[Bug driver/47390] [4.6 Regression] Linking with -export-dynamic broken

["joseph at codesourcery dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47390

--- Comment #2 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-01-24 23:37:39 UTC ---
On Fri, 21 Jan 2011, rguenth at gcc dot gnu.org wrote:

> Joseph - 4.5 handled -export-dynamic by passing it through to the linker
> (not exactly sure why).  Can we restore this behavior to avoid regressions?
> If not, can we diagnose this invalid option then?  It seems to be passed
> as -e xport-dynamic to the linker now, resulting in an undefined symbol
> for me with a trivial hello-world.

-export-dynamic was passed down by an accident of %{e*} in 
LINK_COMMAND_SPEC.  If you want this to continue to work then add

export-dynamic
Driver

to common.opt, and probably put a comment on LINK_COMMAND_SPEC saying that 
%{e*} deliberately covers -export-dynamic.  (Alternatively, I think using 
%{export-dynamic} %{e}, together with the common.opt change, will make the 
passed options explicit, and successfully pass to the linker (in separate 
argument form) -e options passed to the driver in either joined or 
separate form - but verify this before making that change.)