Bug 863041 – sci-libs/xgks-pmel-2.5.5 fails to compile (lto): gdadds.c:100:32: error: type of [-Werror=lto-type-mismatch]

• Product: Gentoo Linux
• Status: RESOLVED OBSOLETE

[Description Agostino Sarubbo 2022-08-02 14:07:57 UTC]

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

Issue: sci-libs/xgks-pmel-2.5.5 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 14:08:00 UTC]

Created attachment 796888 [details]
build.log

build log and emerge --info

[Comment 2 Larry the Git Cow 2024-03-24 06:57:20 UTC]

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=88f3ffaa28b37fde4b1419942078d6901990a93b

commit 88f3ffaa28b37fde4b1419942078d6901990a93b
Author:     Eli Schwartz <[e-mail]>
AuthorDate: 2024-03-24 06:43:02 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2024-03-24 06:56:36 +0000

    package.mask: Last rite sci-libs/xgks-pmel
    
    Bug: https://bugs.gentoo.org/731942
    Bug: https://bugs.gentoo.org/863041
    Bug: https://bugs.gentoo.org/879763
    Bug: https://bugs.gentoo.org/886587
    Bug: https://bugs.gentoo.org/898298
    Signed-off-by: Eli Schwartz <[e-mail]>
    Signed-off-by: Sam James <[e-mail]>

 profiles/package.mask | 6 ++++++
 1 file changed, 6 insertions(+)

[Comment 3 Larry the Git Cow 2024-04-27 14:53:16 UTC]

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=d353a32c9b6785f0c744d9b10bd673d4d4a61f1b

commit d353a32c9b6785f0c744d9b10bd673d4d4a61f1b
Author:     Arthur Zamarin <[e-mail]>
AuthorDate: 2024-04-27 14:50:39 +0000
Commit:     Arthur Zamarin <[e-mail]>
CommitDate: 2024-04-27 14:53:04 +0000

    sci-libs/xgks-pmel: treeclean
    
    Closes: https://bugs.gentoo.org/731942
    Bug: https://bugs.gentoo.org/898298
    Bug: https://bugs.gentoo.org/863041
    Bug: https://bugs.gentoo.org/886587
    Bug: https://bugs.gentoo.org/879763
    Bug: https://bugs.gentoo.org/295724
    Signed-off-by: Arthur Zamarin <[e-mail]>

 profiles/package.mask                     |   6 --
 sci-libs/xgks-pmel/Manifest               |   1 -
 sci-libs/xgks-pmel/files/aclocal.patch    | 146 ------------------------------
 sci-libs/xgks-pmel/metadata.xml           |  13 ---
 sci-libs/xgks-pmel/xgks-pmel-2.5.5.ebuild |  77 ----------------
 5 files changed, 243 deletions(-)