Bug 630066

Summary:	sys-devel/gcc-config should set symlink lto linker plugins
Product:	Gentoo Linux	Reporter:	Martin Väth <martin>
Component:	Current packages	Assignee:	Gentoo Toolchain Maintainers <toolchain>
Status:	RESOLVED FIXED
Severity:	normal	CC:	gentoo, jj, lookatyouhacker, pageexec, public+gentoo, tdalman, tsmksubc
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
See Also:	https://bugs.gentoo.org/show_bug.cgi?id=494228
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:
Bug Blocks:	618550
Attachments:	Add LTO symlink support to gcc-config

Description Martin Väth 2017-09-06 09:35:00 UTC

Quite some packages fail with -flto if the gcc's flto linker plugin library /usr/libexec/gcc/$ARCH/$GCC_VERSION/liblto_plugin.so.0.0.0 is not symlinked into /usr/$ARCH/binutils-bin/lib/bfd-plugins

In particular, without this symlink, all packages creating static archives with "ar" or "$ARCH-ar" (in contrast to "gcc-ar" or "$ARCH-gcc-ar") do not do this correctly (unless -ffat-lto objects is in effect - but the latter simply means that flto cannot be used with that archive).

Note that tc-getAR from toolchain-funcs outputs $ARCH-ar (and not $ARCH-gcc-ar), so that e.g. meson.eclass exports a value for AR which requires the plugin.

This leads to such problems as discussed in
https://github.com/mesonbuild/meson/issues/2129

In my opinion, the correct solution would be that gentoo manages the above mentioned plugin symlink. Since this symlink should better point to the plugin corresponding to the currently selected gcc version, I suggest that this be done in gcc-config.

Comment 1 Shane Peelar 2017-09-21 17:08:17 UTC

Created attachment 495798 [details, diff]
Add LTO symlink support to gcc-config

Comment 2 Andreas K. Hüttel archtester

2017-12-16 21:12:29 UTC

https://gitweb.gentoo.org/proj/gcc-config.git/commit/?id=aab6bf7095a0ab921c78b07a202db207ce07a5f8

Pushed, thanks!

Comment 3 Larry the Git Cow gentoo-dev

2017-12-17 00:24:09 UTC

The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=f29fde782b79bc0bf7a8603a86e238412dc2ddfe

commit f29fde782b79bc0bf7a8603a86e238412dc2ddfe
Author:     Andreas K. Hüttel <dilfridge@gentoo.org>
AuthorDate: 2017-12-17 00:23:49 +0000
Commit:     Andreas K. Hüttel <dilfridge@gentoo.org>
CommitDate: 2017-12-17 00:24:00 +0000

    sys-devel/gcc-config: Version bump; fixes prefix issues (bug 641096) and adds support for LTO linker plugins (bug 630066)
    
    Closes: https://bugs.gentoo.org/630066
    Bug: https://bugs.gentoo.org/641096
    Package-Manager: Portage-2.3.19, Repoman-2.3.6

 sys-devel/gcc-config/Manifest                |  1 +
 sys-devel/gcc-config/gcc-config-1.9.1.ebuild | 54 ++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)

Comment 4 Shane Peelar 2017-12-17 00:51:36 UTC

Awesome!  Now I can remove this from lto-overlay and advise users to use gcc-config-9999.  Thank you!

Comment 5 Andreas K. Hüttel archtester

2017-12-27 22:43:03 UTC

*** Bug 612816 has been marked as a duplicate of this bug. ***