CGAL users discussion list

[Marc Glisse <>]

On Tue, 31 Jan 2017, Oren Shpigel wrote:

> Hi again,
> I tried compiling everything again with the correct flags, and I still get
> this error when linking my code to CGAL:
>
> # clang++-3.8 -o build/release/my_output_file -stdlib=libc++
> -lc++ my_code_stuff -lCGAL -lCGAL_Core -lprofiler -ltcmalloc -lgtest

Better put -lc++ much later in the command line, but clang already adds 
one anyway.

> -lpthread -lboost_date_time -lboost_filesystem -lcurl -ljson -lz
> -lboost_system -lprotobuf -lglog -lgflags -lblas -llapack
> //usr/local/lib/libCGAL.so: undefined reference to
> `std::__1::basic_istream<char, std::__1::char_traits<char>
> > ::operator>>(std::__1::basic_istream<char, std::__1::char_traits<char> >&
> (*)(std::__1::basic_istream<char, std::__1::char_traits<char> >&))'
> //usr/local/lib/libCGAL.so: undefined reference to
> `std::__1::basic_istream<char, std::__1::char_traits<char>
> > ::operator>>(std::__1::basic_istream<char, std::__1::char_traits<char> >&
> (*)(std::__1::basic_istream<char, std::__1::char_traits<char> >&))'
>
> When checking my CGAL's dependencies it looks good, no libstdc++ anywhere:
> # ldd -r /usr/local/lib/libCGAL.so
> linux-vdso.so.1 =>  (0x00007fff3f2ae000)
> libmpfr.so.4 => /usr/local/lib/libmpfr.so.4 (0x00007f77e491f000)
> libgmp.so.10 => /usr/local/lib/libgmp.so.10 (0x00007f77e46a9000)
> libboost_thread.so.1.55.0 => /usr/local/lib/libboost_thread.so.1.55.0
> (0x00007f77e448f000)
> libboost_system.so.1.55.0 => /usr/local/lib/libboost_system.so.1.55.0
> (0x00007f77e428b000)
> libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0
> (0x00007f77e406d000)
> libc++.so.1 => /usr/lib/libc++.so.1 (0x00007f77e3d15000)
> libc++abi.so.1 => /usr/lib/libc++abi.so.1 (0x00007f77e3aa0000)
> libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f77e379a000)
> libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f77e3584000)
> libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f77e31bf000)
> /lib64/ld-linux-x86-64.so.2 (0x00007f77e4da6000)
> librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f77e2fb7000)
> undefined symbol:
> _ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRS3_S4_E
> (/usr/local/lib/libCGAL.so)
>
> But again, also ldd says this same undefined symbol:
> # c++filt _ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRS3_S4_E
> std::__1::basic_istream<char, std::__1::char_traits<char>
> > ::operator>>(std::__1::basic_istream<char, std::__1::char_traits<char> >&
> (*)(std::__1::basic_istream<char, std::__1::char_traits<char> >&))

nm -D /usr/lib/x86_64-linux-gnu/libc++.so.1|grep 
_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRS3_S4_E
000000000009f784 W 
_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRS3_S4_E

This symbol is provided by libc++ here...

> Anyone has any idea about why it's missing? Or what is using it?
> Has anyone ever compiled CGAL 4.8 with clang 3.8 and libc++?

Just tried CGAL-4.9 with CXX='clang++-3.8 -stdlib=libc++' and it is 
working fine. I expect the issue is with your installation of clang or 
libc++, not with CGAL.

--
Marc Glisse