`get_stdopt` caters only to the c++ kernel

[anutosh491]

xeus-cpp/src/xinterpreter.cpp

Lines 76 to 101 in c7628c6

	static std::string get_stdopt()
	{
	// We need to find what's the C++ version the interpreter runs with.
	const char* code = R"(
	int __get_cxx_version () {
	#if __cplusplus > 202302L
	return 26;
	#elif __cplusplus > 202002L
	return 23;
	#elif __cplusplus > 201703L
	return 20;
	#elif __cplusplus > 201402L
	return 17;
	#elif __cplusplus > 201103L || (defined(_WIN32) && _MSC_VER >= 1900)
	return 14;
	#elif __cplusplus >= 201103L
	return 11;
	#else
	return 0;
	#endif
	}
	__get_cxx_version ()
	)";
	auto cxx_version = Cpp::Evaluate(code);
	return std::to_string(cxx_version);
	}

Defines version for the kernel based on __get_cxx_version and this variable ends up taking 0 for the kernel version (for any C kernel). For example from the wasm kernel (pasting the wasm content)

  (func $__get_cxx_version (;2;) (export "__get_cxx_version") (result i32)
    i32.const 0
  )

So a kernel info request would show the version to be 0 instead of C23.

We should probably fetch information from the Kernel spec whether a C or C++ kernel is defined and use get_stdopt accordingly !

[anutosh491]

Probably can try this

int __get_lang_version() {
#if defined(__cplusplus)
    // ---- C++ version ----
    #if __cplusplus > 202302L
        return 26;
    #elif __cplusplus > 202002L
        return 23;
    #elif __cplusplus > 201703L
        return 20;
    #elif __cplusplus > 201402L
        return 17;
    #elif __cplusplus > 201103L || (defined(_WIN32) && _MSC_VER >= 1900)
        return 14;
    #elif __cplusplus >= 201103L
        return 11;
    #else
        return 0;
    #endif

#elif defined(__STDC_VERSION__)
    // ---- C version ----
    #if __STDC_VERSION__ >= 202000L
        return 23;
    #elif __STDC_VERSION__ >= 201112L
        return 11;
    #elif __STDC_VERSION__ >= 199901L
        return 99;   // C99
    #elif __STDC_VERSION__ >= 199409L
        return 95;
    #else
        return 90;   // C90
    #endif

#else
    return 0;
#endif
}

[mcbarton]

Probably can try this

int __get_lang_version() {
#if defined(__cplusplus)
    // ---- C++ version ----
    #if __cplusplus > 202302L
        return 26;
    #elif __cplusplus > 202002L
        return 23;
    #elif __cplusplus > 201703L
        return 20;
    #elif __cplusplus > 201402L
        return 17;
    #elif __cplusplus > 201103L || (defined(_WIN32) && _MSC_VER >= 1900)
        return 14;
    #elif __cplusplus >= 201103L
        return 11;
    #else
        return 0;
    #endif

#elif defined(__STDC_VERSION__)
    // ---- C version ----
    #if __STDC_VERSION__ >= 202000L
        return 23;
    #elif __STDC_VERSION__ >= 201112L
        return 11;
    #elif __STDC_VERSION__ >= 199901L
        return 99;   // C99
    #elif __STDC_VERSION__ >= 199409L
        return 95;
    #else
        return 90;   // C90
    #endif

#else
    return 0;
#endif
}

I got something similar from prompts to chatgpt. One noticeably ommision from the c versions in the snippet above is c17. Also although they are c standards, do we really want to include c95 and c90 (I know someone could technically create themselves a kernel with the standard, but is this likely?). There has to be a cut off somewhere I guess since we don't have c++98 or c++03 versions looked for.

[mcbarton]

I say this without knowing its feasibility, could this be provided by CppInterOp like the future interface to provide the language?