C++ g++；编译时出现未定义的引用错误

我试图在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上执行相同操作时，会出现以下错误：

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

我添加CXXFLAGS只是为了解决一个C+98编译器错误。我也可以用这种方式编译Sample.cpp，但是当我尝试在我的文件上执行同样的操作时，会出现错误。谢谢你的帮助

所以问题似乎出在Leap.h头上

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

看看makefile如何构建示例程序：它链接到

libleap.so

您也需要这样做：

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）。

首先，阅读要求：请阅读至少与外部库组件相关的答案，然后返回此问题

---

好的，那么在您的情况下，您正在运行一个link命令，而不指定外部库。怎么会？为什么您能够编译软件包附带的示例

看看makefile。上面说

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

这条规则告诉

make

三件事：构建什么（冒号前的第一行），从什么构建它（冒号后），以及如何构建它（第二行）。因此，当您运行以下命令时

make Sample

make

非常清楚该怎么做

现在如果你说

make Prueba1

事情有点不同。makefile中没有谈论

Prueba1

的特殊规则，因此

make

获取其（庞大的）内置规则集，并寻找一个允许它为您构建

Prueba1

的规则集。确实有这样一个内置规则，但它不知道

libLeap.so

。这就是为什么在构建日志中看不到它的原因

当然，您可以在makefile中添加如下内容：

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

Prueba1: Prueba1.cpp
    $(CXX) -Wall  -g -I../include Prueba1.cpp -o Prueba1 $(LEAP_LIBRARY)

但我敢大胆猜测，当你到了Prueba99，它会变得有点老。我们能做得更好吗

是的，我们可以，但是让我们先回答另一个问题。为什么编译命令知道

-std=c++0x

这是因为您将此标志添加到内置宏

cxflags

，而内置规则使用此宏。顺便说一下，您不需要指定两次

-std=c++0x

有没有一种方法可以像对待编译器标志一样对待库？绝对地有两个内置宏

LDLIBS

和

LDFLAGS

。如果您这样定义它们：

LDLIBS := ../lib/x64/libLeap.so
LDFLAGS := -Wl,-rpath,../lib/x64

或者（或者）

你的MaFoIP文件应该能够构建任何针对LILUAP的C++程序（如果它是作为一个C++源文件编写的）。

---

将

-I../include

添加到

CPPFLAGS

可能是明智的，因为示例规则使用它。您的编译似乎可以在没有它的情况下运行，但如果您更改工作目录，则可能会失败

我感觉make没有正确识别操作系统。Try:UNAME_S:=$（shell UNAME-S）ifeq（$（UNAME_S），Linux）--你在这里写东西吗--endif。。。。查看更多：@fritzone看起来OP根本没有使用makefile.libLeap.so在编译行中丢失。这意味着您要么不使用makefile，要么在没有为程序更新makefile的情况下使用它。如前所述，它只适用于名为Sample的程序。您必须修改makefile以使用您的程序名，或者（高级任务）对其进行改进，使其可以使用任何程序名，并使用标准宏（如LDLIBS）。

LDLIBS := ../lib/x64/libLeap.so
LDFLAGS := -Wl,-rpath,../lib/x64

LDLIBS := -lLeap
LDFLAGS := -L ../lib/x64 -Wl,-rpath,../lib/x64