Fix build errors due to missing dependency stdc++fs

[mbrunnen]

I had errors when linking:

[ 67%] Linking CXX executable inkcpp_cl
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `test_directory(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
test.cpp:(.text+0x12c7): undefined reference to `std::filesystem::__cxx11::directory_iterator::operator*() const'
/usr/bin/ld: test.cpp:(.text+0x13d2): undefined reference to `std::filesystem::__cxx11::directory_iterator::operator++()'
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `std::filesystem::__cxx11::path::path(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&&, std::filesystem::__cxx11::path::format)':
test.cpp:(.text._ZNSt10filesystem7__cxx114pathC2EONSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEENS1_6formatE[_ZNSt10filesystem7__cxx114pathC5EONSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEENS1_6formatE]+0x4f): undefined reference to `std::filesystem::__cxx11::path::_M_split_cmpts()'
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `std::filesystem::__cxx11::operator==(std::filesystem::__cxx11::path const&, std::filesystem::__cxx11::path const&)':
test.cpp:(.text._ZNSt10filesystem7__cxx11eqERKNS0_4pathES3_[_ZNSt10filesystem7__cxx11eqERKNS0_4pathES3_]+0x1f): undefined reference to `std::filesystem::__cxx11::path::compare(std::filesystem::__cxx11::path const&) const'
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `std::filesystem::__cxx11::path::extension() const':
test.cpp:(.text._ZNKSt10filesystem7__cxx114path9extensionEv[_ZNKSt10filesystem7__cxx114path9extensionEv]+0x19): undefined reference to `std::filesystem::__cxx11::path::_M_find_extension() const'
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `std::filesystem::__cxx11::directory_iterator::directory_iterator(std::filesystem::__cxx11::path const&)':
test.cpp:(.text._ZNSt10filesystem7__cxx1118directory_iteratorC2ERKNS0_4pathE[_ZNSt10filesystem7__cxx1118directory_iteratorC5ERKNS0_4pathE]+0x26): undefined reference to `std::filesystem::__cxx11::directory_iterator::directory_iterator(std::filesystem::__cxx11::path const&, std::filesystem::directory_options, std::error_code*)'
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `std::filesystem::__cxx11::path::path<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::filesystem::__cxx11::path>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::filesystem::__cxx11::path::format)':
test.cpp:(.text._ZNSt10filesystem7__cxx114pathC2INSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES1_EERKT_NS1_6formatE[_ZNSt10filesystem7__cxx114pathC5INSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES1_EERKT_NS1_6formatE]+0x64): undefined reference to `std::filesystem::__cxx11::path::_M_split_cmpts()'
/usr/bin/ld: CMakeFiles/inkcpp_cl.dir/test.cpp.o: in function `std::filesystem::__cxx11::path::path<char [5], std::filesystem::__cxx11::path>(char const (&) [5], std::filesystem::__cxx11::path::format)':
test.cpp:(.text._ZNSt10filesystem7__cxx114pathC2IA5_cS1_EERKT_NS1_6formatE[_ZNSt10filesystem7__cxx114pathC5IA5_cS1_EERKT_NS1_6formatE]+0x5e): undefined reference to `std::filesystem::__cxx11::path::_M_split_cmpts()'
collect2: error: ld returned 1 exit status
make[2]: *** [inkcpp_cl/CMakeFiles/inkcpp_cl.dir/build.make:101: inkcpp_cl/inkcpp_cl] Error 1
make[1]: *** [CMakeFiles/Makefile2:254: inkcpp_cl/CMakeFiles/inkcpp_cl.dir/all] Error 2
make: *** [Makefile:141: all] Error 2

My compiler:

Using built-in specs.
COLLECT_GCC=c++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 8.3.0-6' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-8 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 8.3.0 (Debian 8.3.0-6)

Adding stdc++fs as library solved the issue.

[JBenda]

Thanks, we some how never spotted it.
Which compiler was you using?

[mbrunnen]

Thanks, we some how never spotted it.
Which compiler was you using?

Strange. I am using GCC 8.3.0:

Package: gcc
Version: 4:8.3.0-1
Priority: optional
Build-Essential: yes
Section: devel
Source: gcc-defaults (1.181)
Maintainer: Debian GCC Maintainers <[email protected]>
Installed-Size: 46.1 kB
Provides: c-compiler, gcc-x86-64-linux-gnu (= 4:8.3.0-1)
Depends: cpp (= 4:8.3.0-1), gcc-8 (>= 8.3.0-1~)
Recommends: libc6-dev | libc-dev
Suggests: gcc-multilib, make, manpages-dev, autoconf, automake, libtool, flex, bison, gdb, gcc-doc
Conflicts: gcc-doc (<< 1:2.95.3)
Tag: devel::compiler, devel::lang:c, devel::library, implemented-in::c,
 interface::commandline, role::devel-lib, role::metapackage,
 role::program, suite::gnu, works-with::software:source
Download-Size: 5,196 B
APT-Manual-Installed: yes
APT-Sources: http://deb.debian.org/debian buster/main amd64 Packages
Description: GNU C compiler
 This is the GNU C compiler, a fairly portable optimizing compiler for C.
 .
 This is a dependency package providing the default GNU C compiler.

[mbrunnen]

Ok, I looked a bit into it and found this:

https://en.cppreference.com/w/cpp/filesystem#Notes:

Notes
Using this library may require additional compiler/linker options. GNU implementation prior to 9.1 requires linking with -lstdc++fs and LLVM implementation prior to LLVM 9.0 requires linking with -lc++fs.

So, requiring a minimum compiler version in cmake would also do the trick.

[JBenda]

Looks good, thank you for the research.
But why the different between public/private for GNU and clang?

[JBenda]

Thanks for the PR.
If you have questions or ideas feel free to contact me. Or look in the c-port channel of the inkle Discord