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Bug 860090

Summary: media-libs/svt-av1-1.1.0 fails to compile (lto): firstpass.c:494:6: error: type of set_dlf_controls does not match original declaration [-Werror=lto-type-mismatch]
Product: Gentoo Linux Reporter: Agostino Sarubbo <ago>
Component: Current packagesAssignee: James Beddek <telans>
Status: RESOLVED UPSTREAM    
Severity: normal CC: media-video, proxy-maint
Priority: Normal    
Version: unspecified   
Hardware: All   
OS: Linux   
Whiteboard:
Package list:
Runtime testing required: ---
Bug Depends on:    
Bug Blocks: 618550    
Attachments: build.log

Description Agostino Sarubbo gentoo-dev 2022-07-22 13:08:19 UTC
https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: media-libs/svt-av1-1.1.0 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
Comment 1 Agostino Sarubbo gentoo-dev 2022-07-22 13:08:21 UTC
Created attachment 793205 [details]
build.log

build log and emerge --info
Comment 2 Agostino Sarubbo gentoo-dev 2022-07-22 13:08:23 UTC
Error(s) that match a know pattern in addition to what has been reported in the summary:


FAILED: libSvtAv1Enc.so.1.1.0 
/var/tmp/portage/media-libs/svt-av1-1.1.0/work/SVT-AV1-v1.1.0/Source/Lib/Encoder/Codec/firstpass.c:494:6: error: type of ‘set_dlf_controls’ does not match original declaration [-Werror=lto-type-mismatch]
Comment 3 Agostino Sarubbo gentoo-dev 2022-07-26 09:02:36 UTC
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 4 Kostadin Shishmanov 2023-06-14 09:11:30 UTC
Can't reproduce this on media-libs/svt-av1-1.5.0-r1. Might've been solved way earlier, but I just noticed this bug is open.
Comment 5 Sam James archtester Gentoo Infrastructure gentoo-dev Security 2023-06-14 13:55:05 UTC
Thanks!