Proper way to compile a project

[CybersShell]

Hi,

I am getting errors compiling a sample file, using some of the code in the examples. I am using https://github.com/karastojko/mailio/blob/master/examples/smtps_simple_msg.cpp as a test, using my own mail server.

• OS: Debian Bullseye
• Boost version: 1.74 from the Debian repos
• Compile command: clang++-15 -std=c++17 mail.cpp -o mail
• also tried with g++

Got this error:

/usr/bin/ld: /tmp/mail-7b0f79.o: in function `main':
mail.cpp:(.text+0xcc): undefined reference to `mailio::message::message()'
/usr/bin/ld: mail.cpp:(.text+0x11a): undefined reference to `mailio::mail_address::mail_address(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: mail.cpp:(.text+0x132): undefined reference to `mailio::message::from(mailio::mail_address const&)'
/usr/bin/ld: mail.cpp:(.text+0x1a4): undefined reference to `mailio::mail_address::mail_address(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: mail.cpp:(.text+0x1bc): undefined reference to `mailio::message::add_recipient(mailio::mail_address const&)'
/usr/bin/ld: mail.cpp:(.text+0x22a): undefined reference to `mailio::message::subject(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: mail.cpp:(.text+0x28c): undefined reference to `mailio::mime::content(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: mail.cpp:(.text+0x2e7): undefined reference to `mailio::smtps::smtps(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned int, std::chrono::duration<long, std::ratio<1l, 1000l> >)'
/usr/bin/ld: mail.cpp:(.text+0x310): undefined reference to `mailio::smtps::authenticate(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, mailio::smtps::auth_method_t)'
/usr/bin/ld: mail.cpp:(.text+0x33b): undefined reference to `mailio::smtp::submit[abi:cxx11](mailio::message const&)'
/usr/bin/ld: /tmp/mail-7b0f79.o: in function `mailio::smtps::~smtps()':
mail.cpp:(.text._ZN6mailio5smtpsD2Ev[_ZN6mailio5smtpsD2Ev]+0x11): undefined reference to `mailio::smtp::~smtp()'
/usr/bin/ld: /tmp/mail-7b0f79.o: in function `mailio::message::~message()':
mail.cpp:(.text._ZN6mailio7messageD2Ev[_ZN6mailio7messageD2Ev]+0x17): undefined reference to `vtable for mailio::message'
/usr/bin/ld: /tmp/mail-7b0f79.o: in function `boost::asio::error::detail::ssl_category::message[abi:cxx11](int) const':
mail.cpp:(.text._ZNK5boost4asio5error6detail12ssl_category7messageB5cxx11Ei[_ZNK5boost4asio5error6detail12ssl_category7messageB5cxx11Ei]+0x23): undefined reference to `ERR_reason_error_string'
/usr/bin/ld: /tmp/mail-7b0f79.o: in function `mailio::mime::~mime()':
mail.cpp:(.text._ZN6mailio4mimeD2Ev[_ZN6mailio4mimeD2Ev]+0x17): undefined reference to `vtable for mailio::mime'
/usr/bin/ld: /tmp/mail-7b0f79.o: in function `boost::asio::ssl::detail::openssl_init_base::do_init::~do_init()':
mail.cpp:(.text._ZN5boost4asio3ssl6detail17openssl_init_base7do_initD2Ev[_ZN5boost4asio3ssl6detail17openssl_init_base7do_initD2Ev]+0x12): undefined reference to `CONF_modules_unload'
clang: error: linker command failed with exit code 1 (use -v to see invocation)

[karastojko]

Try something like:

g++ -std=c++17 -I ./include/ -I /opt/boost-1.75.0/include/ -L ./build/ -L /opt/boost-1.75.0/lib/ -L /usr/lib/x86_64-linux-gnu/ test.cpp -o test -lboost_system -lboost_regex -lboost_date_time  -lpthread -lcrypto -lssl -lmailio

Adjust the paths according to your setup.

[CybersShell]

After running the above command I get the following error:

/usr/bin/ld: /usr/local/lib/libmailio.a(dialog.cpp.o): undefined reference to symbol 'pthread_condattr_setclock@@GLIBC_2.3.3'
/usr/bin/ld: /usr/lib/x86_64-linux-gnu//libpthread.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

It is weird because I am including the -lpthread link in the g++ command. I have tried solutions mentioned in this thread https://stackoverflow.com/questions/19901934/libpthread-so-0-error-adding-symbols-dso-missing-from-command-line, but no joy so far.

[karastojko]

I believe you are mixing the static library libmailio.a together with the shared pthread library. Can you build the shared library version libmailio.so and try again?

[CybersShell]

I am closing this issue as I am moving on to Go because I want to create a web mail app.

Also, the README should be updated, specifically this line in the CMAKE section:

Other available options are MAILIO_BUILD_SHARED_LIBRARY (by default is on, if turned off then the static library is built)...

This conflicts with the most recent commit https://github.com/karastojko/mailio/commit/c1d4d2f78bc158045790385471e9ea5fb38fc490.