printing exceptions?

[Jeff Sturm]

On 6 Mar 2002, Adam Megacz wrote:
> > You must never link -lc ahead of -lpthread.  The latter often overrides
> > symbols in the former (e.g. wait).
> 
> BTW, why does the order of -l arguments matter?

The runtime linker resolves symbols by searching libraries in link order.
The order is only important if symbols are duplicated, as in
libpthread.so:

[jsturm@suzy jsturm]$ readelf -s /lib/libpthread.so.0 | grep fork
   218: 00008650   198 FUNC    WEAK   DEFAULT   12 fork@@GLIBC_2.0

[jsturm@suzy jsturm]$ readelf -s /lib/libc.so.6 | grep fork
  1241: 000bb160    50 FUNC    WEAK   DEFAULT   11 fork@@GLIBC_2.0

(output trimmed for clarity.)

By placing -lc first, you will bind to the wrong implementation of fork().

Jeff