curlpp 链接错误

Question

I wrote a c++ program and try to use curlpp to access a http server securely over SSL . The problem is, that I can't link the program.

Operating system: Ubuntu 15.10

Errors:

/usr/bin/cmake -E cmake_link_script CMakeFiles/prtg_probe.dir/link.txt --verbose=1 Wird gelinkt prtg_probe (c++) CMakeFiles/prtg_probe.dir/probe.cpp.o: In function curlpp::internal::OptionContainer, std::allocator >, std::allocator, std::allocator > > >

::OptionContainer(std::__cxx11::list, std::allocator >, std::allocator, std::allocator > > > const&)': /usr/include/curlpp/internal/OptionContainer.inl:38: undefined reference to curlpp::internal::SList::SList(std::__cxx11::list, std::allocator >, std::allocator, std::allocator > > > const&)' CMakeFiles/prtg_probe.dir/probe.cpp.o: In function curlpp::internal::OptionContainer, std::allocator >, std::allocator, std::allocator > > > ::setValue(std::__cxx11::list, std::allocator >, std::allocator, std::allocator > > > const&)': /usr/include/curlpp/internal/OptionContainer.inl:52: undefined reference to `curlpp::internal::SList::operator=(std::__cxx11::list, std::allocator >, std::allocator, std::allocator > > > const&)' ....

This is the code that produces the errors:

#include <iostream>
#include <sstream>
#include <string>
#include <cstring>
#include <cctype>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <fstream>
#include <cerrno>
#include <boost/bind.hpp>
#include <curlpp/cURLpp.hpp>
#include <curlpp/Easy.hpp>
#include <curlpp/Options.hpp>
#include <curlpp/Exception.hpp>

....

class myclass
{

....

try
{
    curlpp::Cleanup cleaner;
    curlpp::Easy request;
    ostringstream os;

    request.setOpt(new curlpp::options::Url(&url_announce[0]));
    request.setOpt(new curlpp::options::SslEngineDefault());
    list<string> header;
    header.push_back("Content-Type: text/*");
    request.setOpt(new curlpp::options::HttpHeader(header));
    request.setOpt(new curlpp::options::PostFields(data_announce));
    request.setOpt(new curlpp::options::PostFieldSize((long)data_announce.length()));
    request.setOpt(new curlpp::options::WriteStream(&os));
    request.perform();
    request_announce = os.str();
}
catch (curlpp::LogicError & e)
{
    syslog(LOG_DAEMON, "Error accessing PRTG server: %s", e.what());
}
catch (curlpp::RuntimeError & e)
{
    syslog(LOG_DAEMON, "Error accessing PRTG server: %s", e.what());
}

Every line with curlpp::options::... produces one error at link time. I've looked around and searched Google for hours now, but all I found was to link libcurl together with libcurl. I do that, but still get this errors.

Here is the complete link line:

/usr/bin/c++   -g    CMakeFiles/prtg_probe.dir/sensors.cpp.o 
CMakeFiles/prtg_probe.dir/mini_probe.cpp.o CMakeFiles/prtg_probe.dir/probe.cpp.o
CMakeFiles/prtg_probe.dir/helper.cpp.o 
CMakeFiles/prtg_probe.dir/config.cpp.o CMakeFiles/prtg_probe.dir/main.cpp.o
-o prtg_probe -rdynamic -lm -lpthread -lcrypto -lssl -lcurlpp -lcurl -lboost_system -lboost_filesystem -ljsoncpp -luuid

Does anybody know what I'm missing? Do I have to add one more library and if yes which one?

---

I've tried to compile the example00.cpp with the following command:

g++ -o example00 example00.cpp -lm -lcurl -lcurlpp

and the result:

/tmp/cc3pcvDc.o: In Funktion `curlpp::OptionTrait<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, (CURLoption)10002>::updateHandleToMe(curlpp::internal::CurlHandle*) const':
example00.cpp: (.text._ZNK6curlpp11OptionTraitINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEL10CURLoption10002EE16updateHandleToMeEPNS_8internal10CurlHandleE[_ZNK6curlpp11OptionTraitINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEL10CURLoption10002EE16updateHandleToMeEPNS_8internal10CurlHandleE]+0x68):
Nicht definierter Verweis auf `curlpp::UnsetOption::UnsetOption(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/tmp/cc3pcvDc.o: In Funktion `curlpp::Option<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::getValue() const':
example00.cpp: (.text._ZNK6curlpp6OptionINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEE8getValueEv[_ZNK6curlpp6OptionINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEE8getValueEv]+0x68):
Nicht definierter Verweis auf `curlpp::UnsetOption::UnsetOption(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
collect2: error: ld returned 1 exit status

This looks like the same problem to me.

Answer 1

The problem is that linkage of ccurlcpp::UnsetOption::UnsetOption is partially defective in the lipcurlcpp.so binary.

The linker's complaint with:

g++ -o example00 example00.cpp -lm -lcurl -lcurlpp

is:

undefined reference to `curlpp::UnsetOption::UnsetOption(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'

But if I demangle the constructor signatures in libcurlpp.so :

nm -D -C libcurlpp.so | grep UnsetOption::UnsetOption

I see:

0000000000021776 T curlpp::UnsetOption::UnsetOption(char const*)
000000000002173e T curlpp::UnsetOption::UnsetOption(std::string const&)

The std::string hasn't been properly de-typedefed for some reason. If I get the source file in which this constructor is defined from the curlpp 0.7.3 source package, Exception.cpp , compile it:

curlpp-0.7.3/src/curlpp$ g++ -I../../include -I. -c Exception.cpp

and then demangle the constructor signatures from the object file:

nm -C Exception.o | grep UnsetOption::UnsetOption

I get:

00000000000003f4 T curlpp::UnsetOption::UnsetOption(char const*)
00000000000003c2 T curlpp::UnsetOption::UnsetOption(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)

So:

curlpp::UnsetOption::UnsetOption(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)

is the signature the compiler is telling the linker to look for, but that is not the signature in the library. The short explanation of the error is: the library is broken.

However, we see that no such inconsistency affects the other overload of the constructor:

curlpp::UnsetOption::UnsetOption(char const*)

nor could it, since the char const * is a builtin type.

This enables a hack fix. The file in which the undefined-reference call is compiled is (as installed) /usr/include/curlpp/Option.inl , at the line:

throw UnsetOption(std::string("You are trying to set an unset option to a handle"));

Edit this file, as root, and you see that it (inconsistently) contains two instances of:

throw UnsetOption(std::string("blah blah"));

and one instance of:

throw UnsetOption("blah blah");

Change the occurrences of UnsetOption(std::string("blah blah")) to UnsetOption("blah blah") . Then only the good constructor is called in this file and example00 , at least, will compile and link.

If you dislike the hack, or find that the problem re-surfaces elsewhere, then you may download the ubuntu source package curlpp_0.7.3.orig.tar.gz and build and install it yourself. That is the right remedy.

Answer 2

You can try to compile your project using old ABI:
g++ -o example00 example00.cpp -D_GLIBCXX_USE_CXX11_ABI=0 -lm -lcurl -lcurlpp

Answer 3

For me the following worked on Ubuntu 18.04:

apt-get install libcurl4-openssl-dev
apt-get install libcurlpp-dev

Cmake:

...
add_executable(HTTPPostTest HTTPPostTest.cpp)
TARGET_LINK_LIBRARIES(HTTPPostTest -lcurl -lcurlpp stdc++fs )
...

HTTPPostTest.cpp:

#include <curlpp/cURLpp.hpp>
#include <curlpp/Easy.hpp>
#include <curlpp/Options.hpp>
#include <curlpp/Exception.hpp>

int main(int argc, char *argv[]) {
    try {
        curlpp::Cleanup cleaner;
        curlpp::Easy request;
        request.setOpt(new curlpp::options::Url("https://postman-echo.com/post"));
        request.setOpt(new curlpp::options::Verbose(true));
        std::list<std::string> header;
        header.push_back("Content-Type: application/octet-stream");
        request.setOpt(new curlpp::options::HttpHeader(header));
        request.setOpt(new curlpp::options::PostFields("abcd"));
        request.setOpt(new curlpp::options::PostFieldSize(5));
        request.perform();
    } catch ( curlpp::LogicError & e ) {
        std::cout << e.what() << std::endl;
    } catch ( curlpp::RuntimeError & e ) {
        std::cout << e.what() << std::endl;
    }
    return EXIT_SUCCESS;
}