Easiest Solution by "Prof. Dr. Michael Helbig" . it will switch your mode to c99 so you don't have to add flag every time in make file
http://www.bigdev.de/2014/10/eclipse-cc-for-loop-initial.html?showComment=1447925473870#c6845437481920903532
Solution: use the option -std=c99 for your compiler! Go to: Project > Properties > C/C++ Buils > Settings > Tool Settings > GCC C Compiler > Dialect > Language Standard: choose "ISO C99"
