Date: Fri, 15 Oct 1999 20:09:57 +0200 (CEST) From: Wilko Bulte <wilko@yedi.iaf.nl> To: eischen@vigrid.com (Daniel Eischen) Cc: eischen@vigrid.com, jb@cimlogic.com.au, current@FreeBSD.ORG, jdp@polstra.com, marcel@scc.nl Subject: Re: World breakage in libc_r? Message-ID: <199910151809.UAA63994@yedi.iaf.nl> In-Reply-To: <199910142225.SAA06440@pcnet1.pcnet.com> from Daniel Eischen at "Oct 14, 1999 6:25:41 pm"
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As Daniel Eischen wrote ... Sheer curiosity and most likely a somewhat dim question: what the h* is a weak versus a strong symbol? Thanks, Wilko > John Birrell wrote: > > Weak symbols don't work too well _between_ libraries. If libc is linked > > before libpthread, any unresolved references when libc is searched will > > use the weak symbols from there, regardless of the fact that a strong > > symbol exists in libpthread. If libc is linked after libpthread, then > > you can have libc internal references to things that should been resolved > > to things in libpthread, but end up using the weak symbols in libc > > because that is all there is left. 8-( > > > > Not a simple problem to solve. The current tools don't help at all. A > > second library pass to resolve weak symbols would have been better. It's > > too late for that now, though, since you can change the semantics on the > > shared loader. > > It'd be interesting to know how Solaris does this. I see they don't > supply a static libpthread, just the dynamic. It seems they do use > a strong symbol in libpthread, and a weak one in libc: > > vfr [80] $ nm /usr/lib/libc.so.1 | grep pthread_mutex_lock > [4394] | 596188| 44|FUNC |WEAK |0 |12 |_pthread_mutex_lock > [2980] | 596188| 44|FUNC |WEAK |0 |12 |pthread_mutex_lock > vfr [81] $ nm /usr/lib/libpthread.so.1 | grep pthread_mutex_lock > [333] | 20704| 8|FUNC |GLOB |0 |8 |_pthread_mutex_lock > [107] | 20704| 8|FUNC |WEAK |0 |8 |pthread_mutex_lock -- | / o / / _ Arnhem, The Netherlands - Powered by FreeBSD - |/|/ / / /( (_) Bulte WWW : http://www.tcja.nl http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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