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Bug 854534 - app-emulation/softgun-0.22 fails to compile (lto): instructions_m16c.h:163:6: error: type of [-Werror=lto-type-mismatch]
Summary: app-emulation/softgun-0.22 fails to compile (lto): instructions_m16c.h:163:6:...
Alias: None
Product: Gentoo Linux
Classification: Unclassified
Component: Current packages (show other bugs)
Hardware: All Linux
: Normal normal (vote)
Assignee: Gentoo ARM Porters
Keywords: PullRequest
Depends on:
Blocks: lto
  Show dependency tree
Reported: 2022-06-27 06:20 UTC by Agostino Sarubbo
Modified: 2023-09-21 18:47 UTC (History)
0 users

See Also:
Package list:
Runtime testing required: ---

build.log (build.log,357.61 KB, text/plain)
2022-06-27 06:20 UTC, Agostino Sarubbo

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Description Agostino Sarubbo gentoo-dev 2022-06-27 06:20:02 UTC

Issue: app-emulation/softgun-0.22 fails to compile (lto).
Discovered on: amd64 (internal ref: lto_tinderbox)

This machine uses lto with CFLAGS=-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing
Comment 1 Agostino Sarubbo gentoo-dev 2022-06-27 06:20:04 UTC
Created attachment 787892 [details]

build log and emerge --info
Comment 2 Agostino Sarubbo gentoo-dev 2022-07-26 09:00:18 UTC
Here is a bit of explanation:

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.

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

Used to find possible runtime issues in packages. These bugs are a problem anyway but may be even worse when combined with LTO.

- 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:
Comment 3 Larry the Git Cow gentoo-dev 2023-09-21 18:47:23 UTC
The bug has been closed via the following commit(s):

commit b6a09b8fbe446b9c9990065fabbd07deb4ef85f3
Author:     Pascal Jäger <>
AuthorDate: 2023-09-21 12:05:54 +0000
Commit:     Arthur Zamarin <>
CommitDate: 2023-09-21 18:47:18 +0000

    app-emulation/softgun: fix build for clang16, lto
    EAPI bump
    Signed-off-by: Pascal Jäger <>
    Signed-off-by: Arthur Zamarin <>

 ....22-fix-declarations-with-type-mismatches.patch | 148 +++++++++++++++++++++
 .../files/softgun-0.22-fix-implicit-int.patch      |  33 +++++
 app-emulation/softgun/softgun-0.22-r1.ebuild       |  38 ++++++
 3 files changed, 219 insertions(+)