NAME

linkage_problems - observe possible linkage problems in RPM repo

SYNOPSIS

workdir=$PWD linkage_problems -p $sisyphus/files/i586/RPMS

DESCRIPTION

Warning: you must provide 4G capable workdir.

Possible linkage problems are:

unjoined

I.e. undefined symbol is not resolved into any shared library the binary is linked against. Note: this is similar to bad_elf_symbols but is a lot more rigorous. Example:

    libcdf    /usr/lib/libcdf_idl.so.0.0.0    U    IDL_MakeTempArray
    libcdf    /usr/lib/libcdf_idl.so.0.0.0    U    IDL_StoreScalar
    libcdf    /usr/lib/libcdf_idl.so.0.0.0    U    IDL_StrDelete
    libcdf    /usr/lib/libcdf_idl.so.0.0.0    U    IDL_StrStore
    libcdf    /usr/lib/libcdf_idl.so.0.0.0    U    IDL_VarCopy
    

Basically it is impossible to link with this shared library and/or use it:

    $ ldd -r /usr/lib/libcdf_idl.so.0.0.0
            linux-gate.so.1 =>  (0xffffe000)
            libc.so.6 => /lib/i686/libc.so.6 (0xb7e77000)
            /lib/ld-linux.so.2 (0x80000000)
    undefined symbol: IDL_StoreScalar       (/usr/lib/libcdf_idl.so.0.0.0)
    undefined symbol: IDL_VarCopy   (/usr/lib/libcdf_idl.so.0.0.0)
    undefined symbol: IDL_StrStore  (/usr/lib/libcdf_idl.so.0.0.0)
    undefined symbol: IDL_StrDelete (/usr/lib/libcdf_idl.so.0.0.0)
    undefined symbol: IDL_MakeTempArray     (/usr/lib/libcdf_idl.so.0.0.0)
    $
    

Here is more subtle problem:

    chess    /usr/bin/gnuchess    U    add_history
    chess    /usr/bin/gnuchess    U    using_history
    

gnuchess is linked with libreadline.so.4.3, while libreadline.so.4.3 is linked with libhistory.so.4.3; the latter provides add_history() and using_history(), so the linker does not complain. However symbol versionig is possibly broken.

multijoined

I.e. undefined symbol is resolved into a few shared libraries the binary is linked against. Example:

    AutoScan    /usr/bin/AutoScan    libxml     /usr/lib/libxml.so.1.8.17     libxml.so.1     T    xmlAddChild
    AutoScan    /usr/bin/AutoScan    libxml2    /usr/lib/libxml2.so.2.6.22    libxml2.so.2    T    xmlAddChild
    

Here AutoScan is linked with both libxml and libxml2, while using xmlAddChild() function, which is provided by both (incompatible) libraries.

unneed

I.e. no undefined symbols is resolved into this shared library the binary is linked against. To put it another way, the library is linked in but possibly unused. Example:

    7colors /usr/bin/sevencolors    libICE.so.6
    7colors /usr/bin/sevencolors    libSM.so.6
    7colors /usr/bin/sevencolors    libX11.so.6
    7colors /usr/bin/sevencolors    libXext.so.6
    7colors /usr/bin/sevencolors    libXi.so.6
    7colors /usr/bin/sevencolors    libart_lgpl.so.2
    7colors /usr/bin/sevencolors    libaudiofile.so.0
    7colors /usr/bin/sevencolors    libdb.so.2
    7colors /usr/bin/sevencolors    libdl.so.2
    7colors /usr/bin/sevencolors    libesd.so.0
    7colors /usr/bin/sevencolors    libgmodule-1.2.so.0
    7colors /usr/bin/sevencolors    libm.so.6
    

To make it clear, the following libraries are actually used by 7colors (directly):

    libc.so.6
    libgdk-1.2.so.0
    libgdk_imlib.so.1
    libglib-1.2.so.0
    libgnome.so.32
    libgnomesupport.so.0
    libgnomeui.so.32
    libgtk-1.2.so.0
    

Now some stats (i.e. "most unneded libraries").

    $ cut -f3 unneed |sort |uniq -c |sort -n |tail
       1037 libc.so.6
       1207 libX11.so.6
       1240 libSM.so.6
       1244 libICE.so.6
       1247 libgcc_s.so.1
       1511 libXext.so.6
       2066 libz.so.1
       3164 libpthread.so.0
       3177 libdl.so.2
       5348 libm.so.6
    $
    

You see libm.so.6 is plugged by g++ by default.

AUTHOR

Written by Alexey Tourbin <at@altlinux.org>.

COPYING

Copyright (c) 2006 Alexey Tourbin, ALT Linux Team.

This is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.