Re: -no-undefined vs gcc 4.6.0

[LRN]

On 19.03.2011 13:29, Vincent Torri wrote:
> On Sat, 19 Mar 2011, LRN wrote:
>
> > On 19.03.2011 0:17, Vincent Torri wrote:
> > > On Sat, 19 Mar 2011, LRN wrote:
> > >
> > > > On 18.03.2011 23:51, Vincent Torri wrote:
> > > > > On Fri, 18 Mar 2011, LRN wrote:
> > > > >
> > > > > > Since gcc 4.6.0 it is no longer possible to use 
> > > > > > LDFLAGS=-no-undefined
> > > > > > gcc now says something like this:
> > > > > > gcc.exe: error: unrecognized option '-no-undefined'
> > > > > > Before 4.6.0 it was possible to do that, and gcc said only this:
> > > > > > gcc.exe: unrecognized option '-no-undefined'
> > > > > > That is, unrecognized option was not considered a show-stopper, 
> > > > > > and everything worked just fine - the option, being part of 
> > > > > > LDFLAGS, eventually reached libtool, and libtool were taking the 
> > > > > > clue to disallow undefined symbols. Not anymore. Now i have to 
> > > > > > pass LDFLAGS=-Wl,-no-undefined. Which is ok from gcc' point of 
> > > > > > view, but libtool is unable to recognize this argument in such 
> > > > > > form and simply refuses to build shared libraries outright.
> > > > > > Not sure if it's a bug or a feature, and how to work through that 
> > > > > > without making groundbreaking changes in software packages that 
> > > > > > use libtool.
> > > > >
> > > > > I think that you have to pass -no-undefined to the ***_LDFLAGS 
> > > > > variable of your library:
> > > > >
> > > > > lib_LTLIBRARIES = libproject.la
> > > > > libproject_la_LDFLAGS = -no-undefined
> > > > >
> > > > > or, globally:
> > > > >
> > > > > AM_LDFLAGS = -no-undefined
> > > > >
> > > > > it has always worked for me, without gcc warning.
> > > > It's not my library. I'm compiling mpc-0.8.2
> > >
> > > ok. Anyway you have to pass -Wl,-no-undefined. It's an option for 
> > > the linker [1], not for gcc [2]
> > >
> > > Vincent Torri
> > >
> > > [1] http://unixhelp.ed.ac.uk/CGI/man-cgi?ld
> > > [2] http://gcc.gnu.org/onlinedocs/gcc/Link-Options.html#Link-Options
> > I *know* that it's a linker option. And i know that i have to pass it 
> > with -Wl because of that. What i do not know is how to make libtool 
> > see it when it is passed like that.
> >
> > Finally got it to work with `make libmpc_la_LDFLAGS="-version-info 
> > 2:0:0 -no-undefined"', because mpc does not use AM_LDFLAGS in the 
> > link command that
>
> i'm wondering if you ever read my first answer...
>
> Vincent
I did. I thought you were referring to Makefile.am