// Copyright 2011 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #include "v8.h" #if defined(V8_TARGET_ARCH_X64) #include "assembler.h" #include "codegen.h" #include "debug.h" namespace v8 { namespace internal { #ifdef ENABLE_DEBUGGER_SUPPORT 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-x64.cc // for the precise return instructions sequence. void BreakLocationIterator::SetDebugBreakAtReturn() { ASSERT(Assembler::kJSReturnSequenceLength >= Assembler::kCallInstructionLength); rinfo()->PatchCodeWithCall( Isolate::Current()->debug()->debug_break_return()->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(v8::internal::RelocInfo* rinfo) { ASSERT(RelocInfo::IsJSReturn(rinfo->rmode())); return rinfo->IsPatchedReturnSequence(); } bool BreakLocationIterator::IsDebugBreakAtSlot() { ASSERT(IsDebugBreakSlot()); // Check whether the debug break slot instructions have been patched. return !Assembler::IsNop(rinfo()->pc()); } void BreakLocationIterator::SetDebugBreakAtSlot() { ASSERT(IsDebugBreakSlot()); rinfo()->PatchCodeWithCall( Isolate::Current()->debug()->debug_break_slot()->entry(), Assembler::kDebugBreakSlotLength - Assembler::kCallInstructionLength); } void BreakLocationIterator::ClearDebugBreakAtSlot() { ASSERT(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); // 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 as two smis causing it to be untouched by GC. ASSERT((object_regs & ~kJSCallerSaved) == 0); ASSERT((non_object_regs & ~kJSCallerSaved) == 0); ASSERT((object_regs & non_object_regs) == 0); for (int i = 0; i < kNumJSCallerSaved; i++) { int r = JSCallerSavedCode(i); Register reg = { r }; ASSERT(!reg.is(kScratchRegister)); if ((object_regs & (1 << r)) != 0) { __ push(reg); } // Store the 64-bit value as two smis. if ((non_object_regs & (1 << r)) != 0) { __ movq(kScratchRegister, reg); __ Integer32ToSmi(reg, reg); __ push(reg); __ sar(kScratchRegister, Immediate(32)); __ Integer32ToSmi(kScratchRegister, kScratchRegister); __ push(kScratchRegister); } } #ifdef DEBUG __ RecordComment("// Calling from debug break to runtime - come in - over"); #endif __ Set(rax, 0); // No arguments (argc == 0). __ movq(rbx, ExternalReference::debug_break(masm->isolate())); CEntryStub ceb(1); __ CallStub(&ceb); // Restore the register values from the expression stack. for (int i = kNumJSCallerSaved - 1; i >= 0; i--) { int r = JSCallerSavedCode(i); Register reg = { r }; if (FLAG_debug_code) { __ Set(reg, kDebugZapValue); } if ((object_regs & (1 << r)) != 0) { __ pop(reg); } // Reconstruct the 64-bit value from two smis. if ((non_object_regs & (1 << r)) != 0) { __ pop(kScratchRegister); __ SmiToInteger32(kScratchRegister, kScratchRegister); __ shl(kScratchRegister, Immediate(32)); __ pop(reg); __ SmiToInteger32(reg, reg); __ or_(reg, kScratchRegister); } } // 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) { __ addq(rsp, 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_Address::AfterBreakTarget(), masm->isolate()); __ movq(kScratchRegister, after_break_target); __ jmp(Operand(kScratchRegister, 0)); } void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) { // Register state for IC load call (from ic-x64.cc). // ----------- S t a t e ------------- // -- rax : receiver // -- rcx : name // ----------------------------------- Generate_DebugBreakCallHelper(masm, rax.bit() | rcx.bit(), 0, false); } void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) { // Register state for IC store call (from ic-x64.cc). // ----------- S t a t e ------------- // -- rax : value // -- rcx : name // -- rdx : receiver // ----------------------------------- Generate_DebugBreakCallHelper( masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false); } void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { // Register state for keyed IC load call (from ic-x64.cc). // ----------- S t a t e ------------- // -- rax : key // -- rdx : receiver // ----------------------------------- Generate_DebugBreakCallHelper(masm, rax.bit() | rdx.bit(), 0, false); } void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { // Register state for keyed IC load call (from ic-x64.cc). // ----------- S t a t e ------------- // -- rax : value // -- rcx : key // -- rdx : receiver // ----------------------------------- Generate_DebugBreakCallHelper( masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false); } void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) { // Register state for IC call call (from ic-x64.cc) // ----------- S t a t e ------------- // -- rcx: function name // ----------------------------------- Generate_DebugBreakCallHelper(masm, rcx.bit(), 0, false); } void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) { // Register state just before return from JS function (from codegen-x64.cc). // ----------- S t a t e ------------- // -- rax: return value // ----------------------------------- Generate_DebugBreakCallHelper(masm, rax.bit(), 0, true); } void Debug::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) { // Register state for CallFunctionStub (from code-stubs-x64.cc). // ----------- S t a t e ------------- // -- rdi : function // ----------------------------------- Generate_DebugBreakCallHelper(masm, rdi.bit(), 0, false); } void Debug::GenerateCallFunctionStubRecordDebugBreak(MacroAssembler* masm) { // Register state for CallFunctionStub (from code-stubs-x64.cc). // ----------- S t a t e ------------- // -- rdi : function // -- rbx: cache cell for call target // ----------------------------------- Generate_DebugBreakCallHelper(masm, rbx.bit() | rdi.bit(), 0, false); } void Debug::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) { // Register state for CallConstructStub (from code-stubs-x64.cc). // rax is the actual number of arguments not encoded as a smi, see comment // above IC call. // ----------- S t a t e ------------- // -- rax: number of arguments // ----------------------------------- // The number of arguments in rax is not smi encoded. Generate_DebugBreakCallHelper(masm, rdi.bit(), rax.bit(), false); } void Debug::GenerateCallConstructStubRecordDebugBreak(MacroAssembler* masm) { // Register state for CallConstructStub (from code-stubs-x64.cc). // rax is the actual number of arguments not encoded as a smi, see comment // above IC call. // ----------- S t a t e ------------- // -- rax: number of arguments // -- rbx: cache cell for call target // ----------------------------------- // The number of arguments in rax is not smi encoded. Generate_DebugBreakCallHelper(masm, rbx.bit() | rdi.bit(), rax.bit(), false); } void Debug::GenerateSlot(MacroAssembler* masm) { // Generate enough nop's to make space for a call instruction. Label check_codesize; __ bind(&check_codesize); __ RecordDebugBreakSlot(); __ Nop(Assembler::kDebugBreakSlotLength); ASSERT_EQ(Assembler::kDebugBreakSlotLength, masm->SizeOfCodeGeneratedSince(&check_codesize)); } void Debug::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 Debug::GeneratePlainReturnLiveEdit(MacroAssembler* masm) { masm->ret(0); } void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { ExternalReference restarter_frame_function_slot = ExternalReference(Debug_Address::RestarterFrameFunctionPointer(), masm->isolate()); __ movq(rax, restarter_frame_function_slot); __ movq(Operand(rax, 0), Immediate(0)); // We do not know our frame height, but set rsp based on rbp. __ lea(rsp, Operand(rbp, -1 * kPointerSize)); __ pop(rdi); // Function. __ pop(rbp); // Load context from the function. __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset)); // Get function code. __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset)); __ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset)); __ lea(rdx, FieldOperand(rdx, Code::kHeaderSize)); // Re-run JSFunction, rdi is function, rsi is context. __ jmp(rdx); } const bool Debug::kFrameDropperSupported = true; #undef __ #endif // ENABLE_DEBUGGER_SUPPORT } } // namespace v8::internal #endif // V8_TARGET_ARCH_X64