4

I can't get my g++ to compile and link a minimal boost co-routine program (and I guess other components as well) on my machine.

// example.cpp

#include <boost/coroutine/all.hpp>
#include <iostream>
using namespace boost::coroutines;

void mycorofunc(coroutine<void>::push_type &sink){
  std::cout << "1";
  sink();
  std::cout << " 3";
}

int main() {
  coroutine<void>::pull_type source{mycorofunc};
  std::cout << " 2";
  source();
  std::cout << " 4!" << std::endl;
}

I used apt-get to install boost (libboost-all-dev), but neither 

g++ example.cpp -lboost_coroutine -lboost_system

nor

g++ example.cpp -I/usr/include -L/usr/lib/x86_64-linux-gnu -lboost_coroutine -lboost_system

works. g++'s output is as follows:

In file included from /usr/include/boost/coroutine/v1/coroutine.hpp:19:0,
                 from /usr/include/boost/coroutine/coroutine.hpp:13,
                 from /usr/include/boost/coroutine/all.hpp:11,
                 from example.cpp:3:
/usr/include/boost/type_traits/function_traits.hpp: In instantiation of ‘struct boost::function_traits<void>’:
example.cpp:7:31:   required from here
/usr/include/boost/type_traits/function_traits.hpp:168:8: error: invalid use of incomplete type ‘struct boost::detail::function_traits_helper<void*>’
 struct function_traits : 
        ^
/usr/include/boost/type_traits/function_traits.hpp:21:36: error: declaration of ‘struct boost::detail::function_traits_helper<void*>’
 template<typename Function> struct function_traits_helper;
                                    ^
example.cpp:7:31: error: ‘arity’ is not a member of ‘boost::function_traits<void>’
 void mycorofunc(coroutine<void>::push_type &sink){
                               ^
example.cpp:7:31: error: template argument 2 is invalid
example.cpp:7:44: error: expected ‘,’ or ‘...’ before ‘&amp;’ token
 void mycorofunc(coroutine<void>::push_type &sink){
                                            ^
example.cpp: In function ‘void mycorofunc(int)’:
example.cpp:9:8: error: ‘sink’ was not declared in this scope
   sink();
        ^
example.cpp: In function ‘int main()’:
example.cpp:14:17: error: ‘arity’ is not a member of ‘boost::function_traits<void>’
   coroutine<void>::pull_type source{mycorofunc};
                 ^
example.cpp:14:17: error: template argument 2 is invalid
example.cpp:14:30: error: expected initializer before ‘source’
   coroutine<void>::pull_type source{mycorofunc};
                              ^
example.cpp:16:10: error: ‘source’ was not declared in this scope
   source();

Some more information about my environment:

$$ locate coroutine/all.hpp
/usr/include/boost/coroutine/all.hpp
/usr/local/boost_1_58_0/boost/coroutine/all.hpp

$$ locate boost_system
/usr/lib/x86_64-linux-gnu/libboost_system.a
/usr/lib/x86_64-linux-gnu/libboost_system.so
/usr/lib/x86_64-linux-gnu/libboost_system.so.1.54.0

$$ locate boost_coroutine
/usr/lib/x86_64-linux-gnu/libboost_coroutine.a

$$ g++ -E -x c++ - -v < /dev/null  # printing g++ include path 
Using built-in specs.
COLLECT_GCC=g++
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.2-19ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) 
COLLECT_GCC_OPTIONS='-E' '-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/4.8/cc1plus -E -quiet -v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE - -mtune=generic -march=x86-64 -fstack-protector -Wformat -Wformat-security
ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/4.8"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.8
 /usr/include/x86_64-linux-gnu/c++/4.8
 /usr/include/c++/4.8/backward
 /usr/lib/gcc/x86_64-linux-gnu/4.8/include
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
# 1 "<stdin>"
# 1 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 1 "<command-line>" 2
# 1 "<stdin>"
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-E' '-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'

Compiler: have tried both g++ (v. 4.8.2) and g++-5

Distro: Ubuntu 14.04.1 LTS

4

1 回答 1

4

After days of debugging, this is the solution I found. It is possible that even a subset of the following instructions is equally enough to go about the problem.

Quick instructions without much detail

Perform the following instructions:

  1. Install g++-6 (any version newer than 5.2 which supports c++14 will most likely work as well, though I have not tested them).
  2. Install boost 1.58 or newer (support for coroutine2). As of the date of this post, the latest version available in Ubuntu PPA is 1.54. Therefore, you need to manually install boost. If you do not know how, follow this link.
  3. Run your program using -std=c++14 flag. Also, if you are working with coroutines like me, make sure to link against libboost_context. I have noticed that for coroutines 2, libboost_system is not needed, perhaps because it is automally pulled in by libboost_context, though I'm not sure about the reason.
  4. Make sure that you link against your newly installed boost libraries, and not the old one. See this SO question to see what might go wrong. In my case, I had to delete all the previously installed boost from my machines.

To put these points together, here's the command I used to compile and link my code (let's say I install boost in /usr/local/):

g++-6 -std=c++14 example.cpp -I/usr/local/include -L/usr/local/lib -lboost_coroutine -lboost_context -lboost_system

More details

Apparently, boost.coroutine library in boost 1.54 is implemented with the deprecated C-like fcontext-API from boost.context [source]. I have noticed that my machine had problem compiling those parts. Unfortunately, Ubuntu PPA does not offer any newer version than 1.54 at this moment. Boost.coroutine2 is the recommended library to use, which can be found in version 1.59 or newer. Therefore, you need to manually download a suitable version of boost from its website and install it.

After doing so, my code successfully compilied, but not linked:

... undefined reference to `ontop_fcontext'  `boost::context::basic_fixedsize_stack<boost::context::stack_traits>::deallocate(boost::context::stack_context&)':
example.cpp:(...): undefined reference to `boost::context::stack_traits::minimum_size()'
example.cpp:(...): undefined reference to `boost::context::stack_traits::is_unbounded()'
example.cpp:(...): undefined reference to `boost::context::stack_traits::maximum_size()'

Surprisingly, adding -lboost_context flag to the compile command did not remove this link error, suggesting that libboost_context is not properly linked against.

I then came across a question in boost forum wherein the original poster had somewhat similar problem to what I had. In short, there are a number of C macros that prevent execution_context to be properly included, and thus the problem with libboost_context. The code to know if your compiler has some of these macros enabled is as follows (I'm not sure if all of these macros are relevant): 

#include <boost/config.hpp> 

#if defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) || \
     defined(BOOST_NO_CXX11_CONSTEXPR) || \
     defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) || \
     defined(BOOST_NO_CXX11_FINAL) || \
     defined(BOOST_NO_CXX11_HDR_TUPLE) || \
     defined(BOOST_NO_CXX11_NOEXCEPT) || \
     defined(BOOST_NO_CXX11_NULLPTR) || \
     defined(BOOST_NO_CXX11_RVALUE_REFERENCES) || \
     defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) || \
     defined(BOOST_NO_CXX11_UNIFIED_INITIALISATION_SYNTAX) || \
     defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || \
     defined(BOOST_NO_HDR_ATOMIC) || \
     defined(BOOST_NO_HDR_TUPLE)
#error "execution_context is prevented to be included in this compiler"; 
#endif

The solution is easy: installing g++-6 (or I guess 5.2 or newer), and compiling the code with std=-c++14.

于 2017-01-02T15:12:07.340 回答