Compilation of skype_dsp_hijacker on AMD64
by Danyel Ceccaldi, <danyel.ceccaldi@gmx.de>
(original version: http://juljas.net/linux/skype/amd64.html)
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I want to submit informations back to you, as I tried to compile the library on
opensuse10, on an AMD64 / x86_64 platform.  I encountered the following
problem:

  $ make
  gcc -O2 -Wall -ldl -shared -fpic skype_dsp_hijacker.c -o libskype_dsp_hijacker.so
  
  $ file libskype_dsp_hijacker.so
  libskype_dsp_hijacker.so: ELF 64-bit LSB shared object, AMD x86-64, version 1
  (SYSV), not stripped

  $ ./skype_dsp_hijacker skype
  ERROR: ld.so: object './libskype_dsp_hijacker.so' from LD_PRELOAD cannot be
  preloaded: ignored.

Reason:
on this environment, the default architecture to build is 64-Bit, but skype is
32-bit.

Simply adding CFLAGS=-m32 will not help, as the build environment is not
prepared.

Solution:
assure the following rpm's are installed:
glibc-devel-32bit
glibc-locale-32bit
glibc-32bit

# cd /lib
# ln -s /lib/libdl.so.2 libdl.so
# ln -s /lib/libc.so.6 libc.so
# rpm -i suse/x86_64/glibc-devel-32bit-2.3.5-40.x86_64.rpm

$ gcc -m32 -ldl -shared -fpic skype_dsp_hijacker.c -o libskype_dsp_hijacker.so

$ file libskype_dsp_hijacker.so
libskype_dsp_hijacker.so: ELF 32-bit LSB shared object, Intel 80386, version 1
(SYSV), not stripped


(some hints indicated using also -L/lib, but it seems not necessary on
opensuse10 or not necessary at all)