Is there a way to get function name inside a C++ function?

C99 has __func__, but for C++ this will be compiler specific. On the plus side, some of the compiler-specific versions provide additional type information, which is particularly nice when you're tracing inside a templatized function/class.

• MSVC: __FUNCTION__, __FUNCDNAME__, __FUNCSIG__
• GCC: __func__, __FUNCTION__, __PRETTY_FUNCTION__

Boost library has defined macro BOOST_CURRENT_FUNCTION for most C++ compilers in header boost/current_function.hpp. If the compiler is too old to support this, the result will be "(unknown)".

VC++ has

__FUNCTION__ for undecorated names

and

__FUNCDNAME__ for decorated names

And you can write a macro that will itself allocate an object and pass the name-yelding macro inside the constructor. Smth like

#define ALLOC_LOGGER FuncTracer ____tracer( __FUNCTION__ );

C++20 std::source_location::function_name

This does basically exactly what you want.

https://en.cppreference.com/w/cpp/utility/source_location claims usage will be like:

#include <iostream>
#include <string_view>
#include <source_location>
 
void log(std::string_view message,
         const std::source_location& location = std::source_location::current()
) {
    std::cout << "info:"
              << location.file_name() << ":"
              << location.line() << ":"
              << location.function_name() << " "
              << message << '\n';
}
 
int main() {
    log("Hello world!");
}

Possible output:

info:main.cpp:16:main Hello world!

so note how the call preserves caller information, so we see the desired main call location instead of log.

I have covered the relevant standards in a bit more detail at: What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?