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Message-ID: <3A2BB83C.2B394F6A@ece.gatech.edu>
Date: Mon, 04 Dec 2000 10:29:00 -0500
From: "Charles S. Wilson" <cwilson AT ece DOT gatech DOT edu>
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To: "Steven O'Brien" <steven_obrien AT lineone DOT net>
CC: cygwin AT cygwin DOT com
Subject: Re: building dlls, C and C++
References: <001401c05df0$e4dd0c80$95698cd4 AT emerald>
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> Indexes are useful
> mainly for release management, because as long as each exported symbol keeps
> the same index across releases the users of the DLL do not have to re-link
> their applications when upgrading the DLL. 

Sort of.  It depends on whether the application was "linked by name" or
"linked by number".  Windows provides for both possibilities, but I am
not sure which one is used by gcc/ld or if one can specify which link
method to use.  Link by number gives an executable that loads a bit
faster, but prone to breakage when new dll's are released.  That's why
most of the packages I've released include .def files rather than
relying on --export-[all|dynamic] and/or __declspec(dllexport) alone,
just to be safe.

(All my information about link-by-name or link-by-number comes
secondhand from discussions on the libpng-developers mailing list.  I'm
no expert).

--Chuck

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