Tool #1: gcc -finstrument-functions flag https://balau82.wordpress.com/2010/10/06/trace-and-profile-function-calls-with-gcc/

To use it, $ gcc -finstrument-functions -g -c -o foo.o foo.c $ gcc -c -o trace.o trace.c $ gcc foo.o trace.o -o foo $ ./foo

$ ./readtracelog.sh foo trace.out