| // 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. |
| |
| |
| |
| #include "src/v8.h" |
| |
| #if V8_TARGET_ARCH_MIPS |
| |
| #include "src/codegen.h" |
| #include "src/debug.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| bool BreakLocationIterator::IsDebugBreakAtReturn() { |
| return Debug::IsDebugBreakAtReturn(rinfo()); |
| } |
| |
| |
| void BreakLocationIterator::SetDebugBreakAtReturn() { |
| // Mips return sequence: |
| // mov sp, fp |
| // lw fp, sp(0) |
| // lw ra, sp(4) |
| // addiu sp, sp, 8 |
| // addiu sp, sp, N |
| // jr ra |
| // nop (in branch delay slot) |
| |
| // Make sure this constant matches the number if instrucntions we emit. |
| DCHECK(Assembler::kJSReturnSequenceInstructions == 7); |
| CodePatcher patcher(rinfo()->pc(), Assembler::kJSReturnSequenceInstructions); |
| // li and Call pseudo-instructions emit two instructions each. |
| patcher.masm()->li(v8::internal::t9, Operand(reinterpret_cast<int32_t>( |
| debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry()))); |
| patcher.masm()->Call(v8::internal::t9); |
| patcher.masm()->nop(); |
| patcher.masm()->nop(); |
| patcher.masm()->nop(); |
| |
| // TODO(mips): Open issue about using breakpoint instruction instead of nops. |
| // patcher.masm()->bkpt(0); |
| } |
| |
| |
| // Restore the JS frame exit code. |
| void BreakLocationIterator::ClearDebugBreakAtReturn() { |
| rinfo()->PatchCode(original_rinfo()->pc(), |
| Assembler::kJSReturnSequenceInstructions); |
| } |
| |
| |
| // A debug break in the exit code is identified by the JS frame exit code |
| // having been patched with li/call psuedo-instrunction (liu/ori/jalr). |
| 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() { |
| DCHECK(IsDebugBreakSlot()); |
| // 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) |
| CodePatcher patcher(rinfo()->pc(), Assembler::kDebugBreakSlotInstructions); |
| patcher.masm()->li(v8::internal::t9, Operand(reinterpret_cast<int32_t>( |
| debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry()))); |
| patcher.masm()->Call(v8::internal::t9); |
| } |
| |
| |
| void BreakLocationIterator::ClearDebugBreakAtSlot() { |
| DCHECK(IsDebugBreakSlot()); |
| rinfo()->PatchCode(original_rinfo()->pc(), |
| Assembler::kDebugBreakSlotInstructions); |
| } |
| |
| |
| #define __ ACCESS_MASM(masm) |
| |
| |
| |
| static void Generate_DebugBreakCallHelper(MacroAssembler* masm, |
| RegList object_regs, |
| RegList non_object_regs) { |
| { |
| 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); |
| |
| // Store the registers containing live values on the expression stack to |
| // make sure that these are correctly updated during GC. Non object values |
| // are stored as a smi causing it to be untouched by GC. |
| DCHECK((object_regs & ~kJSCallerSaved) == 0); |
| DCHECK((non_object_regs & ~kJSCallerSaved) == 0); |
| DCHECK((object_regs & non_object_regs) == 0); |
| if ((object_regs | non_object_regs) != 0) { |
| for (int i = 0; i < kNumJSCallerSaved; i++) { |
| int r = JSCallerSavedCode(i); |
| Register reg = { r }; |
| if ((non_object_regs & (1 << r)) != 0) { |
| if (FLAG_debug_code) { |
| __ And(at, reg, 0xc0000000); |
| __ Assert(eq, kUnableToEncodeValueAsSmi, at, Operand(zero_reg)); |
| } |
| __ sll(reg, reg, kSmiTagSize); |
| } |
| } |
| __ MultiPush(object_regs | non_object_regs); |
| } |
| |
| #ifdef DEBUG |
| __ RecordComment("// Calling from debug break to runtime - come in - over"); |
| #endif |
| __ PrepareCEntryArgs(0); // No arguments. |
| __ PrepareCEntryFunction(ExternalReference::debug_break(masm->isolate())); |
| |
| CEntryStub ceb(masm->isolate(), 1); |
| __ CallStub(&ceb); |
| |
| // Restore the register values from the expression stack. |
| if ((object_regs | non_object_regs) != 0) { |
| __ MultiPop(object_regs | non_object_regs); |
| for (int i = 0; i < kNumJSCallerSaved; i++) { |
| int r = JSCallerSavedCode(i); |
| Register reg = { r }; |
| if ((non_object_regs & (1 << r)) != 0) { |
| __ srl(reg, reg, kSmiTagSize); |
| } |
| if (FLAG_debug_code && |
| (((object_regs |non_object_regs) & (1 << r)) == 0)) { |
| __ 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::GenerateCallICStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallICStub |
| // ----------- S t a t e ------------- |
| // -- a1 : function |
| // -- a3 : slot in feedback array (smi) |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, a1.bit() | a3.bit(), 0); |
| } |
| |
| |
| void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) { |
| Register receiver = LoadDescriptor::ReceiverRegister(); |
| Register name = LoadDescriptor::NameRegister(); |
| RegList regs = receiver.bit() | name.bit(); |
| if (FLAG_vector_ics) { |
| regs |= VectorLoadICTrampolineDescriptor::SlotRegister().bit(); |
| } |
| Generate_DebugBreakCallHelper(masm, regs, 0); |
| } |
| |
| |
| void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for IC store (from ic-mips.cc). |
| Register receiver = StoreDescriptor::ReceiverRegister(); |
| Register name = StoreDescriptor::NameRegister(); |
| Register value = StoreDescriptor::ValueRegister(); |
| Generate_DebugBreakCallHelper( |
| masm, receiver.bit() | name.bit() | value.bit(), 0); |
| } |
| |
| |
| void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for keyed IC load (from ic-mips.cc). |
| GenerateLoadICDebugBreak(masm); |
| } |
| |
| |
| void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { |
| // Calling convention for IC keyed store call (from ic-mips.cc). |
| Register receiver = StoreDescriptor::ReceiverRegister(); |
| Register name = StoreDescriptor::NameRegister(); |
| Register value = StoreDescriptor::ValueRegister(); |
| Generate_DebugBreakCallHelper( |
| masm, receiver.bit() | name.bit() | value.bit(), 0); |
| } |
| |
| |
| void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) { |
| // Register state for CompareNil IC |
| // ----------- S t a t e ------------- |
| // -- a0 : value |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, a0.bit(), 0); |
| } |
| |
| |
| void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) { |
| // In places other than IC call sites it is expected that v0 is TOS which |
| // is an object - this is not generally the case so this should be used with |
| // care. |
| Generate_DebugBreakCallHelper(masm, v0.bit(), 0); |
| } |
| |
| |
| void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallFunctionStub (from code-stubs-mips.cc). |
| // ----------- S t a t e ------------- |
| // -- a1 : function |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, a1.bit(), 0); |
| } |
| |
| |
| void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) { |
| // Calling convention for CallConstructStub (from code-stubs-mips.cc). |
| // ----------- S t a t e ------------- |
| // -- a0 : number of arguments (not smi) |
| // -- a1 : constructor function |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, a1.bit() , a0.bit()); |
| } |
| |
| |
| void DebugCodegen::GenerateCallConstructStubRecordDebugBreak( |
| MacroAssembler* masm) { |
| // Calling convention for CallConstructStub (from code-stubs-mips.cc). |
| // ----------- S t a t e ------------- |
| // -- a0 : number of arguments (not smi) |
| // -- a1 : constructor function |
| // -- a2 : feedback array |
| // -- a3 : feedback slot (smi) |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, a1.bit() | a2.bit() | a3.bit(), a0.bit()); |
| } |
| |
| |
| void DebugCodegen::GenerateSlot(MacroAssembler* masm) { |
| // 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_trampoline_pool(masm); |
| Label check_codesize; |
| __ bind(&check_codesize); |
| __ RecordDebugBreakSlot(); |
| for (int i = 0; i < Assembler::kDebugBreakSlotInstructions; i++) { |
| __ nop(MacroAssembler::DEBUG_BREAK_NOP); |
| } |
| DCHECK_EQ(Assembler::kDebugBreakSlotInstructions, |
| masm->InstructionsGeneratedSince(&check_codesize)); |
| } |
| |
| |
| 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); |
| } |
| |
| |
| 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()); |
| __ li(at, Operand(restarter_frame_function_slot)); |
| __ sw(zero_reg, MemOperand(at, 0)); |
| |
| // We do not know our frame height, but set sp based on fp. |
| __ Subu(sp, fp, Operand(kPointerSize)); |
| |
| __ Pop(ra, fp, a1); // Return address, Frame, Function. |
| |
| // Load context from the function. |
| __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset)); |
| |
| // 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 v8::internal |
| |
| #endif // V8_TARGET_ARCH_MIPS |