2

After upgrading from Ubuntu 18.04 with clang/lld 7 and boost 1.65 to 20.04 with clang/lld 10 and boost 1.71, I have encountered a linker errors that I don't know how to address. Is clang & boost on Ubuntu 20.04 known to be an incompatible pair? What are my options to get things compiling on Ubuntu 20.04 using clang?

The minimal example of the error is

#include <boost/thread/shared_mutex.hpp>
int main() {
  boost::shared_mutex sm;
}

Notes:

  • It works just fine with GCC 9 and gold linker.
  • The clang + gold linker combo fails with very much the same error message and bfd linker fails with a very short one which I'll show the output for below as well.
  • The same errors occur with clang/lld 9 instead of 10.

I have created a minimal example that can easily be reproduced in a ubuntu 20.04 system or container, for my reproduction I used the plain ubuntu:focal container from dockerhub.

  1. Install clang/lld 10 and boost 1.71
apt update && apt install clang lld libboost-thread-dev
update-alternatives --install "/usr/bin/ld" "ld" "/usr/bin/ld.lld-10" 30

Now all requirements are installed and LLD is the default linker.

  1. create minimal example and compile/link it
root@d66452260792:/# cat x.cpp 
#include <boost/thread/shared_mutex.hpp>
int main() {
  boost::shared_mutex sm;
}

root@d66452260792:/# clang -lboost_thread x.cpp
  1. Expected result:
successful compilation
  1. Actual result
  • with BFD linker (GNU ld 2.34):
/usr/bin/ld: /tmp/x-a145e4.o: undefined reference to symbol '_ZTVN10__cxxabiv121__vmi_class_type_infoE@@CXXABI_1.3'
/usr/bin/ld: /lib/x86_64-linux-gnu/libstdc++.so.6: error adding symbols: DSO missing from command line
clang: error: linker command failed with exit code 1 (use -v to see invocation)
  • with LLD 10 as linker (but gold linker errors looks very similar):
ld: error: undefined symbol: std::allocator<char>::allocator()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::generic_error_category_message[abi:cxx11](int))

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::generic_error_category_message[abi:cxx11](int))

ld: error: undefined symbol: std::allocator<char>::~allocator()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::generic_error_category_message[abi:cxx11](int))
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::generic_error_category_message[abi:cxx11](int))

ld: error: undefined symbol: std::_V2::generic_category()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(int, std::error_condition const&) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(std::error_code const&, int) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(std::error_code const&, int) const)

ld: error: undefined symbol: typeinfo for std::_V2::error_category
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(int, std::error_condition const&) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(std::error_code const&, int) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(typeinfo for boost::system::detail::std_category)

ld: error: undefined symbol: __dynamic_cast
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(int, std::error_condition const&) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::equivalent(std::error_code const&, int) const)

ld: error: undefined symbol: __cxa_begin_catch
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(__clang_call_terminate)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::error_category::message(int, char*, unsigned long) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(void std::_Rb_tree<boost::system::error_category const*, std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > >, std::_Select1st<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >, boost::system::detail::cat_ptr_less, std::allocator<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > > >::_M_construct_node<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >(std::_Rb_tree_node<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >*, std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > >&&))

ld: error: undefined symbol: std::terminate()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(__clang_call_terminate)

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::empty() const
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)

ld: error: undefined symbol: std::runtime_error::what() const
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator=(char const*)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator+=(char const*)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator+=(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::error_category::message(int, char*, unsigned long) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::~system_error())

ld: error: undefined symbol: __cxa_end_catch
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::error_category::message(int, char*, unsigned long) const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(void std::_Rb_tree<boost::system::error_category const*, std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > >, std::_Select1st<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >, boost::system::detail::cat_ptr_less, std::allocator<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > > >::_M_construct_node<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >(std::_Rb_tree_node<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >*, std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > >&&))

ld: error: undefined symbol: std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::c_str() const
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::what() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::error_category::message(int, char*, unsigned long) const)

ld: error: undefined symbol: std::_V2::error_category::~error_category()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::~std_category())

ld: error: undefined symbol: operator delete(void*)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::std_category::~std_category())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::~system_error())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::to_std_category(boost::system::error_category const&))
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > > >::deallocate(std::_Rb_tree_node<std::pair<boost::system::error_category const* const, std::unique_ptr<boost::system::detail::std_category, std::default_delete<boost::system::detail::std_category> > > >*, unsigned long))
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::exception_detail::error_info_injector<boost::thread_resource_error>::~error_info_injector())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::thread_resource_error::~thread_resource_error())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::thread_exception::~thread_exception())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::thread_resource_error> >::~clone_impl())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::thread_resource_error> >::clone() const)
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::wrapexcept<boost::thread_resource_error>::~wrapexcept())

ld: error: undefined symbol: std::runtime_error::~runtime_error()
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::~system_error())
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::system_error::system_error(boost::system::system_error const&))

ld: error: undefined symbol: __cxa_guard_acquire
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::to_std_category(boost::system::error_category const&))
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::to_std_category(boost::system::error_category const&))
>>> referenced by x.cpp
>>>               /tmp/x-dd4c59.o:(boost::system::detail::to_std_category(boost::system::error_category const&))

ld: error: too many errors emitted, stopping now (use -error-limit=0 to see all errors)
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Severin Fichtl
  • 21
  • 4

1 Answers1

3

First of all, order matters when linking with libraries. Always put libraries last on the command line.

Secondly, boost_thread depends on the boost_system library (which should be listed before boost_thread).

Thirdly, the clang front-end program is for linking C programs, not C++. For C++ use clang++.

To use POSIX thread functionality on supported systems, one also needs to use the -pthread flag when building.

So to put it all together:

$ clang++ -pthread x.cpp -lboost_system -lboost_thread
Some programmer dude
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  • This does indeed change things, but it doesn't solve everything. I still get this: ```root@b3afdc7eb046:/# clang++ x.cpp -lboost_system -lboost_thread ld: error: undefined symbol: pthread_condattr_setclock >>> referenced by x.cpp >>> /tmp/x-9b1f30.o:(boost::condition_variable::condition_variable()) clang: error: linker command failed with exit code 1 (use -v to see invocation)``` – Severin Fichtl Apr 08 '21 at 08:45
  • @SeverinFichtl Updated, another flag needed when building – Some programmer dude Apr 08 '21 at 08:56