https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: media-libs/plib-1.8.5-r3 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 793142 [details] build.log build log and emerge --info
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
lto_tinderbox has reproduced this issue with version 1.8.5-r4 - Updating summary.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=aec66421746a0ac2dc2b2eebed6e0f0d2abe3405 commit aec66421746a0ac2dc2b2eebed6e0f0d2abe3405 Author: Eli Schwartz <eschwartz93@gmail.com> AuthorDate: 2024-02-28 22:30:22 +0000 Commit: Sam James <sam@gentoo.org> CommitDate: 2024-02-28 22:57:01 +0000 media-libs/plib: mark LTO-unsafe, mark strict-aliasing unsafe This code is formally terrible. It is so terrible, because upstream claims: "PLIB has been obsolete and unmaintained for at LEAST 15 years!!" https://sourceforge.net/p/plib/bugs/55/#88e9 And that was already 3 years ago. We can't fix it so limit the extent to which compilers are allowed to misinterpret it. Closes: https://bugs.gentoo.org/860048 Signed-off-by: Eli Schwartz <eschwartz93@gmail.com> Signed-off-by: Sam James <sam@gentoo.org> media-libs/plib/plib-1.8.5-r4.ebuild | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
