Hi to every one I couldn't generate a control flow graph for a c program by gcc3.4.5. if it is possible help me to generate cfg. I use the following commands but I couldn't find the cfg file. $ gcc -o -dv prog.c -o prog result: unrecognized command line option "-fdump-tree-fixupcfg" $ gcc -fdump-tree-cfg prog.c result: it is not generate any cfg file. Regards.