154 void setReturnPC(void* value) { static_cast<Register*>(this)[RegisterFile::ReturnPC] = (Instruction*)value; }
157 static const intptr_t HostCallFrameFlag = 1;
159 RegisterFile* registerFile();
167 #endif // CallFrame_h