FreeBSD_demangle_issue.cpp

#include <cxxabi.h>
#include <iostream>

void demangle_name(const std::string& mangled_name)
{
    std::size_t len = 0;
    int status = 0;
    auto name = __cxxabiv1::__cxa_demangle(mangled_name.c_str(), nullptr, &len, &status);
    if (status == 0)
    {
        std::cout << "demangled name:" << name << "\n";
    }
    else
    {
        std::cout << "demangle error\n";
    }
    std::free(name);
        
}

template <typename T>
void demangle(T &&v)
{
    std::size_t len = 0;
    int status = 0;
    auto name = __cxxabiv1::__cxa_demangle(typeid(T).name(), nullptr, &len, &status);

    if (status == 0)
    {
        std::cout << "demangled name:" << name << "\n";
    }
    else
    {
        std::cout << "demangle error\n";
    }
    std::free(name);
}

void f1(std::string &s1) {}
void f2(std::string &&s1) {}

int main()
{
    demangle(f1); // Good on FreeBSD 12. Fail on FreeBSD 13
    demangle(f2); // Fail on FreeBSD 12. Fail on FreeBSD 13
    
    demangle_name("i"); // Fail on FreeBSD 13
    demangle_name("8SayHello"); // Fail on FreeBSD 13
}