Bug 878525 – sci-libs/indilib-1.9.8 fails to compile (lto): ConnectionMock.cpp:195:6: error: type XmlStatus violates the C++ One Definition Rule [-Werror=odr]

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Agostino Sarubbo 2022-10-28 10:15:14 UTC]

https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: sci-libs/indilib-1.9.8 fails to compile (lto).
Discovered on: amd64 (internal ref: lto_tinderbox)

NOTE:
This machine uses lto with CFLAGS=-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing

Here is a bit of explanation:

-Werror=lto-type-mismatch:
User to find possible runtime issues in packages. It likely means the package is unsafe to build & use with LTO.
For projects using the same identifier but with different types across different files, they must be fixed to be consistent across the codebase.

-Werror=odr:
Used to find possible runtime issues in packages. These bugs are a problem anyway but may be even worse when combined with LTO. C++ code must comply with the One Definition Rule (ODR) - see https://en.cppreference.com/w/cpp/language/definition#One_Definition_Rule.

-Werror=strict-aliasing:
Used to find possible runtime issues in packages. These bugs are a problem anyway but may be even worse when combined with LTO.

Workarounds:
- If upstream is friendly and still active, file a bug upstream. For emulators, codecs, games, or multimedia packages, it may be worth just applying a workaround instead, as upstreams sometimes aren't receptive to these bugs (VALID FOR ALL).
- Use the new 'filter-lto' from flag-o-matic.eclass as it's likely to be unsafe with LTO (VALID FOR lto-type-mismatch - odr).
- Fix it yourself if interested, of course (VALID FOR ALL).
- Append-flags -fno-strict-aliasing (VALID FOR strict-aliasing).
- Use memcpy() but a union is sometimes suitable too (VALID FOR strict-aliasing).
- -fstrict-aliasing is implied by -O2, so this must be addressed in some form (VALID FOR strict-aliasing).

See also: https://marc.info/?l=gentoo-dev&m=165639574126280&w=2

[Comment 1 Agostino Sarubbo 2022-10-28 10:15:17 UTC]

Created attachment 825697 [details]
build.log

build log and emerge --info

[Comment 2 Agostino Sarubbo 2022-10-28 10:15:20 UTC]

Error(s) that match a know pattern in addition to what has been reported in the summary:


FAILED: integs/TestIndiserverSingleDriver integs/TestIndiserverSingleDriver[1]_tests.cmake /var/tmp/portage/sci-libs/indilib-1.9.8/work/indi-1.9.8_build/integs/TestIndiserverSingleDriver[1]_tests.cmake 
fatal: not a git repository (or any parent up to mount point /var/tmp)
/var/tmp/portage/sci-libs/indilib-1.9.8/work/indi-1.9.8/integs/ConnectionMock.cpp:195:6: error: type ‘XmlStatus’ violates the C++ One Definition Rule [-Werror=odr]

[Comment 3 Eli Schwartz 2024-03-07 07:22:12 UTC]

The issue is gone in

[Comment 4 Eli Schwartz 2024-03-07 07:23:05 UTC]

Sorry, the issue is NOT gone in anything, that was random text in the comment box when I tried to add a "See Also" and submit...

[Comment 5 Larry the Git Cow 2024-03-07 11:51:00 UTC]

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

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=47a5f36df8789f2d55065407af24e0ee83a8a118

commit 47a5f36df8789f2d55065407af24e0ee83a8a118
Author:     Eli Schwartz <[e-mail]>
AuthorDate: 2024-03-07 07:21:26 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2024-03-07 11:46:26 +0000

    sci-libs/indilib: mark as LTO-unsafe
    
    Closes: https://bugs.gentoo.org/878525
    Signed-off-by: Eli Schwartz <[e-mail]>
    Signed-off-by: Sam James <[e-mail]>

 sci-libs/indilib/indilib-2.0.4.ebuild | 9 +++++++--
 sci-libs/indilib/indilib-2.0.6.ebuild | 7 ++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)