Hello,
I worked on this for a while. There were issues that I discuss here:
Bumping the clang version itself on Jenkins is straightforward, and is
done in this patch:
Bump linux_clang_dbgutil_64 to clang 18.1.8
https://gerrit.libreoffice.org/c/lode/+/182317
On the other hand, there are issues that rises from the fact that when
someone compiles the code with clang++ 18 or 19 on Linux, the compiler
uses the standard C++ library from the distribution, which may not be up
to date. Therefore, I get warnings/errors for deprecation on Ubuntu
22.04 LTS:
$ make svl
...
In file included from
/home/user/lode/dev/core/svl/source/items/stylepool.cxx:20:
In file included from
/home/user/lode/dev/core/include/svl/stylepool.hxx:21:
In file included from
/home/user/lode/dev/core/include/rtl/ustring.hxx:38:
In file included from
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/algorithm:61:
In file included from
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_algo.h:61:
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_tempbuf.h:263:8:
error: 'get_temporary_buffer<const SfxItemSet *>' is deprecated
[-Werror,-Wdeprecated-declarations]
263 |
std::get_temporary_buffer<value_type>(_M_original_len));
| ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_algo.h:4996:15:
note: in instantiation of member function
'std::_Temporary_buffer<__gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<const
SfxItemSet **, std::__cxx1998::vector<const SfxItemSet *>>,
std::vector<const SfxItemSet *>>, const SfxItemSet
*>::_Temporary_buffer' requested here
4996 | _TmpBuf __buf(__first, (__last - __first + 1) / 2);
| ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_algo.h:5070:23:
note: in instantiation of function template specialization
'std::__stable_sort<__gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<const
SfxItemSet **, std::__cxx1998::vector<const SfxItemSet *>>,
std::vector<const SfxItemSet *>>,
__gnu_cxx::__ops::_Iter_comp_iter<(lambda at
/home/user/lode/dev/core/svl/source/items/stylepool.cxx:264:27)>>'
requested here
5070 | _GLIBCXX_STD_A::__stable_sort(__first, __last,
| ^
/home/user/lode/dev/core/svl/source/items/stylepool.cxx:263:22: note: in
instantiation of function template specialization
'std::stable_sort<__gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<const
SfxItemSet **, std::__cxx1998::vector<const SfxItemSet *>>,
std::vector<const SfxItemSet *>>, (lambda at
/home/user/lode/dev/core/svl/source/items/stylepool.cxx:264:27)>'
requested here
263 | std::stable_sort(maParents.begin(),
maParents.end(),
| ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_tempbuf.h:99:5:
note: 'get_temporary_buffer<const SfxItemSet *>' has been explicitly
marked deprecated here
99 | _GLIBCXX17_DEPRECATED
| ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/x86_64-linux-gnu/c++/12/bits/c++config.h:119:34:
note: expanded from macro '_GLIBCXX17_DEPRECATED'
119 | # define _GLIBCXX17_DEPRECATED [[__deprecated__]]
| ^
1 error generated.
make[1]: *** [/home/user/lode/dev/core/solenv/gbuild/LinkTarget.mk:339:
/home/user/lode/dev/core/workdir/CxxObject/svl/source/items/stylepool.o]
Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:128: svl] Error 2
To fix these issues, we may:
1. Bundle and use standard C++ library from LLVM on Jenkins and
elsewhere
2. Internally re-define deprecated function, stable_sort
3. Accept the deprecated implementation and avoid error with
--disable-werror in the autogen.input, in case one face such a problem.
I suggest defining this function:
template<typename Iterator, typename Compare>
void stable_sort_custom(Iterator first, Iterator last, Compare comp) {
#if defined(__clang__) && defined(__GLIBCXX__)
// new stable_sort implementation
}
#else
std::stable_sort(first, last, comp);
#endif
}
It defines a new custom_stable_sort, in case clang and GNU standard C++
library are used. It falls back to std::stable_sort otherwise.
Regards,
Hossein
On 17.02.2025 21:15, Hossein Nourikhah wrote:
Hello,
The baseline for LibreOffice C++ source code is now C++20. But, the
clang 12 installed on CI machines is quite old, and lacks some
important C++20 features.
("/home/tdf/lode/opt_private/clang-llvmorg-12.0.1/bin/clang" is visible
in the build logs)
C++ ranges library is one example:
https://en.cppreference.com/w/cpp/ranges/reverse_view
This is a related CI failure because of lacking C++ ranges library
support:
https://ci.libreoffice.org/job/gerrit_master_ml/35822/
More details about C++20 support from different compilers can be seen
here:
C++20 library features
https://en.cppreference.com/w/cpp/compiler_support#C.2B.2B20_library_features
Looking into the details of clang releases, I think clang versions
until and including 17 are no longer supported.
https://llvm.org/docs/HowToReleaseLLVM.html
The current stable release is 19, an the preview release is 20.
https://releases.llvm.org/
I am not sure about 18, but it is the version available in many Linux
distributions, and it seems to build LibreOffice from sources smoothly.
Ubuntu LTS: 20.04, 24.04, 22.04 (via llvm apt repository), RHEL 8 and 9
(via Clang and LLVM Toolset) and many other distributions:
https://packages.ubuntu.com/search?searchon=contents&keywords=clang&mode=exactfilename&suite=focal-updates&arch=any
https://packages.ubuntu.com/search?searchon=contents&keywords=clang&mode=exactfilename&suite=noble-updates&arch=any
Is it possible upgrade clang on CI machines to version 18 (or possibly,
19)?
Regards,
Hossein
--
Hossein Nourikhah, Ph.D., Developer Community Architect
Tel: +49 30 5557992-65 | Email: hossein@xxxxxxxxxxxxxxx
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