c++ - g++ 编译时出现 undefined reference 错误

Question

我正在尝试在 Linux 上编译我的程序。它在 Windows 上运行良好(在 Visual Studio 2015 下编译)。但是当我尝试在 Linux 上做同样的事情时，我得到了这个错误:

g++ -std=c++0x -std=c++0x    Prueba1.cpp   -o Prueba1
/tmp/cc9HTgYi.o: In function `Escuchador::onFrame(Leap::Controller const&)':
Prueba1.cpp:(.text+0x51): undefined reference to `Leap::Controller::frame(int) const'
Prueba1.cpp:(.text+0x6c): undefined reference to `Leap::Frame::fingers() const'
Prueba1.cpp:(.text+0x7d): undefined reference to `Leap::FingerList::count() const'
Prueba1.cpp:(.text+0x97): undefined reference to `Leap::Frame::hands() const'
Prueba1.cpp:(.text+0xa8): undefined reference to `Leap::HandList::count() const'
Prueba1.cpp:(.text+0xbc): undefined reference to `Leap::Frame::timestamp() const'
Prueba1.cpp:(.text+0xce): undefined reference to `Leap::Frame::id() const'
Prueba1.cpp:(.text+0x1ac): undefined reference to `Leap::Frame::hands() const'
Prueba1.cpp:(.text+0x1c7): undefined reference to `Leap::HandList::begin() const'
Prueba1.cpp:(.text+0x203): undefined reference to `Leap::Hand::isLeft() const'
Prueba1.cpp:(.text+0x245): undefined reference to `Leap::Hand::id() const'
Prueba1.cpp:(.text+0x2fc): undefined reference to `Leap::Hand::palmNormal() const'
Prueba1.cpp:(.text+0x317): undefined reference to `Leap::Hand::direction() const'
Prueba1.cpp:(.text+0x332): undefined reference to `Leap::Hand::fingers() const'
Prueba1.cpp:(.text+0x34d): undefined reference to `Leap::FingerList::begin() const'
Prueba1.cpp:(.text+0x37e): undefined reference to `Leap::Pointable::id() const'
Prueba1.cpp:(.text+0x38e): undefined reference to `Leap::Finger::type() const'
Prueba1.cpp:(.text+0x47b): undefined reference to `Leap::Finger::bone(Leap::Bone::Type) const'
Prueba1.cpp:(.text+0x510): undefined reference to `Leap::Frame::hands() const'
Prueba1.cpp:(.text+0x533): undefined reference to `Leap::HandList::operator[](int) const'
Prueba1.cpp:(.text+0x54e): undefined reference to `Leap::Hand::fingers() const'
Prueba1.cpp:(.text+0x582): undefined reference to `Leap::FingerList::begin() const'
Prueba1.cpp:(.text+0x595): undefined reference to `Leap::Bone::Bone()'
Prueba1.cpp:(.text+0x5ea): undefined reference to `Leap::Finger::bone(Leap::Bone::Type) const'
Prueba1.cpp:(.text+0x63e): undefined reference to `Leap::Finger::type() const'
Prueba1.cpp:(.text+0x67f): undefined reference to `Leap::operator<<(std::ostream&, Leap::Bone const&)'
Prueba1.cpp:(.text+0x6ee): undefined reference to `Leap::FingerList::end() const'
Prueba1.cpp:(.text+0x726): undefined reference to `Leap::Hand::fingers() const'
Prueba1.cpp:(.text+0x74d): undefined reference to `Leap::FingerList::begin() const'
Prueba1.cpp:(.text+0x768): undefined reference to `Leap::FingerList::end() const'
Prueba1.cpp:(.text+0x7ab): undefined reference to `Leap::Finger::bone(Leap::Bone::Type) const'
Prueba1.cpp:(.text+0x7ce): undefined reference to `Leap::Finger::bone(Leap::Bone::Type) const'
Prueba1.cpp:(.text+0x7f1): undefined reference to `Leap::Finger::bone(Leap::Bone::Type) const'
Prueba1.cpp:(.text+0x814): undefined reference to `Leap::Finger::bone(Leap::Bone::Type) const'
Prueba1.cpp:(.text+0x825): undefined reference to `Leap::Finger::type() const'
Prueba1.cpp:(.text+0x848): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0x863): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0x89e): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0x8b9): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0x8f4): undefined reference to `Leap::Bone::direction() const'
/tmp/cc9HTgYi.o:Prueba1.cpp:(.text+0x90c): more undefined references to `Leap::Bone::direction() const' follow
/tmp/cc9HTgYi.o: In function `Escuchador::onFrame(Leap::Controller const&)':
Prueba1.cpp:(.text+0xa15): undefined reference to `Leap::Finger::type() const'
Prueba1.cpp:(.text+0xa37): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xa4f): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xa87): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xa9f): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xad7): undefined reference to `Leap::Bone::direction() const'
/tmp/cc9HTgYi.o:Prueba1.cpp:(.text+0xaef): more undefined references to `Leap::Bone::direction() const' follow
/tmp/cc9HTgYi.o: In function `Escuchador::onFrame(Leap::Controller const&)':
Prueba1.cpp:(.text+0xbf8): undefined reference to `Leap::Finger::type() const'
Prueba1.cpp:(.text+0xc1b): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xc33): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xc6b): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xc83): undefined reference to `Leap::Bone::direction() const'
Prueba1.cpp:(.text+0xcbb): undefined reference to `Leap::Bone::direction() const'
/tmp/cc9HTgYi.o:Prueba1.cpp:(.text+0xcd3): more undefined references to `Leap::Bone::direction() const' follow
/tmp/cc9HTgYi.o: In function `Escuchador::onFrame(Leap::Controller const&)':
Prueba1.cpp:(.text+0xeb4): undefined reference to `Leap::FingerList::end() const'
Prueba1.cpp:(.text+0xf27): undefined reference to `Leap::HandList::end() const'
/tmp/cc9HTgYi.o: In function `main':
Prueba1.cpp:(.text+0x11a3): undefined reference to `Leap::Controller::Controller()'
Prueba1.cpp:(.text+0x11b7): undefined reference to `Leap::Controller::addListener(Leap::Listener&)'
Prueba1.cpp:(.text+0x11fb): undefined reference to `Leap::Controller::removeListener(Leap::Listener&)'
Prueba1.cpp:(.text+0x120c): undefined reference to `Leap::Controller::~Controller()'
Prueba1.cpp:(.text+0x122a): undefined reference to `Leap::Controller::~Controller()'
/tmp/cc9HTgYi.o: In function `Leap::Pointable::~Pointable()':
Prueba1.cpp:(.text._ZN4Leap9PointableD2Ev[_ZN4Leap9PointableD5Ev]+0x16): undefined reference to `Leap::Interface::~Interface()'
/tmp/cc9HTgYi.o: In function `Leap::Bone::operator=(Leap::Bone&&)':
Prueba1.cpp:(.text._ZN4Leap4BoneaSEOS0_[_ZN4Leap4BoneaSEOS0_]+0x14): undefined reference to `Leap::Interface::operator=(Leap::Interface const&)'
/tmp/cc9HTgYi.o: In function `Leap::ConstListIterator<Leap::HandList, Leap::Hand>::operator*() const':
Prueba1.cpp:(.text._ZNK4Leap17ConstListIteratorINS_8HandListENS_4HandEEdeEv[_ZNK4Leap17ConstListIteratorINS_8HandListENS_4HandEEdeEv]+0x20): undefined reference to `Leap::HandList::operator[](int) const'
/tmp/cc9HTgYi.o: In function `Leap::ConstListIterator<Leap::FingerList, Leap::Finger>::operator*() const':
Prueba1.cpp:(.text._ZNK4Leap17ConstListIteratorINS_10FingerListENS_6FingerEEdeEv[_ZNK4Leap17ConstListIteratorINS_10FingerListENS_6FingerEEdeEv]+0x20): undefined reference to `Leap::FingerList::operator[](int) const'
/tmp/cc9HTgYi.o: In function `Leap::Frame::~Frame()':
Prueba1.cpp:(.text._ZN4Leap5FrameD2Ev[_ZN4Leap5FrameD5Ev]+0x16): undefined reference to `Leap::Interface::~Interface()'
/tmp/cc9HTgYi.o: In function `Leap::HandList::~HandList()':
Prueba1.cpp:(.text._ZN4Leap8HandListD2Ev[_ZN4Leap8HandListD5Ev]+0x16): undefined reference to `Leap::Interface::~Interface()'
/tmp/cc9HTgYi.o: In function `Leap::FingerList::~FingerList()':
Prueba1.cpp:(.text._ZN4Leap10FingerListD2Ev[_ZN4Leap10FingerListD5Ev]+0x16): undefined reference to `Leap::Interface::~Interface()'
/tmp/cc9HTgYi.o: In function `Leap::Hand::~Hand()':
Prueba1.cpp:(.text._ZN4Leap4HandD2Ev[_ZN4Leap4HandD5Ev]+0x16): undefined reference to `Leap::Interface::~Interface()'
/tmp/cc9HTgYi.o: In function `Leap::Bone::~Bone()':
Prueba1.cpp:(.text._ZN4Leap4BoneD2Ev[_ZN4Leap4BoneD5Ev]+0x16): undefined reference to `Leap::Interface::~Interface()'
/tmp/cc9HTgYi.o:(.rodata._ZTIN4Leap5FrameE[_ZTIN4Leap5FrameE]+0x8): undefined reference to `typeinfo for Leap::Interface'
/tmp/cc9HTgYi.o:(.rodata._ZTIN4Leap8HandListE[_ZTIN4Leap8HandListE]+0x8): undefined reference to `typeinfo for Leap::Interface'
/tmp/cc9HTgYi.o:(.rodata._ZTIN4Leap10FingerListE[_ZTIN4Leap10FingerListE]+0x8): undefined reference to `typeinfo for Leap::Interface'
/tmp/cc9HTgYi.o:(.rodata._ZTIN4Leap4HandE[_ZTIN4Leap4HandE]+0x8): undefined reference to `typeinfo for Leap::Interface'
/tmp/cc9HTgYi.o:(.rodata._ZTIN4Leap4BoneE[_ZTIN4Leap4BoneE]+0x8): undefined reference to `typeinfo for Leap::Interface'
/tmp/cc9HTgYi.o:(.rodata._ZTIN4Leap9PointableE[_ZTIN4Leap9PointableE]+0x8): more undefined references to `typeinfo for Leap::Interface' follow
collect2: error: ld returned 1 exit status
make: *** [Prueba1] Error 1

我的#include 是:

#include <iostream>
#include <cstring>
#include "Leap.h"

看来问题出在 Leap.h header 上。在 SDK 中有一个我可以编译并运行良好的 Sample.cpp。我使用相同的 makefile 和相同的文件系统；我使用与 Sample.cpp 相同的 #include，所以我将我的 .cpp 文件移动到与 Sample.cpp 相同的文件夹中并尝试编译，但出现错误。我不知道如何解决它，有什么想法吗？这是生成文件:

OS := $(shell uname)
ARCH := $(shell uname -m)
CXXFLAGS := -std=c++0x -std=c++0x

ifeq ($(OS), Linux)
  ifeq ($(ARCH), x86_64)
LEAP_LIBRARY := ../lib/x64/libLeap.so -Wl,-rpath,../lib/x64
  else
LEAP_LIBRARY := ../lib/x86/libLeap.so -Wl,-rpath,../lib/x86
  endif
else
  # OS X
LEAP_LIBRARY := ../lib/libLeap.dylib
endif

Sample: Sample.cpp
$(CXX) -Wall  -g -I../include Sample.cpp -o Sample $(LEAP_LIBRARY)

ifeq ($(OS), Darwin)
install_name_tool -change @loader_path/libLeap.dylib ../lib/libLeap.dylib Sample
endif

clean:
rm -rf Sample Sample.dSYM

我只是添加了 CXXFLAGS 来解决 C+98 编译器错误。我也可以用这种方式编译 Sample.cpp，但是当我尝试对我的文件执行相同操作时，出现错误。感谢您的帮助!

Answer 1

So it seems the problem is with the Leap.h header.

不，标题没有问题。您只是没有链接到提供这些函数定义的库。

查看 makefile 如何构建示例程序:它链接到 libleap.so，

你需要做同样的事情:

g++ -std=c++0x -std=c++0x    Prueba1.cpp   -o Prueba1 ../lib/x64/libleap.so -Wl,-rpath,../lib/x64

(如果您使用的是 32 位系统，请将 x64 替换为 x86)。