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// Copyright 2012 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_X64
#include "src/assembler.h"
#include "src/codegen.h"
#include "src/debug/debug.h"
namespace v8 {
namespace internal {
#define __ ACCESS_MASM(masm)
void EmitDebugBreakSlot(MacroAssembler* masm) {
Label check_codesize;
__ bind(&check_codesize);
__ Nop(Assembler::kDebugBreakSlotLength);
DCHECK_EQ(Assembler::kDebugBreakSlotLength,
masm->SizeOfCodeGeneratedSince(&check_codesize));
}
void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode,
int call_argc) {
// Generate enough nop's to make space for a call instruction.
masm->RecordDebugBreakSlot(mode, call_argc);
EmitDebugBreakSlot(masm);
}
void DebugCodegen::ClearDebugBreakSlot(Address pc) {
CodePatcher patcher(pc, Assembler::kDebugBreakSlotLength);
EmitDebugBreakSlot(patcher.masm());
}
void DebugCodegen::PatchDebugBreakSlot(Address pc, Handle<Code> code) {
DCHECK_EQ(Code::BUILTIN, code->kind());
static const int kSize = Assembler::kDebugBreakSlotLength;
CodePatcher patcher(pc, kSize);
Label check_codesize;
patcher.masm()->bind(&check_codesize);
patcher.masm()->movp(kScratchRegister, reinterpret_cast<void*>(code->entry()),
Assembler::RelocInfoNone());
patcher.masm()->call(kScratchRegister);
// Check that the size of the code generated is as expected.
DCHECK_EQ(kSize, patcher.masm()->SizeOfCodeGeneratedSince(&check_codesize));
}
void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm,
DebugBreakCallHelperMode mode) {
__ RecordComment("Debug break");
// Enter an internal frame.
{
FrameScope scope(masm, StackFrame::INTERNAL);
// Load padding words on stack.
for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) {
__ Push(Smi::FromInt(LiveEdit::kFramePaddingValue));
}
__ Push(Smi::FromInt(LiveEdit::kFramePaddingInitialSize));
if (mode == SAVE_RESULT_REGISTER) __ Push(rax);
__ Set(rax, 0); // No arguments (argc == 0).
__ Move(rbx, ExternalReference(Runtime::FunctionForId(Runtime::kDebugBreak),
masm->isolate()));
CEntryStub ceb(masm->isolate(), 1);
__ CallStub(&ceb);
if (FLAG_debug_code) {
for (int i = 0; i < kNumJSCallerSaved; ++i) {
Register reg = {JSCallerSavedCode(i)};
__ Set(reg, kDebugZapValue);
}
}
if (mode == SAVE_RESULT_REGISTER) __ Pop(rax);
// Read current padding counter and skip corresponding number of words.
__ Pop(kScratchRegister);
__ SmiToInteger32(kScratchRegister, kScratchRegister);
__ leap(rsp, Operand(rsp, kScratchRegister, times_pointer_size, 0));
// Get rid of the internal frame.
}
// This call did not replace a call , so there will be an unwanted
// return address left on the stack. Here we get rid of that.
__ addp(rsp, Immediate(kPCOnStackSize));
// 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());
__ Move(kScratchRegister, after_break_target);
__ Jump(Operand(kScratchRegister, 0));
}
void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
masm->ret(0);
}
void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
ExternalReference restarter_frame_function_slot =
ExternalReference::debug_restarter_frame_function_pointer_address(
masm->isolate());
__ Move(rax, restarter_frame_function_slot);
__ movp(Operand(rax, 0), Immediate(0));
// We do not know our frame height, but set rsp based on rbp.
__ leap(rsp, Operand(rbp, -1 * kPointerSize));
__ Pop(rdi); // Function.
__ popq(rbp);
// Load context from the function.
__ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
// Get function code.
__ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
__ movp(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
__ leap(rdx, FieldOperand(rdx, Code::kHeaderSize));
// Re-run JSFunction, rdi is function, rsi is context.
__ jmp(rdx);
}
const bool LiveEdit::kFrameDropperSupported = true;
#undef __
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_X64
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