链接错误与curlpp

Question

我写了一个c ++程序,并尝试使用curlpp安全地访问http服务器SSL.问题是,我无法链接该程序.

操作系统:Ubuntu 15.10

错误:

/ 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:在函数curlpp :: internal :: OptionContainer中,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引用curlpp :: internal :: SList :: SList(std :: __ cxx11 :: list,std :: allocator>,std :: allocator,std :: allocator >>> const&)'CMakeFiles/prtg_probe.dir/probe. cpp.o:在函数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:对`curlpp :: internal :: SList :: operator =(std ::)的未定义引用__cxx11 :: list,std :: allocator>,std :: allocator,std :: allocator >>> const&)'....

这是产生错误的代码:

#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());
}

每一行都会curlpp::options::...在链接时产生一个错误.我环顾四周,搜索谷歌几个小时,但我发现只是将libcurl与libcurl链接在一起.我这样做,但仍然得到这个错误.

这是完整的链接:

/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

有人知道我错过了什么吗？我是否需要再添加一个库,如果是,那么哪一个？

---

我尝试使用以下命令编译example00.cpp:

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

结果:

/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

这看起来像我一样的问题.

Answer 1

问题是二进制中的链接ccurlcpp::UnsetOption::UnsetOption 部分有缺陷lipcurlcpp.so.

链接器的抱怨:

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

是:

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

但是如果我在libcurlpp.so以下位置解构构造函数签名:

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

我知道了:

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

由于std::string某种原因,没有正确地去除类型.如果我从curlpp 0.7.3源包中获取了定义此构造函数的源文件 Exception.cpp,请编译它:

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

然后从目标文件中解构构造函数签名:

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

我明白了:

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&)

所以:

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

是编译器告诉链接器要查找的签名,但这不是库中的签名.错误的简短说明是:库已损坏.

但是,我们发现没有这种不一致性会影响构造函数的其他重载:

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

也不是,因为它char const *是一种内置类型.

这可以实现黑客修复.编译未定义引用调用的文件是(如安装的) /usr/include/curlpp/Option.inl,在以下行:

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

以root身份编辑此文件,您会看到它(不一致)包含两个实例:

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

和一个例子:

throw UnsetOption("blah blah");

更改的事件UnsetOption(std::string("blah blah"))来UnsetOption("blah blah").然后只在这个文件中调用好的构造函数example00,至少会编译和链接.

如果您不喜欢黑客攻击,或者发现问题重新出现在其他地方,那么您可以下载ubuntu源代码包curlpp_0.7.3.orig.tar.gz 并自行构建和安装.这是正确的补救措施.

Answer 2

您可以尝试使用旧的 ABI 编译您的项目：
g++ -o example00 example00.cpp -D_GLIBCXX_USE_CXX11_ABI=0 -lm -lcurl -lcurlpp