Do you generally connect to your Pi using SSH and do your error messages from the gcc compiler look like this?
The odd characters are because SSH requires a basic locale to ensure that the characters are reproduced correctly. You can change the locale using raspi-config or by running dpkg-reconfigure. Change your current locale to en_GB ISO-8859-1 or en_GB ISO-8859-15.
sudo dpkg-reconfigure locales
When you have made the change to your locale, error messages will now be displayed correctly.