Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!brunix!phg
From: phg@cs.brown.edu (Peter H. Golde)
Newsgroups: comp.software-eng
Subject: Re: assert(): a "tutorial"
Keywords: assert()
Message-ID: <36218@brunix.UUCP>
Date: 12 Apr 90 22:59:20 GMT
References: <48461@lanl.gov>
Sender: news@brunix.UUCP
Reply-To: phg@cs.brown.edu (Peter H. Golde)
Organization: Brown University Department of Computer Science
Lines: 32

In article <48461@lanl.gov> u096000@lanl.gov (Roger A. Cole) writes:
>With these goals in mind, I have settled on the following form for assert(),
>which I'm using with the Sun3 C compiler.  There is a xxx.h part and a
>xxx.c part.
>
>#ifdef DEBUG
>#   define assert(expr) \
>		((void)((expr) || assertFail(__FILE__, __LINE__)))
>#else
>#    define assert(expr)
>#endif

Many C compilers will not put identical string literals into
the same piece of storage.  Using this method results in
many copies of the file name in your data space.  You
by be more efficient by using:

#ifdef DEBUG
static char _CurrentFileName = __FILE__;

    #define assert(expr) \
		((void)((expr) || assertFail(_CurrentFileName, __LINE__)))
#else

    #define assert(expr)

#endif

When doing this, you have to guard against including the .h file
multiple times.

--Peter Golde (phg@cs.brown.edu)