Bug 862930 – sci-libs/stellarsolver-2.4 fails to compile (lto): kdtree.c:589:1: error: type of kdtree_node_node_mindist2_exceeds_dss does not match original declaration [-Werror=lto-type-mismatch]

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Agostino Sarubbo 2022-08-02 06:59:57 UTC]

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

Issue: sci-libs/stellarsolver-2.2 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 2022-08-02 07:00:00 UTC]

Created attachment 796777 [details]
build.log

build log and emerge --info

[Comment 2 Agostino Sarubbo 2022-08-02 07:00:03 UTC]

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


FAILED: libstellarsolver.so.2.2 
/var/tmp/portage/sci-libs/stellarsolver-2.2/work/stellarsolver-2.2/stellarsolver/astrometry/libkd/kdtree.c:589:1: error: type of ‘kdtree_node_node_mindist2_exceeds_dss’ does not match original declaration [-Werror=lto-type-mismatch]

[Comment 3 Agostino Sarubbo 2022-11-02 06:04:26 UTC]

lto_tinderbox has reproduced this issue with version 2.4 - Updating summary.

[Comment 4 Larry the Git Cow 2024-03-17 08:42:33 UTC]

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

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=681f94760646bda2d7089ed485a6dbe985b97def

commit 681f94760646bda2d7089ed485a6dbe985b97def
Author:     Sam James <[e-mail]>
AuthorDate: 2024-03-17 08:40:04 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2024-03-17 08:42:04 +0000

    sci-libs/stellarsolver: filter LTO
    
    I haven't reported this upstream because I can't even build it with GCC 14
    (bug #886465).
    
    Bug: https://bugs.gentoo.org/886465
    Closes: https://bugs.gentoo.org/862930
    Signed-off-by: Sam James <[e-mail]>

 sci-libs/stellarsolver/stellarsolver-2.5.ebuild | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)