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.
9 #include "src/assembler.h"
10 #include "src/codegen.h"
11 #include "src/debug.h"
17 bool BreakLocationIterator::IsDebugBreakAtReturn() {
18 return Debug::IsDebugBreakAtReturn(rinfo());
22 // Patch the JS frame exit code with a debug break call. See
23 // CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-x64.cc
24 // for the precise return instructions sequence.
25 void BreakLocationIterator::SetDebugBreakAtReturn() {
26 DCHECK(Assembler::kJSReturnSequenceLength >= Assembler::kCallSequenceLength);
27 rinfo()->PatchCodeWithCall(
28 debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(),
29 Assembler::kJSReturnSequenceLength - Assembler::kCallSequenceLength);
33 // Restore the JS frame exit code.
34 void BreakLocationIterator::ClearDebugBreakAtReturn() {
35 rinfo()->PatchCode(original_rinfo()->pc(),
36 Assembler::kJSReturnSequenceLength);
40 // A debug break in the frame exit code is identified by the JS frame exit code
41 // having been patched with a call instruction.
42 bool Debug::IsDebugBreakAtReturn(v8::internal::RelocInfo* rinfo) {
43 DCHECK(RelocInfo::IsJSReturn(rinfo->rmode()));
44 return rinfo->IsPatchedReturnSequence();
48 bool BreakLocationIterator::IsDebugBreakAtSlot() {
49 DCHECK(IsDebugBreakSlot());
50 // Check whether the debug break slot instructions have been patched.
51 return rinfo()->IsPatchedDebugBreakSlotSequence();
55 void BreakLocationIterator::SetDebugBreakAtSlot() {
56 DCHECK(IsDebugBreakSlot());
57 rinfo()->PatchCodeWithCall(
58 debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry(),
59 Assembler::kDebugBreakSlotLength - Assembler::kCallSequenceLength);
63 void BreakLocationIterator::ClearDebugBreakAtSlot() {
64 DCHECK(IsDebugBreakSlot());
65 rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength);
69 #define __ ACCESS_MASM(masm)
72 static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
74 RegList non_object_regs,
75 bool convert_call_to_jmp) {
76 // Enter an internal frame.
78 FrameScope scope(masm, StackFrame::INTERNAL);
80 // Load padding words on stack.
81 for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) {
82 __ Push(Smi::FromInt(LiveEdit::kFramePaddingValue));
84 __ Push(Smi::FromInt(LiveEdit::kFramePaddingInitialSize));
86 // Store the registers containing live values on the expression stack to
87 // make sure that these are correctly updated during GC. Non object values
88 // are stored as as two smis causing it to be untouched by GC.
89 DCHECK((object_regs & ~kJSCallerSaved) == 0);
90 DCHECK((non_object_regs & ~kJSCallerSaved) == 0);
91 DCHECK((object_regs & non_object_regs) == 0);
92 for (int i = 0; i < kNumJSCallerSaved; i++) {
93 int r = JSCallerSavedCode(i);
95 DCHECK(!reg.is(kScratchRegister));
96 if ((object_regs & (1 << r)) != 0) {
99 if ((non_object_regs & (1 << r)) != 0) {
100 __ PushRegisterAsTwoSmis(reg);
105 __ RecordComment("// Calling from debug break to runtime - come in - over");
107 __ Set(rax, 0); // No arguments (argc == 0).
108 __ Move(rbx, ExternalReference::debug_break(masm->isolate()));
110 CEntryStub ceb(masm->isolate(), 1);
113 // Restore the register values from the expression stack.
114 for (int i = kNumJSCallerSaved - 1; i >= 0; i--) {
115 int r = JSCallerSavedCode(i);
116 Register reg = { r };
117 if (FLAG_debug_code) {
118 __ Set(reg, kDebugZapValue);
120 if ((object_regs & (1 << r)) != 0) {
123 // Reconstruct the 64-bit value from two smis.
124 if ((non_object_regs & (1 << r)) != 0) {
125 __ PopRegisterAsTwoSmis(reg);
129 // Read current padding counter and skip corresponding number of words.
130 __ Pop(kScratchRegister);
131 __ SmiToInteger32(kScratchRegister, kScratchRegister);
132 __ leap(rsp, Operand(rsp, kScratchRegister, times_pointer_size, 0));
134 // Get rid of the internal frame.
137 // If this call did not replace a call but patched other code then there will
138 // be an unwanted return address left on the stack. Here we get rid of that.
139 if (convert_call_to_jmp) {
140 __ addp(rsp, Immediate(kPCOnStackSize));
143 // Now that the break point has been handled, resume normal execution by
144 // jumping to the target address intended by the caller and that was
145 // overwritten by the address of DebugBreakXXX.
146 ExternalReference after_break_target =
147 ExternalReference::debug_after_break_target_address(masm->isolate());
148 __ Move(kScratchRegister, after_break_target);
149 __ Jump(Operand(kScratchRegister, 0));
153 void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) {
154 // Register state for CallICStub
155 // ----------- S t a t e -------------
156 // -- rdx : type feedback slot (smi)
158 // -----------------------------------
159 Generate_DebugBreakCallHelper(masm, rdx.bit() | rdi.bit(), 0, false);
163 void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) {
164 // Register state for IC load call (from ic-x64.cc).
165 Register receiver = LoadDescriptor::ReceiverRegister();
166 Register name = LoadDescriptor::NameRegister();
167 RegList regs = receiver.bit() | name.bit();
168 if (FLAG_vector_ics) {
169 regs |= VectorLoadICTrampolineDescriptor::SlotRegister().bit();
171 Generate_DebugBreakCallHelper(masm, regs, 0, false);
175 void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) {
176 // Register state for IC store call (from ic-x64.cc).
177 Register receiver = StoreDescriptor::ReceiverRegister();
178 Register name = StoreDescriptor::NameRegister();
179 Register value = StoreDescriptor::ValueRegister();
180 Generate_DebugBreakCallHelper(
181 masm, receiver.bit() | name.bit() | value.bit(), 0, false);
185 void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
186 // Register state for keyed IC load call (from ic-x64.cc).
187 GenerateLoadICDebugBreak(masm);
191 void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
192 // Register state for keyed IC store call (from ic-x64.cc).
193 Register receiver = StoreDescriptor::ReceiverRegister();
194 Register name = StoreDescriptor::NameRegister();
195 Register value = StoreDescriptor::ValueRegister();
196 Generate_DebugBreakCallHelper(
197 masm, receiver.bit() | name.bit() | value.bit(), 0, false);
201 void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) {
202 // Register state for CompareNil IC
203 // ----------- S t a t e -------------
205 // -----------------------------------
206 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, false);
210 void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) {
211 // Register state just before return from JS function (from codegen-x64.cc).
212 // ----------- S t a t e -------------
213 // -- rax: return value
214 // -----------------------------------
215 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, true);
219 void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
220 // Register state for CallFunctionStub (from code-stubs-x64.cc).
221 // ----------- S t a t e -------------
223 // -----------------------------------
224 Generate_DebugBreakCallHelper(masm, rdi.bit(), 0, false);
228 void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
229 // Register state for CallConstructStub (from code-stubs-x64.cc).
230 // rax is the actual number of arguments not encoded as a smi, see comment
232 // ----------- S t a t e -------------
233 // -- rax: number of arguments
234 // -----------------------------------
235 // The number of arguments in rax is not smi encoded.
236 Generate_DebugBreakCallHelper(masm, rdi.bit(), rax.bit(), false);
240 void DebugCodegen::GenerateCallConstructStubRecordDebugBreak(
241 MacroAssembler* masm) {
242 // Register state for CallConstructStub (from code-stubs-x64.cc).
243 // rax is the actual number of arguments not encoded as a smi, see comment
245 // ----------- S t a t e -------------
246 // -- rax: number of arguments
247 // -- rbx: feedback array
248 // -- rdx: feedback slot (smi)
249 // -----------------------------------
250 // The number of arguments in rax is not smi encoded.
251 Generate_DebugBreakCallHelper(masm, rbx.bit() | rdx.bit() | rdi.bit(),
256 void DebugCodegen::GenerateSlot(MacroAssembler* masm) {
257 // Generate enough nop's to make space for a call instruction.
258 Label check_codesize;
259 __ bind(&check_codesize);
260 __ RecordDebugBreakSlot();
261 __ Nop(Assembler::kDebugBreakSlotLength);
262 DCHECK_EQ(Assembler::kDebugBreakSlotLength,
263 masm->SizeOfCodeGeneratedSince(&check_codesize));
267 void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) {
268 // In the places where a debug break slot is inserted no registers can contain
270 Generate_DebugBreakCallHelper(masm, 0, 0, true);
274 void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
279 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
280 ExternalReference restarter_frame_function_slot =
281 ExternalReference::debug_restarter_frame_function_pointer_address(
283 __ Move(rax, restarter_frame_function_slot);
284 __ movp(Operand(rax, 0), Immediate(0));
286 // We do not know our frame height, but set rsp based on rbp.
287 __ leap(rsp, Operand(rbp, -1 * kPointerSize));
289 __ Pop(rdi); // Function.
292 // Load context from the function.
293 __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
295 // Get function code.
296 __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
297 __ movp(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
298 __ leap(rdx, FieldOperand(rdx, Code::kHeaderSize));
300 // Re-run JSFunction, rdi is function, rsi is context.
304 const bool LiveEdit::kFrameDropperSupported = true;
308 } } // namespace v8::internal
310 #endif // V8_TARGET_ARCH_X64