| // Copyright 2013 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/v8.h" |
| |
| #if V8_TARGET_ARCH_ARM64 |
| |
| #include "src/codegen.h" |
| #include "src/debug.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| #define __ ACCESS_MASM(masm) |
| |
| bool BreakLocationIterator::IsDebugBreakAtReturn() { |
| return Debug::IsDebugBreakAtReturn(rinfo()); |
| } |
| |
| |
| void BreakLocationIterator::SetDebugBreakAtReturn() { |
| // Patch the code emitted by FullCodeGenerator::EmitReturnSequence, changing |
| // the return from JS function sequence from |
| // mov sp, fp |
| // ldp fp, lr, [sp] #16 |
| // lrd ip0, [pc, #(3 * kInstructionSize)] |
| // add sp, sp, ip0 |
| // ret |
| // <number of paramters ... |
| // ... plus one (64 bits)> |
| // to a call to the debug break return code. |
| // ldr ip0, [pc, #(3 * kInstructionSize)] |
| // blr ip0 |
| // hlt kHltBadCode @ code should not return, catch if it does. |
| // <debug break return code ... |
| // ... entry point address (64 bits)> |
| |
| // The patching code must not overflow the space occupied by the return |
| // sequence. |
| STATIC_ASSERT(Assembler::kJSRetSequenceInstructions >= 5); |
| PatchingAssembler patcher(reinterpret_cast<Instruction*>(rinfo()->pc()), 5); |
| byte* entry = |
| debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(); |
| |
| // The first instruction of a patched return sequence must be a load literal |
| // loading the address of the debug break return code. |
| patcher.ldr_pcrel(ip0, (3 * kInstructionSize) >> kLoadLiteralScaleLog2); |
| // TODO(all): check the following is correct. |
| // The debug break return code will push a frame and call statically compiled |
| // code. By using blr, even though control will not return after the branch, |
| // this call site will be registered in the frame (lr being saved as the pc |
| // of the next instruction to execute for this frame). The debugger can now |
| // iterate on the frames to find call to debug break return code. |
| patcher.blr(ip0); |
| patcher.hlt(kHltBadCode); |
| patcher.dc64(reinterpret_cast<int64_t>(entry)); |
| } |
| |
| |
| void BreakLocationIterator::ClearDebugBreakAtReturn() { |
| // Reset the code emitted by EmitReturnSequence to its original state. |
| rinfo()->PatchCode(original_rinfo()->pc(), |
| Assembler::kJSRetSequenceInstructions); |
| } |
| |
| |
| bool Debug::IsDebugBreakAtReturn(RelocInfo* rinfo) { |
| DCHECK(RelocInfo::IsJSReturn(rinfo->rmode())); |
| return rinfo->IsPatchedReturnSequence(); |
| } |
| |
| |
| bool BreakLocationIterator::IsDebugBreakAtSlot() { |
| DCHECK(IsDebugBreakSlot()); |
| // Check whether the debug break slot instructions have been patched. |
| return rinfo()->IsPatchedDebugBreakSlotSequence(); |
| } |
| |
| |
| void BreakLocationIterator::SetDebugBreakAtSlot() { |
| // Patch the code emitted by DebugCodegen::GenerateSlots, changing the debug |
| // break slot code from |
| // mov x0, x0 @ nop DEBUG_BREAK_NOP |
| // mov x0, x0 @ nop DEBUG_BREAK_NOP |
| // mov x0, x0 @ nop DEBUG_BREAK_NOP |
| // mov x0, x0 @ nop DEBUG_BREAK_NOP |
| // to a call to the debug slot code. |
| // ldr ip0, [pc, #(2 * kInstructionSize)] |
| // blr ip0 |
| // <debug break slot code ... |
| // ... entry point address (64 bits)> |
| |
| // TODO(all): consider adding a hlt instruction after the blr as we don't |
| // expect control to return here. This implies increasing |
| // kDebugBreakSlotInstructions to 5 instructions. |
| |
| // The patching code must not overflow the space occupied by the return |
| // sequence. |
| STATIC_ASSERT(Assembler::kDebugBreakSlotInstructions >= 4); |
| PatchingAssembler patcher(reinterpret_cast<Instruction*>(rinfo()->pc()), 4); |
| byte* entry = |
| debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry(); |
| |
| // The first instruction of a patched debug break slot must be a load literal |
| // loading the address of the debug break slot code. |
| patcher.ldr_pcrel(ip0, (2 * kInstructionSize) >> kLoadLiteralScaleLog2); |
| // TODO(all): check the following is correct. |
| // The debug break slot code will push a frame and call statically compiled |
| // code. By using blr, event hough control will not return after the branch, |
| // this call site will be registered in the frame (lr being saved as the pc |
| // of the next instruction to execute for this frame). The debugger can now |
| // iterate on the frames to find call to debug break slot code. |
| patcher.blr(ip0); |
| patcher.dc64(reinterpret_cast<int64_t>(entry)); |
| } |
| |
| |
| void BreakLocationIterator::ClearDebugBreakAtSlot() { |
| DCHECK(IsDebugBreakSlot()); |
| rinfo()->PatchCode(original_rinfo()->pc(), |
| Assembler::kDebugBreakSlotInstructions); |
| } |
| |
| |
| static void Generate_DebugBreakCallHelper(MacroAssembler* masm, |
| RegList object_regs, |
| RegList non_object_regs, |
| Register scratch) { |
| { |
| FrameScope scope(masm, StackFrame::INTERNAL); |
| |
| // Load padding words on stack. |
| __ Mov(scratch, Smi::FromInt(LiveEdit::kFramePaddingValue)); |
| __ PushMultipleTimes(scratch, LiveEdit::kFramePaddingInitialSize); |
| __ Mov(scratch, Smi::FromInt(LiveEdit::kFramePaddingInitialSize)); |
| __ Push(scratch); |
| |
| // Any live values (object_regs and non_object_regs) in caller-saved |
| // registers (or lr) need to be stored on the stack so that their values are |
| // safely preserved for a call into C code. |
| // |
| // Also: |
| // * object_regs may be modified during the C code by the garbage |
| // collector. Every object register must be a valid tagged pointer or |
| // SMI. |
| // |
| // * non_object_regs will be converted to SMIs so that the garbage |
| // collector doesn't try to interpret them as pointers. |
| // |
| // TODO(jbramley): Why can't this handle callee-saved registers? |
| DCHECK((~kCallerSaved.list() & object_regs) == 0); |
| DCHECK((~kCallerSaved.list() & non_object_regs) == 0); |
| DCHECK((object_regs & non_object_regs) == 0); |
| DCHECK((scratch.Bit() & object_regs) == 0); |
| DCHECK((scratch.Bit() & non_object_regs) == 0); |
| DCHECK((masm->TmpList()->list() & (object_regs | non_object_regs)) == 0); |
| STATIC_ASSERT(kSmiValueSize == 32); |
| |
| CPURegList non_object_list = |
| CPURegList(CPURegister::kRegister, kXRegSizeInBits, non_object_regs); |
| while (!non_object_list.IsEmpty()) { |
| // Store each non-object register as two SMIs. |
| Register reg = Register(non_object_list.PopLowestIndex()); |
| __ Lsr(scratch, reg, 32); |
| __ SmiTagAndPush(scratch, reg); |
| |
| // Stack: |
| // jssp[12]: reg[63:32] |
| // jssp[8]: 0x00000000 (SMI tag & padding) |
| // jssp[4]: reg[31:0] |
| // jssp[0]: 0x00000000 (SMI tag & padding) |
| STATIC_ASSERT(kSmiTag == 0); |
| STATIC_ASSERT(static_cast<unsigned>(kSmiShift) == kWRegSizeInBits); |
| } |
| |
| if (object_regs != 0) { |
| __ PushXRegList(object_regs); |
| } |
| |
| #ifdef DEBUG |
| __ RecordComment("// Calling from debug break to runtime - come in - over"); |
| #endif |
| __ Mov(x0, 0); // No arguments. |
| __ Mov(x1, ExternalReference::debug_break(masm->isolate())); |
| |
| CEntryStub stub(masm->isolate(), 1); |
| __ CallStub(&stub); |
| |
| // Restore the register values from the expression stack. |
| if (object_regs != 0) { |
| __ PopXRegList(object_regs); |
| } |
| |
| non_object_list = |
| CPURegList(CPURegister::kRegister, kXRegSizeInBits, non_object_regs); |
| while (!non_object_list.IsEmpty()) { |
| // Load each non-object register from two SMIs. |
| // Stack: |
| // jssp[12]: reg[63:32] |
| // jssp[8]: 0x00000000 (SMI tag & padding) |
| // jssp[4]: reg[31:0] |
| // jssp[0]: 0x00000000 (SMI tag & padding) |
| Register reg = Register(non_object_list.PopHighestIndex()); |
| __ Pop(scratch, reg); |
| __ Bfxil(reg, scratch, 32, 32); |
| } |
| |
| // Don't bother removing padding bytes pushed on the stack |
| // as the frame is going to be restored right away. |
| |
| // Leave the internal frame. |
| } |
| |
| // Now that the break point has been handled, resume normal execution by |
| // jumping to the target address intended by the caller and that was |
| // overwritten by the address of DebugBreakXXX. |
| ExternalReference after_break_target = |
| ExternalReference::debug_after_break_target_address(masm->isolate()); |
| __ Mov(scratch, after_break_target); |
| __ Ldr(scratch, MemOperand(scratch)); |
| __ Br(scratch); |
| } |
| |
| |
| void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallICStub |
| // ----------- S t a t e ------------- |
| // -- x1 : function |
| // -- x3 : slot in feedback array |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, x1.Bit() | x3.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for IC load (from ic-arm.cc). |
| Register receiver = LoadIC::ReceiverRegister(); |
| Register name = LoadIC::NameRegister(); |
| Generate_DebugBreakCallHelper(masm, receiver.Bit() | name.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for IC store (from ic-arm64.cc). |
| Register receiver = StoreIC::ReceiverRegister(); |
| Register name = StoreIC::NameRegister(); |
| Register value = StoreIC::ValueRegister(); |
| Generate_DebugBreakCallHelper( |
| masm, receiver.Bit() | name.Bit() | value.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for keyed IC load (from ic-arm.cc). |
| GenerateLoadICDebugBreak(masm); |
| } |
| |
| |
| void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for IC keyed store call (from ic-arm64.cc). |
| Register receiver = KeyedStoreIC::ReceiverRegister(); |
| Register name = KeyedStoreIC::NameRegister(); |
| Register value = KeyedStoreIC::ValueRegister(); |
| Generate_DebugBreakCallHelper( |
| masm, receiver.Bit() | name.Bit() | value.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) { |
| // Register state for CompareNil IC |
| // ----------- S t a t e ------------- |
| // -- r0 : value |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, x0.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) { |
| // In places other than IC call sites it is expected that r0 is TOS which |
| // is an object - this is not generally the case so this should be used with |
| // care. |
| Generate_DebugBreakCallHelper(masm, x0.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallFunctionStub (from code-stubs-arm64.cc). |
| // ----------- S t a t e ------------- |
| // -- x1 : function |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, x1.Bit(), 0, x10); |
| } |
| |
| |
| void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) { |
| // Calling convention for CallConstructStub (from code-stubs-arm64.cc). |
| // ----------- S t a t e ------------- |
| // -- x0 : number of arguments (not smi) |
| // -- x1 : constructor function |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, x1.Bit(), x0.Bit(), x10); |
| } |
| |
| |
| void DebugCodegen::GenerateCallConstructStubRecordDebugBreak( |
| MacroAssembler* masm) { |
| // Calling convention for CallConstructStub (from code-stubs-arm64.cc). |
| // ----------- S t a t e ------------- |
| // -- x0 : number of arguments (not smi) |
| // -- x1 : constructor function |
| // -- x2 : feedback array |
| // -- x3 : feedback slot (smi) |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper( |
| masm, x1.Bit() | x2.Bit() | x3.Bit(), x0.Bit(), x10); |
| } |
| |
| |
| void DebugCodegen::GenerateSlot(MacroAssembler* masm) { |
| // Generate enough nop's to make space for a call instruction. Avoid emitting |
| // the constant pool in the debug break slot code. |
| InstructionAccurateScope scope(masm, Assembler::kDebugBreakSlotInstructions); |
| |
| __ RecordDebugBreakSlot(); |
| for (int i = 0; i < Assembler::kDebugBreakSlotInstructions; i++) { |
| __ nop(Assembler::DEBUG_BREAK_NOP); |
| } |
| } |
| |
| |
| void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) { |
| // In the places where a debug break slot is inserted no registers can contain |
| // object pointers. |
| Generate_DebugBreakCallHelper(masm, 0, 0, x10); |
| } |
| |
| |
| void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) { |
| __ Ret(); |
| } |
| |
| |
| void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { |
| ExternalReference restarter_frame_function_slot = |
| ExternalReference::debug_restarter_frame_function_pointer_address( |
| masm->isolate()); |
| UseScratchRegisterScope temps(masm); |
| Register scratch = temps.AcquireX(); |
| |
| __ Mov(scratch, restarter_frame_function_slot); |
| __ Str(xzr, MemOperand(scratch)); |
| |
| // We do not know our frame height, but set sp based on fp. |
| __ Sub(masm->StackPointer(), fp, kPointerSize); |
| __ AssertStackConsistency(); |
| |
| __ Pop(x1, fp, lr); // Function, Frame, Return address. |
| |
| // Load context from the function. |
| __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset)); |
| |
| // Get function code. |
| __ Ldr(scratch, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset)); |
| __ Ldr(scratch, FieldMemOperand(scratch, SharedFunctionInfo::kCodeOffset)); |
| __ Add(scratch, scratch, Code::kHeaderSize - kHeapObjectTag); |
| |
| // Re-run JSFunction, x1 is function, cp is context. |
| __ Br(scratch); |
| } |
| |
| |
| const bool LiveEdit::kFrameDropperSupported = true; |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_TARGET_ARCH_ARM64 |