链接时 C++ undefined reference

Question

我想知道是否有人能够帮助我，因为我已经为此挠头两天了。

我已经完成了编译，并且在尝试链接 linux 上的源代码时得到 undefined reference

编译使用，

g++ -g -I/u01/kasunt/workspace/corelibCORBA/include -I/u01/kasunt/workspace/corelibCORBA/installed_components/include -I/u01/kasunt/workspace/corelibCORBA/idl -I/u01/kasunt/workspace/corelibCORBA/src/Server -I/u01/kasunt/workspace/corelibCORBA/installed_components/idl -I/u01/kasunt/workspace/corelibCORBA/installed_components/src/Server -I/u01/kasunt/workspace/corelibCORBA/installed_components/imake -DNARROWPROTO -I . -I/u01/kasunt/workspace/corelibCORBA/installed_components/include -W -Wall -Wpointer-arith -pipe -D_POSIX_THREADS -D_POSIX_THREAD_SAFE_FUNCTIONS -g -O -I/u01/kasunt/workspace/corelibCORBA/include -g -O -I/u01/kasunt/workspace/corelibCORBA/include -fvisibility=hidden -fvisibility-inlines-hidden -DACE_GCC_HAS_TEMPLATE_INSTANTIATION_VISIBILITY_ATTRS=1 -W -Wall -Wpointer-arith -ggdb -pipe -Wall -g -D__linux__ -D__x86__ -rdynamic -D_REENTRANT -DTAO_HAS_INTERCEPTORS=0 -DTAO_HAS_VALUETYPE=1 -D_REENTRANT -DACE_HAS_AIO_CALLS -D_GNU_SOURCE -I/usr/local/ACE+TAO+CIAO-5.7.9/ACE_wrappers -I/usr/local/ACE+TAO+CIAO-5.7.9/ACE_wrappers/TAO -I/usr/local/ACE+TAO+CIAO-5.7.9/ACE_wrappers/TAO/orbsvcs -DACE_HAS_EXCEPTIONS -D__ACE_INLINE__ -c -o TestSeqWrapper.o TestSeqWrapper.cpp

链接使用，

g++ -o TestSeqWrapper TestSeqWrapper.o -g -L/u01/kasunt/workspace/corelibCORBA/lib -L/u01/kasunt/workspace/corelibCORBA/installed_components/lib -g -O -Wl,-E -L/usr/local/ACE+TAO+CIAO-5.7.9/ACE_wrappers/lib -L/usr/local/ACE+TAO+CIAO-5.7.9/ACE_wrappers/lib -L/usr/local/ACE+TAO+CIAO-5.7.9/ACE_wrappers/TAO/tao -L/u01/kasunt/workspace/corelibCORBA/installed_components/idl -lcorelibCORBA -lcorelibCORBA /u01/kasunt/workspace/corelibCORBA/installed_components/lib/corelibCORBA3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/CorbaController3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/EConcurrency3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/corelibLogger3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/LeakTracker3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/trace3r.lib -lDefineTimeZone /u01/kasunt/workspace/corelibCORBA/installed_components/lib/timestamp3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/ApplConfig3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/appl3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/logstream3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/disklog3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/timeout3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/getpnam3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/config3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/strl3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/string3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/command3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/cmdargs3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/CppUtils3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/BuildTag3r.lib /u01/kasunt/workspace/corelibCORBA/installed_components/lib/exception3r.lib -lCorbaIdl -lTAO_Valuetype -lTAO_PortableServer -lTAO_IORTable -lTAO_AnyTypeCode -lTAO_CosEvent -lTAO_CosNaming -lTAO -lACE

TestSeqWrapper.o: In function `SeqWrapper':
/u01/kasunt/workspace/corelibCORBA/include/corelibCORBA/SeqWrapper.hpp:165: undefined reference to `ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T()'

对库执行 nm 我可以看到包含了上面的构造函数，

nm --demangle ../installed_components/lib/libCorbaIdl.so | grep "ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T"
000327ba t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T(ECONZ::Corba::ComboElementSeq_T const&)
000331c2 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T(unsigned int)
0002edb0 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T(unsigned int, unsigned int, ECONZ::Corba::ComboElement_T*, bool)
0002d768 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T()
00032e52 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T(ECONZ::Corba::ComboElementSeq_T const&)
0003172a t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T(unsigned int)
0002d8e0 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T(unsigned int, unsigned int, ECONZ::Corba::ComboElement_T*, bool)
0002d8a6 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T()

源代码上的违规行(第 165 行)，SeqWrapper() : var_( new SequenceType ), size_( 0 ) { }

部分代码，

template< typename SEQUENCE >
class SeqWrapper : CppUtils::NonCopy
{
public:
   typedef SEQUENCE SequenceType;
   typedef typename SequenceType::_var_type SequenceType_var;

   typedef typename ElementTypeOf<SequenceType_var>::ElementType ElementType;
   typedef typename ElementTypeOf<SequenceType_var>::ReturnType ReturnType;
   typedef typename ElementTypeOf<SequenceType_var>::ConstReturnType ConstReturnType;

private:
   SequenceType_var var_;
   CORBA::ULong size_;

  void expand_( CORBA::ULong size )
  {
     // NOTE: current implementation assumes size only increases by small increments
     if (size > var_->length()) {
        var_->length( (size < 16)? 16 : (size > 256? size+256 : 2*size-2) );
     }
  }

public:
   SeqWrapper() : var_( new SequenceType ), size_( 0 ) { }
   SeqWrapper( CORBA::ULong reserve ) : var_( new SequenceType( reserve ) ), size_( 0 ) { var_->length( reserve ); }
   SeqWrapper( SequenceType *ownSeq ) : var_( ownSeq ), size_( ownSeq->length() ) { }

.....

TestSeqWrapper.cpp 的源代码(我删除了大部分不需要的东西以减少混淆)

#include <iostream>
#include <CppUtils/StringHelpers.hpp>
#include <corelibCORBA/SeqWrapper.hpp>
#include <CorbaC.h>

using namespace std;

int main()
{
    ECONZ::Corba::SeqWrapper< ECONZ::Corba::StringSeq_T > seq;
}

你可以看到我在链接选项中指定了共享库(以粗体显示)。我最初认为这可能是由于某种依赖关系，并将库标志移到开头没有影响。

我很感激。

Answer 1

既然你说

nm --demangle ../installed_components/lib/libCorbaIdl.so
> 0002d768 t ECONZ::Corba::ComboElementSeq_T::ComboElementSeq_T()

这意味着 ComboElementSeq_T() 在库中 -lCorbaIdl
如果未找到引用，则它正被此库之后指定的库之一使用:

> -lCorbaIdl -lTAO_Valuetype -lTAO_PortableServer -lTAO_IORTable
> -lTAO_AnyTypeCode -lTAO_CosEvent -lTAO_CosNaming -lTAO -lACE

因此，以下内容之一包含:TestSeqWrapper.o: In functionSeqWrapper'`

• -lTAO_Valuetype
• -lTAO_PortableServer
• -lTAO_IORTable
• -lTAO_AnyTypeCode
• -lTAO_CosEvent
• -lTAO_CosNaming
• -lTAO
• -lACE

参见:GCC C++ Linker errors: Undefined reference to 'vtable for XXX', Undefined reference to 'ClassName::ClassName()'

如果您将所有库构建为共享库，那么这个问题就会消失。