From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
To: Jim Wilson <wilson@cygnus.com>
Cc: jbuck@synopsys.com, egcs@cygnus.com
Subject: Re: Strange warning (variable might be clobbered by `longjmp' or `vfork') 
Date: Wed, 03 Sep 1997 02:29:00 -0000
Message-id: <9709030929.AA21411@issan.informatik.uni-dortmund.de>
References: <9709010239.AA21568@beeblebrox-84.synopsys.com> <199709011909.MAA19869@cygnus.com>
X-SW-Source: 1997-09/msg00088.html

Jim Wilson <wilson@cygnus.com> writes:

|> It is not a bug in user programs.  It is a bug in gcc'c EH support.
|> I have discussed this in other mesages, but the basic problem is that flow
|> can't understand the RTL emitted when exception handling is enabled.  This
|> causes the dataflow info computed by flow to be incorrect.  This incorrect
|> info is know to cause at least two problems:
|> 1) Some C++ programs get compiler core dumps due to unallocated pseudos.
|> 2) Some C++ programs get bogus warnings when -Wall is used.

Another problem is that -fdefer-pop breaks due to sjlj EH, especially
visible when a complicated expression involves multiple EH regions.

Andreas.