Use the following method to show the gcc
# readlink -f $(which gcc)
# which gcc
# ls -la /usr/lib/ccache/gcc
lrwxrwxrwx 1 root root 16 2008-02-27 01:05 /usr/lib/ccache/gcc -> ../../bin/ccache ==> Actually the gcc was link as a ccache
ccache is a compiler cache. It acts as a caching pre-processor to C/C++ compilers, using the -E compiler switch and a hash to detect when a compilation can be satisfied from cache. This often results in a 5 to 10 times speedup in common compilations.
The idea came from Erik Thiele wrote the original compilercache program as a bourne shell script. ccache is a re-implementation of Erik's idea in C with more features and better performance.