Peter Volkov wrote:
> В Срд, 12/08/2009 в 00:03 +0200, Thomas Kahle пишет:
>> the following check in configure.ac fails with --as-needed but works
>> without it. Any hints what is wrong ? Thanks / Thomas
> 
> Common reason for failure with --as-needed is the order of libraries. In
> you previous mail you wrote that with 
> 
> sed "s/\"-lntl\"/\"-lntl\" \"-lgf2x -lntl\"/" -i "${S}/configure.ac"
> 
> it works but here: 
> 
>> for lib in "" "-lntl" "-lntl -lgf2x"
> 
> I see different order. Try to change order of -lgf2x and -lntl inside
> ebuild. Also 

This change of order is actually since I tried what you suggested. I
find that this check fails just because the compile fails. It has
nothing to do with configure. So here is my problem stripped down:

$cat ntlcheck.c
#include <NTL/tools.h>
int main () { _ntl_GetTime(); }

g++ ntlcheck.c -lntl -lgf2x
works

$g++ -Wl,--as-needed ntlcheck.c -lntl -lgf2x
/usr/lib/gcc/i686-pc-linux-gnu/4.3.2/../../../libntl.so: undefined
reference to `gf2x_mul'
collect2: ld returned 1 exit status

$ g++ -Wl,--as-needed ntlcheck.c -lgf2x -lntl
/usr/lib/gcc/i686-pc-linux-gnu/4.3.2/../../../libntl.so: undefined
reference to `gf2x_mul'
collect2: ld returned 1 exit status

BTW, installing ntl without gf2x support makes
$g++ -Wl,--as-needed ntlcheck.c -lntl
work !

It feels like it has something to do with ntl-headers having gf2x includes.

> sed 's/"-lntl"/"-lntl" "-lgf2x -lntl"/' -i "${S}/configure.ac"
good point. No need to escape the ' " ' :)

thanks
Thomas



-- 
Thomas Kahle

The fundamental theorem of algebra is open source. Like any other
mathematical theorem it can be applied free of charge and everybody
has access to its proof and can convince himself how it works. Why
should software be any different?