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Bug 864761 - x11-misc/xlockmore-5.69 fails to compile (lto): vtlock.c:80:12: error: type of [-Werror=lto-type-mismatch]
Summary: x11-misc/xlockmore-5.69 fails to compile (lto): vtlock.c:80:12: error: type o...
Status: RESOLVED FIXED
Alias: None
Product: Gentoo Linux
Classification: Unclassified
Component: Current packages (show other bugs)
Hardware: All Linux
: Normal normal (vote)
Assignee: No maintainer - Look at https://wiki.gentoo.org/wiki/Project:Proxy_Maintainers if you want to take care of it
URL:
Whiteboard:
Keywords: PullRequest
Depends on:
Blocks: lto
  Show dependency tree
 
Reported: 2022-08-10 06:47 UTC by Agostino Sarubbo
Modified: 2022-12-07 21:29 UTC (History)
0 users

See Also:
Package list:
Runtime testing required: ---


Attachments
build.log (build.log,114.30 KB, text/plain)
2022-08-10 06:47 UTC, Agostino Sarubbo
Details

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Description Agostino Sarubbo gentoo-dev 2022-08-10 06:47:40 UTC
https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: x11-misc/xlockmore-5.69 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 gentoo-dev 2022-08-10 06:47:42 UTC
Created attachment 799071 [details]
build.log

build log and emerge --info
Comment 2 Larry the Git Cow gentoo-dev 2022-12-07 21:29:31 UTC
The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=71ae0b143a55fd45d4fd56cff13438cdbc602089

commit 71ae0b143a55fd45d4fd56cff13438cdbc602089
Author:     Pascal Jäger <pascal.jaeger@leimstift.de>
AuthorDate: 2022-12-07 16:18:40 +0000
Commit:     Sam James <sam@gentoo.org>
CommitDate: 2022-12-07 21:29:22 +0000

    x11-misc/xlockmore: version bump to 5.71, patch
    
    - version bump to 5.71
    - patch to fix build on clang16
    - add filter-lto
    
    Closes: https://bugs.gentoo.org/880909
    Closes: https://bugs.gentoo.org/864761
    
    Signed-off-by: Pascal Jäger <pascal.jaeger@leimstift.de>
    Closes: https://github.com/gentoo/gentoo/pull/28590
    Signed-off-by: Sam James <sam@gentoo.org>

 x11-misc/xlockmore/Manifest                        |   1 +
 .../xlockmore-5.71-fix-build-for-clang16.patch     |  28 +++++
 x11-misc/xlockmore/xlockmore-5.71.ebuild           | 125 +++++++++++++++++++++
 3 files changed, 154 insertions(+)