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.
7 #if V8_TARGET_ARCH_IA32
9 #include "src/codegen.h"
10 #include "src/debug.h"
16 bool BreakLocationIterator::IsDebugBreakAtReturn() {
17 return Debug::IsDebugBreakAtReturn(rinfo());
21 // Patch the JS frame exit code with a debug break call. See
22 // CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-ia32.cc
23 // for the precise return instructions sequence.
24 void BreakLocationIterator::SetDebugBreakAtReturn() {
25 DCHECK(Assembler::kJSReturnSequenceLength >=
26 Assembler::kCallInstructionLength);
27 rinfo()->PatchCodeWithCall(
28 debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(),
29 Assembler::kJSReturnSequenceLength - Assembler::kCallInstructionLength);
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(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 Isolate* isolate = debug_info_->GetIsolate();
58 rinfo()->PatchCodeWithCall(
59 isolate->builtins()->Slot_DebugBreak()->entry(),
60 Assembler::kDebugBreakSlotLength - Assembler::kCallInstructionLength);
64 void BreakLocationIterator::ClearDebugBreakAtSlot() {
65 DCHECK(IsDebugBreakSlot());
66 rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength);
70 #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(Immediate(Smi::FromInt(LiveEdit::kFramePaddingValue)));
84 __ push(Immediate(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 a smi 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 if ((object_regs & (1 << r)) != 0) {
98 if ((non_object_regs & (1 << r)) != 0) {
99 if (FLAG_debug_code) {
100 __ test(reg, Immediate(0xc0000000));
101 __ Assert(zero, kUnableToEncodeValueAsSmi);
109 __ RecordComment("// Calling from debug break to runtime - come in - over");
111 __ Move(eax, Immediate(0)); // No arguments.
112 __ mov(ebx, Immediate(ExternalReference::debug_break(masm->isolate())));
114 CEntryStub ceb(masm->isolate(), 1);
117 // Automatically find register that could be used after register restore.
118 // We need one register for padding skip instructions.
119 Register unused_reg = { -1 };
121 // Restore the register values containing object pointers from the
123 for (int i = kNumJSCallerSaved; --i >= 0;) {
124 int r = JSCallerSavedCode(i);
125 Register reg = { r };
126 if (FLAG_debug_code) {
127 __ Move(reg, Immediate(kDebugZapValue));
129 bool taken = reg.code() == esi.code();
130 if ((object_regs & (1 << r)) != 0) {
134 if ((non_object_regs & (1 << r)) != 0) {
144 DCHECK(unused_reg.code() != -1);
146 // Read current padding counter and skip corresponding number of words.
148 // We divide stored value by 2 (untagging) and multiply it by word's size.
149 STATIC_ASSERT(kSmiTagSize == 1 && kSmiShiftSize == 0);
150 __ lea(esp, Operand(esp, unused_reg, times_half_pointer_size, 0));
152 // Get rid of the internal frame.
155 // If this call did not replace a call but patched other code then there will
156 // be an unwanted return address left on the stack. Here we get rid of that.
157 if (convert_call_to_jmp) {
158 __ add(esp, Immediate(kPointerSize));
161 // Now that the break point has been handled, resume normal execution by
162 // jumping to the target address intended by the caller and that was
163 // overwritten by the address of DebugBreakXXX.
164 ExternalReference after_break_target =
165 ExternalReference::debug_after_break_target_address(masm->isolate());
166 __ jmp(Operand::StaticVariable(after_break_target));
170 void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) {
171 // Register state for CallICStub
172 // ----------- S t a t e -------------
173 // -- edx : type feedback slot (smi)
175 // -----------------------------------
176 Generate_DebugBreakCallHelper(masm, edx.bit() | edi.bit(),
181 void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) {
182 // Register state for IC load call (from ic-ia32.cc).
183 Register receiver = LoadIC::ReceiverRegister();
184 Register name = LoadIC::NameRegister();
185 Generate_DebugBreakCallHelper(masm, receiver.bit() | name.bit(), 0, false);
189 void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) {
190 // Register state for IC store call (from ic-ia32.cc).
191 Register receiver = StoreIC::ReceiverRegister();
192 Register name = StoreIC::NameRegister();
193 Register value = StoreIC::ValueRegister();
194 Generate_DebugBreakCallHelper(
195 masm, receiver.bit() | name.bit() | value.bit(), 0, false);
199 void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
200 // Register state for keyed IC load call (from ic-ia32.cc).
201 GenerateLoadICDebugBreak(masm);
205 void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
206 // Register state for keyed IC store call (from ic-ia32.cc).
207 Register receiver = KeyedStoreIC::ReceiverRegister();
208 Register name = KeyedStoreIC::NameRegister();
209 Register value = KeyedStoreIC::ValueRegister();
210 Generate_DebugBreakCallHelper(
211 masm, receiver.bit() | name.bit() | value.bit(), 0, false);
215 void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) {
216 // Register state for CompareNil IC
217 // ----------- S t a t e -------------
219 // -----------------------------------
220 Generate_DebugBreakCallHelper(masm, eax.bit(), 0, false);
224 void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) {
225 // Register state just before return from JS function (from codegen-ia32.cc).
226 // ----------- S t a t e -------------
227 // -- eax: return value
228 // -----------------------------------
229 Generate_DebugBreakCallHelper(masm, eax.bit(), 0, true);
233 void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
234 // Register state for CallFunctionStub (from code-stubs-ia32.cc).
235 // ----------- S t a t e -------------
237 // -----------------------------------
238 Generate_DebugBreakCallHelper(masm, edi.bit(), 0, false);
242 void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
243 // Register state for CallConstructStub (from code-stubs-ia32.cc).
244 // eax is the actual number of arguments not encoded as a smi see comment
246 // ----------- S t a t e -------------
247 // -- eax: number of arguments (not smi)
248 // -- edi: constructor function
249 // -----------------------------------
250 // The number of arguments in eax is not smi encoded.
251 Generate_DebugBreakCallHelper(masm, edi.bit(), eax.bit(), false);
255 void DebugCodegen::GenerateCallConstructStubRecordDebugBreak(
256 MacroAssembler* masm) {
257 // Register state for CallConstructStub (from code-stubs-ia32.cc).
258 // eax is the actual number of arguments not encoded as a smi see comment
260 // ----------- S t a t e -------------
261 // -- eax: number of arguments (not smi)
262 // -- ebx: feedback array
263 // -- edx: feedback slot (smi)
264 // -- edi: constructor function
265 // -----------------------------------
266 // The number of arguments in eax is not smi encoded.
267 Generate_DebugBreakCallHelper(masm, ebx.bit() | edx.bit() | edi.bit(),
272 void DebugCodegen::GenerateSlot(MacroAssembler* masm) {
273 // Generate enough nop's to make space for a call instruction.
274 Label check_codesize;
275 __ bind(&check_codesize);
276 __ RecordDebugBreakSlot();
277 __ Nop(Assembler::kDebugBreakSlotLength);
278 DCHECK_EQ(Assembler::kDebugBreakSlotLength,
279 masm->SizeOfCodeGeneratedSince(&check_codesize));
283 void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) {
284 // In the places where a debug break slot is inserted no registers can contain
286 Generate_DebugBreakCallHelper(masm, 0, 0, true);
290 void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
295 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
296 ExternalReference restarter_frame_function_slot =
297 ExternalReference::debug_restarter_frame_function_pointer_address(
299 __ mov(Operand::StaticVariable(restarter_frame_function_slot), Immediate(0));
301 // We do not know our frame height, but set esp based on ebp.
302 __ lea(esp, Operand(ebp, -1 * kPointerSize));
304 __ pop(edi); // Function.
307 // Load context from the function.
308 __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
310 // Get function code.
311 __ mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
312 __ mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset));
313 __ lea(edx, FieldOperand(edx, Code::kHeaderSize));
315 // Re-run JSFunction, edi is function, esi is context.
320 const bool LiveEdit::kFrameDropperSupported = true;
324 } } // namespace v8::internal
326 #endif // V8_TARGET_ARCH_IA32