Path: utzoo!attcan!uunet!mcvax!cernvax!ethz!iis!prl
From: prl@iis.UUCP (Peter Lamb)
Newsgroups: comp.lang.c++
Subject: Re: profiling C++ programs
Message-ID: <714@eiger.iis.UUCP>
Date: 13 Dec 88 10:49:17 GMT
References: <1790@kano.cs.vu.nl>
Reply-To: prl@iis.UUCP (Peter Lamb)
Organization: Integrated Systems Lab., ETH Zuerich
Lines: 47

In article <1790@kano.cs.vu.nl> frans@cs.vu.nl (Frans Heeman) writes:
>I tried to make a profile of a C++ program, using the -p (or -pg) flag:
>	CC -p *.c
>During linking, the following error was produced:
>	_exit: /usr/lib/libc_p.a(exit.o): multiply defined
>
The problem is that exit() is defined in /lib/mcrt0.o and /lib/gcrt0.o .

The reason for this is so that you don't have to have a different
exit() function in /lib/libc.a .

It is quite difficult to get profiling to work correctly, especially if you
want to support a number of programming environments (we have AT&T 1.2.1
on Vax, Sun, Alliant and Sequent).

I couldn't make the combination of profiling, executing destructors
and doing stdio cleanup work correctly for an exit function called
exit().

So, what I have done is to change the distributed exit.c code
to do the following:

#ifndef PROFILE_LIB

... Original AT&T code for C++ exit

#endif

void Exit(int i)
{
	dtors();
	exit(i);
}

The library must be compiled for profiling with PROFILE_LIB
defined. If you want to use profiling, you have to exit with Exit(i)
rather than exit(i).

This is *ugly*, and I would really appreciate someone giving me a better
solution.


-- 
Peter Lamb
uucp:  uunet!mcvax!ethz!prl	eunet: prl@ethz.uucp	Tel:   +411 256 5241
Integrated Systems Laboratory
ETH-Zentrum, 8092 Zurich