Bug 28352 – GCC 3.3.1 miscompiles Mozilla(Thunderbird/Firebird) without -fno-strict-aliasing.

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Ernst Sjöstrand 2003-09-10 06:24:43 UTC]

I thought I'd like to help put gcc 3.3 in stable or at least testing for ppc so I'm running a system 
with GCC 3.3.1-r1, glibc 2.3.2-r4 with NPTL and 2.6.0-test4.

Everything works good so far, except when I compiled MozillaThunderbird. It segfaulted.
So after some googling I found that I should add -fno-strict-aliasing to make it work.
It works. So, maybe a check for gcc>=3.3 and then add the C and CXX flag -fno-strict-aliasing?

Reproducible: Always
Steps to Reproduce:

[Comment 1 Andy Dustman 2003-09-12 06:47:30 UTC]

I had the same problem in i386 (gcc-3.3.1-r1 and glibc-2.3.2-r1 and kernel 2.6.0-test5). It appeared to be an internal compiler error. I'll see if -fno-strict-aliasing helps and report back.

[Comment 2 Andy Dustman 2003-09-12 07:43:47 UTC]

Created attachment 17568 [details]
Output from broken build

This is the broken part of the mozilla build with gcc-3.3.1. Note that the
ebuild filters out -fno-strict-aliasing, so I haven't tested that.

[Comment 3 Andy Dustman 2003-09-12 07:48:03 UTC]

Created attachment 17569 [details]
Preprocessed source

[Comment 4 Andy Dustman 2003-09-12 07:52:17 UTC]

My portage settings:

Portage 2.0.49-r4 (default-x86-1.4, gcc-3.3.1, glibc-2.3.2-r1, 2.6.0-test5)
=================================================================
System uname: 2.6.0-test5 i686 Intel(R) Pentium(R) 4 CPU 2.00GHz
ACCEPT_KEYWORDS="x86 ~x86"
AUTOCLEAN="yes"
CFLAGS="-march=pentium3 -mcpu=pentium4 -O2 -fno-strict-aliasing -fstack-protector -finline-functions -falign-jumps=5 -falign-loops=5 -falign-functions=64 -pipe"
CHOST="i686-pc-linux-gnu"
COMPILER="gcc3"
CONFIG_PROTECT="/etc /var/qmail/control /usr/kde/2/share/config /usr/kde/3/share/config /usr/X11R6/lib/X11/xkb /usr/kde/3.1/share/config /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/config"
CONFIG_PROTECT_MASK="/etc/gconf /etc/env.d"
CXXFLAGS="-march=pentium3 -mcpu=pentium4 -O2 -fno-strict-aliasing -fstack-protector -finline-functions -falign-jumps=5 -falign-loops=5 -falign-functions=64 -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="sandbox ccache autoaddcvs"
GENTOO_MIRRORS="ftp://ftp.gtlib.cc.gatech.edu/pub/gentoo http://distro.ibiblio.org/gentoo http://gentoo.oregonstate.edu "
MAKEOPTS="-j2"
PKGDIR="/usr/portage/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/local/portage"
SYNC="rsync://rsync.us.gentoo.org/gentoo-portage"
USE="x86 oss apm avi crypt encode foomaticdb gif jpeg libg++ mad mikmod mmx mpeg ncurses nls pdflib png quicktime spell truetype xml2 xmms xv zlib gtkhtml gdbm berkdb slang readline arts tetex bonobo java guile mysql X sdl gpm tcpd pam libwww ssl perl python esd imlib oggvorbis gnome gtk qt kde motif opengl mozilla cdr -svga gtk2 alsa innodb cups ldap i8x0 doc"

[Comment 5 Luca Barbato 2003-09-12 14:27:32 UTC]

mozilla is fixed 
I'll add the same fix to the mozi firebird and thuderbird in few min

please check and reopen is something is wrong

[Comment 6 Andy Dustman 2003-09-13 22:35:03 UTC]

This isn't fixed; it's still broken on i386. However, since it's an internal compiler error, I think it's gcc bug.

[Comment 7 Luca Barbato 2003-09-14 08:51:24 UTC]

strange last time I tried on x86 it works, on ppc mozilla is working with the added flags.