Re: How to build an RPATH into gcc?

[Ian Lance Taylor <ian at wasabisystems dot com>]

Adrian Bunk <bunk@fs.tum.de> writes:

> > > > >   LDFLAGS="-L/usr/local/lib -R/usr/local/lib" ../configure
> > > > > didn't work
> > > > 
> > > > Why didn't this work?  Does the sparc-netbsdelf1.5 linker support the
> > > > -R option?  If it does not support -R, does it support --rpath?  Was
> > > 
> > > -R is not an option for ld, it's an option for gcc.
> > 
> > That turns out not to be the case.  Insofar as gcc supports the -R
> > option, it supports it by passing it on to the linker.
> > 
> > In fact, the gcc documentation does not even document -R.  The GNU
> > linker documentation does document -R.
> > 
> > On my i386 GNU/Linux system (Fedora Core 1) I get this:
> > 
> > gossamer> gcc -R/tmp -o hello hello.o
> > gcc: unrecognized option `-R/tmp'
> > gossamer> gcc -Wl,-R/tmp -o hello hello.o
> > gossamer> objdump -p hello | grep RPATH
> >   RPATH       /tmp
> 
> Yes, you are on Linux.
> 
> On NetBSD, it's available (see gcc/config/netbsd-elf.h).

True.  And note, in that file, how gcc implements -R by simply passing
it directly to the linker.

> > > > the -R option actually used when linking gcc?
> > > 
> > > Obviously were the LDFLAGS not used...
> > 
> > The obvious case is that things work correctly.  When things fail to
> > work, you must look at what actually happened, not at what is obvious.
> > 
> > It might possibly be worth trying
> >     LDFLAGS="-Wl,-R/usr/local/lib" ../configure
> > Hard to say.
> 
> This wouldn't make any difference:
> - the -R option works fine on my platform

Good to hear.  That answers my initial question.

> - if LDFLAGS were used and -R wouldn't work, I should have gotten an 
>   error while bootstrapping gcc

That is not necessarily the case, as when the gcc driver sees an
unrecognized option, it will issue a warning but will still exit with
a successful status (I think this is a bug and in fact I just filed a
PR about it, but it is true nonetheless).

Have you tried
    make LDFLAGS="-L/usr/local/lib -R/usr/local/lib"
?

Ian