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Re: Help debugging a dll issue
- From: Eliot Moss <moss at cs dot umass dot edu>
- To: Sam Habiel <sam dot habiel at gmail dot com>, "cygwin at cygwin dot com" <cygwin at cygwin dot com>
- Date: Fri, 20 May 2016 06:37:57 -0400
- Subject: Re: Help debugging a dll issue
- Authentication-results: sourceware.org; auth=none
- References: <b21c0ab1-341b-d6f5-915b-f73973b8079b at cs dot umass dot edu> <CABHT960Yx_bg-NaHWcxePEV+Xz74NaVtsu+NjkrSZs4-62rCOA at mail dot gmail dot com>
- Reply-to: moss at cs dot umass dot edu
On 5/19/2016 11:28 PM, Sam Habiel wrote:
I had trouble with dlopen in Cygwin, where it did not behave intuitively. In my case, I was
dlopening libicu and friends. If you search using my name on the Cygwin mailing list, you should be
able to find out how I resolved the issue. I don't recall exactly what I did, but I think it was
that Cygwin put everything in a global namespace, and you need to dlsym NULL to grab the function
addresses.
I just tried using NULL for the handle in dlsym, and I get the same result as before, and it
does not change between using RTLD_LOCAL or RTLD_GLOBAL in dlopen.
What I am seeing is that looking up one symbol is giving the value for a totally different
one -- it's not returning an error indication.
And this same wrong value is what happens if I just allow the natural linking to take place
(which is what I really want to happen -- the dl calls simply help focus the issue).
I will look up your previous issue, though, to see if there is something else there of use
in this situation.
Regards -- EM
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