| // 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. |
| |
| #if V8_TARGET_ARCH_ARM64 |
| |
| #include "src/arm64/frames-arm64.h" |
| #include "src/codegen.h" |
| #include "src/debug/debug.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| #define __ ACCESS_MASM(masm) |
| |
| |
| void EmitDebugBreakSlot(Assembler* masm) { |
| Label check_size; |
| __ bind(&check_size); |
| for (int i = 0; i < Assembler::kDebugBreakSlotInstructions; i++) { |
| __ nop(Assembler::DEBUG_BREAK_NOP); |
| } |
| DCHECK_EQ(Assembler::kDebugBreakSlotInstructions, |
| static_cast<int>(masm->InstructionsGeneratedSince(&check_size))); |
| } |
| |
| |
| void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode) { |
| // 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); |
| masm->RecordDebugBreakSlot(mode); |
| EmitDebugBreakSlot(masm); |
| } |
| |
| |
| void DebugCodegen::ClearDebugBreakSlot(Isolate* isolate, Address pc) { |
| PatchingAssembler patcher(isolate, reinterpret_cast<Instruction*>(pc), |
| Assembler::kDebugBreakSlotInstructions); |
| EmitDebugBreakSlot(&patcher); |
| } |
| |
| |
| void DebugCodegen::PatchDebugBreakSlot(Isolate* isolate, Address pc, |
| Handle<Code> code) { |
| DCHECK_EQ(Code::BUILTIN, code->kind()); |
| PatchingAssembler patcher(isolate, reinterpret_cast<Instruction*>(pc), |
| Assembler::kDebugBreakSlotInstructions); |
| // 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 |
| // mov x0, x0 @ nop DEBUG_BREAK_NOP |
| // to a call to the debug slot code. |
| // ldr ip0, [pc, #(2 * kInstructionSize)] |
| // blr ip0 |
| // b skip |
| // <debug break slot code entry point address (64 bits)> |
| // skip: |
| |
| Label skip_constant; |
| // 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); |
| patcher.b(&skip_constant); |
| patcher.dc64(reinterpret_cast<int64_t>(code->entry())); |
| patcher.bind(&skip_constant); |
| // TODO(all): check the following is correct. |
| // The debug break slot code will push a frame and call statically compiled |
| // code. By using blr, this call site will be registered in the frame. |
| // The debugger can now iterate on the frames to find this call. |
| patcher.blr(ip0); |
| } |
| |
| |
| void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm, |
| DebugBreakCallHelperMode mode) { |
| __ RecordComment("Debug break"); |
| Register scratch = x10; |
| { |
| 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); |
| |
| if (mode == SAVE_RESULT_REGISTER) __ Push(x0); |
| |
| __ Mov(x0, 0); // No arguments. |
| __ Mov(x1, ExternalReference(Runtime::FunctionForId(Runtime::kDebugBreak), |
| masm->isolate())); |
| |
| CEntryStub stub(masm->isolate(), 1); |
| __ CallStub(&stub); |
| |
| if (FLAG_debug_code) { |
| for (int i = 0; i < kNumJSCallerSaved; i++) { |
| Register reg = Register::XRegFromCode(JSCallerSavedCode(i)); |
| __ Mov(reg, Operand(kDebugZapValue)); |
| } |
| } |
| |
| // Restore the register values from the expression stack. |
| if (mode == SAVE_RESULT_REGISTER) __ Pop(x0); |
| |
| // 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::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { |
| // 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. |
| |
| ParameterCount dummy(0); |
| __ FloodFunctionIfStepping(x1, no_reg, dummy, dummy); |
| |
| UseScratchRegisterScope temps(masm); |
| Register scratch = temps.AcquireX(); |
| |
| // Load context from the function. |
| __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset)); |
| |
| // Clear new.target as a safety measure. |
| __ LoadRoot(x3, Heap::kUndefinedValueRootIndex); |
| |
| // 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 internal |
| } // namespace v8 |
| |
| #endif // V8_TARGET_ARCH_ARM64 |