Bug 861458 – net-irc/hexchat-2.16.1 fails to compile (lto): plugin-notification.h:23:5: error: type of notification_plugin_deinit does not match original declaration [-Werror=lto-type-mismatch]

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Agostino Sarubbo 2022-07-27 12:30:16 UTC]

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

Issue: net-irc/hexchat-2.16.1 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 2022-07-27 12:30:19 UTC]

Created attachment 794948 [details]
build.log

build log and emerge --info

[Comment 2 Agostino Sarubbo 2022-07-27 12:30:21 UTC]

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


FAILED: src/fe-gtk/hexchat 
../hexchat-2.16.1/src/fe-gtk/plugin-notification.h:23:5: error: type of ‘notification_plugin_deinit’ does not match original declaration [-Werror=lto-type-mismatch]

[Comment 3 Adrian Schollmeyer 2022-08-21 18:50:45 UTC]

Problem reproduced locally, upstream issue opened and patch provided upstream.
I'll be stripping the LTO flags in the current versions of the package for now.

[Comment 4 Larry the Git Cow 2022-08-23 05:24:15 UTC]

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

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=8fbc406e3fdc55d1e623ce2610f03a943d0d1e36

commit 8fbc406e3fdc55d1e623ce2610f03a943d0d1e36
Author:     Adrian Schollmeyer <[e-mail]>
AuthorDate: 2022-08-21 19:13:20 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2022-08-23 05:23:55 +0000

    net-irc/hexchat: Filter LTO flags
    
    Workaround for LTO type mismatch issue until upstream applies
    the fix for this issue [1].
    
    [1] https://github.com/hexchat/hexchat/issues/2726
    
    Closes: https://bugs.gentoo.org/861458
    Signed-off-by: Adrian Schollmeyer <[e-mail]>
    Closes: https://github.com/gentoo/gentoo/pull/26949
    Signed-off-by: Sam James <[e-mail]>

 net-irc/hexchat/hexchat-2.16.1-r1.ebuild | 139 +++++++++++++++++++++++++++++++
 net-irc/hexchat/hexchat-9999.ebuild      |   5 +-
 2 files changed, 143 insertions(+), 1 deletion(-)

[Comment 5 Larry the Git Cow 2024-02-29 16:14:34 UTC]

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

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=fffac1da6ee00707a8a535509de85914348cce56

commit fffac1da6ee00707a8a535509de85914348cce56
Author:     Adrian Schollmeyer <[e-mail]>
AuthorDate: 2024-02-20 17:26:30 +0000
Commit:     Viorel Munteanu <[e-mail]>
CommitDate: 2024-02-29 16:14:23 +0000

    net-irc/hexchat: drop unnecessary filter-lto
    
    The bug that required filter-lto was fixed a while ago and is in the
    current upstream release now.
    
    Bug: https://bugs.gentoo.org/861458
    Signed-off-by: Adrian Schollmeyer <[e-mail]>
    Signed-off-by: Viorel Munteanu <[e-mail]>

 net-irc/hexchat/hexchat-9999.ebuild | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)