[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Several questions about libtool

From: Bob Friesenhahn
Subject: Re: Several questions about libtool
Date: Sat, 7 Jan 2012 13:49:56 -0600 (CST)
User-agent: Alpine 2.01 (GSO 1266 2009-07-14)

On Sat, 7 Jan 2012, Russ Allbery wrote:

I wouldn't argue for breaking Libtool's ability to handle such platforms,
or for that matter old UNIX platforms that don't support transitive
resolution of shared library dependencies.  But I think Libtool needs some
mechanism to correctly support platforms where adding spurious NEEDED ELF
metadata is wrong and causes serious issues for distributions.  The
pkg-config approach seems to work reasonably well in practice.

I think that it is wrong to solely blame libtool for this state of affairs. In order for a project to work properly on non-ELF systems, or where installed shared libraries have abbreviated/truncated ELF implicit dependencies, or where static libraries are involved, the project needs to add all dependencies to LIBS during the configure run. This is well before libtool is even involved. If configure scripts do not do this, then linker errors (due to missing libraries) will block tests for symbols and library features.

Because of the need to extend LIBS in configure, and because of the desire to support more systems than just GNU/Linux (or ELF-based systems which behave similarly) many carefully-maintained projects are already requesting/applying far more libraries than would be necessary to link the application/library under GNU/Linux. My own project is a good example of this.

The library-dependency problems are more complex than they have been made out to be since they are due to responsible-project behavior and not only due to excessively-pedantic libtool behavior.

I do agree that a tool can help solve these issues. The linker itself is in the best position to know which library dependencies are really needed and to skip those which are not.

Libltdl's automatic loading of dependency libraries based on the content of .la files is a secondary issue to be addressed.

Bob Friesenhahn
GraphicsMagick Maintainer,

reply via email to

[Prev in Thread] Current Thread [Next in Thread]