C++ Thread::GetRegisterContext方法代码示例

ValueObjectSP ABISysV_s390x::GetReturnValueObjectImpl(
    Thread &thread, CompilerType &return_compiler_type) const {
  ValueObjectSP return_valobj_sp;

  if (!return_compiler_type)
    return return_valobj_sp;

  ExecutionContext exe_ctx(thread.shared_from_this());
  return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);
  if (return_valobj_sp)
    return return_valobj_sp;

  RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
  if (!reg_ctx_sp)
    return return_valobj_sp;

  if (return_compiler_type.IsAggregateType()) {
    // FIXME: This is just taking a guess, r2 may very well no longer hold the
    // return storage location.
    // If we are going to do this right, when we make a new frame we should
    // check to see if it uses a memory return, and if we are at the first
    // instruction and if so stash away the return location.  Then we would
    // only return the memory return value if we know it is valid.

    unsigned r2_id =
        reg_ctx_sp->GetRegisterInfoByName("r2", 0)->kinds[eRegisterKindLLDB];
    lldb::addr_t storage_addr =
        (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r2_id, 0);
    return_valobj_sp = ValueObjectMemory::Create(
        &thread, "", Address(storage_addr, nullptr), return_compiler_type);
  }

  return return_valobj_sp;
}

ValueObjectSP
ABISysV_i386::GetReturnValueObjectImpl (Thread &thread, CompilerType &return_clang_type) const
{
    ValueObjectSP return_valobj_sp;

    if (!return_clang_type)
        return return_valobj_sp;

    ExecutionContext exe_ctx (thread.shared_from_this());
    return_valobj_sp = GetReturnValueObjectSimple(thread, return_clang_type);
    if (return_valobj_sp)
        return return_valobj_sp;

    RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
    if (!reg_ctx_sp)
       return return_valobj_sp;

    if (return_clang_type.IsAggregateType())
    {
        unsigned eax_id = reg_ctx_sp->GetRegisterInfoByName("eax", 0)->kinds[eRegisterKindLLDB];
        lldb::addr_t storage_addr = (uint32_t)(thread.GetRegisterContext()->ReadRegisterAsUnsigned(eax_id, 0) & 0xffffffff);
        return_valobj_sp = ValueObjectMemory::Create (&thread,
                                                      "",
                                                      Address (storage_addr, nullptr),
                                                      return_clang_type);
    }

    return return_valobj_sp;
}

static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,
                                bool is_signed, Thread &thread,
                                uint32_t *argument_register_ids,
                                unsigned int &current_argument_register,
                                addr_t &current_stack_argument) {
  if (bit_width > 64)
    return false; // Scalar can't hold large integer arguments

  if (current_argument_register < 6) {
    scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
        argument_register_ids[current_argument_register], 0);
    current_argument_register++;
    if (is_signed)
      scalar.SignExtend(bit_width);
  } else {
    uint32_t byte_size = (bit_width + (8 - 1)) / 8;
    Status error;
    if (thread.GetProcess()->ReadScalarIntegerFromMemory(
            current_stack_argument, byte_size, is_signed, scalar, error)) {
      current_stack_argument += byte_size;
      return true;
    }
    return false;
  }
  return true;
}

bool
ABIMacOSX_i386::GetArgumentValues (Thread &thread,
                                   ValueList &values) const
{
    unsigned int num_values = values.GetSize();
    unsigned int value_index;

    // Get the pointer to the first stack argument so we have a place to start
    // when reading data

    RegisterContext *reg_ctx = thread.GetRegisterContext().get();

    if (!reg_ctx)
        return false;

    addr_t sp = reg_ctx->GetSP(0);

    if (!sp)
        return false;

    addr_t current_stack_argument = sp + 4; // jump over return address

    for (value_index = 0;
            value_index < num_values;
            ++value_index)
    {
        Value *value = values.GetValueAtIndex(value_index);

        if (!value)
            return false;

        // We currently only support extracting values with Clang QualTypes.
        // Do we care about others?
        CompilerType compiler_type (value->GetCompilerType());
        if (compiler_type)
        {
            bool is_signed;

            if (compiler_type.IsIntegerType (is_signed))
            {
                ReadIntegerArgument(value->GetScalar(),
                                    compiler_type.GetBitSize(&thread),
                                    is_signed,
                                    thread.GetProcess().get(),
                                    current_stack_argument);
            }
            else if (compiler_type.IsPointerType())
            {
                ReadIntegerArgument(value->GetScalar(),
                                    compiler_type.GetBitSize(&thread),
                                    false,
                                    thread.GetProcess().get(),
                                    current_stack_argument);
            }
        }
    }

    return true;
}

UnwindLibUnwind::UnwindLibUnwind (Thread &thread, unw_addr_space_t addr_space) :
    Unwind (thread),
    m_addr_space (addr_space),
    m_cursors()
{
    m_pc_regnum = thread.GetRegisterContext()->ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
    m_sp_regnum = thread.GetRegisterContext()->ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
}

ThreadPlanCallFunction::ThreadPlanCallFunction (Thread &thread,
                                                Address &function,
                                                ValueList &args,
                                                bool stop_other_threads,
                                                bool discard_on_error) :
    ThreadPlan (ThreadPlan::eKindCallFunction, "Call function plan", thread, eVoteNoOpinion, eVoteNoOpinion),
    m_valid (false),
    m_stop_other_threads (stop_other_threads),
    m_arg_addr (0),
    m_args (&args),
    m_process (thread.GetProcess()),
    m_thread (thread)
{
    
    SetOkayToDiscard (discard_on_error);
    
    Process& process = thread.GetProcess();
    Target& target = process.GetTarget();
    const ABI *abi = process.GetABI();
    
    if(!abi)
        return;
    
    lldb::addr_t spBelowRedZone = thread.GetRegisterContext()->GetSP() - abi->GetRedZoneSize();
    
    SymbolContextList contexts;
    SymbolContext context;
    ModuleSP executableModuleSP (target.GetExecutableModule());
    
    if (!executableModuleSP ||
        !executableModuleSP->FindSymbolsWithNameAndType(ConstString ("start"), eSymbolTypeCode, contexts))
        return;
    
    contexts.GetContextAtIndex(0, context);
    
    m_start_addr = context.symbol->GetValue();
    lldb::addr_t StartLoadAddr = m_start_addr.GetLoadAddress(&process);
    
    if(!thread.SaveFrameZeroState(m_register_backup))
        return;
    
    m_function_addr = function;
    lldb::addr_t FunctionLoadAddr = m_function_addr.GetLoadAddress(&process);
    
    if (!abi->PrepareNormalCall(thread, 
                                spBelowRedZone, 
                                FunctionLoadAddr, 
                                StartLoadAddr, 
                                *m_args))
        return;
    
    m_valid = true;    
}

bool
ABISysV_i386::GetArgumentValues (Thread &thread,
                                   ValueList &values) const
{
    unsigned int num_values = values.GetSize();
    unsigned int value_index;

    RegisterContext *reg_ctx = thread.GetRegisterContext().get();

    if (!reg_ctx)
        return false;

    // Get pointer to the first stack argument
    addr_t sp = reg_ctx->GetSP(0);
    if (!sp)
        return false;

    addr_t current_stack_argument = sp + 4; // jump over return address

    for (value_index = 0;
         value_index < num_values;
         ++value_index)
    {
        Value *value = values.GetValueAtIndex(value_index);

        if (!value)
            return false;

        // Currently: Support for extracting values with Clang QualTypes only.
        CompilerType clang_type (value->GetCompilerType());
        if (clang_type)
        {
            bool is_signed;
            if (clang_type.IsIntegerType (is_signed))
            {
                ReadIntegerArgument(value->GetScalar(),
                                    clang_type.GetBitSize(&thread),
                                    is_signed,
                                    thread.GetProcess().get(),
                                    current_stack_argument);
            }
            else if (clang_type.IsPointerType())
            {
                ReadIntegerArgument(value->GetScalar(),
                                    clang_type.GetBitSize(&thread),
                                    false,
                                    thread.GetProcess().get(),
                                    current_stack_argument);
            }
        }
    }
    return true;
}

bool UnwindAssembly_x86::GetNonCallSiteUnwindPlanFromAssembly(
    AddressRange &func, Thread &thread, UnwindPlan &unwind_plan) {
  if (!func.GetBaseAddress().IsValid() || func.GetByteSize() == 0)
    return false;
  if (m_assembly_inspection_engine == nullptr)
    return false;
  ProcessSP process_sp(thread.GetProcess());
  if (process_sp.get() == nullptr)
    return false;
  const bool prefer_file_cache = true;
  std::vector<uint8_t> function_text(func.GetByteSize());
  Status error;
  if (process_sp->GetTarget().ReadMemory(
          func.GetBaseAddress(), prefer_file_cache, function_text.data(),
          func.GetByteSize(), error) == func.GetByteSize()) {
    RegisterContextSP reg_ctx(thread.GetRegisterContext());
    m_assembly_inspection_engine->Initialize(reg_ctx);
    return m_assembly_inspection_engine->GetNonCallSiteUnwindPlanFromAssembly(
        function_text.data(), func.GetByteSize(), func, unwind_plan);
  }
  return false;
}

bool
ABISysV_i386::PrepareTrivialCall (Thread &thread,
                                    addr_t sp,
                                    addr_t func_addr,
                                    addr_t return_addr,
                                    llvm::ArrayRef<addr_t> args) const
{
    RegisterContext *reg_ctx = thread.GetRegisterContext().get();

    if (!reg_ctx)
        return false;

    uint32_t pc_reg_num = reg_ctx->ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
    uint32_t sp_reg_num = reg_ctx->ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);

    // While using register info to write a register value to memory, the register info
    // just needs to have the correct size of a 32 bit register, the actual register it
    // pertains to is not important, just the size needs to be correct.
    // "eax" is used here for this purpose.
    const RegisterInfo *reg_info_32 = reg_ctx->GetRegisterInfoByName("eax");
    if (!reg_info_32)
        return false; // TODO this should actually never happen

    Error error;
    RegisterValue reg_value;

    // Make room for the argument(s) on the stack
    sp -= 4 * args.size();

    // SP Alignment
    sp &= ~(16ull-1ull); // 16-byte alignment

    // Write arguments onto the stack
    addr_t arg_pos = sp;
    for (addr_t arg : args)
    {
        reg_value.SetUInt32(arg);
        error = reg_ctx->WriteRegisterValueToMemory (reg_info_32,
                                                     arg_pos,
                                                     reg_info_32->byte_size,
                                                     reg_value);
        if (error.Fail())
            return false;
        arg_pos += 4;
    }

    // The return address is pushed onto the stack
    sp -= 4;
    reg_value.SetUInt32(return_addr);
    error = reg_ctx->WriteRegisterValueToMemory (reg_info_32,
                                                 sp,
                                                 reg_info_32->byte_size,
                                                 reg_value);
    if (error.Fail())
        return false;

    // Setting %esp to the actual stack value.
    if (!reg_ctx->WriteRegisterFromUnsigned (sp_reg_num, sp))
        return false;

    // Setting %eip to the address of the called function.
    if (!reg_ctx->WriteRegisterFromUnsigned (pc_reg_num, func_addr))
        return false;

    return true;
}

//----------------------------------------------------------------------
// ThreadPlanCallFunction: Plan to call a single function
//----------------------------------------------------------------------
bool
ThreadPlanCallFunction::ConstructorSetup (Thread &thread,
                                          ABI *& abi,
                                          lldb::addr_t &start_load_addr,
                                          lldb::addr_t &function_load_addr)
{
    SetIsMasterPlan (true);
    SetOkayToDiscard (false);
    SetPrivate (true);

    ProcessSP process_sp (thread.GetProcess());
    if (!process_sp)
        return false;
    
    abi = process_sp->GetABI().get();
    
    if (!abi)
        return false;
    
    Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_STEP));
    
    SetBreakpoints();
    
    m_function_sp = thread.GetRegisterContext()->GetSP() - abi->GetRedZoneSize();
    // If we can't read memory at the point of the process where we are planning to put our function, we're
    // not going to get any further...
    Error error;
    process_sp->ReadUnsignedIntegerFromMemory(m_function_sp, 4, 0, error);
    if (!error.Success())
    {
        m_constructor_errors.Printf ("Trying to put the stack in unreadable memory at: 0x%" PRIx64 ".", m_function_sp);
        if (log)
            log->Printf ("ThreadPlanCallFunction(%p): %s.", this, m_constructor_errors.GetData());
        return false;
    }
    
    Module *exe_module = GetTarget().GetExecutableModulePointer();

    if (exe_module == NULL)
    {
        m_constructor_errors.Printf ("Can't execute code without an executable module.");
        if (log)
            log->Printf ("ThreadPlanCallFunction(%p): %s.", this, m_constructor_errors.GetData());
        return false;
    }
    else
    {
        ObjectFile *objectFile = exe_module->GetObjectFile();
        if (!objectFile)
        {
            m_constructor_errors.Printf ("Could not find object file for module \"%s\".", 
                                         exe_module->GetFileSpec().GetFilename().AsCString());

            if (log)
                log->Printf ("ThreadPlanCallFunction(%p): %s.", this, m_constructor_errors.GetData());
            return false;
        }
        
        m_start_addr = objectFile->GetEntryPointAddress();
        if (!m_start_addr.IsValid())
        {
            m_constructor_errors.Printf ("Could not find entry point address for executable module \"%s\".", 
                                         exe_module->GetFileSpec().GetFilename().AsCString());
            if (log)
                log->Printf ("ThreadPlanCallFunction(%p): %s.", this, m_constructor_errors.GetData());
            return false;
        }
    }
    
    start_load_addr = m_start_addr.GetLoadAddress (&GetTarget());
    
    // Checkpoint the thread state so we can restore it later.
    if (log && log->GetVerbose())
        ReportRegisterState ("About to checkpoint thread before function call.  Original register state was:");

    if (!thread.CheckpointThreadState (m_stored_thread_state))
    {
        m_constructor_errors.Printf ("Setting up ThreadPlanCallFunction, failed to checkpoint thread state.");
        if (log)
            log->Printf ("ThreadPlanCallFunction(%p): %s.", this, m_constructor_errors.GetData());
        return false;
    }
    function_load_addr = m_function_addr.GetLoadAddress (&GetTarget());
    
    return true;
}

ValueObjectSP ABISysV_ppc64::GetReturnValueObjectImpl(
    Thread &thread, CompilerType &return_compiler_type) const {
  ValueObjectSP return_valobj_sp;

  if (!return_compiler_type)
    return return_valobj_sp;

  ExecutionContext exe_ctx(thread.shared_from_this());
  return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);
  if (return_valobj_sp)
    return return_valobj_sp;

  RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
  if (!reg_ctx_sp)
    return return_valobj_sp;

  const size_t bit_width = return_compiler_type.GetBitSize(&thread);
  if (return_compiler_type.IsAggregateType()) {
    Target *target = exe_ctx.GetTargetPtr();
    bool is_memory = true;
    if (bit_width <= 128) {
      ByteOrder target_byte_order = target->GetArchitecture().GetByteOrder();
      DataBufferSP data_sp(new DataBufferHeap(16, 0));
      DataExtractor return_ext(data_sp, target_byte_order,
                               target->GetArchitecture().GetAddressByteSize());

      const RegisterInfo *r3_info = reg_ctx_sp->GetRegisterInfoByName("r3", 0);
      const RegisterInfo *rdx_info =
          reg_ctx_sp->GetRegisterInfoByName("rdx", 0);

      RegisterValue r3_value, rdx_value;
      reg_ctx_sp->ReadRegister(r3_info, r3_value);
      reg_ctx_sp->ReadRegister(rdx_info, rdx_value);

      DataExtractor r3_data, rdx_data;

      r3_value.GetData(r3_data);
      rdx_value.GetData(rdx_data);

      uint32_t fp_bytes =
          0; // Tracks how much of the xmm registers we've consumed so far
      uint32_t integer_bytes =
          0; // Tracks how much of the r3/rds registers we've consumed so far

      const uint32_t num_children = return_compiler_type.GetNumFields();

      // Since we are in the small struct regime, assume we are not in memory.
      is_memory = false;

      for (uint32_t idx = 0; idx < num_children; idx++) {
        std::string name;
        uint64_t field_bit_offset = 0;
        bool is_signed;
        bool is_complex;
        uint32_t count;

        CompilerType field_compiler_type = return_compiler_type.GetFieldAtIndex(
            idx, name, &field_bit_offset, nullptr, nullptr);
        const size_t field_bit_width = field_compiler_type.GetBitSize(&thread);

        // If there are any unaligned fields, this is stored in memory.
        if (field_bit_offset % field_bit_width != 0) {
          is_memory = true;
          break;
        }

        uint32_t field_byte_width = field_bit_width / 8;
        uint32_t field_byte_offset = field_bit_offset / 8;

        DataExtractor *copy_from_extractor = nullptr;
        uint32_t copy_from_offset = 0;

        if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||
            field_compiler_type.IsPointerType()) {
          if (integer_bytes < 8) {
            if (integer_bytes + field_byte_width <= 8) {
              // This is in RAX, copy from register to our result structure:
              copy_from_extractor = &r3_data;
              copy_from_offset = integer_bytes;
              integer_bytes += field_byte_width;
            } else {
              // The next field wouldn't fit in the remaining space, so we
              // pushed it to rdx.
              copy_from_extractor = &rdx_data;
              copy_from_offset = 0;
              integer_bytes = 8 + field_byte_width;
            }
          } else if (integer_bytes + field_byte_width <= 16) {
            copy_from_extractor = &rdx_data;
            copy_from_offset = integer_bytes - 8;
            integer_bytes += field_byte_width;
          } else {
            // The last field didn't fit.  I can't see how that would happen w/o
            // the overall size being
            // greater than 16 bytes.  For now, return a nullptr return value
            // object.
            return return_valobj_sp;
          }
        } else if (field_compiler_type.IsFloatingPointType(count, is_complex)) {
          // Structs with long doubles are always passed in memory.
//.........这里部分代码省略.........

ValueObjectSP ABISysV_s390x::GetReturnValueObjectSimple(
    Thread &thread, CompilerType &return_compiler_type) const {
  ValueObjectSP return_valobj_sp;
  Value value;

  if (!return_compiler_type)
    return return_valobj_sp;

  // value.SetContext (Value::eContextTypeClangType, return_value_type);
  value.SetCompilerType(return_compiler_type);

  RegisterContext *reg_ctx = thread.GetRegisterContext().get();
  if (!reg_ctx)
    return return_valobj_sp;

  const uint32_t type_flags = return_compiler_type.GetTypeInfo();
  if (type_flags & eTypeIsScalar) {
    value.SetValueType(Value::eValueTypeScalar);

    bool success = false;
    if (type_flags & eTypeIsInteger) {
      // Extract the register context so we can read arguments from registers.
      llvm::Optional<uint64_t> byte_size =
          return_compiler_type.GetByteSize(nullptr);
      if (!byte_size)
        return return_valobj_sp;
      uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
          reg_ctx->GetRegisterInfoByName("r2", 0), 0);
      const bool is_signed = (type_flags & eTypeIsSigned) != 0;
      switch (*byte_size) {
      default:
        break;

      case sizeof(uint64_t):
        if (is_signed)
          value.GetScalar() = (int64_t)(raw_value);
        else
          value.GetScalar() = (uint64_t)(raw_value);
        success = true;
        break;

      case sizeof(uint32_t):
        if (is_signed)
          value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);
        else
          value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
        success = true;
        break;

      case sizeof(uint16_t):
        if (is_signed)
          value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);
        else
          value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
        success = true;
        break;

      case sizeof(uint8_t):
        if (is_signed)
          value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);
        else
          value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
        success = true;
        break;
      }
    } else if (type_flags & eTypeIsFloat) {
      if (type_flags & eTypeIsComplex) {
        // Don't handle complex yet.
      } else {
        llvm::Optional<uint64_t> byte_size =
            return_compiler_type.GetByteSize(nullptr);
        if (byte_size && *byte_size <= sizeof(long double)) {
          const RegisterInfo *f0_info = reg_ctx->GetRegisterInfoByName("f0", 0);
          RegisterValue f0_value;
          if (reg_ctx->ReadRegister(f0_info, f0_value)) {
            DataExtractor data;
            if (f0_value.GetData(data)) {
              lldb::offset_t offset = 0;
              if (*byte_size == sizeof(float)) {
                value.GetScalar() = (float)data.GetFloat(&offset);
                success = true;
              } else if (*byte_size == sizeof(double)) {
                value.GetScalar() = (double)data.GetDouble(&offset);
                success = true;
              } else if (*byte_size == sizeof(long double)) {
                // Don't handle long double yet.
              }
            }
          }
        }
      }
    }

    if (success)
      return_valobj_sp = ValueObjectConstResult::Create(
          thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
  } else if (type_flags & eTypeIsPointer) {
    unsigned r2_id =
        reg_ctx->GetRegisterInfoByName("r2", 0)->kinds[eRegisterKindLLDB];
    value.GetScalar() =
//.........这里部分代码省略.........

ThreadPlanSP
ObjCTrampolineHandler::GetStepThroughDispatchPlan (Thread &thread, bool stop_others)
{
    ThreadPlanSP ret_plan_sp;
    lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC();

    MsgsendMap::iterator pos;
    pos = m_msgSend_map.find (curr_pc);
    if (pos != m_msgSend_map.end())
    {
        Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP);

        const DispatchFunction *this_dispatch = &g_dispatch_functions[(*pos).second];

        lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);

        Process *process = thread.CalculateProcess();
        const ABI *abi = process->GetABI();
        if (abi == NULL)
            return ret_plan_sp;

        Target *target = thread.CalculateTarget();

        // FIXME: Since neither the value nor the Clang QualType know their ASTContext,
        // we have to make sure the type we put in our value list comes from the same ASTContext
        // the ABI will use to get the argument values.  THis is the bottom-most frame's module.

        ClangASTContext *clang_ast_context = target->GetScratchClangASTContext();
        ValueList argument_values;
        Value input_value;
        void *clang_void_ptr_type = clang_ast_context->GetVoidPtrType(false);
        input_value.SetValueType (Value::eValueTypeScalar);
        input_value.SetContext (Value::eContextTypeOpaqueClangQualType, clang_void_ptr_type);

        int obj_index;
        int sel_index;

        // If this is a struct return dispatch, then the first argument is the
        // return struct pointer, and the object is the second, and the selector is the third.
        // Otherwise the object is the first and the selector the second.
        if (this_dispatch->stret_return)
        {
            obj_index = 1;
            sel_index = 2;
            argument_values.PushValue(input_value);
            argument_values.PushValue(input_value);
            argument_values.PushValue(input_value);
        }
        else
        {
            obj_index = 0;
            sel_index = 1;
            argument_values.PushValue(input_value);
            argument_values.PushValue(input_value);
        }


        bool success = abi->GetArgumentValues (thread, argument_values);
        if (!success)
            return ret_plan_sp;

        // Okay, the first value here is the object, we actually want the class of that object.
        // For now we're just going with the ISA.
        // FIXME: This should really be the return value of [object class] to properly handle KVO interposition.

        Value isa_value(*(argument_values.GetValueAtIndex(obj_index)));

        // This is a little cheesy, but since object->isa is the first field,
        // making the object value a load address value and resolving it will get
        // the pointer sized data pointed to by that value...
        ExecutionContext exec_ctx;
        thread.Calculate (exec_ctx);

        isa_value.SetValueType(Value::eValueTypeLoadAddress);
        isa_value.ResolveValue(&exec_ctx, clang_ast_context->getASTContext());

        if (this_dispatch->fixedup == DispatchFunction::eFixUpFixed)
        {
            // For the FixedUp method the Selector is actually a pointer to a
            // structure, the second field of which is the selector number.
            Value *sel_value = argument_values.GetValueAtIndex(sel_index);
            sel_value->GetScalar() += process->GetAddressByteSize();
            sel_value->SetValueType(Value::eValueTypeLoadAddress);
            sel_value->ResolveValue(&exec_ctx, clang_ast_context->getASTContext());
        }
        else if (this_dispatch->fixedup == DispatchFunction::eFixUpToFix)
        {
            // FIXME: If the method dispatch is not "fixed up" then the selector is actually a
            // pointer to the string name of the selector.  We need to look that up...
            // For now I'm going to punt on that and just return no plan.
            if (log)
                log->Printf ("Punting on stepping into un-fixed-up method dispatch.");
            return ret_plan_sp;
        }

        // FIXME: If this is a dispatch to the super-class, we need to get the super-class from
        // the class, and disaptch to that instead.
        // But for now I just punt and return no plan.
        if (this_dispatch->is_super)
        {
//.........这里部分代码省略.........

bool
ABISysV_mips::PrepareTrivialCall (Thread &thread,
                                  addr_t sp,
                                  addr_t func_addr,
                                  addr_t return_addr,
                                  llvm::ArrayRef<addr_t> args) const
{
    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));

    if (log)
    {
        StreamString s;
        s.Printf("ABISysV_mips::PrepareTrivialCall (tid = 0x%" PRIx64 ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64 ", return_addr = 0x%" PRIx64,
                    thread.GetID(),
                    (uint64_t)sp,
                    (uint64_t)func_addr,
                    (uint64_t)return_addr);

        for (size_t i = 0; i < args.size(); ++i)
            s.Printf (", arg%zd = 0x%" PRIx64, i + 1, args[i]);
        s.PutCString (")");
        log->PutCString(s.GetString().c_str());
    }

    RegisterContext *reg_ctx = thread.GetRegisterContext().get();
    if (!reg_ctx)
        return false;

    const RegisterInfo *reg_info = NULL;

    RegisterValue reg_value;

    // Argument registers
    const char *reg_names[] = { "r4", "r5", "r6", "r7" };

    llvm::ArrayRef<addr_t>::iterator ai = args.begin(), ae = args.end();

    // Write arguments to registers
    for (size_t i = 0; i < llvm::array_lengthof(reg_names); ++i)
    {
        if (ai == ae)
            break;

        reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + i);
        if (log)
            log->Printf("About to write arg%zd (0x%" PRIx64 ") into %s", i + 1, args[i], reg_info->name);

        if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))
            return false;

        ++ai;
    }

    // If we have more than 4 arguments --Spill onto the stack
    if (ai != ae)
    {
        // No of arguments to go on stack 
        size_t num_stack_regs = args.size();

        // Allocate needed space for args on the stack
        sp -= (num_stack_regs * 4);

        // Keep the stack 8 byte aligned
        sp &= ~(8ull-1ull);

        // just using arg1 to get the right size
        const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);
        
        addr_t arg_pos = sp+16;
        
        size_t i = 4;
        for (; ai != ae; ++ai)
        {
            reg_value.SetUInt32(*ai);
            if (log)
                log->Printf("About to write arg%zd (0x%" PRIx64 ") at  0x%" PRIx64 "", i+1, args[i], arg_pos);
            
            if (reg_ctx->WriteRegisterValueToMemory(reg_info, arg_pos, reg_info->byte_size, reg_value).Fail())
                return false;
            arg_pos += reg_info->byte_size;
            i++;
        }
    }

    Error error;
    const RegisterInfo *pc_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
    const RegisterInfo *sp_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
    const RegisterInfo *ra_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA);

    if (log)
    log->Printf("Writing SP: 0x%" PRIx64, (uint64_t)sp);

    // Set "sp" to the requested value
    if (!reg_ctx->WriteRegisterFromUnsigned (sp_reg_info, sp))
        return false;

    if (log)
    log->Printf("Writing RA: 0x%" PRIx64, (uint64_t)return_addr);

    // Set "ra" to the return address
//.........这里部分代码省略.........

bool ABISysV_ppc64::PrepareTrivialCall(Thread &thread, addr_t sp,
                                       addr_t func_addr, addr_t return_addr,
                                       llvm::ArrayRef<addr_t> args) const {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));

  if (log) {
    StreamString s;
    s.Printf("ABISysV_ppc64::PrepareTrivialCall (tid = 0x%" PRIx64
             ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64
             ", return_addr = 0x%" PRIx64,
             thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,
             (uint64_t)return_addr);

    for (size_t i = 0; i < args.size(); ++i)
      s.Printf(", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1),
               args[i]);
    s.PutCString(")");
    log->PutString(s.GetString());
  }

  RegisterContext *reg_ctx = thread.GetRegisterContext().get();
  if (!reg_ctx)
    return false;

  const RegisterInfo *reg_info = nullptr;

  if (args.size() > 8) // TODO handle more than 8 arguments
    return false;

  for (size_t i = 0; i < args.size(); ++i) {
    reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,
                                        LLDB_REGNUM_GENERIC_ARG1 + i);
    if (log)
      log->Printf("About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s",
                  static_cast<uint64_t>(i + 1), args[i], reg_info->name);
    if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))
      return false;
  }

  // First, align the SP

  if (log)
    log->Printf("16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64,
                (uint64_t)sp, (uint64_t)(sp & ~0xfull));

  sp &= ~(0xfull); // 16-byte alignment

  sp -= 8;

  Status error;
  const RegisterInfo *pc_reg_info =
      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
  const RegisterInfo *sp_reg_info =
      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
  ProcessSP process_sp(thread.GetProcess());

  RegisterValue reg_value;

  if (log)
    log->Printf("Pushing the return address onto the stack: 0x%" PRIx64
                ": 0x%" PRIx64,
                (uint64_t)sp, (uint64_t)return_addr);

  // Save return address onto the stack
  if (!process_sp->WritePointerToMemory(sp, return_addr, error))
    return false;

  // %r1 is set to the actual stack value.

  if (log)
    log->Printf("Writing SP: 0x%" PRIx64, (uint64_t)sp);

  if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))
    return false;

  // %pc is set to the address of the called function.

  if (log)
    log->Printf("Writing IP: 0x%" PRIx64, (uint64_t)func_addr);

  if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_info, func_addr))
    return false;

  return true;
}