显式链接错误 - 语法错误：缺少 ';'由 bazel 编译时在 '*' 之前

Posted 2023-02-21

【中文标题】显式链接错误 - 语法错误：缺少 \';\'由 bazel 编译时在 \'*\' 之前

【英文标题】：Errors on explicit link - syntax error : missing ';' before '*' while compiling by bazel显式链接错误 - 语法错误：缺少 ';'由 bazel 编译时在 '*' 之前

【发布时间】：2018-04-06 04:13:35

【问题描述】：

我试图建立一个明确的链接来导出一个类。代码中不应该有语法错误。我认为可能是 cl.exe 有问题。 我希望这些只是一些愚蠢的语法错误，而不是由 cl.exe 引起的。 我需要你的帮助。 错误如下：

tensorflow/detector0405/expdetect.cpp(25): error C2143: syntax error : missing ';' before '*'
tensorflow/detector0405/expdetect.cpp(25): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
tensorflow/detector0405/expdetect.cpp(25): error C2065: 'pDtctor' undeclared identifier
tensorflow/detector0405/expdetect.cpp(26): error C2065: 'pDtctor' undeclared identifier
tensorflow/detector0405/expdetect.cpp(26): error C2146: syntax error : missing ';' before identifier 'Get'
tensorflow/detector0405/expdetect.cpp(26): error C2065: 'Get' undeclared identifier
tensorflow/detector0405/expdetect.cpp(26): error C2146: syntax error : missing ';' before identifier 'GetProcAddress'
tensorflow/detector0405/expdetect.cpp(27): error C2065: 'Get' undeclared identifier
tensorflow/detector0405/expdetect.cpp(32): error C2065: 'Get' undeclared identifier
tensorflow/detector0405/expdetect.cpp(38): error C2227: left of '->createGraph' must point to class/struct/union/generic type
tensorflow/detector0405/expdetect.cpp(38): note: type is ‘ExpDetector *’
tensorflow/detector0405/expdetect.cpp(39): error C2227: left of '->setInput' must point to class/struct/union/generic type
tensorflow/detector0405/expdetect.cpp(39): note: type is ‘ExpDetector *’
tensorflow/detector0405/expdetect.cpp(40): error C2227: left of '->detection' must point to class/struct/union/generic type
tensorflow/detector0405/expdetect.cpp(40): note: type is ‘ExpDetector *’
tensorflow/detector0405/expdetect.cpp(43): error C2227: left of '->getOutput' must point to class/struct/union/generic type
tensorflow/detector0405/expdetect.cpp(43): note: type is ‘ExpDetector *’
Target //tensorflow/detector0405:expdetect failed to build
INFO: Elapsed time: 9.515s, Critical Path: 3.54s
FAILED: Build did NOT complete successfully

这是主要功能：

expdetect.cpp

//expdetect.cpp    
#include <windows.h>
#include <stdio.h>
#include <iostream>
using namespace std;

int main(int argc, char* argv[]) 

    HINSTANCE dtctDll ;
    dtctDll = LoadLibrary(TEXT("expdtctlib.dll")) ; 
    if(dtctDll == NULL)
    
        FreeLibrary(dtctDll) ;
        std::cout << "Load Dll Failed!" << std::endl ;
        return 0 ;
    

    typedef ExpDetector*  (*pDtctor)() ; //(25)Here the first error occured.
    pDtctor Get = (pDtctor)GetProcAddress(dtctDll, TEXT("createDtctor")) ; //(26)
    if(Get == NULL)//(27)
    
        std::cout <<"Load Address Failed!"<< std::endl ;
        return 0;
    
    ExpDetector *detector = (Get)() ; //(32)

    char* model_path = "models/graph.pb" ;
    double a = 100.0;
    double b = 23.33;

    detector->createGraph(model_path) ; //(38)
    detector->setInput(a, b) ;//(39)
    detector->detection() ;//(40)

    float output_ ;
    output_ = detector->getOutput() ;//(43)
    std::cout << output_ << "\n" ;

    delete detector ; 
    FreeLibrary(dtctDll) ; 

    return 0 ;

这是 DLL 定义：

expdtctlib.cpp

//expdtctlib.cpp
#include "tensorflow/core/public/session.h"
#include "tensorflow/core/platform/env.h" 
#include <iostream>
using namespace tensorflow;

class ExpDetector
  
private:
    Session* session ; 
    Status status ;
    std::vector<std::pair<string, tensorflow::Tensor>> inputs ;
    std::vector<tensorflow::Tensor> outputs;
public: 

    ExpDetector() ;  
    virtual int createGraph(char* graph_path) ;  
    ~ExpDetector() ;
    virtual void setInput(double a0,double b0) ;  
    virtual int ExpDetector::detection() ;
    virtual double ExpDetector::getOutput() ;
;

ExpDetector::ExpDetector()

    std::cout << "Detector was created." << std::endl ;
 
int ExpDetector::createGraph(char* graph_path)

    std::cout << "Detector Initiating..." << std::endl ;
    status = NewSession(SessionOptions(), &session) ;
    if (!status.ok()) 
        std::cout << status.ToString() << "\n";
        return 1;
    

    GraphDef graph_def;
    status = ReadBinaryProto(Env::Default(), graph_path, &graph_def);
    if (!status.ok()) 
        std::cout << status.ToString() << "\n";
        return 1;
    

      // Add the graph to the session
    status = session->Create(graph_def);
    if (!status.ok()) 
        std::cout << status.ToString() << "\n";
        return 1;
     
    std::cout << "Detector Initiated." << std::endl ;


ExpDetector::~ExpDetector()

    session->Close();
    std::cout << "Detector Destroied !" << std::endl ;


void ExpDetector::setInput(double a0,double b0)

    std::cout << "Feeding Data to Detector..." << std::endl ;
    Tensor a(DT_FLOAT, TensorShape());
    a.scalar<float>()() = a0;

    Tensor b(DT_FLOAT, TensorShape());
    b.scalar<float>()() = b0;

    inputs = 
         "a", a ,
         "b", b ,
    ;
    std::cout << "Done Feeding Data." << std::endl ;


int ExpDetector::detection()

    status = session->Run(inputs, "c", , &outputs);
    if (!status.ok()) 
        std::cout << status.ToString() << "\n";
        return 1;
    



double ExpDetector::getOutput()

    auto output_c = outputs[0].scalar<float>();

    std::cout << outputs[0].DebugString() << "\n";
    std::cout << output_c() << "\n";

    return output_c() ;



extern "C" __declspec(dllexport) ExpDetector* createDtctor(void)

     return new ExpDetector() ;

非常感谢您给我的所有回复。希望我们可以轻松解决。

【问题讨论】：

您需要将您的ExpDetector 类声明移动到一个expdtctlib.h 文件并# 将其包含在expdetect.cpp 中。

@MFisherKDX 谢谢！我已经解决了这个问题！

【参考方案1】：

ExpDetector 类在 expdetect.cpp 中不可见。

您应该将类​​声明放在头文件中，将实现放在源文件中。然后在main.cpp中包含头文件。

如果链接为 DLL，则无需在 main.cpp 中使用 #include "expdtctlib.h"，但需要单独构建 DLL。 Here is an example.

标头包含声明

// expdtctlib.h
#ifndef expdtctlib_h_
#define expdtctlib_h_

namespace tensorflow 
    class ExpDetector 
        Session* session;
        ...

    public:
        ExpDetector();
        ...
    ;


#endif

源包含定义

// expdtctlib.cpp
#include "expdtctlib.h"

ExpDetector::ExpDetector()

    std::cout << "Detector was created." << std::endl ;

 ....

在 main 中包含标题

//expdetect.cpp  
#include "expdtctlib.h" // If not DLL

int main() 
....

【讨论】：

非常感谢！但是为什么显式链接需要包含头文件？我在这里阅读了一个显式链接示例Linking Explicitly。

要作为 dll 链接，您需要先单独构建 dll。在构建 dll 时，您仍然需要将代码拆分为头文件/源文件。 Here is a guid one creating a DLL.