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Date: Thu, 21 Jun 2007 22:00:00 -0500
From: "Yaakov (Cygwin Ports)" <yselkowitz AT users DOT sourceforge DOT net>
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Subject: dlopen()/dlsym() and symbols in deps
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It would appear that Cygwin's dlopen() implementation does not support
the automatic loading of dependencies.  This matters in the case that
one dlsym()'s a *handle to find a symbol in the dependencies rather than
in itself.

On linux, this is apparently possible:

"Note that some implementations permit the construction of dependencies
between such objects that are embedded within files. In such cases, a
dlopen() operation shall load such dependencies in addition to the
object referenced by file." [1]

[1] http://www.opengroup.org/onlinepubs/009695399/functions/dlopen.html

I came across this when reporting what I originally thought was a bug in
glade3 [2] (with a testcase[3]), but now I have found it to be a
deficiency in Cygwin itself.  While I think I have a fix for gmodule to
work around this, based on tml's gmodule-win32.c code (and therefore I
can't propose a patch myself), it would be nice to see this implemented
in Cygwin proper.

[2] http://bugzilla.gnome.org/show_bug.cgi?id=449562
[3] http://bugzilla.gnome.org/attachment.cgi?id=90416

Could someone more familiar with the internal workings of Cygwin please
provide some input on this issue?


Yaakov

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