Autosar Guidelines C++14, example code compile list(62)Rule A7-1-7 Each identifier shall be declared on a separate line.

Guidelines for the use of the C++14 language in critical and
safety-related systems Sample code compile list(62)
https://www.autosar.org/fileadmin/user_upload/standards/adaptive/17-03/AUTOSAR_RS_CPP14Guidelines.pdf
Autosar Guidelines C++14, example code compile list(
#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。


#A7-1-7.cpp
##算譜(source code)

```c++:A7-1-7.cpp
//Guidelines for the use of the C++14 language in critical and safety-related systems
const char* msg="Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.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: A7-1-7.cpp 271715 2017-03-23 10:13:51Z piotr.tanski $
#include <cstdint>
#include <vector>

typedef std::int32_t* ptr; // Compliant
typedef std::int32_t *pointer, value; // Non-compliant

void fn1() noexcept
{
  std::int32_t x = 0; // Compliant
  std::int32_t y = 7, *p1 = nullptr; // Non-compliant
  std::int32_t const *p2, z = 1; // Non-compliant
  cout << "x="<<x<<" y="<<y<<" z="<<z<<endl;/// @ line for output
}

void fn2()
{
  std::vector<std::int32_t> v{1, 2, 3, 4, 5};
  for (auto iter{v.begin()}, end{v.end()}; iter != end;
       ++iter) // Compliant by exception
  {
// ...
  }
}
///end AUTOSAR
int start() { /// @{} for start
  fn1();
  fn2();
  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 a7-1-7
$ clang++ a7-1-7.cpp -I./ -std=c++14 -Wall
a7-1-7.cpp:23:23: warning: unused variable 'p1' [-Wunused-variable]
 std::int32_t y = 7, *p1 = nullptr; // Non-compliant
                      ^
a7-1-7.cpp:24:22: warning: unused variable 'p2' [-Wunused-variable]
 std::int32_t const *p2, z = 1; // Non-compliant
                     ^
2 warnings generated.
x=0 y=7 z=1
Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.cpp
$ clang++ a7-1-7.cpp  -I./ -std=c++17 -Wall
a7-1-7.cpp:24:22: warning: unused variable 'p2' [-Wunused-variable]
 std::int32_t const *p2, z = 1; // Non-compliant
                     ^
a7-1-7.cpp:23:23: warning: unused variable 'p1' [-Wunused-variable]
 std::int32_t y = 7, *p1 = nullptr; // Non-compliant
                      ^
2 warnings generated.
x=0 y=7 z=1
Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.cpp
$ clang++ a7-1-7.cpp  -I./ -std=c++2a -Wall
a7-1-7.cpp:24:22: warning: unused variable 'p2' [-Wunused-variable]
 std::int32_t const *p2, z = 1; // Non-compliant
                     ^
a7-1-7.cpp:23:23: warning: unused variable 'p1' [-Wunused-variable]
 std::int32_t y = 7, *p1 = nullptr; // Non-compliant
                      ^
2 warnings generated.
x=0 y=7 z=1
Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.cpp

$ g++-8 a7-1-7.cpp  -I./ -std=c++14  -Wall
a7-1-7.cpp: In function 'void fn1()':
a7-1-7.cpp:23:23: warning: unused variable 'p1' [-Wunused-variable]
  std::int32_t y = 7, *p1 = nullptr; // Non-compliant
                       ^~
a7-1-7.cpp:24:22: warning: unused variable 'p2' [-Wunused-variable]
  std::int32_t const *p2, z = 1; // Non-compliant
                      ^~
x=0 y=7 z=1
Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.cpp
$ g++-8 a7-1-7.cpp  -I./ -std=c++17  -Wall
a7-1-7.cpp: In function 'void fn1()':
a7-1-7.cpp:23:23: warning: unused variable 'p1' [-Wunused-variable]
  std::int32_t y = 7, *p1 = nullptr; // Non-compliant
                       ^~
a7-1-7.cpp:24:22: warning: unused variable 'p2' [-Wunused-variable]
  std::int32_t const *p2, z = 1; // Non-compliant
                      ^~
x=0 y=7 z=1
Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.cpp
$ g++-8 a7-1-7.cpp  -I./ -std=c++2a  -Wall
a7-1-7.cpp: In function 'void fn1()':
a7-1-7.cpp:23:23: warning: unused variable 'p1' [-Wunused-variable]
  std::int32_t y = 7, *p1 = nullptr; // Non-compliant
                       ^~
a7-1-7.cpp:24:22: warning: unused variable 'p2' [-Wunused-variable]
  std::int32_t const *p2, z = 1; // Non-compliant
                      ^~
x=0 y=7 z=1
Rule A7-1-7 (required, implementation, automated)Each identifier shall be declared on a separate line.(62)A7-1-7.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 20180611