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_IA32
6
7 #include "src/debug/debug.h"
8
9 #include "src/codegen.h"
10 #include "src/debug/liveedit.h"
11 #include "src/ia32/frames-ia32.h"
12
13 namespace v8 {
14 namespace internal {
15
16 #define __ ACCESS_MASM(masm)
17
18
EmitDebugBreakSlot(MacroAssembler * masm)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
GenerateSlot(MacroAssembler * masm,RelocInfo::Mode mode)28 void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode) {
29 // Generate enough nop's to make space for a call instruction.
30 masm->RecordDebugBreakSlot(mode);
31 EmitDebugBreakSlot(masm);
32 }
33
34
ClearDebugBreakSlot(Isolate * isolate,Address pc)35 void DebugCodegen::ClearDebugBreakSlot(Isolate* isolate, Address pc) {
36 CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotLength);
37 EmitDebugBreakSlot(patcher.masm());
38 }
39
40
PatchDebugBreakSlot(Isolate * isolate,Address pc,Handle<Code> code)41 void DebugCodegen::PatchDebugBreakSlot(Isolate* isolate, Address pc,
42 Handle<Code> code) {
43 DCHECK(code->is_debug_stub());
44 static const int kSize = Assembler::kDebugBreakSlotLength;
45 CodePatcher patcher(isolate, 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
DebugBreakSlotIsPatched(Address pc)55 bool DebugCodegen::DebugBreakSlotIsPatched(Address pc) {
56 return !Assembler::IsNop(pc);
57 }
58
GenerateDebugBreakStub(MacroAssembler * masm,DebugBreakCallHelperMode mode)59 void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm,
60 DebugBreakCallHelperMode mode) {
61 __ RecordComment("Debug break");
62
63 // Enter an internal frame.
64 {
65 FrameScope scope(masm, StackFrame::INTERNAL);
66
67 // Push arguments for DebugBreak call.
68 if (mode == SAVE_RESULT_REGISTER) {
69 // Break on return.
70 __ push(eax);
71 } else {
72 // Non-return breaks.
73 __ Push(masm->isolate()->factory()->the_hole_value());
74 }
75 __ Move(eax, Immediate(1));
76 __ mov(ebx,
77 Immediate(ExternalReference(
78 Runtime::FunctionForId(Runtime::kDebugBreak), masm->isolate())));
79
80 CEntryStub ceb(masm->isolate(), 1);
81 __ CallStub(&ceb);
82
83 if (FLAG_debug_code) {
84 for (int i = 0; i < kNumJSCallerSaved; ++i) {
85 Register reg = {JSCallerSavedCode(i)};
86 // Do not clobber eax if mode is SAVE_RESULT_REGISTER. It will
87 // contain return value of the function.
88 if (!(reg.is(eax) && (mode == SAVE_RESULT_REGISTER))) {
89 __ Move(reg, Immediate(kDebugZapValue));
90 }
91 }
92 }
93 // Get rid of the internal frame.
94 }
95
96 __ MaybeDropFrames();
97
98 // Return to caller.
99 __ ret(0);
100 }
101
GenerateHandleDebuggerStatement(MacroAssembler * masm)102 void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
103 {
104 FrameScope scope(masm, StackFrame::INTERNAL);
105 __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
106 }
107 __ MaybeDropFrames();
108
109 // Return to caller.
110 __ ret(0);
111 }
112
GenerateFrameDropperTrampoline(MacroAssembler * masm)113 void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
114 // Frame is being dropped:
115 // - Drop to the target frame specified by ebx.
116 // - Look up current function on the frame.
117 // - Leave the frame.
118 // - Restart the frame by calling the function.
119 __ mov(ebp, ebx);
120 __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
121 __ leave();
122
123 __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
124 __ mov(ebx,
125 FieldOperand(ebx, SharedFunctionInfo::kFormalParameterCountOffset));
126
127 ParameterCount dummy(ebx);
128 __ InvokeFunction(edi, dummy, dummy, JUMP_FUNCTION,
129 CheckDebugStepCallWrapper());
130 }
131
132
133 const bool LiveEdit::kFrameDropperSupported = true;
134
135 #undef __
136
137 } // namespace internal
138 } // namespace v8
139
140 #endif // V8_TARGET_ARCH_IA32
141