Guidelines for the use of the C++14 language in critical and
safety-related systems Sample code compile list(59)
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。
#A7-1-4.cpp
##算譜(source code)
//Guidelines for the use of the C++14 language in critical and safety-related systems
const char* msg="Rule A7-1-4 (required, implementation, automated)The register keyword shall not be used.(59)A7-1-4.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: A7-1-4.cpp 271687 2017-03-23 08:57:35Z piotr.tanski $
#include <cstdint>
std::int32_t f1(register std::int16_t number) noexcept // Non-compliant
{
return ((number * number) + number);
}
void f2(std::int16_t number) noexcept // Compliant
{
register std::int8_t x = 10; // Non-compliant
std::int32_t result = f1(number); // Compliant
// ...
}
///end AUTOSAR
int start() { /// @{} for start
register int16_t i=256;
cout << "f1="<<f1(i)<<endl;
f2(i);
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 a7-1-4
$ clang++ a7-1-4.cpp -I./ -std=c++14 -Wall
a7-1-4.cpp:17:17: warning: 'register' storage class specifier is deprecated and incompatible with C++17
[-Wdeprecated-register]
std::int32_t f1(register std::int16_t number) noexcept // Non-compliant
^~~~~~~~~
a7-1-4.cpp:23:1: warning: 'register' storage class specifier is deprecated and incompatible with C++17
[-Wdeprecated-register]
register std::int8_t x = 10; // Non-compliant
^~~~~~~~~
2 warnings generated.
f1=65792
x=
result=65792
Rule A7-1-4 (required, implementation, automated)The register keyword shall not be used.(59)A7-1-4.cpp
$ clang++ a7-1-4.cpp -I./ -std=c++17 -Wall
a7-1-4.cpp:17:17: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
std::int32_t f1(register std::int16_t number) noexcept // Non-compliant
^~~~~~~~~
a7-1-4.cpp:23:1: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
register std::int8_t x = 10; // Non-compliant
^~~~~~~~~
2 errors generated.
$ clang++ a7-1-4.cpp -I./ -std=c++2a -Wall
a7-1-4.cpp:17:17: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
std::int32_t f1(register std::int16_t number) noexcept // Non-compliant
^~~~~~~~~
a7-1-4.cpp:23:1: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
register std::int8_t x = 10; // Non-compliant
^~~~~~~~~
2 errors generated.
$ g++-8 a7-1-4.cpp -I./ -std=c++14 -Wall
f1=65792
x=
result=65792
Rule A7-1-4 (required, implementation, automated)The register keyword shall not be used.(59)A7-1-4.cpp
$ g++-8 a7-1-4.cpp -I./ -std=c++17 -Wall
a7-1-4.cpp:17:39: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
std::int32_t f1(register std::int16_t number) noexcept // Non-compliant
^~~~~~
a7-1-4.cpp: In function 'void f2(int16_t)':
a7-1-4.cpp:23:22: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
register std::int8_t x = 10; // Non-compliant
^
f1=65792
x=
result=65792
Rule A7-1-4 (required, implementation, automated)The register keyword shall not be used.(59)A7-1-4.cpp
$ g++-8 a7-1-4.cpp -I./ -std=c++2a -Wall
a7-1-4.cpp:17:39: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
std::int32_t f1(register std::int16_t number) noexcept // Non-compliant
^~~~~~
a7-1-4.cpp: In function 'void f2(int16_t)':
a7-1-4.cpp:23:22: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
register std::int8_t x = 10; // Non-compliant
^
f1=65792
x=
result=65792
Rule A7-1-4 (required, implementation, automated)The register keyword shall not be used.(59)A7-1-4.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
C++2017以降でclang++がコンパイルエラー、他は警告。
###4. clang++, g++の比較検討項目
C++2017以降でclang++がコンパイルエラー、g++は警告。
###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 20180610