RE: Libtool and Pkg-Config

[Bernard Dautrevaux]

> -----Original Message-----
> From: Havoc Pennington [mailto:address@hidden
> Sent: Sunday, April 22, 2001 4:46 PM
> To: Alexandre Oliva
> Cc: Eric Lemings; address@hidden; address@hidden
> Subject: Re: Libtool and Pkg-Config
> 
> 
> 
> Alexandre Oliva <address@hidden> writes:
> > On Apr 22, 2001, Havoc Pennington <address@hidden> wrote:
> > 
> > > pkg-config has some intelligence, i.e. if you request two 
> libs at once
> > > it will nuke duplicate flags and order the -l flags properly.
> > 
> > Err...  It won't always remove duplicate -l flags, will it?  This
> > isn't always correct.
> 
> It does. The tool does not understand how to create a portable link
> line; this is why we're having this conversation. ;-)

Hi all,

Excuse me if I jump into this conversation having possibly missed an
important point, but this (and another thread about removing duplicates -l
flags) remember of a problem I've had some time ago about ordering object
files in libraries on a systems wheer there weer no 'ranlib' or equivalent.

A necessary (and sufficient AFAICT) condition would be that, given the fact
that libtool remember library dependencies, one use a tsort-like tool to
topologically sort all the libraries, while detecting loops in the
dependencies, and emitting every loop twice. Note that for non-libtool libs
one can consider the user-provided order as a dependency-correct order
before sorting; the only problem could be some spurious cycles between some
system libraries, but we will anyway eliminate most of the redundant
libraries.

I've done that several years ago (I could probably find the modified tsort
source code I was using if someone is interested) and it worked perfectly,
until it was no more useful :-)

Just thinking loud a bit ;-)

Regards,

        Bernard

PS: If libtool already do something like that please don't flame me on the
"why don't you look at the code before stating the obvious" line :-) I'm not
so familiar with the internals of libtool, just VERY HAPPY to see that it
usually "just work" when I need to port or adapt some libtoolized package...


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Bernard Dautrevaux
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