GCC 4.9 testing thread

mDup · Apprentice Joined: 14 Apr 2006 Posts: 212

fwiw mythtv does not build

see Gentoo's Bugzilla Bug 516692

perhaps gcc 4.9.1 might take care

CaptainBlood · Advocate Joined: 24 Jan 2010 Posts: 3627

Hi dear all,

Can't get -lto working

Patched lastest binutils-2.24.51.0.3 with Markus's patch https://sourceware.org/ml/binutils/2014-01/msg00213.html
Created symlink as in marxin's blog http://marxin.github.io/blog/2014/04/24/gentoo-linux-packages-with-gcc-4-dot-9-lto/
[EDIT]modifing

CaptainBlood · Advocate Joined: 24 Jan 2010 Posts: 3627

I've just tried with binutils-2.24.

-ffat-lto-object seems to work, patchless & symlinkless.

Let's notice gcc 4.8/binutils-2.24 never required this compile flag to be activated. A possible explanation:
Comparing 4.8.3 and 4.9. gnu docs seems like defaulting to -ffat-lto-object has now become defaulted to -fno-fat-lto-object. As a result it is very likely that including -ffat-lto-object in CFLAGS brings me back to my previous emerge environment, lto wise.

Since I decided to go for gcc 4.9 freshly after a lto activation for gcc-4.8 :

I remain unsure which of the two (fat or no-fat) should bring lto to the max efficiency?
I also remain unsure if I consequently get lto at link time since -ffat-lto-object (defaulted to or forced) seems to allow lto less link time (gnu doc), assuming lto is forced in my LDFLAGS.

The more I tweak around it (lto) the more I feel like I'm understanding it. I regret finding information is so time consuming.

Thks 4 ur attention, interest & support.

mv · Watchman Joined: 20 Apr 2005 Posts: 6747

CaptainBlood · Advocate Joined: 24 Jan 2010 Posts: 3627

So I never got lto really involved to the max...

, if I understand you well.

Anyone here with good kownledge which non system small ebuild which is concerned by -lto and working with -fno-fat-lto-objects, so that I can validate my lto/gcc/binutils env to start with?

I fear lto link time breakage.

Thks 4 ur attention, interest & support.

EDIT: remember I had to -fno-fat-lto-object for sys-apps/acl which initially caused gvfs mounting to fail. Giving a try. => failed :twisted:

Wonder if I shouldn't go back to gcc 4.8/binutils 2.24.0 env, trying to activate fno-fat-lto-object as much as possible and then wait for better visibility on gcc 4.9 lto readyness.EOE

Jerry_McBride · n00b Joined: 23 Mar 2004 Posts: 10

I find that tigervnc fails to compile with the later GCC, I am not able to test LTO or GRAPHITE till I can resolve this error during vncviewer compile.

tigervnc-1.3.1/vncviewer/CConn.h:43:27: error: 'FL_SOCKET' has not been declared

Old versions of GCC, no problems...

Maitreya · Guru Joined: 11 Jan 2006 Posts: 441

Helena · Posted: Sun Jan 18, 2015 7:56 pm Post subject:

I would welcome some advice. What are the important changes from 4.8.x to 4.9.2? Is a world recompile advisable or not? If so, how? I am well aware of lengthy discussions in the past whether or not to do a two-pass recompile, to include only a few compiler tools or the entire “system” group of packages etc. I prefer to use the wiki guide: http://wiki.gentoo.org/wiki/Upgrading_GCC is that what most of you use?

Side note: I no longer have the time to do a lot of experimentation myself :cry:

lutel · Posted: Mon Aug 17, 2015 8:31 am Post subject: still no gcc 4.9

What is the current status of tests? Why it takes so long to unmask 4.9, even though 5.2 is on the horizon, and 5.1 being used in Debian? I think its crucial for Gentoo to stay on high gcc version, as for lots of people Gentoo is chosen for optimization reasons...

Roman_Gruber · Posted: Mon Aug 17, 2015 8:51 am Post subject:

You may check gentoo bugzilla regarding those gcc constraints. As far as I can remember those Gcc had a several bug for any version and until not everything is fixed its masked ...

I get the feeling we have less developers as in the past. So many packages fail to build recently, some bugs are open for months. .... Just a slice of what I have seen but it seems like that. On the other hand we did not had all those gentoo derived distros in teh past liek these days. I would not be surprised that these devs went to those calculate / sabayon / funtoo and the main distro lacks developers ...

e.g. https://bugs.gentoo.org/show_bug.cgi?id=555886

like those i reported. They stay unconfirmed for ages ...

e.g. https://bugs.gentoo.org/buglist.cgi?quicksearch=gcc%205.2&list_id=2880478

7 results. 1 confirmed 6 unconfirmed ...

I hardly remember in the past that ebuilds lack so many dependencies as these days. I have so many emerge ... failed messages because there are missing dependencies.

No idea what happened to the gentoo bug fixing day? It used to be one day in a month a bug fixing day ...

check eternal lands ebuild. The client can not be used anymore, and its still in the tree. My humble request to ditch it out of the tree is ignored. when there are no maintainers and the current client can not be used anymore (a new client since 2-3 years for htis game) it should be removed. the ebuild for the outdated game client is still in many overlays so its not lost anyway.

I suggest tree cleaners to purge more software with open bugs especially when its outdated or when there are newer pacakges in the tree. that will reduce the bugs and gives developers more space to fix the essential things ...

jorgicio · n00b Joined: 17 Oct 2014 Posts: 47

I just reinstalled Gentoo (coming from Funtoo), with the Unstable branch (ergo, with GCC 4.9.3), and no breakages at all. Using ~amd64.
I hope the same for everyone who wants to do that.

Roman_Gruber · Posted: Thu Aug 20, 2015 8:19 pm Post subject:

destroyedlolo · Posted: Fri Aug 21, 2015 1:10 pm Post subject:

Hello,

I'm stuck with a VirtualBox installation and it seems it's due to a bug w/ GCC ... so I'm considering to upgrade GCC.

Is full world rebuild necessary ?
Is still Icetea failling ?

Thanks

Laurent

Roman_Gruber · Posted: Fri Aug 21, 2015 2:06 pm Post subject:

there was a gentoo page about upgrading gcc for general questions. https://wiki.gentoo.org/wiki/Upgrading_GCC

destroyedlolo · Posted: Fri Aug 21, 2015 3:15 pm Post subject:

Ok, I'll try my chance with 4.9 then

Last question : how can I prevent emerge --depclean to remove the current GCC ? I would like keeping the last 2 versions.

Thanks

Laurent

ct85711 · Veteran Joined: 27 Sep 2005 Posts: 1791

well, I can say that I haven't had any issues using 4.9 here yet (I am not using gold linker or anything outside the default, with normal safe compiler flags used).

destroyedlolo · Posted: Sat Aug 22, 2015 8:00 am Post subject:

To precise my question, I'm doing

Apheus · Guru Joined: 12 Jul 2008 Posts: 422

ian.au · Guru Joined: 07 Apr 2011 Posts: 591 Location: Australia

Virtualbox is the reason I upgraded to 4.9.2 in May, it's not a full rebuild, just emerge and switch compiler with gcc-config and rebuilt libtool from memory.

I always keep the stable version around when one package pushes me 'off the reservation', emerge noreplace is the method as already described.

destroyedlolo · Posted: Mon Aug 24, 2015 1:17 pm Post subject:

Hello,

I successfully installed VirtualBox guests ... but I'm facing an error while upgrading glibc :

destroyedlolo · Posted: Mon Aug 31, 2015 3:58 pm Post subject:

Upgraded my system and GLibC is now compiling