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: |
40 | JSObject* callee() const { return this[RegisterFile::Callee].object(); } |
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, JSObject* callee) |
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(i: returnValueRegister); |
127 | setArgumentCount(argc); // original argument count (for the sake of the "arguments" object) |
128 | setCallee(callee); |
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(i: count); } |
144 | void setCallee(JSObject* 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 | |