[klibc] multiple definition of `_start' when using -ld with klcc

[Jon Ringle]

On Wednesday 01 July 2009 00:00:04 H. Peter Anvin wrote:
> Jon Ringle wrote:
> > Hi,
> > 
> > I am trying to setup an environment where I can build external projects
> > against klibc. It works - except if I have a program that links to libc.
> > Then I get a multiple definition of `_start' message. Here is a simple
> > test case.   
> > 
> 
> You can't do that.  It's as simple as that.  Sorry.

I actually encountered this problem while trying to build udev-141 with klcc cross compiler targeting armeb. The problem came about when udev configure ran the following test from configure.ac:

AC_CHECK_LIB(c, inotify_init,
        [AC_DEFINE([HAVE_INOTIFY], 1, [inotify available])],
        [AC_MSG_WARN([inotify support disabled])])

This test should pass since inotify_init is available in klibc's libc.so, but fails with:

configure:11683: checking for inotify_init in -lc
configure:11718: klcc -o conftest -g -O2   conftest.c -lc   >&5
/home/ringlej/WAVE/git/Platform/Volcano/os/ptxdist/isc/platform-ISC/sysroot-target/usr/lib/klibc/lib/libc.so: In function `_start':
bpabi.c:(.text+0x0): multiple definition of `_start'
/home/ringlej/WAVE/git/Platform/Volcano/os/ptxdist/isc/platform-ISC/sysroot-target/usr/lib/klibc/lib/crt0.o:(.text+0x0): first defined here

I worked around this by setting ac_cv_lib_c_inotify_init=yes in the environment.

Jon