使用带有 go 的 swig 包装的 c++ 库

Question

我已经成功地用SWIG包装了一个大型C++库。 我发布了该模块并且可以安装它，但是当我 go 构建它时，我收到大量undefined reference错误，指向生成的c文件中包含的函数。

我把生成的so lib文件放在我的系统lib目录下，把库中的header文件放到我的系统include目录下，但是并没有解决问题。 我猜我还需要一个 header 文件来包装c文件，这样解释器就可以知道so文件中有什么，但是考虑到SWIG没有生成一个文件，我不知道我是否遗漏了其他任何东西。 我将尝试编写自己的 header 文件以查看是否可以解决错误，但即使可以， SWIG不应该自动执行此操作吗？

我的源文件如下

/** file: golibraw.i **/
%module librawgo
%{
#define LIBRAW_LIBRARY_BUILD
/* Put headers and other declarations here */
#include "libraw/libraw.h"
#include "libraw/libraw_alloc.h"
#include "libraw/libraw_const.h"
#include "libraw/libraw_datastream.h"
#include "libraw/libraw_internal.h"
#include "libraw/libraw_types.h"
#include "libraw/libraw_version.h"
%}

%include "libraw/libraw.h"
%include "libraw/libraw_alloc.h"
%include "libraw/libraw_const.h"
%include "libraw/libraw_datastream.h"
%include "libraw/libraw_internal.h"
%include "libraw/libraw_types.h"
%include "libraw/libraw_version.h"

cmake_minimum_required(VERSION 3.14)

if ( ${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR} )
    message( FATAL_ERROR "In-source builds not allowed. Please make a new directory and run CMake from there. You may need to remove CMakeCache.txt." )
endif()

find_package(SWIG 4.0 COMPONENTS python OPTIONAL_COMPONENTS go)
if(SWIG_FOUND)
  message("SWIG found: ${SWIG_EXECUTABLE}")
  include (UseSWIG)
  if(NOT SWIG_go_FOUND)
    message(FATAL_ERROR "SWIG go bindings cannot be generated")
  endif()
else()
    message(FATAL_ERROR "SWIG NOT FOUND")
endif()

set(PROJECT_NAME librawgo)
project(${PROJECT_NAME})

SET (CMAKE_LIBRARY_OUTPUT_DIRECTORY
        ${CMAKE_SOURCE_DIR}/librawgo
        CACHE PATH
        "Single Directory for all"
    )

find_program( CLANG_TIDY NAMES clang-tidy)



set(${PROJECT_NAME}_sources ${CMAKE_SOURCE_DIR}/src/librawgo.i )


swig_add_library(${PROJECT_NAME} TYPE SHARED LANGUAGE go SOURCES ${${PROJECT_NAME}_sources})


if(CLANG_TIDY)
set_property(
    TARGET ${PROJECT_NAME}
    PROPERTY CXX_CLANG_TIDY "${CLANG_TIDY}")
endif()

    set_property(TARGET ${PROJECT_NAME} PROPERTY SWIG_COMPILE_OPTIONS -go -intgosize 64 -cpperraswarn)
    set_property(TARGET ${PROJECT_NAME} PROPERTY SWIG_USE_TARGET_INCLUDE_DIRECTORIES TRUE)
    set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
    set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
    target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_SOURCE_DIR})

Answer 1

原因是 Go 编译器不知道库librawgo.so 。

将以下行放在librawgo.go中C评论的顶部：

#cgo LDFLAGS: -L<path/to/dir/with/librawgo.so> -lrawgo -lraw

该指令告诉编译器将此行添加到 linker 标志中。

抱歉，我不知道如何修改您的 CMake 和 SWIG 设置以自动生成此行。