Bug 863896

Summary:	sys-fs/f2fs-tools-1.16.0-r1 fails to compile (lto): f2fs_format.c:37:34: error: type of c does not match original declaration [-Werror=lto-type-mismatch]
Product:	Gentoo Linux	Reporter:	Agostino Sarubbo <ago>
Component:	Current packages	Assignee:	Gentoo's Team for Core System packages <base-system>
Status:	RESOLVED FIXED
Severity:	normal	CC:	ceamac, zlogene
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

2022-08-06 06:21:40 UTC

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

Issue: sys-fs/f2fs-tools-1.15.0 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

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

2022-08-06 06:21:43 UTC

Created attachment 798139 [details]
build.log

build log and emerge --info

Comment 2 Agostino Sarubbo gentoo-dev

2022-11-09 07:49:10 UTC

lto_tinderbox has reproduced this issue with version 1.15.0-r1 - Updating summary.

Comment 3 Agostino Sarubbo gentoo-dev

2024-03-27 08:03:22 UTC

lto_tinderbox has reproduced this issue with version 1.16.0-r1 - Updating summary.

Comment 4 Larry the Git Cow gentoo-dev

2024-04-09 14:44:46 UTC

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

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=3e3e3a68c70353ad1d232d83d328b21443dc87e4

commit 3e3e3a68c70353ad1d232d83d328b21443dc87e4
Author:     Eli Schwartz <eschwartz93@gmail.com>
AuthorDate: 2024-04-09 02:08:08 +0000
Commit:     Sam James <sam@gentoo.org>
CommitDate: 2024-04-09 14:43:28 +0000

    sys-fs/f2fs-tools: mark as LTO-unsafe
    
    Closes: https://bugs.gentoo.org/863896
    Signed-off-by: Eli Schwartz <eschwartz93@gmail.com>
    Signed-off-by: Sam James <sam@gentoo.org>

 sys-fs/f2fs-tools/f2fs-tools-1.16.0-r1.ebuild | 9 +++++++--
 sys-fs/f2fs-tools/f2fs-tools-9999.ebuild      | 7 ++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)