[Top][All Lists]

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

Re: transitive shared library dependencies and installation

From: Bob Friesenhahn
Subject: Re: transitive shared library dependencies and installation
Date: Sat, 4 Jan 2020 17:40:55 -0600 (CST)
User-agent: Alpine 2.20 (GSO 67 2015-01-07)

On Sat, 4 Jan 2020, Russ Allbery wrote:

address@hidden writes:
Bob Friesenhahn <address@hidden> writes:

That sounds like a great idea.  However, there is a problem that
linking on some systems does depend on already installed libraries (or
will end up using them) and so the libraries need to be installed and
linked in a particular order.

Do you happen to know which systems these are?  Where are these
constraints documented?

It's been a very long time since I've built shared libraries for any
platform other than Linux, but my distant recollection is that AIX and
HP-UX encoded the full path to the dynamic library against which a binary
was linked.  Therefore, if you built an executable against uninstalled
libraries, the executable would have a reference to the build directory,
hence the explicit relinking step after installation to pick up the new
paths.  I seem to recall that we caused an outage for campus AIX systems
because of this; I'm less sure about HP-UX.

I don't remember whether this also applied to interdependencies between
shared libraries (or if those platforms even supported encoding
dependencies in shared libraries; a lot of platforms didn't).  I vaguely
recall that mutually-dependent shared libraries were actually impossible
on at least some UNIX platforms, and thus not portable.

The above matches my own memories. I do not know the current level of usage for AIX or HP-UX but expect that they are still used for business purposes because at various times they were market leaders and offered the type of support that large businesses needed for critical systems.

Mutually-dependent shared libraries are to be avoided in any case.

Using Autotools, I do not recall any particular effort involved with supporting AIX, HP-UX, or even IRIX in GraphicsMagick builds.

Bob Friesenhahn
GraphicsMagick Maintainer,
Public Key,

reply via email to

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