Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!eos!agate!ucbvax!ucsd!orion.cf.uci.edu!uci-ics!crimee.ics.uci.edu!schmidt
From: schmidt@crimee.ics.uci.edu (Doug Schmidt)
Newsgroups: gnu.g++.bug
Subject: Re: BUG in GCC & G++ 1.32 using -O & inline & narrowing implicit casts
Message-ID: <6591@paris.ics.uci.edu>
Date: 3 Feb 89 04:05:19 GMT
References: <8901312032.AA24614@riunite.aca.mcc.com> <8902010855.AA06237@marvin.moncam.uucp>
Sender: news@paris.ics.uci.edu
Reply-To: Doug Schmidt <schmidt@crimee.ics.uci.edu>
Distribution: gnu
Organization: University of California at Irvine: ICS Dept.
Lines: 41

In article <8902010855.AA06237@marvin.moncam.uucp> mcvax!moncam!paul@UUNET.UU.NET (Paul Hudson) writes:
++
++As before, suggestions of futher warnings welcome.
++Paul Hudson 
++

Here's a useful warning we could use in gcc and g++, given that it is now
possible to declare ``const'' functions (read gcc.texinfo for gcc 1.33
for details).

Imagine the following perverse program:

----------------------------------------
int external = 10;

int bar () {
   external++;        
}

const int foo (int *i) {
   bar();
   return (external = *i = 10);
}

void main () {
   external = foo(&external) + external;
}
----------------------------------------

Function foo violates just about all the restrictions on const
functions, since it references global variables, changes its
parameters, and calls a non-const function.  However, gcc doesn't
complain about this, yet.  It would be nice to have a -W option that
detected these transgressions.

Doug
--
schmidt@ics.uci.edu (ARPA) |   Per me si va nella citta' dolente.
office: (714) 856-4043     |   Per me si va nell'eterno dolore.
                           |   Per me si va tra la perduta gente.
                           |   Lasciate ogni speranza o voi ch'entrate.