Path: utzoo!attcan!uunet!lll-winken!ames!xanth!mcnc!ecsvax!dukeac!bet
From: bet@dukeac.UUCP (Bennett Todd)
Newsgroups: comp.lang.c
Subject: Re: typechecking
Keywords: typechecking, lint
Message-ID: <1192@dukeac.UUCP>
Date: 18 Jan 89 08:22:21 GMT
References: <19620@uflorida.cis.ufl.EDU>
Reply-To: bet@dukeac.UUCP (Bennett Todd)
Organization: Radiology, Duke Med. Center, Durham, NC
Lines: 26

To get gcc to typecheck parameters to functions you need to have function
prototypes. I have an include file (I posted it here earlier) which contains
ANSI-style function prototypes for all the routines in sections 2 and 3 of the
UNIX Programmer's Manual. I've since enhanced it to include proper "const"
qualifiers (as best I can, I might have still missed some) so that I now can
compile with gcc's "-Wall -Wwrite-strings" options, which gives pretty
aggressive checking. If anybody is interested in this file let me know. As it
stands it #include's everything under the sun; I like this. It doesn't seem to
incur any run-time overhead in space or time (by which I mean to say that the
unneeded declarations and includes don't seem to change the generated code)
and I don't have to #include any of the system files. If you didn't like this
behavior the file could be split into separate sets of function prototypes
which could be imbedded (within #ifdef __STDC__ / #endif) in the appropriate
/usr/include files.

Specifically, to get gcc to give the desired warning on the common error

	fprintf("format", args);

(omitting the needed stream parameter) you would want the following prototype
in scope:

	int fprintf(FILE *, const char *, ...);

-Bennett
bet@orion.mc.duke.edu