目的(purpose)

AutosarのC++ GuidelineをOS, 制御のプログラムで利用するにあたって、(1)hosted, freestandingのどちらを基本にすべきか。(2)C++2014,C++2017, C++202aのどれを用いると良いか, (3)どの処理系を併用すると良いかを検討するため、-std=c++14, -std=c++17, -std=c++2aの3種類で、複数のコンパイラでコンパイルすることにより、誤(error)、警告(warning)、関数・変数連携(link)、出力(output)、にどのような影響があるかを確認する。

成果(outcome)

複数の処理系の特徴が明確になるとともに、各標準段階, hosted, freestandingの特徴と課題を明確にする。

A10-3-5 .cpp

算譜(source code)

A10-3-5.cpp

//Guidelines for the use of the C++14 language in critical and safety-related systems
const char* msg="Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5.cpp";
//https://www.autosar.org/fileadmin/user_upload/standards/adaptive/17-03/AUTOSAR_RS_CPP14Guidelines.pdf
// There is no description about Autosar declear hosted or freestanding.
// If the Autosar intended both depending on the cases, autosar.h can choose one.
// Compile with -DHOSTED work as  hosted environment, -DFREESTANDING work as freestanding.

# include "autosar.h"/// @line add header file https://qiita.com/kaizen_nagoya/items/4bde8f21ab059b96cf2a

using namespace std;/// @line add using

///start AUTOSAR: From here to the "///end AUTOSAR" is from AUTOSAR without code having /// comment in line.
// $Id: A10-3-4.cpp 271687 2017-03-23 08:57:35Z piotr.tanski $
class A
{
public:
  virtual A& operator=(A const& oth) = 0; // Non-compliant
  virtual A& operator+=(A const& rhs) = 0; // Non-compliant
};
class B : public A
{
public:
  B& operator=(A const& oth) override // It needs to take an argument of type
// A& in order to override
  {
    return *this;
  }
  B& operator+=(A const& oth) override // It needs to take an argument of
// type A& in order to override
  {
    return *this;
  }
  B& operator-=(B const& oth) // Compliant
  {
    return *this;
  }
};
class C : public A
{
public:
  C& operator=(A const& oth) override // It needs to take an argument of type
// A& in order to override
  {
    return *this;
  }
  C& operator+=(A const& oth) override // It needs to take an argument of
// type A& in order to override
  {
    return *this;
  }
  C& operator-=(C const& oth) // Compliant
  {
    return *this;
  }
};
// class D : public A
//{
// public:
// D& operator=(D const& oth) override // Compile time error - this method
// does not override because of different
// signature
// {
// return *this;
// }
// D& operator+=(D const& oth) override // Compile time error - this method
// does not override because of different
// signature
// {
// return *this;
// }
//};
void fn() noexcept
{
  B b;
  C c;
  b = c; // Calls B::operator= and accepts an argument of type C
  b += c; // Calls B::operator+= and accepts an argument of type C
  c = b; // Calls C::operator= and accepts an argument of type B
  c += b; // Calls C::operator+= and accepts an argument of type B
// b -= c; // Compilation error, because of types mismatch. Expected
// behavior
// c -= b; // Compilation error, because of types mismatch. Expected
// behavior

  B b2;
  C c2;
  b -= b2;
  c -= c2;
}
///end AUTOSAR
int start() { /// @{} for start
  cout<< msg << endl;
  ShutdownOS()  EXIT_SUCCESS;
/// Autosar OS 3.1.1, 2009: 7.1.2.2 Undefined Behaviour in OSEK OS
/// OS425 If ShutdownOS is called and ShutdownHook() returns then the operating system shall disable all interrupts and enter an endless loop.
}

編纂・実行結果(compile and go)

cpa.sh

OgawaKishinoMBP:as ogawakiyoshi$ ../cpa.sh a10-3-5
$ clang++ a10-3-5.cpp -I./ -std=c++14 -Wall
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp
$ clang++ a10-3-5.cpp  -I./ -std=c++17 -Wall
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp
$ clang++ a10-3-5.cpp  -I./ -std=c++2a -Wall
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp

$ g++-8 a10-3-5.cpp  -I./ -std=c++14  -Wall
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp
$ g++-8 a10-3-5.cpp  -I./ -std=c++17  -Wall
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp
$ g++-8 a10-3-5.cpp  -I./ -std=c++2a  -Wall
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp

Visual Studio 2017

>cl A10-3-5.cpp /EHsc
Microsoft (R) Incremental Linker Version 14.15.26726.0
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:a10-3-5.exe 
a10-3-5.obj 

>A10-3-5
Rule A10-3-5 (required, implementation, automated)A user-defined assignment operator shall not be virtual.(85)A10-3-5 .cpp

検討事項(agenda)

1. 自律(freestanding)環境. 接待(hosted)環境

C++N4606 1.4 Implementation compliance p.4

2. 対応OSの水準、対応通信規約、応用機能による分類

freestanding用の関数、ライブラリ等

3. C++2014, C++2017, C++202aの比較項目

本件なし

4. clang++, g++の比較検討項目

本件なし

5 役立つまたは意味のある出力

参考文献(reference)

C++N4741 2018

Working Draft, Standard for Programming Language C++
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/201８/n4741.pdf

C++N4741, 2018 Standard Working Draft on ISO/IEC 14882 sample code compile list
https://qiita.com/kaizen_nagoya/items/3294c014044550896010

C++N4606 2016

Working Draft, Standard for Programming Language C++
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf

C++N4606, 2016符号断片編纂一覧(example code compile list)
Working Draft 2016, ISO/IEC 14882(1)
https://qiita.com/kaizen_nagoya/items/df5d62c35bd6ed1c3d43/

文書履歴(document history)

ver 0.10 初稿 20180611
ver 0.11 一覧追記 20180613
ver 0.20 Visual Studio 2017追記　20180916