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 // Patch the code at the current PC with a call to the target address.
18 // Additional guard int3 instructions can be added if required.
19 void PatchCodeWithCall(Address pc, Address target, int guard_bytes) {
20 int code_size = Assembler::kCallSequenceLength + guard_bytes;
22 // Create a code patcher.
23 CodePatcher patcher(pc, code_size);
25 // Add a label for checking the size of the code used for returning.
28 patcher.masm()->bind(&check_codesize);
32 patcher.masm()->movp(kScratchRegister, reinterpret_cast<void*>(target),
33 Assembler::RelocInfoNone());
34 patcher.masm()->call(kScratchRegister);
36 // Check that the size of the code generated is as expected.
37 DCHECK_EQ(Assembler::kCallSequenceLength,
38 patcher.masm()->SizeOfCodeGeneratedSince(&check_codesize));
40 // Add the requested number of int3 instructions after the call.
41 for (int i = 0; i < guard_bytes; i++) {
42 patcher.masm()->int3();
45 CpuFeatures::FlushICache(pc, code_size);
49 // Patch the JS frame exit code with a debug break call. See
50 // CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-x64.cc
51 // for the precise return instructions sequence.
52 void BreakLocation::SetDebugBreakAtReturn() {
53 DCHECK(Assembler::kJSReturnSequenceLength >= Assembler::kCallSequenceLength);
55 pc(), debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(),
56 Assembler::kJSReturnSequenceLength - Assembler::kCallSequenceLength);
60 void BreakLocation::SetDebugBreakAtSlot() {
61 DCHECK(IsDebugBreakSlot());
63 pc(), debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry(),
64 Assembler::kDebugBreakSlotLength - Assembler::kCallSequenceLength);
68 #define __ ACCESS_MASM(masm)
71 static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
73 RegList non_object_regs,
74 bool convert_call_to_jmp) {
75 // Enter an internal frame.
77 FrameScope scope(masm, StackFrame::INTERNAL);
79 // Load padding words on stack.
80 for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) {
81 __ Push(Smi::FromInt(LiveEdit::kFramePaddingValue));
83 __ Push(Smi::FromInt(LiveEdit::kFramePaddingInitialSize));
85 // Store the registers containing live values on the expression stack to
86 // make sure that these are correctly updated during GC. Non object values
87 // are stored as as two smis causing it to be untouched by GC.
88 DCHECK((object_regs & ~kJSCallerSaved) == 0);
89 DCHECK((non_object_regs & ~kJSCallerSaved) == 0);
90 DCHECK((object_regs & non_object_regs) == 0);
91 for (int i = 0; i < kNumJSCallerSaved; i++) {
92 int r = JSCallerSavedCode(i);
94 DCHECK(!reg.is(kScratchRegister));
95 if ((object_regs & (1 << r)) != 0) {
98 if ((non_object_regs & (1 << r)) != 0) {
99 __ PushRegisterAsTwoSmis(reg);
104 __ RecordComment("// Calling from debug break to runtime - come in - over");
106 __ Set(rax, 0); // No arguments (argc == 0).
107 __ Move(rbx, ExternalReference::debug_break(masm->isolate()));
109 CEntryStub ceb(masm->isolate(), 1);
112 // Restore the register values from the expression stack.
113 for (int i = kNumJSCallerSaved - 1; i >= 0; i--) {
114 int r = JSCallerSavedCode(i);
115 Register reg = { r };
116 if (FLAG_debug_code) {
117 __ Set(reg, kDebugZapValue);
119 if ((object_regs & (1 << r)) != 0) {
122 // Reconstruct the 64-bit value from two smis.
123 if ((non_object_regs & (1 << r)) != 0) {
124 __ PopRegisterAsTwoSmis(reg);
128 // Read current padding counter and skip corresponding number of words.
129 __ Pop(kScratchRegister);
130 __ SmiToInteger32(kScratchRegister, kScratchRegister);
131 __ leap(rsp, Operand(rsp, kScratchRegister, times_pointer_size, 0));
133 // Get rid of the internal frame.
136 // If this call did not replace a call but patched other code then there will
137 // be an unwanted return address left on the stack. Here we get rid of that.
138 if (convert_call_to_jmp) {
139 __ addp(rsp, Immediate(kPCOnStackSize));
142 // Now that the break point has been handled, resume normal execution by
143 // jumping to the target address intended by the caller and that was
144 // overwritten by the address of DebugBreakXXX.
145 ExternalReference after_break_target =
146 ExternalReference::debug_after_break_target_address(masm->isolate());
147 __ Move(kScratchRegister, after_break_target);
148 __ Jump(Operand(kScratchRegister, 0));
152 void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) {
153 // Register state for CallICStub
154 // ----------- S t a t e -------------
155 // -- rdx : type feedback slot (smi)
157 // -----------------------------------
158 Generate_DebugBreakCallHelper(masm, rdx.bit() | rdi.bit(), 0, false);
162 void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) {
163 // Register state for IC load call (from ic-x64.cc).
164 Register receiver = LoadDescriptor::ReceiverRegister();
165 Register name = LoadDescriptor::NameRegister();
166 RegList regs = receiver.bit() | name.bit();
167 if (FLAG_vector_ics) {
168 regs |= VectorLoadICTrampolineDescriptor::SlotRegister().bit();
170 Generate_DebugBreakCallHelper(masm, regs, 0, false);
174 void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) {
175 // Register state for IC store call (from ic-x64.cc).
176 Register receiver = StoreDescriptor::ReceiverRegister();
177 Register name = StoreDescriptor::NameRegister();
178 Register value = StoreDescriptor::ValueRegister();
179 Generate_DebugBreakCallHelper(
180 masm, receiver.bit() | name.bit() | value.bit(), 0, false);
184 void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
185 // Register state for keyed IC load call (from ic-x64.cc).
186 GenerateLoadICDebugBreak(masm);
190 void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
191 // Register state for keyed IC store call (from ic-x64.cc).
192 Register receiver = StoreDescriptor::ReceiverRegister();
193 Register name = StoreDescriptor::NameRegister();
194 Register value = StoreDescriptor::ValueRegister();
195 Generate_DebugBreakCallHelper(
196 masm, receiver.bit() | name.bit() | value.bit(), 0, false);
200 void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) {
201 // Register state for CompareNil IC
202 // ----------- S t a t e -------------
204 // -----------------------------------
205 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, false);
209 void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) {
210 // Register state just before return from JS function (from codegen-x64.cc).
211 // ----------- S t a t e -------------
212 // -- rax: return value
213 // -----------------------------------
214 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, true);
218 void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
219 // Register state for CallFunctionStub (from code-stubs-x64.cc).
220 // ----------- S t a t e -------------
222 // -----------------------------------
223 Generate_DebugBreakCallHelper(masm, rdi.bit(), 0, false);
227 void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
228 // Register state for CallConstructStub (from code-stubs-x64.cc).
229 // rax is the actual number of arguments not encoded as a smi, see comment
231 // ----------- S t a t e -------------
232 // -- rax: number of arguments
233 // -----------------------------------
234 // The number of arguments in rax is not smi encoded.
235 Generate_DebugBreakCallHelper(masm, rdi.bit(), rax.bit(), false);
239 void DebugCodegen::GenerateCallConstructStubRecordDebugBreak(
240 MacroAssembler* masm) {
241 // Register state for CallConstructStub (from code-stubs-x64.cc).
242 // rax is the actual number of arguments not encoded as a smi, see comment
244 // ----------- S t a t e -------------
245 // -- rax: number of arguments
246 // -- rbx: feedback array
247 // -- rdx: feedback slot (smi)
248 // -----------------------------------
249 // The number of arguments in rax is not smi encoded.
250 Generate_DebugBreakCallHelper(masm, rbx.bit() | rdx.bit() | rdi.bit(),
255 void DebugCodegen::GenerateSlot(MacroAssembler* masm) {
256 // Generate enough nop's to make space for a call instruction.
257 Label check_codesize;
258 __ bind(&check_codesize);
259 __ RecordDebugBreakSlot();
260 __ Nop(Assembler::kDebugBreakSlotLength);
261 DCHECK_EQ(Assembler::kDebugBreakSlotLength,
262 masm->SizeOfCodeGeneratedSince(&check_codesize));
266 void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) {
267 // In the places where a debug break slot is inserted no registers can contain
269 Generate_DebugBreakCallHelper(masm, 0, 0, true);
273 void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
278 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
279 ExternalReference restarter_frame_function_slot =
280 ExternalReference::debug_restarter_frame_function_pointer_address(
282 __ Move(rax, restarter_frame_function_slot);
283 __ movp(Operand(rax, 0), Immediate(0));
285 // We do not know our frame height, but set rsp based on rbp.
286 __ leap(rsp, Operand(rbp, -1 * kPointerSize));
288 __ Pop(rdi); // Function.
291 // Load context from the function.
292 __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
294 // Get function code.
295 __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
296 __ movp(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
297 __ leap(rdx, FieldOperand(rdx, Code::kHeaderSize));
299 // Re-run JSFunction, rdi is function, rsi is context.
303 const bool LiveEdit::kFrameDropperSupported = true;
307 } } // namespace v8::internal
309 #endif // V8_TARGET_ARCH_X64