__FILE__ macro manipulation handling at compile time.

Question

One of the issues I have had in porting some stuff from Solaris to Linux is that the Solaris compiler expands the macro __FILE__ during preprocessing to the file name (e.g. MyFile.cpp) whereas gcc on Linux expandeds out to the full path (e.g. /home/user/MyFile.cpp). This can be reasonably easily resolved using basename() but....if you're using it a lot, then all those calls to basename() have got to add up, right?

Here's the question. Is there a way using templates and static metaprogramming, to run basename() or similar at compile time? Since __FILE__ is constant and known at compile time this might make it easier. What do you think? Can it be done?

Answer 1

There is currently no way of doing full string processing at compile time (the maximum we can work with in templates are the weird four-character-literals).

Why not simply save the processed name statically, e.g.:

namespace 
{
  const std::string& thisFile() 
  {
      static const std::string s(prepocessFileName(__FILE__));
      return s;
  }
}

This way you are only doing the work once per file. Of course you can also wrap this into a macro etc.

Answer 2

you might want to try the BASE_FILE macro. This page describes alot of macros which gcc supports.