| // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include "vm/globals.h" |
| #if defined(TARGET_ARCH_DBC) |
| |
| #include "vm/code_patcher.h" |
| #include "vm/cpu.h" |
| #include "vm/debugger.h" |
| #include "vm/instructions.h" |
| #include "vm/stub_code.h" |
| |
| namespace dart { |
| |
| #ifndef PRODUCT |
| |
| RawCode* CodeBreakpoint::OrigStubAddress() const { |
| return reinterpret_cast<RawCode*>(static_cast<uintptr_t>(saved_value_)); |
| } |
| |
| static Instr* CallInstructionFromReturnAddress(uword pc) { |
| return reinterpret_cast<Instr*>(pc) - 1; |
| } |
| |
| static Instr* FastSmiInstructionFromReturnAddress(uword pc) { |
| return reinterpret_cast<Instr*>(pc) - 2; |
| } |
| |
| void CodeBreakpoint::PatchCode() { |
| ASSERT(!is_enabled_); |
| const Code& code = Code::Handle(code_); |
| const Instructions& instrs = Instructions::Handle(code.instructions()); |
| { |
| WritableInstructionsScope writable(instrs.PayloadStart(), instrs.Size()); |
| saved_value_ = *CallInstructionFromReturnAddress(pc_); |
| switch (breakpoint_kind_) { |
| case RawPcDescriptors::kIcCall: |
| case RawPcDescriptors::kUnoptStaticCall: { |
| // DebugBreak has an A operand matching the call it replaces. |
| // This ensures that Return instructions continue to work - as they |
| // look at calls to figure out how many arguments to drop. |
| *CallInstructionFromReturnAddress(pc_) = SimulatorBytecode::Encode( |
| SimulatorBytecode::kDebugBreak, |
| SimulatorBytecode::DecodeArgc(saved_value_), 0, 0); |
| break; |
| } |
| |
| case RawPcDescriptors::kRuntimeCall: { |
| *CallInstructionFromReturnAddress(pc_) = SimulatorBytecode::kDebugBreak; |
| break; |
| } |
| |
| default: |
| UNREACHABLE(); |
| } |
| |
| // If this call is the fall-through for a fast Smi op, also disable the fast |
| // Smi op. |
| if ((SimulatorBytecode::DecodeOpcode(saved_value_) == |
| SimulatorBytecode::kInstanceCall2) && |
| SimulatorBytecode::IsFastSmiOpcode( |
| *FastSmiInstructionFromReturnAddress(pc_))) { |
| saved_value_fastsmi_ = *FastSmiInstructionFromReturnAddress(pc_); |
| *FastSmiInstructionFromReturnAddress(pc_) = |
| SimulatorBytecode::Encode(SimulatorBytecode::kNop, 0, 0, 0); |
| } else { |
| saved_value_fastsmi_ = SimulatorBytecode::kTrap; |
| } |
| } |
| is_enabled_ = true; |
| } |
| |
| void CodeBreakpoint::RestoreCode() { |
| ASSERT(is_enabled_); |
| const Code& code = Code::Handle(code_); |
| const Instructions& instrs = Instructions::Handle(code.instructions()); |
| { |
| WritableInstructionsScope writable(instrs.PayloadStart(), instrs.Size()); |
| switch (breakpoint_kind_) { |
| case RawPcDescriptors::kIcCall: |
| case RawPcDescriptors::kUnoptStaticCall: |
| case RawPcDescriptors::kRuntimeCall: { |
| *CallInstructionFromReturnAddress(pc_) = saved_value_; |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| |
| if (saved_value_fastsmi_ != SimulatorBytecode::kTrap) { |
| Instr current_instr = *FastSmiInstructionFromReturnAddress(pc_); |
| ASSERT(SimulatorBytecode::DecodeOpcode(current_instr) == |
| SimulatorBytecode::kNop); |
| *FastSmiInstructionFromReturnAddress(pc_) = saved_value_fastsmi_; |
| } |
| } |
| is_enabled_ = false; |
| } |
| |
| #endif // !PRODUCT |
| |
| } // namespace dart |
| |
| #endif // defined TARGET_ARCH_DBC |