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1 // Copyright 2012 the V8 project authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "src/v8.h" | |
6 | |
7 #if V8_TARGET_ARCH_X87 | |
8 | |
9 #include "src/codegen.h" | |
10 #include "src/debug.h" | |
11 | |
12 | |
13 namespace v8 { | |
14 namespace internal { | |
15 | |
16 #define __ ACCESS_MASM(masm) | |
17 | |
18 | |
19 void EmitDebugBreakSlot(MacroAssembler* masm) { | |
20 Label check_codesize; | |
21 __ bind(&check_codesize); | |
22 __ Nop(Assembler::kDebugBreakSlotLength); | |
23 DCHECK_EQ(Assembler::kDebugBreakSlotLength, | |
24 masm->SizeOfCodeGeneratedSince(&check_codesize)); | |
25 } | |
26 | |
27 | |
28 void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode, | |
29 int call_argc) { | |
30 // Generate enough nop's to make space for a call instruction. | |
31 masm->RecordDebugBreakSlot(mode, call_argc); | |
32 EmitDebugBreakSlot(masm); | |
33 } | |
34 | |
35 | |
36 void DebugCodegen::ClearDebugBreakSlot(Address pc) { | |
37 CodePatcher patcher(pc, Assembler::kDebugBreakSlotLength); | |
38 EmitDebugBreakSlot(patcher.masm()); | |
39 } | |
40 | |
41 | |
42 void DebugCodegen::PatchDebugBreakSlot(Address pc, Handle<Code> code) { | |
43 DCHECK_EQ(Code::BUILTIN, code->kind()); | |
44 static const int kSize = Assembler::kDebugBreakSlotLength; | |
45 CodePatcher patcher(pc, kSize); | |
46 | |
47 // Add a label for checking the size of the code used for returning. | |
48 Label check_codesize; | |
49 patcher.masm()->bind(&check_codesize); | |
50 patcher.masm()->call(code->entry(), RelocInfo::NONE32); | |
51 // Check that the size of the code generated is as expected. | |
52 DCHECK_EQ(kSize, patcher.masm()->SizeOfCodeGeneratedSince(&check_codesize)); | |
53 } | |
54 | |
55 | |
56 void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm, | |
57 DebugBreakCallHelperMode mode) { | |
58 __ RecordComment("Debug break"); | |
59 | |
60 // Enter an internal frame. | |
61 { | |
62 FrameScope scope(masm, StackFrame::INTERNAL); | |
63 | |
64 // Load padding words on stack. | |
65 for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) { | |
66 __ push(Immediate(Smi::FromInt(LiveEdit::kFramePaddingValue))); | |
67 } | |
68 __ push(Immediate(Smi::FromInt(LiveEdit::kFramePaddingInitialSize))); | |
69 | |
70 if (mode == SAVE_RESULT_REGISTER) __ push(eax); | |
71 | |
72 __ Move(eax, Immediate(0)); // No arguments. | |
73 __ mov(ebx, | |
74 Immediate(ExternalReference( | |
75 Runtime::FunctionForId(Runtime::kDebugBreak), masm->isolate()))); | |
76 | |
77 CEntryStub ceb(masm->isolate(), 1); | |
78 __ CallStub(&ceb); | |
79 | |
80 if (FLAG_debug_code) { | |
81 for (int i = 0; i < kNumJSCallerSaved; ++i) { | |
82 Register reg = {JSCallerSavedCode(i)}; | |
83 __ Move(reg, Immediate(kDebugZapValue)); | |
84 } | |
85 } | |
86 | |
87 if (mode == SAVE_RESULT_REGISTER) __ pop(eax); | |
88 | |
89 __ pop(ebx); | |
90 // We divide stored value by 2 (untagging) and multiply it by word's size. | |
91 STATIC_ASSERT(kSmiTagSize == 1 && kSmiShiftSize == 0); | |
92 __ lea(esp, Operand(esp, ebx, times_half_pointer_size, 0)); | |
93 | |
94 // Get rid of the internal frame. | |
95 } | |
96 | |
97 // This call did not replace a call , so there will be an unwanted | |
98 // return address left on the stack. Here we get rid of that. | |
99 __ add(esp, Immediate(kPointerSize)); | |
100 | |
101 // Now that the break point has been handled, resume normal execution by | |
102 // jumping to the target address intended by the caller and that was | |
103 // overwritten by the address of DebugBreakXXX. | |
104 ExternalReference after_break_target = | |
105 ExternalReference::debug_after_break_target_address(masm->isolate()); | |
106 __ jmp(Operand::StaticVariable(after_break_target)); | |
107 } | |
108 | |
109 | |
110 void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) { | |
111 masm->ret(0); | |
112 } | |
113 | |
114 | |
115 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { | |
116 ExternalReference restarter_frame_function_slot = | |
117 ExternalReference::debug_restarter_frame_function_pointer_address( | |
118 masm->isolate()); | |
119 __ mov(Operand::StaticVariable(restarter_frame_function_slot), Immediate(0)); | |
120 | |
121 // We do not know our frame height, but set esp based on ebp. | |
122 __ lea(esp, Operand(ebp, -1 * kPointerSize)); | |
123 | |
124 __ pop(edi); // Function. | |
125 __ pop(ebp); | |
126 | |
127 // Load context from the function. | |
128 __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset)); | |
129 | |
130 // Get function code. | |
131 __ mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset)); | |
132 __ mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset)); | |
133 __ lea(edx, FieldOperand(edx, Code::kHeaderSize)); | |
134 | |
135 // Re-run JSFunction, edi is function, esi is context. | |
136 __ jmp(edx); | |
137 } | |
138 | |
139 | |
140 const bool LiveEdit::kFrameDropperSupported = true; | |
141 | |
142 #undef __ | |
143 | |
144 } // namespace internal | |
145 } // namespace v8 | |
146 | |
147 #endif // V8_TARGET_ARCH_X87 | |
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