https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: gui-libs/libadwaita-1.1.3 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
Created attachment 792479 [details] build.log build log and emerge --info
Error(s) that match a know pattern in addition to what has been reported in the summary: FAILED: src/libadwaita-1.so.0.p/adw-tab-box.c.o FAILED: src/libadwaita-1.so.0.p/adw-tab-view.c.o ../libadwaita-1.1.3/src/adw-tab-view.c:1308:20: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
I see the same issue in libhandy as well.
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
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=33e354c16be0dbd7b8033e4ae76e0800a78e6dde commit 33e354c16be0dbd7b8033e4ae76e0800a78e6dde Author: Matt Turner <mattst88@gentoo.org> AuthorDate: 2022-08-05 22:34:53 +0000 Commit: Matt Turner <mattst88@gentoo.org> CommitDate: 2022-08-06 02:17:28 +0000 gui-libs/libadwaita: Version bump to 1.1.4 Closes: https://bugs.gentoo.org/859466 Signed-off-by: Matt Turner <mattst88@gentoo.org> gui-libs/libadwaita/Manifest | 1 + gui-libs/libadwaita/files/1.1.4-fix-aliasing.patch | 204 +++++++++++++++++++++ gui-libs/libadwaita/libadwaita-1.1.4.ebuild | 69 +++++++ 3 files changed, 274 insertions(+)