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/codegen.h"
10 #include "src/debug.h"
15 void BreakLocation::SetDebugBreakAtReturn() {
16 // Patch the code changing the return from JS function sequence from
18 // ldmia sp!, {fp, lr}
21 // to a call to the debug break return code.
24 // <debug break return code entry point address>
26 CodePatcher patcher(pc(), Assembler::kJSReturnSequenceInstructions);
27 patcher.masm()->ldr(v8::internal::ip, MemOperand(v8::internal::pc, 0));
28 patcher.masm()->blx(v8::internal::ip);
30 debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry());
31 patcher.masm()->bkpt(0);
35 void BreakLocation::SetDebugBreakAtSlot() {
36 DCHECK(IsDebugBreakSlot());
37 // Patch the code changing the debug break slot code from
41 // to a call to the debug break slot code.
44 // <debug break slot code entry point address>
45 CodePatcher patcher(pc(), Assembler::kDebugBreakSlotInstructions);
46 patcher.masm()->ldr(v8::internal::ip, MemOperand(v8::internal::pc, 0));
47 patcher.masm()->blx(v8::internal::ip);
49 debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry());
53 #define __ ACCESS_MASM(masm)
56 static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
58 RegList non_object_regs) {
60 FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
62 // Load padding words on stack.
63 __ mov(ip, Operand(Smi::FromInt(LiveEdit::kFramePaddingValue)));
64 for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) {
67 __ mov(ip, Operand(Smi::FromInt(LiveEdit::kFramePaddingInitialSize)));
70 // Store the registers containing live values on the expression stack to
71 // make sure that these are correctly updated during GC. Non object values
72 // are stored as a smi causing it to be untouched by GC.
73 DCHECK((object_regs & ~kJSCallerSaved) == 0);
74 DCHECK((non_object_regs & ~kJSCallerSaved) == 0);
75 DCHECK((object_regs & non_object_regs) == 0);
76 if ((object_regs | non_object_regs) != 0) {
77 for (int i = 0; i < kNumJSCallerSaved; i++) {
78 int r = JSCallerSavedCode(i);
80 if ((non_object_regs & (1 << r)) != 0) {
81 if (FLAG_debug_code) {
82 __ tst(reg, Operand(0xc0000000));
83 __ Assert(eq, kUnableToEncodeValueAsSmi);
88 __ stm(db_w, sp, object_regs | non_object_regs);
92 __ RecordComment("// Calling from debug break to runtime - come in - over");
94 __ mov(r0, Operand::Zero()); // no arguments
95 __ mov(r1, Operand(ExternalReference::debug_break(masm->isolate())));
97 CEntryStub ceb(masm->isolate(), 1);
100 // Restore the register values from the expression stack.
101 if ((object_regs | non_object_regs) != 0) {
102 __ ldm(ia_w, sp, object_regs | non_object_regs);
103 for (int i = 0; i < kNumJSCallerSaved; i++) {
104 int r = JSCallerSavedCode(i);
105 Register reg = { r };
106 if ((non_object_regs & (1 << r)) != 0) {
109 if (FLAG_debug_code &&
110 (((object_regs |non_object_regs) & (1 << r)) == 0)) {
111 __ mov(reg, Operand(kDebugZapValue));
116 // Don't bother removing padding bytes pushed on the stack
117 // as the frame is going to be restored right away.
119 // Leave the internal frame.
122 // Now that the break point has been handled, resume normal execution by
123 // jumping to the target address intended by the caller and that was
124 // overwritten by the address of DebugBreakXXX.
125 ExternalReference after_break_target =
126 ExternalReference::debug_after_break_target_address(masm->isolate());
127 __ mov(ip, Operand(after_break_target));
128 __ ldr(ip, MemOperand(ip));
133 void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) {
134 // Register state for CallICStub
135 // ----------- S t a t e -------------
137 // -- r3 : slot in feedback array (smi)
138 // -----------------------------------
139 Generate_DebugBreakCallHelper(masm, r1.bit() | r3.bit(), 0);
143 void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) {
144 // Calling convention for IC load (from ic-arm.cc).
145 Register receiver = LoadDescriptor::ReceiverRegister();
146 Register name = LoadDescriptor::NameRegister();
147 RegList regs = receiver.bit() | name.bit();
148 if (FLAG_vector_ics) {
149 regs |= VectorLoadICTrampolineDescriptor::SlotRegister().bit();
151 Generate_DebugBreakCallHelper(masm, regs, 0);
155 void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) {
156 // Calling convention for IC store (from ic-arm.cc).
157 Register receiver = StoreDescriptor::ReceiverRegister();
158 Register name = StoreDescriptor::NameRegister();
159 Register value = StoreDescriptor::ValueRegister();
160 Generate_DebugBreakCallHelper(
161 masm, receiver.bit() | name.bit() | value.bit(), 0);
165 void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
166 // Calling convention for keyed IC load (from ic-arm.cc).
167 GenerateLoadICDebugBreak(masm);
171 void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
172 // Calling convention for IC keyed store call (from ic-arm.cc).
173 Register receiver = StoreDescriptor::ReceiverRegister();
174 Register name = StoreDescriptor::NameRegister();
175 Register value = StoreDescriptor::ValueRegister();
176 Generate_DebugBreakCallHelper(
177 masm, receiver.bit() | name.bit() | value.bit(), 0);
181 void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) {
182 // Register state for CompareNil IC
183 // ----------- S t a t e -------------
185 // -----------------------------------
186 Generate_DebugBreakCallHelper(masm, r0.bit(), 0);
190 void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) {
191 // In places other than IC call sites it is expected that r0 is TOS which
192 // is an object - this is not generally the case so this should be used with
194 Generate_DebugBreakCallHelper(masm, r0.bit(), 0);
198 void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
199 // Register state for CallFunctionStub (from code-stubs-arm.cc).
200 // ----------- S t a t e -------------
202 // -----------------------------------
203 Generate_DebugBreakCallHelper(masm, r1.bit(), 0);
207 void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
208 // Calling convention for CallConstructStub (from code-stubs-arm.cc)
209 // ----------- S t a t e -------------
210 // -- r0 : number of arguments (not smi)
211 // -- r1 : constructor function
212 // -----------------------------------
213 Generate_DebugBreakCallHelper(masm, r1.bit(), r0.bit());
217 void DebugCodegen::GenerateCallConstructStubRecordDebugBreak(
218 MacroAssembler* masm) {
219 // Calling convention for CallConstructStub (from code-stubs-arm.cc)
220 // ----------- S t a t e -------------
221 // -- r0 : number of arguments (not smi)
222 // -- r1 : constructor function
223 // -- r2 : feedback array
224 // -- r3 : feedback slot (smi)
225 // -----------------------------------
226 Generate_DebugBreakCallHelper(masm, r1.bit() | r2.bit() | r3.bit(), r0.bit());
230 void DebugCodegen::GenerateSlot(MacroAssembler* masm) {
231 // Generate enough nop's to make space for a call instruction. Avoid emitting
232 // the constant pool in the debug break slot code.
233 Assembler::BlockConstPoolScope block_const_pool(masm);
234 Label check_codesize;
235 __ bind(&check_codesize);
236 __ RecordDebugBreakSlot();
237 for (int i = 0; i < Assembler::kDebugBreakSlotInstructions; i++) {
238 __ nop(MacroAssembler::DEBUG_BREAK_NOP);
240 DCHECK_EQ(Assembler::kDebugBreakSlotInstructions,
241 masm->InstructionsGeneratedSince(&check_codesize));
245 void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) {
246 // In the places where a debug break slot is inserted no registers can contain
248 Generate_DebugBreakCallHelper(masm, 0, 0);
252 void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
257 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
258 ExternalReference restarter_frame_function_slot =
259 ExternalReference::debug_restarter_frame_function_pointer_address(
261 __ mov(ip, Operand(restarter_frame_function_slot));
262 __ mov(r1, Operand::Zero());
263 __ str(r1, MemOperand(ip, 0));
265 // Load the function pointer off of our current stack frame.
266 __ ldr(r1, MemOperand(fp,
267 StandardFrameConstants::kConstantPoolOffset - kPointerSize));
269 // Pop return address, frame and constant pool pointer (if
270 // FLAG_enable_ool_constant_pool).
271 __ LeaveFrame(StackFrame::INTERNAL);
273 { ConstantPoolUnavailableScope constant_pool_unavailable(masm);
274 // Load context from the function.
275 __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
277 // Get function code.
278 __ ldr(ip, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
279 __ ldr(ip, FieldMemOperand(ip, SharedFunctionInfo::kCodeOffset));
280 __ add(ip, ip, Operand(Code::kHeaderSize - kHeapObjectTag));
282 // Re-run JSFunction, r1 is function, cp is context.
288 const bool LiveEdit::kFrameDropperSupported = true;
292 } } // namespace v8::internal
294 #endif // V8_TARGET_ARCH_ARM