Something between __func__ and __PRETTY_FUNCTION__?

c++, gcc, macros

Solution

Inspired by this, I created the following macro `__COMPACT_PRETTY_FUNCTION__`:

std::string computeMethodName(const std::string& function, const std::string& prettyFunction);

#define __COMPACT_PRETTY_FUNCTION__ computeMethodName(__FUNCTION__,__PRETTY_FUNCTION__).c_str() //c_str() is optional


std::string computeMethodName(const std::string& function, const std::string& prettyFunction) {
    size_t locFunName = prettyFunction.find(function); //If the input is a constructor, it gets the beginning of the class name, not of the method. That's why later on we have to search for the first parenthesys
    size_t begin = prettyFunction.rfind(" ",locFunName) + 1;
    size_t end = prettyFunction.find("(",locFunName + function.length()); //Adding function.length() make this faster and also allows to handle operator parenthesys!
    if (prettyFunction[end + 1] == ')')
        return (prettyFunction.substr(begin,end - begin) + "()");
    else
        return (prettyFunction.substr(begin,end - begin) + "(...)");
}

What it does:

- It takes `__PRETTY_FUNCTION__`

- It removes return type and all arguments

- If the function has zero arguments, it appends `()`, otherwise `(...)`

Features:

- Handles namespaces, constructors and so on

- Works also with the parenthesis operator!

Limitations:

- It only works with gcc

- Created at runtime rather than compile time

- Heap allocated.

- Does not work for lambdas, `__FUNCTION__` and `__PRETTY_FUNCTION__` don't match... I would almost call it a compiler bug :)

- `__FUNCTION__` sees an `operator()`

- `__PRETTY_FUNCTION__` sees `<lambda(...)>`

Problem

I work with g++ 4.8.1 and use these two macros for debugging. However, the `__func__` macro gives me only the function name, which might be misleading in the case you have many functions with the same name in different classes. The `__PRETTY_FUNCTION__` macro produces the whole function signature - with return type, class name and all arguments, which can be very long. I'd like to have something between - a macro, which will give me only class name and function name. Any way to achieve that?

Original source

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