SWIG + CMAKE：缺少初始化函數

Question

我爲C++代碼提供了一個CMAKE文件，並希望將其函數包裝到Python中。每當我嘗試導入功能，它給了我一個導入錯誤：

動態模塊沒有定義初始化函數（init_main）

這是C++代碼：

#include <iostream> 
#include <string> 
#include <boost/bind.hpp> 
#include <Memory/Interface.hpp> 
#include <Memory/Subscription.hpp> 

using namespace memory::interface; 
using namespace memory; 

MemoryPtr mMem; 
Subscription *s; 

std::string write_document; 







void subscriber_callback(const Event &event) { 

    std::cout << "Received an event:" << std::endl; 
    switch (event.getType()) { 

     case Event::INSERT: 
       std::cout << "Insert event with document ID = " << event.getID() << std::endl; 
       break; 

     case Event::REMOVE: 
       std::cout << "Remove event with document ID = " << event.getID() << std::endl; 
       break; 

     case Event::QUERY: 
       std::cout << "Query event with document ID = " << event.getID() << std::endl; 
       break; 

     case Event::REPLACE: 
       std::cout << "Replace event with document ID = " << event.getID() << std::endl; 
       break; 

     case Event::ALL: 
       std::cout << "Generic event with document ID = " << event.getID() << std::endl; 
       break; 

     default: std::cout << "Unknown event type." << std::endl; 
    } 
    std::cout << "Contained document is: " << event.getDocument() << std::endl; 

} 



extern "C" int main(int argc, char *argv[]) { 
    // validate app arguments 
    if(argc < 3) { 
    std::cerr << "Usage : " << argv[0] << " <xcf:ShortTerm> <XPATH-trigger>" << std::endl; 
    return 1; 
    } 
    try { 
    // instantiate the memory interface 
    mMem = MemoryInterface::getInstance(argv[1]); 
    std::cout << "Memory interface initialized" << std::endl; 

    // create the trigger 
    std::string xpath(argv[2]); 

    // create a subscriber to a specific xpath event 
    s = new Subscription(
     Condition(Event::INSERT, xpath), 
     TriggeredAction(boost::bind(&subscriber_callback, _1)) 
    ); 
    mMem->subscribe (*s); 
    std::cout << "Memory interface subscriber initialized" << std::endl; 

    // insert command/text to memory 
    write_document = "<command><stop /></command>"; 
    mMem->insert(write_document); 
    std::cout << "Written to Memory interface" << std::endl; 

    // wait for key press 
    std::string end; 
    std::cin >> end; 
    } 
    catch (const MemoryInterfaceException& e) { 
    std::cerr << "MemoryInterfaceException: " << e.what() << std::endl; 
    return 1; 
    } 
    catch(std::exception &e) { 
    std::cerr << std::endl << "Could not initialize memory::interface. Reason:" 
    << std::endl << e.what() << std::endl; 
    return 1; 
    } 
    return 0; 
} 

這是CMake的文件而我添加的最後一個部分SWIG：

cmake_minimum_required(VERSION 3.0.2) 
project(xcf_minimal_readwrite) 

find_package(PkgConfig) 

IF(PKG_CONFIG_FOUND) 
    message(STATUS "found pkgconfig") 

    SET(MODULE "Memory") 

    IF(Memory_FIND_REQUIRED) 
    SET(Memory_REQUIRED "REQUIRED") 
    ENDIF() 
    PKG_CHECK_MODULES(Memory ${Memory_REQUIRED} ${MODULE}) 

    FIND_LIBRARY(Memory_LIBRARY 
    NAMES ${Memory_LIBRARIES} 
    HINTS ${Memory_LIBRARY_DIRS} 
) 
    SET(Memory_LIBRARIES ${Memory_LIBRARY}) 


    SET(MODULE "xmltio") 

    IF(xmltio_FIND_REQUIRED) 
    SET(xmltio_REQUIRED "REQUIRED") 
    ENDIF() 
    PKG_CHECK_MODULES(xmltio ${xmltio_REQUIRED} ${MODULE}) 

    FIND_LIBRARY(xmltio_LIBRARY 
    NAMES ${xmltio_LIBRARIES} 
    HINTS ${xmltio_LIBRARY_DIRS} 
) 
    SET(xmltio_LIBRARIES ${xmltio_LIBRARY}) 


ENDIF() 

IF(Memory_FOUND) 
    message(STATUS "found Memory") 
    include_directories(${Memory_INCLUDE_DIRS} ${xmltio_INCLUDE_DIRS}) 

    add_executable(${PROJECT_NAME} main.cc) 
    target_link_libraries(${PROJECT_NAME} ${Memory_LIBRARIES} ${xmltio_LIBRARIES}) 


    install(TARGETS ${PROJECT_NAME} 
    RUNTIME DESTINATION bin) 


ENDIF() 




# This is the part for Python SWIG: 

FIND_PACKAGE(SWIG REQUIRED) 
INCLUDE(${SWIG_USE_FILE}) 

FIND_PACKAGE(PythonLibs) 
INCLUDE_DIRECTORIES(${PYTHON_INCLUDE_PATH}) 

INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR}) 

SET(CMAKE_SWIG_FLAGS "") 

SET_SOURCE_FILES_PROPERTIES(main.i PROPERTIES CPLUSPLUS ON) 
SET_SOURCE_FILES_PROPERTIES(main.i PROPERTIES SWIG_FLAGS "-includeall") 
SWIG_ADD_MODULE(main python main.i main.cc) 
SWIG_LINK_LIBRARIES(main ${Memory_LIBRARIES} ${xmltio_LIBRARIES} ${PYTHON_LIBRARIES}) 

這是我main.i看起來像：

/* File : main.i */ 
%module main 
%{ 
/* Put headers and other declarations here */ 
extern int main(int argc, char *argv[]); 
%} 


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

任何線索在這裏出了什麼問題？

「主」也許是一個壞名字？

Answer 1

swig調用會生成一個定義init_main函數的源文件。這個文件不是編譯的，或者它的目標文件沒有鏈接到構成你的python擴展的共享對象中。

是的，main是一個不好的名字，但是在這裏你被困在比這可能成爲問題更早的階段。