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 #if V8_TARGET_ARCH_X64
6
7 #include "src/assembler.h"
8 #include "src/codegen.h"
9 #include "src/debug/debug.h"
10
11
12 namespace v8 {
13 namespace internal {
14
15 #define __ ACCESS_MASM(masm)
16
17
EmitDebugBreakSlot(MacroAssembler * masm)18 void EmitDebugBreakSlot(MacroAssembler* masm) {
19 Label check_codesize;
20 __ bind(&check_codesize);
21 __ Nop(Assembler::kDebugBreakSlotLength);
22 DCHECK_EQ(Assembler::kDebugBreakSlotLength,
23 masm->SizeOfCodeGeneratedSince(&check_codesize));
24 }
25
26
GenerateSlot(MacroAssembler * masm,RelocInfo::Mode mode)27 void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode) {
28 // Generate enough nop's to make space for a call instruction.
29 masm->RecordDebugBreakSlot(mode);
30 EmitDebugBreakSlot(masm);
31 }
32
33
ClearDebugBreakSlot(Isolate * isolate,Address pc)34 void DebugCodegen::ClearDebugBreakSlot(Isolate* isolate, Address pc) {
35 CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotLength);
36 EmitDebugBreakSlot(patcher.masm());
37 }
38
39
PatchDebugBreakSlot(Isolate * isolate,Address pc,Handle<Code> code)40 void DebugCodegen::PatchDebugBreakSlot(Isolate* isolate, Address pc,
41 Handle<Code> code) {
42 DCHECK_EQ(Code::BUILTIN, code->kind());
43 static const int kSize = Assembler::kDebugBreakSlotLength;
44 CodePatcher patcher(isolate, pc, kSize);
45 Label check_codesize;
46 patcher.masm()->bind(&check_codesize);
47 patcher.masm()->movp(kScratchRegister, reinterpret_cast<void*>(code->entry()),
48 Assembler::RelocInfoNone());
49 patcher.masm()->call(kScratchRegister);
50 // Check that the size of the code generated is as expected.
51 DCHECK_EQ(kSize, patcher.masm()->SizeOfCodeGeneratedSince(&check_codesize));
52 }
53
54
GenerateDebugBreakStub(MacroAssembler * masm,DebugBreakCallHelperMode mode)55 void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm,
56 DebugBreakCallHelperMode mode) {
57 __ RecordComment("Debug break");
58
59 // Enter an internal frame.
60 {
61 FrameScope scope(masm, StackFrame::INTERNAL);
62
63 // Load padding words on stack.
64 for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) {
65 __ Push(Smi::FromInt(LiveEdit::kFramePaddingValue));
66 }
67 __ Push(Smi::FromInt(LiveEdit::kFramePaddingInitialSize));
68
69 if (mode == SAVE_RESULT_REGISTER) __ Push(rax);
70
71 __ Set(rax, 0); // No arguments (argc == 0).
72 __ Move(rbx, ExternalReference(Runtime::FunctionForId(Runtime::kDebugBreak),
73 masm->isolate()));
74
75 CEntryStub ceb(masm->isolate(), 1);
76 __ CallStub(&ceb);
77
78 if (FLAG_debug_code) {
79 for (int i = 0; i < kNumJSCallerSaved; ++i) {
80 Register reg = {JSCallerSavedCode(i)};
81 __ Set(reg, kDebugZapValue);
82 }
83 }
84
85 if (mode == SAVE_RESULT_REGISTER) __ Pop(rax);
86
87 // Read current padding counter and skip corresponding number of words.
88 __ Pop(kScratchRegister);
89 __ SmiToInteger32(kScratchRegister, kScratchRegister);
90 __ leap(rsp, Operand(rsp, kScratchRegister, times_pointer_size, 0));
91
92 // Get rid of the internal frame.
93 }
94
95 // This call did not replace a call , so there will be an unwanted
96 // return address left on the stack. Here we get rid of that.
97 __ addp(rsp, Immediate(kPCOnStackSize));
98
99 // Now that the break point has been handled, resume normal execution by
100 // jumping to the target address intended by the caller and that was
101 // overwritten by the address of DebugBreakXXX.
102 ExternalReference after_break_target =
103 ExternalReference::debug_after_break_target_address(masm->isolate());
104 __ Move(kScratchRegister, after_break_target);
105 __ Jump(Operand(kScratchRegister, 0));
106 }
107
108
GenerateFrameDropperLiveEdit(MacroAssembler * masm)109 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
110 // We do not know our frame height, but set rsp based on rbp.
111 __ leap(rsp, Operand(rbp, -1 * kPointerSize));
112
113 __ Pop(rdi); // Function.
114 __ popq(rbp);
115
116 ParameterCount dummy(0);
117 __ FloodFunctionIfStepping(rdi, no_reg, dummy, dummy);
118
119 // Load context from the function.
120 __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
121
122 // Clear new.target as a safety measure.
123 __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
124
125 // Get function code.
126 __ movp(rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
127 __ movp(rbx, FieldOperand(rbx, SharedFunctionInfo::kCodeOffset));
128 __ leap(rbx, FieldOperand(rbx, Code::kHeaderSize));
129
130 // Re-run JSFunction, rdi is function, rsi is context.
131 __ jmp(rbx);
132 }
133
134 const bool LiveEdit::kFrameDropperSupported = true;
135
136 #undef __
137
138 } // namespace internal
139 } // namespace v8
140
141 #endif // V8_TARGET_ARCH_X64
142