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。

A15-5-1.cpp

算譜(source code)

A15-5-1.cpp

//Guidelines for the use of the C++14 language in critical and safety-related systems
const char* msg="Rule A15-5-1 (required, implementation, automated) A class destructor, “delete” operators, move constructor, move assignment operator and “swap” function shall not exit with an exception. They shall be all specified as “noexcept”.(140)A15-5-1.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: A15-5-1.cpp 270728 2017-03-16 10:38:20Z piotr.tanski $
# include <stdexcept>
class C1
{
public:
  C1() = default;
  C1(C1&& rhs)
  noexcept // Compliant - move constructor declared to be noexcept
  {
  }
  C1& operator=(C1&& rhs) noexcept // Compliant - move assignment operator
// declared to be noexcept
  {
    return *this;
  }
  ~C1() noexcept // Compliant - no exceptions thrown from destructor
  {
  }
};
void swap(C1& lhs, C1& rhs) noexcept // Compliant - swap function does not exit
// with an exception
{
// Implementation
}
class C2
{
public:
  C2() = default;
  C2(C2&& rhs)
  noexcept // Compliant - move constructor declared to be noexcept
  {
    try
    {
// ...
      throw std::runtime_error(
        "Error"); // Exception will not leave move constructor
    }

    catch (std::exception& e)
    {
// Handle runtime error
    }
  }
  C2& operator=(C2&& rhs) noexcept // Compliant - move assignment operator
// declared to be noexcept
  {
    try
    {
// ...
      throw std::runtime_error(
        "Error"); // Exception will not leave assignment operator
    }

    catch (std::exception& e)
    {
// Handle runtime error
    }

    return *this;
  }
  ~C2() // Non-compliant - the destructor does not contain the noexcept
// specification
  {
    try
    {
// ...
      throw std::runtime_error(
        "Error"); // Exception will not leave the destructor
    }

    catch (std::exception& e)
    {
// Handle runtime error
    }
  }
};
void swap(C2& lhs, C2& rhs) noexcept(
  false) // Non-compliant - swap function declared to be noexcept(false)
{
// Implementation
  throw std::runtime_error("Swap function failed"); // Non-compliant - swap
// function exits with an
// exception
}
class C3
{
public:
  C3() = default;
  C3(C3&& rhs) // Non-compliant - move constructor throws
  {
// ...
    throw std::runtime_error("Error");
  }
  C3& operator=(C3&& rhs) // Non-compliant - move assignment operator throws
  {
// ...
    throw std::runtime_error("Error");
    return *this;
  }
  ~C3() // Non-compliant - destructor exits with an exception
  {
    throw std::runtime_error("Error");
  }
  static void operator delete(void* ptr, std::size_t sz)
  {
// ...
    throw std::runtime_error("Error"); // Non-compliant - operator delete
// exits with an exception
  }
};
void fn()
{
  C3 c1; // program terminates when c1 is destroyed
  C3* c2 = new C3;
// ...
  delete c2; // program terminates when c2 is deleted
}
/// @ end AUTOSAR
int start() { /// @{} for start
  fn();
  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 a15-5-1
$ clang++ a15-5-1.cpp -I./ -std=c++14 -Wall
a15-5-1.cpp:114:2: warning: '~C3' has a non-throwing exception specification but can still throw [-Wexceptions]
 throw std::runtime_error("Error");
 ^
a15-5-1.cpp:112:2: note: destructor has a implicit non-throwing exception specification
 ~C3() // Non-compliant - destructor exits with an exception
 ^
a15-5-1.cpp:119:2: warning: 'operator delete' has a non-throwing exception specification but can still throw [-Wexceptions]
 throw std::runtime_error("Error"); // Non-compliant - operator delete
 ^
a15-5-1.cpp:116:14: note: deallocator has a implicit non-throwing exception specification
 static void operator delete(void* ptr, std::size_t sz)
             ^
2 warnings generated.
libc++abi.dylib: terminating with uncaught exception of type std::runtime_error: Error
../cpa.sh: line 7: 69039 Abort trap: 6           ./$1l14 $2
$ clang++ a15-5-1.cpp  -I./ -std=c++17 -Wall
a15-5-1.cpp:114:2: warning: '~C3' has a non-throwing exception specification but can still throw [-Wexceptions]
 throw std::runtime_error("Error");
 ^
a15-5-1.cpp:112:2: note: destructor has a implicit non-throwing exception specification
 ~C3() // Non-compliant - destructor exits with an exception
 ^
a15-5-1.cpp:119:2: warning: 'operator delete' has a non-throwing exception specification but can still throw [-Wexceptions]
 throw std::runtime_error("Error"); // Non-compliant - operator delete
 ^
a15-5-1.cpp:116:14: note: deallocator has a implicit non-throwing exception specification
 static void operator delete(void* ptr, std::size_t sz)
             ^
2 warnings generated.
libc++abi.dylib: terminating with uncaught exception of type std::runtime_error: Error
../cpa.sh: line 13: 69044 Abort trap: 6           ./$1l17 $2
$ clang++ a15-5-1.cpp  -I./ -std=c++2a -Wall
a15-5-1.cpp:114:2: warning: '~C3' has a non-throwing exception specification but can still throw [-Wexceptions]
 throw std::runtime_error("Error");
 ^
a15-5-1.cpp:112:2: note: destructor has a implicit non-throwing exception specification
 ~C3() // Non-compliant - destructor exits with an exception
 ^
a15-5-1.cpp:119:2: warning: 'operator delete' has a non-throwing exception specification but can still throw [-Wexceptions]
 throw std::runtime_error("Error"); // Non-compliant - operator delete
 ^
a15-5-1.cpp:116:14: note: deallocator has a implicit non-throwing exception specification
 static void operator delete(void* ptr, std::size_t sz)
             ^
2 warnings generated.
libc++abi.dylib: terminating with uncaught exception of type std::runtime_error: Error
../cpa.sh: line 19: 69050 Abort trap: 6           ./$1l2a $2

$ g++-8 a15-5-1.cpp  -I./ -std=c++14  -Wall
a15-5-1.cpp: In destructor 'C3::~C3()':
a15-5-1.cpp:114:34: warning: throw will always call terminate() [-Wterminate]
  throw std::runtime_error("Error");
                                  ^
a15-5-1.cpp:114:34: note: in C++11 destructors default to noexcept
terminate called after throwing an instance of 'std::runtime_error'
  what():  Error
../cpa.sh: line 26: 69060 Abort trap: 6           ./$1g14 $2
$ g++-8 a15-5-1.cpp  -I./ -std=c++17  -Wall
a15-5-1.cpp: In destructor 'C3::~C3()':
a15-5-1.cpp:114:34: warning: throw will always call terminate() [-Wterminate]
  throw std::runtime_error("Error");
                                  ^
a15-5-1.cpp:114:34: note: in C++11 destructors default to noexcept
terminate called after throwing an instance of 'std::runtime_error'
  what():  Error
../cpa.sh: line 32: 69070 Abort trap: 6           ./$1g17 $2
$ g++-8 a15-5-1.cpp  -I./ -std=c++2a  -Wall
a15-5-1.cpp: In destructor 'C3::~C3()':
a15-5-1.cpp:114:34: warning: throw will always call terminate() [-Wterminate]
  throw std::runtime_error("Error");
                                  ^
a15-5-1.cpp:114:34: note: in C++11 destructors default to noexcept
terminate called after throwing an instance of 'std::runtime_error'
  what():  Error
../cpa.sh: line 38: 69080 Abort trap: 6           ./$1g2a $2

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 20180612
ver 0.11 一覧追記 20180613