| // 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_MIPS |
| |
| #include "src/codegen.h" |
| #include "src/debug/debug.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| #define __ ACCESS_MASM(masm) |
| |
| |
| void EmitDebugBreakSlot(MacroAssembler* masm) { |
| Label check_size; |
| __ bind(&check_size); |
| for (int i = 0; i < Assembler::kDebugBreakSlotInstructions; i++) { |
| __ nop(MacroAssembler::DEBUG_BREAK_NOP); |
| } |
| DCHECK_EQ(Assembler::kDebugBreakSlotInstructions, |
| 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 trampoline pool in the debug break slot code. |
| Assembler::BlockTrampolinePoolScope block_pool(masm); |
| masm->RecordDebugBreakSlot(mode); |
| EmitDebugBreakSlot(masm); |
| } |
| |
| |
| void DebugCodegen::ClearDebugBreakSlot(Isolate* isolate, Address pc) { |
| CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotInstructions); |
| EmitDebugBreakSlot(patcher.masm()); |
| } |
| |
| |
| void DebugCodegen::PatchDebugBreakSlot(Isolate* isolate, Address pc, |
| Handle<Code> code) { |
| DCHECK_EQ(Code::BUILTIN, code->kind()); |
| CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotInstructions); |
| // Patch the code changing the debug break slot code from: |
| // nop(DEBUG_BREAK_NOP) - nop(1) is sll(zero_reg, zero_reg, 1) |
| // nop(DEBUG_BREAK_NOP) |
| // nop(DEBUG_BREAK_NOP) |
| // nop(DEBUG_BREAK_NOP) |
| // to a call to the debug break slot code. |
| // li t9, address (lui t9 / ori t9 instruction pair) |
| // call t9 (jalr t9 / nop instruction pair) |
| patcher.masm()->li(v8::internal::t9, |
| Operand(reinterpret_cast<int32_t>(code->entry()))); |
| patcher.masm()->Call(v8::internal::t9); |
| } |
| |
| bool DebugCodegen::DebugBreakSlotIsPatched(Address pc) { |
| Instr current_instr = Assembler::instr_at(pc); |
| return !Assembler::IsNop(current_instr, Assembler::DEBUG_BREAK_NOP); |
| } |
| |
| void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm, |
| DebugBreakCallHelperMode mode) { |
| __ RecordComment("Debug break"); |
| { |
| FrameScope scope(masm, StackFrame::INTERNAL); |
| |
| // Load padding words on stack. |
| __ li(at, Operand(Smi::FromInt(LiveEdit::kFramePaddingValue))); |
| __ Subu(sp, sp, |
| Operand(kPointerSize * LiveEdit::kFramePaddingInitialSize)); |
| for (int i = LiveEdit::kFramePaddingInitialSize - 1; i >= 0; i--) { |
| __ sw(at, MemOperand(sp, kPointerSize * i)); |
| } |
| __ li(at, Operand(Smi::FromInt(LiveEdit::kFramePaddingInitialSize))); |
| __ push(at); |
| |
| // Push arguments for DebugBreak call. |
| if (mode == SAVE_RESULT_REGISTER) { |
| // Break on return. |
| __ push(v0); |
| } else { |
| // Non-return breaks. |
| __ Push(masm->isolate()->factory()->the_hole_value()); |
| } |
| __ PrepareCEntryArgs(1); |
| __ PrepareCEntryFunction(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)}; |
| // Do not clobber v0 if mode is SAVE_RESULT_REGISTER. It will |
| // contain return value of the function returned by DebugBreak. |
| if (!(reg.is(v0) && (mode == SAVE_RESULT_REGISTER))) { |
| __ li(reg, kDebugZapValue); |
| } |
| } |
| } |
| |
| // 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()); |
| __ li(t9, Operand(after_break_target)); |
| __ lw(t9, MemOperand(t9)); |
| __ Jump(t9); |
| } |
| |
| |
| void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { |
| // We do not know our frame height, but set sp based on fp. |
| __ lw(a1, MemOperand(fp, FrameDropperFrameConstants::kFunctionOffset)); |
| |
| // Pop return address and frame. |
| __ LeaveFrame(StackFrame::INTERNAL); |
| |
| ParameterCount dummy(0); |
| __ FloodFunctionIfStepping(a1, no_reg, dummy, dummy); |
| |
| // Load context from the function. |
| __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset)); |
| |
| // Clear new.target as a safety measure. |
| __ LoadRoot(a3, Heap::kUndefinedValueRootIndex); |
| |
| // Get function code. |
| __ lw(at, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset)); |
| __ lw(at, FieldMemOperand(at, SharedFunctionInfo::kCodeOffset)); |
| __ Addu(t9, at, Operand(Code::kHeaderSize - kHeapObjectTag)); |
| |
| // Re-run JSFunction, a1 is function, cp is context. |
| __ Jump(t9); |
| } |
| |
| |
| const bool LiveEdit::kFrameDropperSupported = true; |
| |
| #undef __ |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_TARGET_ARCH_MIPS |