1/*
2 * Copyright (C) 2016-2019 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include "CatchScope.h"
29#include "StackAlignment.h"
30#include "VM.h"
31
32namespace JSC {
33
34struct EntryFrame;
35
36class SuspendExceptionScope {
37public:
38 SuspendExceptionScope(VM* vm)
39 : m_vm(vm)
40 {
41 auto scope = DECLARE_CATCH_SCOPE(*vm);
42 oldException = scope.exception();
43 scope.clearException();
44 }
45 ~SuspendExceptionScope()
46 {
47 m_vm->restorePreviousException(oldException);
48 }
49private:
50 Exception* oldException;
51 VM* m_vm;
52};
53
54class TopCallFrameSetter {
55public:
56 TopCallFrameSetter(VM& currentVM, CallFrame* callFrame)
57 : vm(currentVM)
58 , oldCallFrame(currentVM.topCallFrame)
59 {
60 currentVM.topCallFrame = callFrame;
61 }
62
63 ~TopCallFrameSetter()
64 {
65 vm.topCallFrame = oldCallFrame;
66 }
67private:
68 VM& vm;
69 CallFrame* oldCallFrame;
70};
71
72ALWAYS_INLINE static void assertStackPointerIsAligned()
73{
74#ifndef NDEBUG
75#if CPU(X86) && !OS(WINDOWS)
76 uintptr_t stackPointer;
77
78 asm("movl %%esp,%0" : "=r"(stackPointer));
79 ASSERT(!(stackPointer % stackAlignmentBytes()));
80#endif
81#endif
82}
83
84class SlowPathFrameTracer {
85public:
86 ALWAYS_INLINE SlowPathFrameTracer(VM& vm, CallFrame* callFrame)
87 {
88 ASSERT(callFrame);
89 ASSERT(reinterpret_cast<void*>(callFrame) < reinterpret_cast<void*>(vm.topEntryFrame));
90 assertStackPointerIsAligned();
91 vm.topCallFrame = callFrame;
92 }
93};
94
95class NativeCallFrameTracer {
96public:
97 ALWAYS_INLINE NativeCallFrameTracer(VM& vm, CallFrame* callFrame)
98 {
99 ASSERT(callFrame);
100 ASSERT(reinterpret_cast<void*>(callFrame) < reinterpret_cast<void*>(vm.topEntryFrame));
101 assertStackPointerIsAligned();
102 vm.topCallFrame = callFrame;
103 }
104};
105
106class JITOperationPrologueCallFrameTracer {
107public:
108 ALWAYS_INLINE JITOperationPrologueCallFrameTracer(VM& vm, CallFrame* callFrame)
109#if !ASSERT_DISABLED
110 : m_vm(vm)
111#endif
112 {
113 UNUSED_PARAM(vm);
114 UNUSED_PARAM(callFrame);
115 ASSERT(callFrame);
116 ASSERT(reinterpret_cast<void*>(callFrame) < reinterpret_cast<void*>(vm.topEntryFrame));
117 assertStackPointerIsAligned();
118#if USE(BUILTIN_FRAME_ADDRESS)
119 // If !ASSERT_DISABLED and USE(BUILTIN_FRAME_ADDRESS), prepareCallOperation() will put the frame pointer into vm.topCallFrame.
120 // We can ensure here that a call to prepareCallOperation() (or its equivalent) is not missing by comparing vm.topCallFrame to
121 // the result of __builtin_frame_address which is passed in as callFrame.
122 ASSERT(vm.topCallFrame == callFrame);
123 vm.topCallFrame = callFrame;
124#endif
125 }
126
127#if !ASSERT_DISABLED
128 ~JITOperationPrologueCallFrameTracer()
129 {
130 // Fill vm.topCallFrame with invalid value when leaving from JIT operation functions.
131 m_vm.topCallFrame = bitwise_cast<CallFrame*>(static_cast<uintptr_t>(0x0badbeef0badbeefULL));
132 }
133
134 VM& m_vm;
135#endif
136};
137
138} // namespace JSC
139