Reproducer for PCA example failures (#3037)

[Vika-F]

Add -Werror=deprecated-copy option to GCC examples build to reproduce the validation tests failures.

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[david-cortes-intel]

Looks like it didn't work.

How about adding it to env. var $CXXFLAGS to see if it works there?

[david-cortes-intel]

/intelci: run

[david-cortes-intel]

Looks like the flag is also supported by clang:
https://clang.llvm.org/docs/DiagnosticsReference.html#wdeprecated-copy

and by extension, should also be supported by icx. Perhaps it could be added unconditionally.

[Vika-F]

@david-cortes-intel

Looks like it didn't work.

How about adding it to env. var $CXXFLAGS to see if it works there?

I do not like the idea of modifying environment variables. They could have impact on other processes besides cmake.

[david-cortes-intel]

@david-cortes-intel

Looks like it didn't work.
How about adding it to env. var $CXXFLAGS to see if it works there?

I do not like the idea of modifying environment variables. They could have impact on other processes besides cmake.

Have you been able to reproduce this locally by adding the same flag?

[Vika-F]

@david-cortes-intel
No. I've added the flag locally, but couldn't get the error.
Anyway I think that the changed in #3037 are valid.

[david-cortes-intel]

@david-cortes-intel No. I've added the flag locally, but couldn't get the error. Anyway I think that the changed in #3037 are valid.

I wasn't able to reproduce it either, neither with gcc nor clang nor icx.

I notice the issue was raised with the "dynamic" variant of the examples. Just to double check: are the examples here compiled against the static or the dynamic-link library?

[david-cortes-intel]

@Vika-F On a deeper look, I was able to reproduce the error when using the exact same compiler version where the issue was reported (gcc==11.3).

Since this happens only with GCC, and only with certain older versions, it leads me to believe that there might actually not be any issue in the code and we might instead be seeing a compiler bug like this:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92145

[Vika-F]

@david-cortes-intel No. I've added the flag locally, but couldn't get the error. Anyway I think that the changed in #3037 are valid.

I wasn't able to reproduce it either, neither with gcc nor clang nor icx.

I notice the issue was raised with the "dynamic" variant of the examples. Just to double check: are the examples here compiled against the static or the dynamic-link library?

Both modes are tested here: static and dynamic. See this log, for example: https://dev.azure.com/daal/c48b0cee-5374-446e-aea4-3de8ba2ac9ca/_apis/build/builds/41717/logs/116

[david-cortes-intel]

While this didn't end up reproducing the original issue, it's still helpful to have this flag enabled anyway, so no harm in merging.