Bug 862663 – sci-libs/ViSP-3.5.0 fails to compile (lto): vpMatrix.cpp:92:20: error: type of dsyev_ does not match original declaration [-Werror=lto-type-mismatch]

• Product: Gentoo Linux
• Status: RESOLVED WORKSFORME

[Description Agostino Sarubbo 2022-08-01 07:41:02 UTC]

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

Issue: sci-libs/ViSP-3.5.0 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 07:41:05 UTC]

Created attachment 796405 [details]
build.log

build log and emerge --info

[Comment 2 Agostino Sarubbo 2022-08-01 07:41:07 UTC]

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


-- Could NOT find Atlas (missing: Atlas_CBLAS_INCLUDE_DIR Atlas_CLAPACK_INCLUDE_DIR Atlas_CBLAS_LIBRARY Atlas_BLAS_LIBRARY Atlas_LAPACK_LIBRARY) 
-- Could NOT find CUDA (missing: CUDA_TOOLKIT_ROOT_DIR CUDA_NVCC_EXECUTABLE CUDA_INCLUDE_DIRS CUDA_CUDART_LIBRARY) 
-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
-- Could NOT find FTIITSDK (missing: FTIITSDK_FT_LIBRARY FTIITSDK_COMMUNICATION_LIBRARY FTIITSDK_INCLUDE_DIR) 
-- Could NOT find JPEG (missing: JPEG_LIBRARY JPEG_INCLUDE_DIR) 
-- Could NOT find MKL (missing: MKL_LIBRARIES MKL_INCLUDE_DIRS MKL_INTERFACE_LIBRARY MKL_SEQUENTIAL_LAYER_LIBRARY MKL_CORE_LIBRARY) 
-- Could not find OpenBLAS include. Turning OpenBLAS_FOUND off
-- Could not find OpenBLAS lib. Turning OpenBLAS_FOUND off
FAILED: lib/libvisp_core.so.3.5.0 
ModuleNotFoundError: No module named 'numpy'
/var/tmp/portage/sci-libs/ViSP-3.5.0/work/visp-3.5.0/modules/core/src/math/matrix/vpMatrix.cpp:92:20: error: type of ‘dsyev_’ does not match original declaration [-Werror=lto-type-mismatch]

[Comment 3 Eli Schwartz 2024-03-17 17:18:03 UTC]

I cannot reproduce this at all.