以下测试用例是从一个真实应用程序精简而来,使用
-fsanitize=undefined
(使用GCC 6.1.1)将无法链接,但不使用它则可以正常链接。有人能告诉我为什么吗?似乎与Qt / QObject、-fvisibility=hidden
和-fsanitize=undefined
的组合有关,但具体问题出在哪里我不得而知。
lib1.h:#include <QObject>
class MyObject : public QObject
{
public:
MyObject (QObject * parent = nullptr);
~MyObject ();
void myMethod ();
};
lib1.cc:
#include "lib1.h"
#define EXPORT __attribute__((visibility("default")))
EXPORT MyObject::MyObject (QObject * parent) : QObject (parent)
{
}
EXPORT MyObject::~MyObject ()
{
}
EXPORT void MyObject::myMethod ()
{
}
lib2.cc:
#include "lib1.h"
void test (MyObject * object)
{
object->myMethod ();
}
构建步骤:
LIBFLAGS="-fPIC -shared -Wall -Wl,-z,defs"
QTFLAGS="-I/usr/include/qt -I/usr/include/qt/QtCore -lQt5Core"
g++ -fsanitize=undefined -fvisibility=hidden \
${QTFLAGS} ${LIBFLAGS} lib1.cc -o lib1.so
g++ -fsanitize=undefined \
${QTFLAGS} ${LIBFLAGS} lib1.so lib2.cc -o lib2.so
构建输出(来自最终步骤):
/tmp/ccY7PHv4.o:(.data.rel+0x18): undefined reference to `typeinfo for MyObject'
collect2: error: ld returned 1 exit status