Bug 179554 – [bad-code/4.2] sigc++-2.0 based code with -fstrict-aliasing crashes with compiled gcc 4.2

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Peter Alfredsen (RETIRED) 2007-05-23 17:53:39 UTC]

This has been reported upstream, see URL in bug description. This may be the same bug that's mentioned here:
[4.2 regression] miscompilation of sigc++-2.0 based code with -fstrict-aliasing
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30252

Having recompiled my system with the new gcc-4.2.0 and glibc-2.6, I tried to run rtorrent. It segfaults:
pa@loki ~/session $ rtorrent
Caught Segmentation fault, dumping stack:
0 rtorrent [0x8058ff1]
1 rtorrent [0x806d6d9]
2 [0xffffe420]
3 [0x82e938e]
4 rtorrent [0x805877d]
5 /lib/libc.so.6(__libc_start_main+0xe0) [0xb7a159d0]
6 rtorrent(_ZN7torrent18set_max_open_filesEj+0x89) [0x8051b01]
Aborted

I have, for now, recompiled just rtorrent and libtorrent with gcc-4.1.2, which works fine. 

Reproducible: Always

Steps to Reproduce:

[Comment 1 Timothy Redaelli (RETIRED) 2007-05-23 18:48:52 UTC]

Can you try to use -fno-strict-aliasing in CFLAGS and see if it works?

[Comment 2 Peter Alfredsen (RETIRED) 2007-05-23 20:45:37 UTC]

I just recompiled libtorrent and rtorrent with these parameters:
CFLAGS="-Os -march=athlon-xp -pipe -ggdb3 -fno-strict-aliasing" CXXFLAGS="-Os -march=athlon-xp -pipe -ggdb3 -fno-strict-aliasing" emerge -1 libtorrent rtorrent
So far, it seems to work fine.

[Comment 3 SpanKY 2007-06-18 04:26:28 UTC]

*** Bug 181124 has been marked as a duplicate of this bug. ***

[Comment 4 SpanKY 2007-06-18 04:29:12 UTC]

rtorrent report: http://libtorrent.rakshasa.no/ticket/926

but in reality, a gcc-4.2 bug

[Comment 5 Ryan Hill (RETIRED) 2007-06-20 00:10:37 UTC]

Created attachment 122558 [details, diff]
41_all_gcc42-PR30252.patch

here's the patch.  this should apply after 40_all_gcc42-PR30052.patch.

[Comment 6 Peter Alfredsen (RETIRED) 2007-06-21 16:44:37 UTC]

(In reply to comment #5)
> Created an attachment (id=122558) [edit]
> 41_all_gcc42-PR30252.patch
> 
> here's the patch.  this should apply after 40_all_gcc42-PR30052.patch.
> 

I've just applied this to my local gcc-4.2.0 and gcc builds and rtorrent runs. (I changed the libtorrent and rtorrent ebuilds to not append-flags fno-strict-aliasing).

[Comment 7 Raul Metsma 2007-06-21 18:40:09 UTC]

Built just new gcc with 1.2 patchet and this patch but still inkscape crashes

[Comment 8 SpanKY 2007-06-22 01:59:23 UTC]

the fix from upstream has been put into the 1.3 patchset

[Comment 9 Raul Metsma 2007-06-23 11:33:10 UTC]

Inkscape is still no good with 1.3 patchet

[Comment 10 SpanKY 2007-06-23 14:33:08 UTC]

what exactly did you re-compile ?  rebuilding just inkscape i dont think would be enough

[Comment 11 Raul Metsma 2007-06-23 16:55:10 UTC]

Rebuild gcc-4.2.0 and after that inkscape

[Comment 12 SpanKY 2007-06-23 17:03:41 UTC]

which isnt sufficient i dont think ... rebuild all the packages related to inkscape, first starting with dev-libs/libsigc++