这段代码如何隐藏链接器中的符号?

时间:2013-03-26 13:39:16

标签: c++ objective-c cocos2d-iphone

在SceneView.h中:

#ifndef ProtoAlpha_SceneView_h
#define ProtoAlpha_SceneView_h

#include "cocos2d.h"
#include "SceneModel.h"
#include "SceneController.h"
#include "CharacterModel.h"
#include "CharacterDerived.h"

USING_NS_CC;

class SceneView : public CCLayer {
private:
    static SceneModel* sceneModel;
    static SceneView* sceneViewLayer;
    static SceneController* sceneControllerLayer;
    CharacterModel* t1;
    CharacterModel* t2;
    CCSprite* t1Sprite;

    // scheduled Update 
    void update(float dt);

在SceneView.ccp中:

CCScene* SceneView::scene() {
    // 'scene' is an autorelease object
    CCScene* scene = CCScene::create();

    // 'layer' is an autorelease object
    sceneModel = new SceneModel;
    sceneViewLayer = SceneView::create();
    sceneControllerLayer = new SceneController(*sceneModel->buffer);

    // add layer as a child to scene
    scene->addChild(sceneViewLayer);
    scene->addChild(sceneControllerLayer);

    // return the scene
    return scene;
}

错误:

Undefined symbols for architecture i386:
  "SceneView::sceneModel", referenced from:
      SceneView::scene() in SceneView.o
      SceneView::update(float) in SceneView.o
  "SceneView::sceneViewLayer", referenced from:
      SceneView::scene() in SceneView.o
  "SceneView::sceneControllerLayer", referenced from:
      SceneView::scene() in SceneView.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

如果我要注释.ccp文件中的代码,链接器错误就会消失,因此不太可能是编译源错误。

通过一些搜索,我发现有一些人引用了这段代码的符号可能有些隐藏,我希望了解这里实际发生了什么。

1 个答案:

答案 0 :(得分:4)

static SceneModel* sceneModel;
static SceneView* sceneViewLayer;
static SceneController* sceneControllerLayer;

这些都是非定义的声明,因为它们是static。您还需要为这些成员提供定义:

SceneModel* SceneView::sceneModel;
SceneView* SceneView::sceneViewLayer;
SceneController* SceneView::sceneControllerLayer;

确保这些只在一个翻译单元中(可能在SceneView.cpp中),否则您将违反一个定义规则。