https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: dev-util/cmake-3.23.2 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 791693 [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
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=602c311c58d4de57d2cc6ee34219f439b0c5d766 commit 602c311c58d4de57d2cc6ee34219f439b0c5d766 Author: Sam James <sam@gentoo.org> AuthorDate: 2022-08-15 00:53:15 +0000 Commit: Sam James <sam@gentoo.org> CommitDate: 2022-08-15 00:56:00 +0000 dev-util/cmake: filter LTO (ODR) Closes: https://bugs.gentoo.org/858335 Signed-off-by: Sam James <sam@gentoo.org> dev-util/cmake/cmake-3.24.0.ebuild | 4 ++++ dev-util/cmake/cmake-9999.ebuild | 4 ++++ 2 files changed, 8 insertions(+)
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=f12bba7363577ac6e63955aa675828363bec7e1b commit f12bba7363577ac6e63955aa675828363bec7e1b Author: Eli Schwartz <eschwartz@gentoo.org> AuthorDate: 2024-07-07 06:53:31 +0000 Commit: Eli Schwartz <eschwartz@gentoo.org> CommitDate: 2024-07-07 07:09:26 +0000 dev-build/cmake: mark as LTO-unsafe under bootstrap as well We filter-lto due to ODR violations. But only in src_configure, which is common enough as that's where we set up the environment for configuring, in general. However cmake is a bit special as we also need to bootstrap it, and we do this in src_prepare(). We need to do that filtering there as well. While we are at it, the solaris linking issue is most probably relevant the same way, although I have not actually tested this... Bug: https://bugs.gentoo.org/858335 Signed-off-by: Eli Schwartz <eschwartz@gentoo.org> Acked-by: Sam James <sam@gentoo.org> dev-build/cmake/cmake-3.28.5.ebuild | 15 +++++++++------ dev-build/cmake/cmake-3.29.6.ebuild | 15 +++++++++------ dev-build/cmake/cmake-3.30.0.ebuild | 15 +++++++++------ dev-build/cmake/cmake-9999.ebuild | 15 +++++++++------ 4 files changed, 36 insertions(+), 24 deletions(-)
