Package manager support and Enterprise Linux

[viniciusferrao]

Hi @zauguin would it be viable to add some package manager support to the software? Since i18n-cpp requires the clang plugin, we need to compile it, and it's a tiresome issue on Enterprise Linux (RHEL) for instance.

On EL8 the latest available fmtlib available is 6.2.1-1.el8, which is kinda old now and it's needed by the clang plugin.

Also in this matter, can i18n-cpp as a library be added to something like Conan? I'm mentioning Conan because it's what I'm using, I don't have any opinion on that, just using because it's readily available on cpp_starter_project

I've spend the last two days trying to make the library happy with RHEL8. Right now I'm able to add the library on my code and it compiles with gcc-toolset-11, just for the updated libstdc++, and llvm-toolset which provides clang on version 12.

Thank you.

[zauguin]

On EL8 the latest available fmtlib available is 6.2.1-1.el8, which is kinda old now and it's needed by the clang plugin.

The joy of "enterprise" software... Does the plugin compile with fmtlib 6.2.1 or is there something which depends on a newer version?

[viniciusferrao]

I haven't bothered trying with 6.2.1 due to the fact that I would like to use the constexpr and consteval features that only fmt/8.0.0 provides.

But I'll try it right now with system's fmt. It's actually not even available on RHEL, we need to use EPEL, which is unsupported, to have fmt-6.2.1-1.el8.x86_64.

Anyway, while I was typing this, it failed:

[71/88] Building CXX object merge/CMakeFiles/i18n-merge-pot.dir/merge.cpp.o
FAILED: merge/CMakeFiles/i18n-merge-pot.dir/merge.cpp.o 
/usr/lib64/ccache/clang++ -DFMT_LOCALE -DFMT_SHARED  -std=c++20 -MD -MT merge/CMakeFiles/i18n-merge-pot.dir/merge.cpp.o -MF merge/CMakeFiles/i18n-merge-pot.dir/merge.cpp.o.d -o merge/CMakeFiles/i18n-merge-pot.dir/merge.cpp.o -c ../merge/merge.cpp
../merge/merge.cpp:15:10: error: no type named 'strong_ordering' in namespace 'std'
    std::strong_ordering order = a.context <=> b.context;
    ~~~~~^
../merge/merge.cpp:26:10: error: no type named 'strong_ordering' in namespace 'std'
    std::strong_ordering order = a.extractedComments <=> b.extractedComments;
    ~~~~~^

It seems that std::strong_ordering is not available. I'll check why and report back. That's probably due to the fact the RHEL8 always tries to load the old and obsolete libstdc++-8.5.0-4.el8_5.x86_64.

[viniciusferrao]

Definitely it's the libstdc++-8.5.0-4.el8_5.x86_64 issue. I've added the following code block to trick clang to get a newer libstdc++ on CMakeLists.txt and I was able to compile, although not able to link due to Boost issues.

# Enterprise Linux (EL) detection code, we may find el2 to el9 kernels.
if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
    string (REGEX MATCH "\\el[2-9]" os_version_suffix ${CMAKE_SYSTEM})
endif()

add_library(project_options INTERFACE)
if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
	if(${os_version_suffix} MATCHES "el8")
		if(CMAKE_CXX_COMPILER_ID MATCHES ".*Clang")
			include_directories(SYSTEM
				/opt/rh/gcc-toolset-11/root/usr/include/c++/11
				/opt/rh/gcc-toolset-11/root/usr/include/c++/11/x86_64-redhat-linux)
			target_compile_options(project_options INTERFACE -nostdinc++)
		        link_directories(/opt/rh/gcc-toolset-11/root/usr/lib/gcc/x86_64-redhat-linux/11)
		endif()
	endif()
endif()

Linking failed due to undefined reference to boost::system::generic_category()':

[76/88] Linking CXX executable merge/i18n-merge-pot
FAILED: merge/i18n-merge-pot 
: && /usr/lib64/ccache/clang++   merge/CMakeFiles/i18n-merge-pot.dir/main.cpp.o merge/CMakeFiles/i18n-merge-pot.dir/messages.cpp.o merge/CMakeFiles/i18n-merge-pot.dir/__/common/write_po.cpp.o merge/CMakeFiles/i18n-merge-pot.dir/merge.cpp.o -o merge/i18n-merge-pot -L/opt/rh/gcc-toolset-11/root/usr/lib/gcc/x86_64-redhat-linux/11 -Wl,-rpath,/opt/rh/gcc-toolset-11/root/usr/lib/gcc/x86_64-redhat-linux/11:  /usr/lib64/libfmt.so.6.2.1  -Wl,--as-needed && :
merge/CMakeFiles/i18n-merge-pot.dir/main.cpp.o: In function `boost::system::error_category::std_category::equivalent(int, std::error_condition const&) const':
main.cpp:(.text._ZNK5boost6system14error_category12std_category10equivalentEiRKSt15error_condition[_ZNK5boost6system14error_category12std_category10equivalentEiRKSt15error_condition]+0xaf): undefined reference to `boost::system::generic_category()'
main.cpp:(.text._ZNK5boost6system14error_category12std_category10equivalentEiRKSt15error_condition[_ZNK5boost6system14error_category12std_category10equivalentEiRKSt15error_condition]+0xe4): undefined reference to `boost::system::generic_category()'
merge/CMakeFiles/i18n-merge-pot.dir/main.cpp.o: In function `boost::system::error_category::std_category::equivalent(std::error_code const&, int) const':
main.cpp:(.text._ZNK5boost6system14error_category12std_category10equivalentERKSt10error_codei[_ZNK5boost6system14error_category12std_category10equivalentERKSt10error_codei]+0xaf): undefined reference to `boost::system::generic_category()'
main.cpp:(.text._ZNK5boost6system14error_category12std_category10equivalentERKSt10error_codei[_ZNK5boost6system14error_category12std_category10equivalentERKSt10error_codei]+0xe1): undefined reference to `boost::system::generic_category()'
main.cpp:(.text._ZNK5boost6system14error_category12std_category10equivalentERKSt10error_codei[_ZNK5boost6system14error_category12std_category10equivalentERKSt10error_codei]+0x1c6): undefined reference to `boost::system::generic_category()'
merge/CMakeFiles/i18n-merge-pot.dir/main.cpp.o: In function `bool boost::spirit::x3::rule<client::parser::message_class, client::ast::Message, false>::parse<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::x3::context<boost::spirit::x3::error_handler_tag, std::reference_wrapper<boost::spirit::x3::error_handler<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::ascii, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> >, client::ast::Message>(__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >&, __gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, boost::spirit::x3::context<boost::spirit::x3::error_handler_tag, std::reference_wrapper<boost::spirit::x3::error_handler<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::ascii, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > const&, boost::spirit::x3::unused_type, client::ast::Message&) const':
main.cpp:(.text._ZNK5boost6spirit2x34ruleIN6client6parser13message_classENS3_3ast7MessageELb0EE5parseIN9__gnu_cxx17__normal_iteratorIPKcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEENS1_7contextINS1_17error_handler_tagEKSt17reference_wrapperINS1_13error_handlerISK_EEENSL_INS1_11skipper_tagEKNS1_10char_classINS0_13char_encoding5asciiENS1_9space_tagEEENS1_11unused_typeEEEEES7_EEbRT_RKS12_RKT0_SZ_RT1_[_ZNK5boost6spirit2x34ruleIN6client6parser13message_classENS3_3ast7MessageELb0EE5parseIN9__gnu_cxx17__normal_iteratorIPKcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEENS1_7contextINS1_17error_handler_tagEKSt17reference_wrapperINS1_13error_handlerISK_EEENSL_INS1_11skipper_tagEKNS1_10char_classINS0_13char_encoding5asciiENS1_9space_tagEEENS1_11unused_typeEEEEES7_EEbRT_RKS12_RKT0_SZ_RT1_]+0x3c): undefined reference to `bool client::parser::parse_rule<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::x3::context<boost::spirit::x3::error_handler_tag, std::reference_wrapper<boost::spirit::x3::error_handler<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::ascii, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> >, client::ast::Message>(boost::spirit::x3::rule<client::parser::message_class, client::ast::Message, false>, __gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >&, __gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, boost::spirit::x3::context<boost::spirit::x3::error_handler_tag, std::reference_wrapper<boost::spirit::x3::error_handler<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::ascii, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > const&, client::ast::Message&)'
clang-12: error: linker command failed with exit code 1 (use -v to see invocation)

I have no idea why the linking failed. Perhaps it's not available on the new toolchain, I don't know.

[zauguin]

Also in this matter, can i18n-cpp as a library be added to something like Conan?

I personally never used Conan and barely used any similar system, but I p;anned to learn Conan at some point. So generally I think that it's a good idea, but I don't know how easy it is to implement. (It's probably relatively easy to set up as long as it's not required to deal with the plugin. But even than it might be useful since for projects with multiple developers only one of them needs to create the pot file.)

[zauguin]

@viniciusferrao In the conan branch I tried adding a conanfile.txt to automatically handle at least some of the dependencies (mostly fmt and boost, clang itself isn't available on conan and in order for the plugin to work it has to link against the local version anyway. Maybe that helps a bit.