From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jim Wilson <wilson@cygnus.com>
To: egcs@cygnus.com
Subject: Re: Strange warning (variable might be clobbered by `longjmp' or `vfork')
Date: Sun, 31 Aug 1997 01:23:00 -0000
Message-id: <199708310123.SAA21826@cygnus.com>
In-reply-to: Strange warning (variable might be clobbered by `longjmp' or `vfork')
X-SW-Source: 1997-08/0821.html

	The following code gives a strange warning.
	~/Prog> g++ -Wall -O -c egcs-feature2.cc
	egcs-feature2.cc: In function `void f()':
	egcs-feature2.cc:15: warning: variable `int maxrows' might be clobbered by
	`longjmp' or `vfork'

This is due to problems with the setjmp/longjmp exception handler support.
It goes away if you use -fno-exceptions or -fno-sjlj-exceptions.

An exception handler block is being inserted into the program.  This involves
adding a (builtin) setjmp call.  This confuses the RTL a little, and flow
ends up thinking that the variable max is live across a setjmp call.
This can probably be fixed by making the sjlj EH support and flow interact
better.

Jim