From: cgf@bbc.com (Chris Faylor) Subject: Re: A TINY BUG 6 Oct 1997 19:36:55 -0700 Message-ID: References: <3438330F.61CF@stockholm.mail.telia.com> Reply-To: cgf@bbc.com To: gnu-win32@cygnus.com In article <34391696.27758E19@softway.com>, Jason Zions wrote: >> I have found that the following bad code gives "exception" at run >> time instead of error message at compilation time (b18 Win95): >> >> #include >> main(){ >> printf("%s\n",sizeof(long)); >> } > >No compiler will detect this error at compile-time. The prototype for >printf is (char *, ...); that is, no specific type information for >anything except the first parameter. A compiler would have to read the >first parameter to figure out the expected types for the remaining >args, and much of the time that first parameter is dynamically computed >at runtime instead of being a static string. There are a couple of >lint-like programs that will catch this error with a >compile-time-evaluatable format string, but that's the best you can do. > >Summary: learn more about the language before whining about compiler >errors. This is a programmer bug, not a compiler bug. Actually, this is a little harsh since GCC does, in fact, have a compile time __attribute__ option for checking the arguments to a printf. If the prototype for printf in /usr/include/stdio.h had included something like: __attribute__((format(printf, 1, 2))); it would have detected that programmer error. -- http://www.bbc.com/ cgf@bbc.com "Strange how unreal VMS=>UNIX Solutions Boston Business Computing the real can be." - For help on using this list (especially unsubscribing), send a message to "gnu-win32-request@cygnus.com" with one line of text: "help".