Date: Wed, 28 Jan 1998 17:11:28 -0800 From: John Polstra <jdp@polstra.com> To: Nate Williams <nate@mt.sri.com> Cc: hackers@FreeBSD.ORG Subject: Re: dladdr: Hel-lo-o-o? Message-ID: <199801290111.RAA01481@austin.polstra.com> In-Reply-To: Your message of "Wed, 28 Jan 1998 17:57:25 MST." <199801290057.RAA07509@mt.sri.com>
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> > haven't received a single report. Grrrrr.
>
> I've tried the patches, and they are indeed running on my 2.2.5
> system. And, yes you did receive a single report pointing out a bug
> in the patch. :)
Well, besides that one. :-}
> Is there an easy way for me to figure out how to check to see if it
> exists so that I can support both old and new systems?
For a compile time check:
#include <link.h>
#ifdef LDSO_VERSION_HAS_DLADDR
...
#endif
I think a run time check should be possible, too, though I haven't
tried it for this particular case:
struct dl_info;
#pragma weak dladdr
extern int dladdr(void *, struct dl_info *);
if (&dladdr == 0)
/* It's not available. */
else
/* It is available. */
Don't ya just love it? If gcc tries to get too smart with you, you
might need to obfuscate the "&dladdr == 0" part. Gcc might try to
assume that the address of a global can't possibly be zero.
John
--
John Polstra jdp@polstra.com
John D. Polstra & Co., Inc. Seattle, Washington USA
"Self-knowledge is always bad news." -- John Barth
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