Suricata

I tested on both x86 and Tile, both don't add -O2 to CFLAGS.

Interesting, I had always assumed -O2 to be the gcc default. But you are right, it's not: http://gcc.gnu.org/onlinedocs/gcc-4.8.2/gcc/Optimize-Options.html#Optimize-Options

-O0
    Reduce compilation time and make debugging produce the expected results. This is the default. 

Respectfully, I disagree that this is not release critical. Compiling without any optimization is going to seriously hurt performance and thus likely limit people moving from previous releases. The git master uses -O2 by default. We need to at least document that you need to build with:

CFLAGS="-O2" ./configure

I would prefer that GCC defaulted to -O2, or some level of optimization, as many people assume that it does.

I agree the flag is important, however at this point in the RC cycle I consider really only crashes and glaring detection holes 'critical'. That said, this may not hurt to add, as much of our testing is done on these levels as well. If you prepare a minimalistic patch I can push it through QA to see if anything breaks.

What is done in the release process that is different from building from git master? I wasn't sure where the flag got lost.

To create a release I do a 'make distcheck' which produces the source tarball with configure etc.

But before the Makefile even exists, autogen and configure need to be run. What is the process for doing that before "make distcheck" to build a release?

Correct. I run autogen.sh and configure (w/o args). Then make distcheck.

When I run (on git master):

./autogen
./configure
make distcheck
cd tmp
tar xf ../suricata-2.0dev.tar.gz
./configure

The Makefile created does contain CFLAGS with -O2. So, I can't figure out how rc2 ended up with CFLAGS without -O2. Is it possible that the CFLAGS environment variable in the shell that created RC2 had CFLAGS defined without -O2?

CFLAGS is also missing -g.

What I don't understand is why git master adds "-g -O2" to CFLAGS, but the release version doesn't.

There is a comment at the top of configure.ac about finding a better place for default CFLAGS.

In configure, I see these lines, which appear to add "-g -O2" to CFLAGS if CFLAGS was not set. I'm not sure how this gets into configure form configure.ac.

if test "$ac_test_CFLAGS" = set; then
CFLAGS=$ac_save_CFLAGS
elif test $ac_cv_prog_cc_g = yes; then
if test "$GCC" = yes; then
CFLAGS="-g -O2"
else
CFLAGS="-g"
fi
else
if test "$GCC" = yes; then
CFLAGS="-O2"
else
CFLAGS=
fi
fi

Looking at the CFLAGS in the two Makefiles, first from 2.0RC2:

CFLAGS = -DRELEASE -Wextra -Werror-implicit-function-declaration -fno-tree-pre -Wall -Wno-unused-parameter -std=gnu\
99 -march=native -DHAVE_LIBNET11 -D_BSD_SOURCE -D__BSD_SOURCE -D__FAVOR_BSD -DHAVE_NET_ETHERNET_H -I/usr/include -D\
LIBPCAP_VERSION_MAJOR=1 -DHAVE_PCAP_SET_BUFF -DHAVE_LIBCAP_NG

Then git master:

CFLAGS = -g -O2 -Wextra -Werror-implicit-function-declaration -fno-tree-pre -Wall -Wno-unused-parameter -std=gnu99 -\
march=native -DHAVE_LIBNET11 -D_BSD_SOURCE -D__BSD_SOURCE -D__FAVOR_BSD -DHAVE_NET_ETHERNET_H -I/usr/include -DLIBP\
CAP_VERSION_MAJOR=1 -DHAVE_PCAP_SET_BUFF -DHAVE_LIBCAP_NG -DREVISION="e04b5f0"

Is is possible the CFLAGS is set to "-DRELEASE" when building a release, which thus doesn't cause configure to add "-g -O2" to cflags?

Interesting, my release script indeed adds that by running:

    sed -i "s/AC_INIT(suricata, 2.0dev)/AC_INIT(suricata, ${VERSION})\\n    CFLAGS=\"\${CFLAGS} -DRELEASE\"/g" configure.ac

Or perhaps it would be better to add it as an AC_DEFINE, e.g.:

AC_DEFINE([RELEASE], [1], [Official release])

Or, have a new OFFICIAL_RELEASE environment variable that gets added to CFLAGS later. Then no sed of the script is required, but it then ends up in git master.