You must be calling your function "save_flags_cli" in the file other than where it is defined. If that is so, you need to declare this function in that file too. As an example, consider the following scenario foo1.c void save_flags(int x) { ......... ......... } foo2.c int main() { ........ save_flags(); ........ } Under this scenario, you would get the warning reported by you. The warning suggests that the function is defined and declared at the same point. To fix it, the structured way is to make a .h file as: foo.h extern void save_flags(int); And update foo2.c as: #include "foo.h" int main() { } Hope that would help you........... Regards Rakesh > -----Original Message----- > From: DEEPA SIVASANKARANE [mailto:aj9035@xxxxxxxxx] > Sent: Thursday, July 31, 2003 8:24 AM > To: gcc-help@xxxxxxxxxxx > Subject: Compiler warning > > > Hi folks, > > Could someone please tell me how to fix this compile > warning: > warning: implicit declaration of function `__save_flags_cli' > > Thanx, > regards, > Deepa >