I have a project with several plugins i want to compile into one library. I get the error:
@./debug\moc_stringoperationsplugin.o: In function qt_plugin_query_metadata': C:\...\ARGS-Plugins\ARGS-Plugins-build-Desktop_Qt_5_0_1_MinGW_32bit-Debug/debug/moc_stringoperationsplugin.cpp:153: multiple definition ofqt_plugin_query_metadata'
./debug\moc_tplugin.o:C:...\ARGS-Plugins\ARGS-Plugins-build-Desktop_Qt_5_0_1_MinGW_32bit-Debug/debug/moc_tplugin.cpp:153: first defined here
./debug\moc_stringoperationsplugin.o: In function qt_plugin_instance': C:\...\ARGS-Plugins\ARGS-Plugins-build-Desktop_Qt_5_0_1_MinGW_32bit-Debug/debug/moc_stringoperationsplugin.cpp:153: multiple definition ofqt_plugin_instance'
./debug\moc_tplugin.o:C:...\ARGS-Plugins\ARGS-Plugins-build-Desktop_Qt_5_0_1_MinGW_32bit-Debug/debug/moc_tplugin.cpp:153: first defined here@
Do i have to have a project for every single plugin or is it possible to have several plugins in one library? If it's possible to have several plugins in one library, what else could cause this error? I could not find a single helpful post online so i think this problem is very rare.
I'll post code if someone thinks that will be necessary but i hope to get a general answer to what could cause this error message.
Thanks in advance!

Edit: Quick question: does the IID in the "Q_PLUGIN_METADATA(IID "reversed.url")" need to be unique, e.g. does every plugin needs its own IID or should it be the same for every plugin? I couldn't find information regarding this.

 
 

[quote] Q_PLUGIN_METADATA(...)
This macro is being used to declare meta data that is part of a plugin that instantiates this object.
The macro needs to declare the IID of the interface implemented through the object, and reference a file containing the meta data for the plugin.
There should be exactly one occurrence of this macro in the source code for a Qt plugin.[/quote]

You can't have multiple Q_PLUGIN_METADATA definitions per plugin (for technical reasons, the plugin metadata is placed in a special region of the binary so the metadata can be fetched without dlopen()'ening the library and for logical reasons, as there has to be a single root object which is instantiated on load), but you can have multiple classes implementing various interfaces.

@
class PluginA : public QObject, public InterfaceA
{
Q_OBJECT
Q_INTERFACES(InterfaceA)
}

class PluginB : public QObject, public InterfaceB
{
Q_OBJECT
Q_INTERFACES(InterfaceB)
}

class PluginCollection : public QObject, public PluginCollectionInterface
{
Q_OBJECT
Q_PLUGIN_METADATA(IID "PluginCollectionInterface")

public:
QList<QObject*> plugins() { return QList<QObject*>{new PluginA, new PluginB}; }

// or

QList<QString> plugins() { ... }
QObject *create(const QString &plugin) { ... };

}
@
Brain to terminal.

multiple definition of qt_plugin_query_metadata的更多相关文章

  1. multiple definition of `err_sys' 《UNIX环境高级编程》

    本文地址:http://www.cnblogs.com/yhLinux/p/4079930.html 问题描述: [点击此处直接看解决方案] 在练习<UNIX环境高级编程>APUE程序清单 ...

  2. gcc: multiple definition of [转]

    /home/tace/openav/source/SeamlessMessage/CPaoFlt.o: In function `CPaoFlt::get_m_strPrmair() const':C ...

  3. 链接错误:multiple definition of 'xxx' 问题解决及其原理

    内容借鉴 于CSDN炸鸡叔 错因 截图: “multiple definition of  'head' ” “multiple definition of  'tail' ” 解决过程: 1.首先要 ...

  4. multiple definition of XXX情况分析

    近日在写代码,各个.cpp源文件编译时没有问题,将*.o进行链接时,出现了许多multiple definition of XXX的链接错误.于是在网上搜索了一番,结合自己的代码包含逻辑,最终发现了问 ...

  5. [err]multiple definition of `***'

    err CMakeFiles/dsm.dir/src/main_stateEstimation.cpp.o: In function `align_mean(cv::Mat, cv::Rect_< ...

  6. QT编译错误: multiple definition of `qMain(int, char**)'

    QT使用过程中来回添加修改代码,结果出现了编译错误:error: multiple definition of `qMain(int, char**)' 一直看我的源文件是都哪里有错误,最后发现是在p ...

  7. qt用mingw编译时报错 multiple definition of

    网上相关回答不少,但过于简单,这里做一下记录. qt用mingw编译程序时报“multiple definition of …”这个错误,错误信息大概是如下图所示: 1 2 3 首先,检查自己的程序是 ...

  8. 解决 multiple definition of

    总结了解决multiple definition of的方法: 问题原因:    当多个文件包含同一个头文件时,并且你的.H里面没有加上条件编译#ifndef TEST_H#define TEST_H ...

  9. C++ "multiple definition of .. first defined here"

    C++ "multiple definition of .. first defined here" 在C++中,有时候需要在不同文件中使用同一个变量.对于这类变量如果处理不当,很 ...

随机推荐

  1. finecms如何调用多个栏目的子栏目

    前面我们说到了finecms如何调用多个指定栏目的内容,finecms如何调用多个栏目的子栏目呢?用下面的代码就可以实现了,其中id是具体的栏目id,用“,”逗号隔开 {list action=cat ...

  2. centos 安装 pcre

    版权声明:本文为博主原创文章,未经博主同意不得转载. https://blog.csdn.net/luozhonghua2014/article/details/37054235 #rpm -qa | ...

  3. windows media player 官方修复工具下载及修复方法

    http://download.microsoft.com/download/E/2/3/E237A32D-E0A9-4863-B864-9E820C1C6F9A/MicrosoftFixit.Win ...

  4. emq数据库插件

  5. 安装OpenSSL中出现的问题及解决

    1.报错:install-record.txt --single-version-externally-managed --compile" failed with error code 1 ...

  6. 【UML】-NO.42.EBook.5.UML.1.002-【UML 大战需求分析】- 活动图 (Activity Diagram)

    1.0.0 Summary Tittle:[UML]-NO.42.EBook.1.UML.1.002-[UML 大战需求分析]- 活动图 Style:DesignPattern Series:Desi ...

  7. zabbix 监控 redis

    redis  可以直接使用zabbix官方的模板 模板地址: https://github.com/blacked/zbx_redis_template redis 主机通过脚本把数据推送到zabbi ...

  8. JDBC 接口学习

    说明:文章所有内容皆选自实验楼教程[JDBC 入门教程],想要学习更多JDBC,可以点击教程进行学习~ JDBC 简介 JDBC 的全称是 Java Database Connectivity,叫做 ...

  9. [LeetCode] 209. Minimum Size Subarray Sum_Medium

    Given an array of n positive integers and a positive integer s, find the minimal length of a contigu ...

  10. selenium元素高亮显示

    selenium元素高亮显示: 采用js注入的方式,通过更改元素样式来实现. border:2px 边框  solid red 红色 def hightlight(self,element): &qu ...