Bill Mahoney wrote: > Brian: > > Thanks for the reply - I appreciate it. > > This much I knew. However! Let me rephrase my question. Suppose I > compile something with -finstrument-functions and don't supply my own > function. Then your program won't link. > The linker must resolve it to something, so I assumed that > there is an empty function (e.g. a "ret" with a global label on it) > somewhere in the runtime library source; otherwise "ld" would barf. Is > this not the case, and the linker is just supplying that silently, or what? If your program links you have a definition of __cyg_ ... from somewhere. A linker map will tell you where it comes from. Andrew.