On 13 March 2011 14:42, Rohit Rehan wrote: > Sir, > How com the compiler of c is written in C. I mean first we need to compile > the source to get object but if we don't have a compiler to compile C source > how can we write a compiler in C. I am totally confused please help me. Yes, you need a C compiler to build GCC from source: http://gcc.gnu.org/install/prerequisites.html This is a common technique, see http://en.wikipedia.org/wiki/Bootstrapping_(compilers) Most operating systems either have pre-built versions of GCC available or provide another C compiler which can be used to compile GC.