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From: Anthony Green <green@redhat.com>
To: Ian Lance Taylor <iant@google.com>
Cc: libffi-discuss@sourceware.org, doko@ubuntu.com
Subject: Re: libffi/configure.ac does not correctly determine writable eh_frame
Date: Thu, 03 Feb 2011 22:45:00 -0000	[thread overview]
Message-ID: <m3sjw43ffs.fsf@redhat.com> (raw)
In-Reply-To: <mcr7heca0t3.fsf@google.com> (Ian Lance Taylor's message of "Mon,	10 Jan 2011 13:47:20 -0800")

Ian Lance Taylor <iant@google.com> writes:

> In the version of libffi distributed with gcc, I see this in
> configure.ac:
>
> 	echo 'extern void foo (void); void bar (void) { foo (); foo (); }' > conftest.c
> 	if $CC $CFLAGS -S -fpic -fexceptions -o conftest.s conftest.c > /dev/null 2>&1; then
> 	    if grep '.section.*eh_frame.*"a"' conftest.s > /dev/null; then
> 		libffi_cv_ro_eh_frame=yes
> 	    elif grep '.section.*eh_frame.*#alloc' conftest.c \
> 		 | grep -v '#write' > /dev/null; then
> 		libffi_cv_ro_eh_frame=yes
> 	    fi
> 	fi
>
> This does not work with current gcc.  When that code is compiled, no
> .eh_frame section is generated.  Therefore the configure script assumes
> that a writable .eh_frame section is appropriate, even when it is not.
>
> This was detected due to a bug in gold; see http://gcc.gnu.org/PR47248
> for more details.  However, this issue in libffi should be fixed
> independently of the gold bug fix.

Thanks Ian.  Any suggestions on what do I need to do to now to force an
.eh_frame section?

AG


>
> Ian

  reply	other threads:[~2011-02-03 22:45 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-10 21:47 Ian Lance Taylor
2011-02-03 22:45 ` Anthony Green [this message]
2011-02-03 23:07   ` Ian Lance Taylor

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