Bug 862684 – sci-libs/cgnslib-4.3.0 fails to compile (lto): cgns_f.F90:4638:53: error: type of cg_goto_f1 does not match original declaration [-Werror=lto-type-mismatch]

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Agostino Sarubbo 2022-08-01 07:47:44 UTC]

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

Issue: sci-libs/cgnslib-4.3.0 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 2022-08-01 07:47:47 UTC]

Created attachment 796426 [details]
build.log

build log and emerge --info

[Comment 2 Agostino Sarubbo 2022-08-01 07:47:49 UTC]

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


FAILED: src/libcgns.so.4.3 
/var/tmp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgns_f.F90:4638:53: error: type of ‘cg_goto_f1’ does not match original declaration [-Werror=lto-type-mismatch]

[Comment 3 Petross404(Petros S) 2022-11-23 16:07:12 UTC]

(In reply to Agostino Sarubbo from comment #2)
> Error(s) that match a know pattern in addition to what has been reported in
> the summary:
> 
> 
> FAILED: src/libcgns.so.4.3 
> /var/tmp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgns_f.F90:4638:
> 53: error: type of ‘cg_goto_f1’ does not match original declaration
> [-Werror=lto-type-mismatch]

I confirm this bug report.

>>> Completed installing sci-libs/cgnslib-4.3.0 into /mnt/Volume_3/Gentoo/temp/portage/sci-libs/cgnslib-4.3.0/image

 * Final size of build directory: 29416 KiB (28.7 MiB)
 * Final size of installed tree:   3428 KiB ( 3.3 MiB)

 * 
 * QA Notice: Package triggers severe warnings which indicate that it
 *            may exhibit random runtime failures.
 * 
 * /mnt/Volume_3/Gentoo/temp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgns_f.F90:4638:53: warning: type of ‘cg_goto_f1’ does not match original declaration [-Wlto-type-mismatch]
 * /mnt/Volume_3/Gentoo/temp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgns_f.F90:4749:52: warning: type of ‘cg_gorel_f1’ does not match original declaration [-Wlto-type-mismatch]
 * /mnt/Volume_3/Gentoo/temp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgnstools/tkogl/tkogl.c:602:8: warning: implicit declaration of function ‘TkWmAddToColormapWindows’ [-Wimplicit-function-declaration]
 * /mnt/Volume_3/Gentoo/temp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgnstools/tkogl/gencyl.c:685:39: warning: passing argument 3 of ‘gluTessCallback’ from incompatible pointer type [-Wincompatible-pointer-types]
 * /mnt/Volume_3/Gentoo/temp/portage/sci-libs/cgnslib-4.3.0/work/CGNS-4.3.0/src/cgnstools/tkogl/gencyl.c:686:40: warning: passing argument 3 of ‘gluTessCallback’ from incompatible pointer type [-Wincompatible-pointer-types]
 *

[Comment 4 Larry the Git Cow 2024-03-08 11:09:43 UTC]

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

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=dd056658c602cf754e9b1d898eacaac73636df2b

commit dd056658c602cf754e9b1d898eacaac73636df2b
Author:     Eli Schwartz <[e-mail]>
AuthorDate: 2024-03-08 01:54:17 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2024-03-08 11:09:01 +0000

    sci-libs/cgnslib: mark as LTO-unsafe
    
    Closes: https://bugs.gentoo.org/862684
    Signed-off-by: Eli Schwartz <[e-mail]>
    Signed-off-by: Sam James <[e-mail]>

 sci-libs/cgnslib/cgnslib-4.3.0-r2.ebuild | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)