Autosar Guidelines C++14, example code compile list(158)Rule A18-5-2  Operators new and delete shall not be called explicitly.

Guidelines for the use of the C++14 language in critical and
safety-related systems Sample code compile list(158)
https://www.autosar.org/fileadmin/user_upload/standards/adaptive/17-03/AUTOSAR_RS_CPP14Guidelines.pdf
Autosar Guidelines C++14, example code compile list will be listed.
#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。


#A18-5-2.cpp
##算譜(source code)

```c++:A18-5-2.cpp
//Guidelines for the use of the C++14 language in critical and safety-related systems
const char* msg="Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.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: A1-7-2.cpp 270728 2017-03-16 10:38:20Z piotr.tanski $
#include <cstdint>
#include <memory>
#include <vector>
std::int32_t fn1()
{
  std::int32_t errorCode{0};

  std::int32_t* ptr =
    new std::int32_t{0}; // Non-compliant - new called explicitly
// ...
  if (errorCode != 0)
  {
    throw std::runtime_error{"Error"}; // Memory leak could occur here
  }
// ...

  if (errorCode != 0)
  {
    return 1; // Memory leak could occur here
  }
// ...
  cout << "ptr="<< ptr << endl;/// @ line for output and warning
  return errorCode; // Memory leak could occur here
}
std::int32_t fn2()
{
  std::int32_t errorCode{0};

  std::unique_ptr<std::int32_t> ptr1 = std::make_unique<std::int32_t>(
                                         0); // Compliant - alternative for ’new std::int32_t(0)’

  std::unique_ptr<std::int32_t> ptr2(new std::int32_t{
    0}); // Non-compliant - unique_ptr provides make_unique
// function which shall be used instead of explicit
// new operator

  std::shared_ptr<std::int32_t> ptr3 =
    std::make_shared<std::int32_t>(0); // Compliant

  std::vector<std::int32_t> array; // Compliant
// alternative for dynamic array

  if (errorCode != 0)
  {
    throw std::runtime_error{"Error"}; // No memory leaks
  }
// ...
  if (errorCode != 0)
  {
    return 1; // No memory leaks
  }
// ...
  return errorCode; // No memory leaks
}
template <typename T>
class ObjectManager
{
public:
  explicit ObjectManager(T* obj) : object{obj} {}
  ~ObjectManager() {
    delete object;
  }
// Implementation

private:
  T* object;
};
std::int32_t fn3()
{
  std::int32_t errorCode{0};

  ObjectManager<std::int32_t> manager{
    new std::int32_t{0}}; // Compliant by exception
  if (errorCode != 0)
  {
    throw std::runtime_error{"Error"}; // No memory leak
  }
// ...
  if (errorCode != 0)
  {
    return 1; // No memory leak
  }
// ...
  return errorCode; // No memory leak
}
/// @ end AUTOSAR
int start() { /// @{} for start
  cout <<"fn1()="<<fn1()<<" fn2()="<<fn2()<<" fn3="<<fn3()<<endl;// for output
  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)

```shell-session:cpa.sh
$ ../cpa.sh a18-5-2
$ clang++ a18-5-2.cpp -I./ -std=c++14 -Wall
fn1()=ptr=0x7fa633c027e0
0 fn2()=0 fn3=0
Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.cpp
$ clang++ a18-5-2.cpp  -I./ -std=c++17 -Wall
fn1()=ptr=0x7f8d2b4027e0
0 fn2()=0 fn3=0
Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.cpp
$ clang++ a18-5-2.cpp  -I./ -std=c++2a -Wall
fn1()=ptr=0x7fdb88c027e0
0 fn2()=0 fn3=0
Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.cpp

$ g++-8 a18-5-2.cpp  -I./ -std=c++14  -Wall
fn1()=ptr=0x7f8617500000
0 fn2()=0 fn3=0
Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.cpp
$ g++-8 a18-5-2.cpp  -I./ -std=c++17  -Wall
fn1()=ptr=0x7fd2d0c027e0
0 fn2()=0 fn3=0
Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.cpp
$ g++-8 a18-5-2.cpp  -I./ -std=c++2a  -Wall
fn1()=ptr=0x7fa0b04027e0
0 fn2()=0 fn3=0
Rule A18-5-2 (required, implementation, partially automated) Operators new and delete shall not be called explicitly.(158)A18-5-2.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.  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/2017/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
ver 0.10 初稿 20180612