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Date: Tue, 19 Apr 2022 23:49:44 +0200
From: Joerg Sonnenberger <joerg@bec.de>
To: freebsd-hackers@freebsd.org
Subject: Re: llvm & RTTI over shared libraries
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Am Thu, Apr 14, 2022 at 04:36:24PM +0000 schrieb jbo@insane.engineer:
> After some research I seem to understand that the way that RTTI is handled over shared library boundaries is different between GCC and LLVM.

I think you are running into the old problem that GCC thinks comparing
types by name makes sense where as everyone else compares types by type
pointer identity. GCC is glaringly wrong because types with identical
names can and often are unrelated. This is especially a problem for
plugins. The correct way to deal with it is making sure that every type
has a key function of appropiate visibility and making sure that the
interface library exports them and every plugin links against it.
If you do that, dlopen without RTLD_GLOBAL or linking the main program
without -rdynamic works fine.

Joerg