Senti wrote:   Hi 1. Does anyone know how -ax option of gcc works ? 2. If yes, what -ax expects from me and what it gives back (in terms of output) ? 3. I remember i found some 3 sentences about that once, but i don't remember where .If anyone knows where i can find something about that please reply.   Thanks in advance Adrian The gcc man page should describe all related  options.  If you're working on either a Unix or Linux platform, then it's easy to access man pages and in case you don't know how, then it's         % man gcc % represents the prompt symbol on the command line and could be % or $ or something else, what ever it's been defined as. If the gcc man page doesn't contain the information you're looking for, then check through the gnu gcc web site, where there should be documentation covering your question.  www.gnu.org is the correct url, I believe.  You might want or need to do this if you're not working on Unix or Linux. I just checked the man page for gcc 2.7.2.3 on my Linux system, and this is an older gcc than the one you're working with, but the man page explains the -a and -x options.  -a is a debug option, takes no arguments, and is used to generate extra code for profiling.  -x is a language specification option and can take an argument, but one isn't required if you want the language to default based on the filename extensions or suffixes, such as .c for example. See the man page for more information on these options, because I didn't include all of it. If the man page has been maintained and these options are the same across these versions of gcc, then I believe that you should find all you need to know about these options from the man page.  Then, it's a question of whether the man page description is entirely consistent with the implementation of gcc being used, and if it's not, then produce a bug report explaining your findings. mike     Â