Explicitly specify C++17 in libslic3r and libslic3r_cgal cmake, fixing build on Fedora 40

[LightTreasure]

Bambu studio currently fails to build on Fedora 40. This is because the CMake configuration of libslic3r and libslic3r_cgal currently does not explicitly specify the C++ standard, but it seems like the libslic3r and libslic3r_cgal code assumes C++17. Without explicit specification, the compiler uses C++20.

Also added -Wno-error=template-id-cdtor to the compiler flags for Clipper2, preventing this warning from being thrown as an error. The template-id-cdtor warning being thrown as an error is a c++20 addition in gcc.

This fixes #4018.

[lanewei120]

can not pass compile on old linux

[LightTreasure]

can not pass compile on old linux

Ah, this flag was introduced in a newer version of gcc. I wonder if there is a way to determine this in cmake...

[LightTreasure]

I put the -Wno-error=template-id-cdtor flag behind a cmake if condition which should only apply if the compiler is gcc and the version is >=14.1 . This should fix the build.

[lanewei120]

some other errors found:

[LightTreasure]

some other errors found:

Could you please point me to the full build log?

[lanewei120]

you can wait the compiling result from https://github.com/bambulab/BambuStudio/actions/runs/9296852419

[LightTreasure]

@lanewei120 Looks like the build succeeded without errors.

[lanewei120]

compiling_error.txt
please find the attached file

[LightTreasure]

@lanewei120 that is from the build before my second commit. It looks like the build after the second commit has no compilation errors and the binary was generated successfully.

Could you please try re-running the build to confirm?

[lanewei120]

the error is not found in clipper2
it is not related with your second commit

i already used all your commits for compiling

[MackBambu]

https://github.com/MackBambu/BambuStudio/actions/runs/9635067680/job/26571467884
ubuntu 20.04 build failed

[LightTreasure]

https://github.com/MackBambu/BambuStudio/actions/runs/9635067680/job/26571467884 ubuntu 20.04 build failed

Investigating.

[LightTreasure]

After some digging, I can see that this error is related to the following discussion: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40856

In summary, seems like the use of the type __int128 is not fully implemented when using -std=c++11. It requires the use of -std=gnu++11. However, using gnu++11 causes the issues I noted in #4018 in newer versions of g++, and this issue got fixed in the newer versions.

This is why the Ubuntu 24.04 build succeeded, but 20.04 failed.

I will put in the same gcc version check in src/libslic3r/CMakeLists.txt as I did in src/clipper2/CMakeLists.txt

[LightTreasure]

@MackBambu I made a change that should make this work. Could you please re-run the build as you did before and check if it works?

[LightTreasure]

@MackBambu Looks like the build succeeded! One thing to note is that the version check for gcc version 14.1 is somewhat arbitrary. I'm not sure which exact version of gcc will make my changes work. However, > 14.1 is a safe choice because that's the version I tested on Fedora 40.

[MackBambu]

https://github.com/MackBambu/BambuStudio/actions/runs/9657794626
All three platforms are fine.
@lanewei120 Need to verify in Fedora 36?

[lanewei120]

https://github.com/MackBambu/BambuStudio/actions/runs/9657794626 All three platforms are fine. @lanewei120 Need to verify in Fedora 36?

yes, we will have a try

[MackBambu]

Fedora 40, ubuntu 20, ubuntu 24 is ok
good job

[LightTreasure]

Fedora 40, ubuntu 20, ubuntu 24 is ok good job

Thank you! This confirms that requiring gcc > 14.1 for the changes I made is a safe choice for
currently supported distros.

But it is important to note that the version number 14.1 is somewhat arbitrary - if a prior version of gcc results in compilation issues as described in the original bug ( #4018 ), then the version check needs to be update to that version.

@lanewei120 If you are okay with these changes, please review and I can submit this PR.

[lanewei120]

thanks for doing this