使用CMake生成的DLL和奇怪的重复模板的不正确行为(C)

// da/Attribute.h:

#ifndef DA_ATTRIBUTE_H
#define DA_ATTRIBUTE_H

namespace da {

typedef unsigned int AttributeId;

class AttributeBase {
public:
    virtual AttributeId getTypeId() const=0;

protected:
    /** Static ID counter.  Every class that derives da::AttributeBase is
        assigned an increment of this counter as its type ID number */
    static AttributeId sNextId;

};

template <class Derived>
class Attribute : public AttributeBase {
private:
    static AttributeId msTypeId;

public:
    Attribute() {
        if (msTypeId == 0) {
            msTypeId = ++sNextId;
        }
    }

    virtual ~Attribute() {

    }

    /** For static contexts */
    static AttributeId typeId() {
        if (msTypeId == 0) {
            msTypeId = ++sNextId;
        }

        return msTypeId;
    }

    AttributeId getTypeId() const {
        return typeId();
    }

};

template <class Derived> AttributeId Attribute<Derived>::msTypeId = 0;

}

#endif

问题是,当我将DLL链接到可执行项目时,似乎与不同的ID方法存在一些不一致.例如：

// Foo.h
struct Foo : public da::Attribute<Foo> {
    Foo() { }
};

…

// main.cpp
Foo *foo = new Foo;    

Foo->getTypeId() == 1 // True
Foo::typeId() == 1 // Should be true,but isn't.  Foo::typeId() == 2

通过GDB运行,在Foo :: getTypeID()中断,我发现“msTypeId”和“Foo :: msTypeId”具有不同的内存地址.我勒个去.

这只发生在DLL中定义Foo时. (仅在Windows 7中,显然 – 我的Debian构建中没有这个问题)如果我在main.cpp中创建派生类,或者如果我只是将库中的所有代码编译成可执行文件,则跳过完全DLL步骤,它没有任何问题.

一切都是使用MSYS和MinGW编译的,在Windows 7 Home Premium上使用GCC 4.7.

这是库的CMakeLists.txt,以防我在那里弄乱了一些东西：

cmake_minimum_required(VERSION 2.6)
project(foo)

add_definitions(-std=c++0x)
set(CMAKE_BUILD_TYPE Debug)

set(sources
    Foo.cpp
)

add_library(foo SHARED ${sources})