Building shared library

Question

I am a new user to Mac and I am trying to build a shared library using gcc. However, I am getting errors when creating a execuatble.
My system info. is:
[email protected] <810> gcc --version
i686-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build 5363)
[email protected] <811> uname -a
Darwin foxtrot.vni.com 8.8.1 Darwin Kernel Version 8.8.1: Mon Sep 25 19:42:00 PD
T 2006; root:xnu-792.13.8.obj~1/RELEASE_I386 i386 i386
Here is a small example for the problem.
========= kk.h ===========
#include<stdio.h>
#include<math.h>
void sub();
=========== sub.c =========
#include "kk.h"
void sub() {
printf("sub = %g\n", fabs(-2.0));
======== main.c ========
#include "kk.h"
main() {
sub();
=====================
[email protected] <792> gcc -c -fPIC sub.c
[email protected] <793> gcc -o libkk.so -dynamic -r sub.o
[email protected] <794> gcc main.c libkk.so -lm
/usr/bin/ld: multiple definitions of symbol _NXArgc
/usr/lib/gcc/i686-apple-darwin8/4.0.1/../../../crt1.o definition of _NXArgc in section (_DATA,_data)
libkk.so definition of _NXArgc in section (_DATA,_data)
/usr/bin/ld: multiple definitions of symbol _NXArgv
/usr/lib/gcc/i686-apple-darwin8/4.0.1/../../../crt1.o definition of _NXArgv in section (_DATA,_data)
libkk.so definition of _NXArgv in section (_DATA,_data)
/usr/bin/ld: multiple definitions of symbol _progname
/usr/lib/gcc/i686-apple-darwin8/4.0.1/../../../crt1.o definition of _progname in section (_DATA,_data)
libkk.so definition of _progname in section (_DATA,_data)
/usr/bin/ld: multiple definitions of symbol _environ
/usr/lib/gcc/i686-apple-darwin8/4.0.1/../../../crt1.o definition of _environ in section (_DATA,_data)
libkk.so definition of _environ in section (_DATA,_data)
/usr/bin/ld: multiple definitions of symbol start
/usr/lib/gcc/i686-apple-darwin8/4.0.1/../../../crt1.o definition of start in section (_TEXT,_text)
libkk.so definition of start in section (_TEXT,_text)
collect2: ld returned 1 exit status
Thank you.

Answer 1

Hi Gschwert,
our developers told me that for X-Code Version 4 you need an additional download. Then, it should also work with Version 4. Here is what they said:
It turned out that Shared Libraries compile fine with XCode 4, it's just that the command line tools that we need for compilation are now an optional download. 
From https://developer.apple.com/xcode/ 
"Xcode includes a new "Downloads" preference pane to install optional components such as command line tools, and previous iOS Simulators." 
So, this is not well documented we will handle that and let make a correction as soon as possible.
Have a nice day,
Abduelkerim
Sales
NI Germany