环境:linux x64,编译器gcc 4.x
项目具有以下结构:
static library "slib"
-- inside this library, there is static object "sobj"
dynamic library "dlib"
-- links statically "slib"
executable "exe":
-- links "slib" statically
-- links "dlib" dynamically
在程序结束时,“sobj”被析构两次。这种行为是预期的,但在相同的内存地址下进行了两次析构,即在析构函数中使用了相同的"this"指针,导致了双重析构问题。我认为这是由于某些符号重叠引起的。那么这个冲突的解决方案是什么?也许可以通过一些链接选项来解决?
以下是测试用例:
main_exe.cpp
#include <cstdlib>
#include "static_lib.h"
#include "dynamic_lib.h"
int main(int argc, char *argv[])
{
stat_useStatic();
din_useStatic();
return EXIT_SUCCESS;
}
static_lib.h
#ifndef STATIC_LIB_H
#define STATIC_LIB_H
#include <cstdio>
void stat_useStatic();
struct CTest
{
CTest(): status(isAlive)
{
printf("CTest() this=%d\n",this);
}
~CTest()
{
printf("~CTest() this=%d, %s\n",this,status==isAlive?"is Alive":"is Dead");
status=isDead;
}
void use()
{
printf("use\n");
}
static const int isAlive=12385423;
static const int isDead=6543421;
int status;
static CTest test;
};
#endif
静态库 static_lib.cpp
#include "static_lib.h"
CTest CTest::test;
void stat_useStatic()
{
CTest::test.use();
}
dynamic_lib.h
#ifndef DYNAMIC_LIB_H
#define DYNAMIC_LIB_H
#include "static_lib.h"
#ifdef WIN32
#define DLLExport __declspec(dllexport)
#else
#define DLLExport
#endif
DLLExport void din_useStatic();
#endif
动态链接库.cpp
#include "dynamic_lib.h"
DLLExport void din_useStatic()
{
CTest::test.use();
}
CMakeLists.txt
project( StaticProblem )
cmake_minimum_required(VERSION 2.6)
if(WIN32)
else(WIN32)
ADD_DEFINITIONS(-fPIC)
endif(WIN32)
ADD_LIBRARY( static_lib STATIC static_lib.cpp static_lib.h)
ADD_LIBRARY( dynamic_lib SHARED dynamic_lib.cpp dynamic_lib.h)
TARGET_LINK_LIBRARIES( dynamic_lib static_lib )
ADD_EXECUTABLE( main_exe main_exe.cpp )
TARGET_LINK_LIBRARIES( main_exe static_lib dynamic_lib )
这个示例在 Windows 上运行得很好,但在 Linux 上会出现问题。 既然它在 Windows 上可以正常运行,解决方案应该是更改某些链接选项或类似的东西,而不是更改项目结构或不使用静态变量。
输出:
Windows
CTest() this=268472624
CTest() this=4231488
use
use
~CTest() this=4231488, is Alive
~CTest() this=268472624, is Alive
Linux
CTest() this=6296204
CTest() this=6296204
use
use
~CTest() this=6296204, is Alive
~CTest() this=6296204, is Dead