>Either rename it or compile with g++, see the manual The make file is generated with a configure script. If I rename to .C I get this error: make[2]: *** No rule to make target `bpred.c', needed by `bpred.o'. Stop. On the other hand, I don't know how to tell makefile to compile *only* bpred.c with g++. >Also, why are you defining all those macros? Don't do that Yes it has some macros but I didn't write them. How did you find that? Let me know thanks // Naderan *Mahmood; ----- Original Message ----- From: Jonathan Wakely <jwakely.gcc@xxxxxxxxx> To: Mahmood Naderan <nt_mahmood@xxxxxxxxx> Cc: gcc <gcc-help@xxxxxxxxxxx> Sent: Wednesday, May 25, 2011 11:09 PM Subject: Re: "fstream: No such file or directory" but it is present Your file is a .c which gcc thinks is a C file Either rename it or compile with g++, see the manual Also, why are you defining all those macros? Don't do that