LoginSignup
0

More than 1 year has passed since last update.

Autosar Guidelines C++14, example code compile list(164)Rule A18-9-2 Forwarding values to other functions

Last updated at Posted at 2018-06-12

Guidelines for the use of the C++14 language in critical and
safety-related systems Sample code compile list(164)
https://www.autosar.org/fileadmin/user_upload/standards/adaptive/17-03/AUTOSAR_RS_CPP14Guidelines.pdf
Autosar Guidelines C++14 example code compile list(1-169)
https://qiita.com/kaizen_nagoya/items/8ccbf6675c3494d57a76
#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、以下を検討する。
(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。
-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。
各標準段階の違いを明確にする。
hostedまたはfreestandingの特徴と課題を明確にする。

#A18-9-2.cpp
##算譜(source code)

A18-9-2.cpp
//Guidelines for the use of the C++14 language in critical and safety-related systems
const char* msg="Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.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" are from the AUTOSAR code without some code having /// comment in line.
// $Id: A18-9-2.cpp 271927 2017-03-24 12:01:35Z piotr.tanski $
#include <cstdint>
#include <string>
#include <utility>
class A
{
public:
  explicit A(std::string&& s)
    : str(std::move(s)) // Compliant - forwarding rvalue reference
  {
  }

private:
  std::string str;
};
class B
{
};
void fn1(const B& lval)
{
}
void fn1(B&& rval)
{
}
template <typename T>
void fn2(T&& param)
{
  fn1(std::forward<T>(param)); // Compliant - forwarding forwarding reference
}
template <typename T>
void fn3(T&& param)
{
  fn1(std::move(param)); // Non-compliant - forwarding forwarding reference
// via std::move
}
void fn4() noexcept
{
  B b1;
  B& b2 = b1;
  fn2(b2); // fn1(const B&) is called
  fn2(std::move(b1)); // fn1(B&&) is called
  fn3(b2); // fn1(B&&) is called
  fn3(std::move(b1)); // fn1(B&&) is called
}
/// @ end AUTOSAR
int start() { /// @{} for start
  B b;
  const B& lval=b;
  fn1(lval);
  fn4();
  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
$ ../cpa.sh a18-9-2
$ clang++ a18-9-2.cpp -I./ -std=c++14 -Wall
Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.cpp
$ clang++ a18-9-2.cpp  -I./ -std=c++17 -Wall
Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.cpp
$ clang++ a18-9-2.cpp  -I./ -std=c++2a -Wall
Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.cpp

$ g++-8 a18-9-2.cpp  -I./ -std=c++14  -Wall
Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.cpp
$ g++-8 a18-9-2.cpp  -I./ -std=c++17  -Wall
Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.cpp
$ g++-8 a18-9-2.cpp  -I./ -std=c++2a  -Wall
Rule A18-9-2 (required, implementation, automated) Forwarding values to other functions shall be done via: (1) std::move if the value is an rvalue reference, (2) std::forward if the value is forwarding reference.(164)A18-9-2.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. template
void fn2(T&& param)
の引数の渡し方

###6. 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 20180612
ver 0.11 一覧追記 20180614

最後までおよみいただきありがとうございました。

いいね 💚、フォローをお願いします。

Thank you very much for reading to the last sentence.

Please press the like icon 💚 and follow me for your happy life.

Register as a new user and use Qiita more conveniently

  1. You get articles that match your needs
  2. You can efficiently read back useful information
  3. You can use dark theme
What you can do with signing up
0