Date: Fri, 7 Sep 2001 23:16:52 +1000 (EST) From: Bruce Evans <bde@zeta.org.au> To: Archie Cobbs <archie@dellroad.org> Cc: Mark Murray <mark@grondar.za>, Maxim Sobolev <sobomax@FreeBSD.org>, Mark Murray <markm@FreeBSD.org>, <cvs-committers@FreeBSD.org>, <cvs-all@FreeBSD.org> Subject: Re: cvs commit: src/usr.bin/su Makefile su.c Message-ID: <20010907230542.I39011-100000@alphplex.bde.org> In-Reply-To: <200109070423.f874Nnv16757@arch20m.dellroad.org>
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On Thu, 6 Sep 2001, Archie Cobbs wrote: > Bruce Evans writes: > > This question is sort of backwards too. You want to get const > > non-built-up stuff into a plain "char *". > > What about.. > > const char *foo = "foo"; > char *bar; > > *((const char **)&bar) = foo; > > or even just > > (const char *)bar = foo; /* gcc-ism? */ Ugh. I just shot down a patch by dd for using this gcc-ism. I think it's a bug in -Wcast-qual that either of the above breaks the warning. -Wcast-qual only claims to work for casts that remove qualifiers (from rvalues). The above casts add qualifiers (to lvalues). But this equivalent. There is also the uintptr_t hack which is used in a couple of places in libc. I prefer the union hack that Mark used in su.c. I think it is less likely to break in future versions of gcc, and less unportable. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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