runtime/vm/debugger_x64.cc

// Copyright (c) 2011, 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_X64)

#include "vm/debugger.h"

#include "vm/assembler.h"
#include "vm/code_patcher.h"
#include "vm/cpu.h"
#include "vm/instructions.h"
#include "vm/stub_code.h"

namespace dart {

RawInstance* ActivationFrame::GetInstanceCallReceiver(
                 intptr_t num_actual_args) {
  ASSERT(num_actual_args > 0);  // At minimum we have a receiver on the stack.
  // Stack pointer points to last argument that was pushed on the stack.
  uword receiver_addr = sp() + ((num_actual_args - 1) * kWordSize);
  return reinterpret_cast<RawInstance*>(
             *reinterpret_cast<uword*>(receiver_addr));
}


RawObject* ActivationFrame::GetClosureObject(intptr_t num_actual_args) {
  // At a minimum we have the closure object on the stack.
  ASSERT(num_actual_args > 0);
  // Stack pointer points to last argument that was pushed on the stack.
  uword closure_addr = sp() + ((num_actual_args - 1) * kWordSize);
  return reinterpret_cast<RawObject*>(
             *reinterpret_cast<uword*>(closure_addr));
}


uword CodeBreakpoint::OrigStubAddress() const {
  const Code& code =
      Code::Handle(Function::Handle(function_).unoptimized_code());
  const Array& object_pool = Array::Handle(code.ObjectPool());
  uword offset = saved_value_ + kHeapObjectTag;
  ASSERT((offset % kWordSize) == 0);
  const intptr_t index = (offset - Array::data_offset()) / kWordSize;
  const uword stub_address = reinterpret_cast<uword>(object_pool.At(index));
  ASSERT(stub_address % kWordSize == 0);
  return stub_address;
}


void CodeBreakpoint::PatchCode() {
  ASSERT(!is_enabled_);
  switch (breakpoint_kind_) {
    case PcDescriptors::kIcCall: {
      int32_t offset = CodePatcher::GetPoolOffsetAt(pc_);
      ASSERT((offset > 0) && ((offset % 8) == 7));
      saved_value_ = static_cast<uword>(offset);
      const int32_t stub_offset =
          InstructionPattern::OffsetFromPPIndex(
              Assembler::kBreakpointDynamicCPIndex);
      CodePatcher::SetPoolOffsetAt(pc_, stub_offset);
      break;
    }
    case PcDescriptors::kUnoptStaticCall: {
      int32_t offset = CodePatcher::GetPoolOffsetAt(pc_);
      ASSERT((offset > 0) && ((offset % 8) == 7));
      saved_value_ = static_cast<uword>(offset);
      const uint32_t stub_offset =
          InstructionPattern::OffsetFromPPIndex(
              Assembler::kBreakpointStaticCPIndex);
      CodePatcher::SetPoolOffsetAt(pc_, stub_offset);
      break;
    }
    case PcDescriptors::kRuntimeCall:
    case PcDescriptors::kClosureCall:
    case PcDescriptors::kReturn: {
      int32_t offset = CodePatcher::GetPoolOffsetAt(pc_);
      ASSERT((offset > 0) && ((offset % 8) == 7));
      saved_value_ = static_cast<uword>(offset);
      const uint32_t stub_offset =
          InstructionPattern::OffsetFromPPIndex(
              Assembler::kBreakpointRuntimeCPIndex);
      CodePatcher::SetPoolOffsetAt(pc_, stub_offset);
      break;
    }
    default:
      UNREACHABLE();
  }
  is_enabled_ = true;
}


void CodeBreakpoint::RestoreCode() {
  ASSERT(is_enabled_);
  switch (breakpoint_kind_) {
    case PcDescriptors::kIcCall:
    case PcDescriptors::kUnoptStaticCall:
    case PcDescriptors::kClosureCall:
    case PcDescriptors::kRuntimeCall:
    case PcDescriptors::kReturn: {
      CodePatcher::SetPoolOffsetAt(pc_, static_cast<int32_t>(saved_value_));
      break;
    }
    default:
      UNREACHABLE();
  }
  is_enabled_ = false;
}


}  // namespace dart

#endif  // defined TARGET_ARCH_X64