| // 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_IA32 |
| |
| #include "src/codegen.h" |
| #include "src/debug.h" |
| |
| |
| namespace v8 { |
| namespace internal { |
| |
| bool BreakLocationIterator::IsDebugBreakAtReturn() { |
| return Debug::IsDebugBreakAtReturn(rinfo()); |
| } |
| |
| |
| // Patch the JS frame exit code with a debug break call. See |
| // CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-ia32.cc |
| // for the precise return instructions sequence. |
| void BreakLocationIterator::SetDebugBreakAtReturn() { |
| DCHECK(Assembler::kJSReturnSequenceLength >= |
| Assembler::kCallInstructionLength); |
| rinfo()->PatchCodeWithCall( |
| debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(), |
| Assembler::kJSReturnSequenceLength - Assembler::kCallInstructionLength); |
| } |
| |
| |
| // Restore the JS frame exit code. |
| void BreakLocationIterator::ClearDebugBreakAtReturn() { |
| rinfo()->PatchCode(original_rinfo()->pc(), |
| Assembler::kJSReturnSequenceLength); |
| } |
| |
| |
| // A debug break in the frame exit code is identified by the JS frame exit code |
| // having been patched with a call instruction. |
| 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()); |
| Isolate* isolate = debug_info_->GetIsolate(); |
| rinfo()->PatchCodeWithCall( |
| isolate->builtins()->Slot_DebugBreak()->entry(), |
| Assembler::kDebugBreakSlotLength - Assembler::kCallInstructionLength); |
| } |
| |
| |
| void BreakLocationIterator::ClearDebugBreakAtSlot() { |
| DCHECK(IsDebugBreakSlot()); |
| rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength); |
| } |
| |
| |
| #define __ ACCESS_MASM(masm) |
| |
| static void Generate_DebugBreakCallHelper(MacroAssembler* masm, |
| RegList object_regs, |
| RegList non_object_regs, |
| bool convert_call_to_jmp) { |
| // Enter an internal frame. |
| { |
| FrameScope scope(masm, StackFrame::INTERNAL); |
| |
| // Load padding words on stack. |
| for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) { |
| __ push(Immediate(Smi::FromInt(LiveEdit::kFramePaddingValue))); |
| } |
| __ push(Immediate(Smi::FromInt(LiveEdit::kFramePaddingInitialSize))); |
| |
| // 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); |
| for (int i = 0; i < kNumJSCallerSaved; i++) { |
| int r = JSCallerSavedCode(i); |
| Register reg = { r }; |
| if ((object_regs & (1 << r)) != 0) { |
| __ push(reg); |
| } |
| if ((non_object_regs & (1 << r)) != 0) { |
| if (FLAG_debug_code) { |
| __ test(reg, Immediate(0xc0000000)); |
| __ Assert(zero, kUnableToEncodeValueAsSmi); |
| } |
| __ SmiTag(reg); |
| __ push(reg); |
| } |
| } |
| |
| #ifdef DEBUG |
| __ RecordComment("// Calling from debug break to runtime - come in - over"); |
| #endif |
| __ Move(eax, Immediate(0)); // No arguments. |
| __ mov(ebx, Immediate(ExternalReference::debug_break(masm->isolate()))); |
| |
| CEntryStub ceb(masm->isolate(), 1); |
| __ CallStub(&ceb); |
| |
| // Automatically find register that could be used after register restore. |
| // We need one register for padding skip instructions. |
| Register unused_reg = { -1 }; |
| |
| // Restore the register values containing object pointers from the |
| // expression stack. |
| for (int i = kNumJSCallerSaved; --i >= 0;) { |
| int r = JSCallerSavedCode(i); |
| Register reg = { r }; |
| if (FLAG_debug_code) { |
| __ Move(reg, Immediate(kDebugZapValue)); |
| } |
| bool taken = reg.code() == esi.code(); |
| if ((object_regs & (1 << r)) != 0) { |
| __ pop(reg); |
| taken = true; |
| } |
| if ((non_object_regs & (1 << r)) != 0) { |
| __ pop(reg); |
| __ SmiUntag(reg); |
| taken = true; |
| } |
| if (!taken) { |
| unused_reg = reg; |
| } |
| } |
| |
| DCHECK(unused_reg.code() != -1); |
| |
| // Read current padding counter and skip corresponding number of words. |
| __ pop(unused_reg); |
| // We divide stored value by 2 (untagging) and multiply it by word's size. |
| STATIC_ASSERT(kSmiTagSize == 1 && kSmiShiftSize == 0); |
| __ lea(esp, Operand(esp, unused_reg, times_half_pointer_size, 0)); |
| |
| // Get rid of the internal frame. |
| } |
| |
| // If this call did not replace a call but patched other code then there will |
| // be an unwanted return address left on the stack. Here we get rid of that. |
| if (convert_call_to_jmp) { |
| __ add(esp, Immediate(kPointerSize)); |
| } |
| |
| // 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()); |
| __ jmp(Operand::StaticVariable(after_break_target)); |
| } |
| |
| |
| void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallICStub |
| // ----------- S t a t e ------------- |
| // -- edx : type feedback slot (smi) |
| // -- edi : function |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, edx.bit() | edi.bit(), |
| 0, false); |
| } |
| |
| |
| void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) { |
| // Register state for IC load call (from ic-ia32.cc). |
| 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, false); |
| } |
| |
| |
| void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) { |
| // Register state for IC store call (from ic-ia32.cc). |
| Register receiver = StoreDescriptor::ReceiverRegister(); |
| Register name = StoreDescriptor::NameRegister(); |
| Register value = StoreDescriptor::ValueRegister(); |
| Generate_DebugBreakCallHelper( |
| masm, receiver.bit() | name.bit() | value.bit(), 0, false); |
| } |
| |
| |
| void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { |
| // Register state for keyed IC load call (from ic-ia32.cc). |
| GenerateLoadICDebugBreak(masm); |
| } |
| |
| |
| void DebugCodegen::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { |
| // Register state for keyed IC store call (from ic-ia32.cc). |
| Register receiver = StoreDescriptor::ReceiverRegister(); |
| Register name = StoreDescriptor::NameRegister(); |
| Register value = StoreDescriptor::ValueRegister(); |
| Generate_DebugBreakCallHelper( |
| masm, receiver.bit() | name.bit() | value.bit(), 0, false); |
| } |
| |
| |
| void DebugCodegen::GenerateCompareNilICDebugBreak(MacroAssembler* masm) { |
| // Register state for CompareNil IC |
| // ----------- S t a t e ------------- |
| // -- eax : value |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, eax.bit(), 0, false); |
| } |
| |
| |
| void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) { |
| // Register state just before return from JS function (from codegen-ia32.cc). |
| // ----------- S t a t e ------------- |
| // -- eax: return value |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, eax.bit(), 0, true); |
| } |
| |
| |
| void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallFunctionStub (from code-stubs-ia32.cc). |
| // ----------- S t a t e ------------- |
| // -- edi: function |
| // ----------------------------------- |
| Generate_DebugBreakCallHelper(masm, edi.bit(), 0, false); |
| } |
| |
| |
| void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) { |
| // Register state for CallConstructStub (from code-stubs-ia32.cc). |
| // eax is the actual number of arguments not encoded as a smi see comment |
| // above IC call. |
| // ----------- S t a t e ------------- |
| // -- eax: number of arguments (not smi) |
| // -- edi: constructor function |
| // ----------------------------------- |
| // The number of arguments in eax is not smi encoded. |
| Generate_DebugBreakCallHelper(masm, edi.bit(), eax.bit(), false); |
| } |
| |
| |
| void DebugCodegen::GenerateCallConstructStubRecordDebugBreak( |
| MacroAssembler* masm) { |
| // Register state for CallConstructStub (from code-stubs-ia32.cc). |
| // eax is the actual number of arguments not encoded as a smi see comment |
| // above IC call. |
| // ----------- S t a t e ------------- |
| // -- eax: number of arguments (not smi) |
| // -- ebx: feedback array |
| // -- edx: feedback slot (smi) |
| // -- edi: constructor function |
| // ----------------------------------- |
| // The number of arguments in eax is not smi encoded. |
| Generate_DebugBreakCallHelper(masm, ebx.bit() | edx.bit() | edi.bit(), |
| eax.bit(), false); |
| } |
| |
| |
| void DebugCodegen::GenerateSlot(MacroAssembler* masm) { |
| // Generate enough nop's to make space for a call instruction. |
| Label check_codesize; |
| __ bind(&check_codesize); |
| __ RecordDebugBreakSlot(); |
| __ Nop(Assembler::kDebugBreakSlotLength); |
| DCHECK_EQ(Assembler::kDebugBreakSlotLength, |
| masm->SizeOfCodeGeneratedSince(&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, true); |
| } |
| |
| |
| 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()); |
| __ mov(Operand::StaticVariable(restarter_frame_function_slot), Immediate(0)); |
| |
| // We do not know our frame height, but set esp based on ebp. |
| __ lea(esp, Operand(ebp, -1 * kPointerSize)); |
| |
| __ pop(edi); // Function. |
| __ pop(ebp); |
| |
| // Load context from the function. |
| __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset)); |
| |
| // Get function code. |
| __ mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset)); |
| __ mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset)); |
| __ lea(edx, FieldOperand(edx, Code::kHeaderSize)); |
| |
| // Re-run JSFunction, edi is function, esi is context. |
| __ jmp(edx); |
| } |
| |
| |
| const bool LiveEdit::kFrameDropperSupported = true; |
| |
| #undef __ |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_TARGET_ARCH_IA32 |