我对我的项目有点不知所措。语言是 C++，编辑器 Visual Studio 2012，一旦完成它应该是一个光线转换渲染器(光线转换位仍然缺失)。 为此，我正在使用数学库 Eigen。但是，当我尝试构建时出现链接错误。我过去没有太多使用 C++ 语言，对这个错误所做的研究对我没有帮助。

这是编译器的输出:

1>------ Build started: Project: TX52-3DStereo-RT-CUDA, Configuration: Debug x64 ------
1>Build started 06/12/2013 10:55:56.
1>InitializeBuildStatus:
1>  Touching "x64\Debug\TX52-3DStereo-RT-CUDA.unsuccessfulbuild".
1>AddCudaCompilePropsDeps:
1>Skipping target "AddCudaCompilePropsDeps" because all output files are up-to-date with respect to the input files.
1>CudaBuild:
1>  Compiling CUDA source file kernel.cu...
1>  
1>  C:\Users\Satanikas\Documents\Visual Studio 2012\Projects\TX52-3DStereo-RT-CUDA\TX52-3DStereo-RT-CUDA>"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.5\bin\nvcc.exe" -gencode=arch=compute_10,code=\"sm_10,compute_10\" --use-local-env --cl-version 2012 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\x86_amd64"  -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.5\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.5\include"  -G   --keep-dir x64\Debug -maxrregcount=0  --machine 64 --compile -cudart static  -g   -DWIN64 -D_DEBUG -D_CONSOLE -D_MBCS -Xcompiler "/EHsc /W3 /nologo /Od /Zi /RTC1 /MDd  " -o x64\Debug\kernel.cu.obj "C:\Users\Satanikas\Documents\Visual Studio 2012\Projects\TX52-3DStereo-RT-CUDA\TX52-3DStereo-RT-CUDA\kernel.cu" 
1>c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Core/arch/SSE/PacketMath.h(169): warning : controlling expression is constant
1>  
1>c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Core/Block.h(102): error : "operator=" has already been declared in the current scope
1>            detected during instantiation of class "Eigen::Block<XprType, BlockRows, BlockCols, InnerPanel> [with XprType=VectorType, BlockRows=<expression>, BlockCols=<expression>, InnerPanel=false]" 
1>  c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Core/VectorBlock.h(58): here
1>  
1>c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Core/Ref.h(122): error : "operator=" has already been declared in the current scope
1>            detected during instantiation of class "Eigen::RefBase<Derived> [with Derived=Eigen::Ref<PlainObjectType, Options, StrideType>]" 
1>  (183): here
1>  
1>c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Core/products/Parallelizer.h(20): warning : variable "m_maxThreads" was set but never used
1>  
1>c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Geometry/RotationBase.h(76): error : function template "Eigen::operator*(const Eigen::EigenBase<OtherDerived> &, const Eigen::Quaternion<_Scalar, _Options> &)" has already been defined
1>            detected during:
1>              instantiation of class "Eigen::RotationBase<Derived, _Dim> [with Derived=Eigen::Quaternion<_Scalar, _Options>, _Dim=3]" 
1>  c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Geometry/Quaternion.h(35): here
1>              instantiation of class "Eigen::QuaternionBase<Derived> [with Derived=Eigen::Quaternion<_Scalar, _Options>]" 
1>  c:\users\satanikas\documents\visual studio 2012\common\inc\eigen\src/Geometry/Quaternion.h(236): here
1>  
1>  3 errors detected in the compilation of "C:/Users/SATANI~1/AppData/Local/Temp/tmpxft_000010c8_00000000-5_kernel.cpp1.ii".
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V110\BuildCustomizations\CUDA 5.5.targets(592,9): error MSB3721: The command ""C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.5\bin\nvcc.exe" -gencode=arch=compute_10,code=\"sm_10,compute_10\" --use-local-env --cl-version 2012 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\x86_amd64"  -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.5\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.5\include"  -G   --keep-dir x64\Debug -maxrregcount=0  --machine 64 --compile -cudart static  -g   -DWIN64 -D_DEBUG -D_CONSOLE -D_MBCS -Xcompiler "/EHsc /W3 /nologo /Od /Zi /RTC1 /MDd  " -o x64\Debug\kernel.cu.obj "C:\Users\Satanikas\Documents\Visual Studio 2012\Projects\TX52-3DStereo-RT-CUDA\TX52-3DStereo-RT-CUDA\kernel.cu"" exited with code 2.
1>
1>Build FAILED.
1>
1>Time Elapsed 00:00:03.40
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

错误来自 3 个类，这是它们的标题:

#pragma once

#include <Eigen\Geometry>

class TransformedObject
{
public:
    TransformedObject(void);
    ~TransformedObject(void);

    void rotate(const Eigen::Quaternionf&);
    void setRotation(const Eigen::Quaternionf&);
    void translate(const Eigen::Vector3f&);
    void setTranslation(const Eigen::Vector3f&);
    void scale(const float&);
    const Eigen::Matrix4f getMatrix(void);

    Eigen::Transform<float, 3, Eigen::Affine> transform;
};


#pragma once

#include "TransformedObject.h"

class Camera
{
public:
    Camera(void);
    ~Camera(void);
    void computeRays();
    void setFOV(float angle);
    void setResolution(int w, int h);
private:
    TransformedObject transformation;
    float fov;
    unsigned int width;
    unsigned int height;
    float* raysDirections;
    Eigen::Vector3f raysOrigin;
};


#pragma once

#include <forward_list>
#include "TransformedObject.h"

class ScenegraphNode
{
public:
    ScenegraphNode(void);
    ~ScenegraphNode(void);
private:
    TransformedObject transformation;
    size_t sceneHash;
    std::forward_list<ScenegraphNode*> children;

    int countVertices() const;
};

如您所见，所有类上都有“pragma once”，Eigen 类都由 ifndef/define/endif 保护。

我收集到的是，这可能是由于我的代码是由不同的 TU 编译的，其中分别包含 Eigen，因此出现了所有“已定义”的错误。但我不知道如何纠正这个问题(我不能使用 extern，因为我使用我的类 TransformedObject 作为其他类的成员)。

提前致谢

最佳答案

正在复制 user3073879(提交者)评论:

“问题已解决，我从包含声明相机的主机函数的文件中删除了所有 CUDA 代码。(这是一个测试函数)。这意味着它确实是 NVCC 的问题”

将此问题标记为已回答。

关于c++ - VS2012 提示 "already defined"类尽管 pragma once，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20421384/