disassembler/disassembler_arm64.cc

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "disassembler_arm64.h"

#include <inttypes.h>

#include <sstream>

#include "base/logging.h"
#include "base/stringprintf.h"
#include "thread.h"

namespace art {
namespace arm64 {

// This enumeration should mirror the declarations in
// runtime/arch/arm64/registers_arm64.h. We do not include that file to
// avoid a dependency on libart.
enum {
  TR  = 19,
  IP0 = 16,
  IP1 = 17,
  FP  = 29,
  LR  = 30
};

void CustomDisassembler::AppendRegisterNameToOutput(
    const vixl::Instruction* instr,
    const vixl::CPURegister& reg) {
  USE(instr);
  if (reg.IsRegister() && reg.Is64Bits()) {
    if (reg.code() == TR) {
      AppendToOutput("tr");
      return;
    } else if (reg.code() == LR) {
      AppendToOutput("lr");
      return;
    }
    // Fall through.
  }
  // Print other register names as usual.
  Disassembler::AppendRegisterNameToOutput(instr, reg);
}

void CustomDisassembler::VisitLoadLiteral(const vixl::Instruction* instr) {
  Disassembler::VisitLoadLiteral(instr);

  if (!read_literals_) {
    return;
  }

  // Get address of literal. Bail if not within expected buffer range to
  // avoid trying to fetch invalid literals (we can encounter this when
  // interpreting raw data as instructions).
  void* data_address = instr->LiteralAddress<void*>();
  if (data_address < base_address_ || data_address >= end_address_) {
    AppendToOutput(" (?)");
    return;
  }

  // Output information on literal.
  vixl::Instr op = instr->Mask(vixl::LoadLiteralMask);
  switch (op) {
    case vixl::LDR_w_lit:
    case vixl::LDR_x_lit:
    case vixl::LDRSW_x_lit: {
      int64_t data = op == vixl::LDR_x_lit ? *reinterpret_cast<int64_t*>(data_address)
                                           : *reinterpret_cast<int32_t*>(data_address);
      AppendToOutput(" (0x%" PRIx64 " / %" PRId64 ")", data, data);
      break;
    }
    case vixl::LDR_s_lit:
    case vixl::LDR_d_lit: {
      double data = (op == vixl::LDR_s_lit) ? *reinterpret_cast<float*>(data_address)
                                            : *reinterpret_cast<double*>(data_address);
      AppendToOutput(" (%g)", data);
      break;
    }
    default:
      break;
  }
}

void CustomDisassembler::VisitLoadStoreUnsignedOffset(const vixl::Instruction* instr) {
  Disassembler::VisitLoadStoreUnsignedOffset(instr);

  if (instr->Rn() == TR) {
    int64_t offset = instr->ImmLSUnsigned() << instr->SizeLS();
    std::ostringstream tmp_stream;
    Thread::DumpThreadOffset<8>(tmp_stream, static_cast<uint32_t>(offset));
    AppendToOutput(" ; %s", tmp_stream.str().c_str());
  }
}

size_t DisassemblerArm64::Dump(std::ostream& os, const uint8_t* begin) {
  const vixl::Instruction* instr = reinterpret_cast<const vixl::Instruction*>(begin);
  decoder.Decode(instr);
    os << FormatInstructionPointer(begin)
     << StringPrintf(": %08x\t%s\n", instr->InstructionBits(), disasm.GetOutput());
  return vixl::kInstructionSize;
}

void DisassemblerArm64::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
  for (const uint8_t* cur = begin; cur < end; cur += vixl::kInstructionSize) {
    Dump(os, cur);
  }
}

}  // namespace arm64
}  // namespace art