CODEWITHSUNDEEP
c++includemaya
shaw2thefloor
shaw2thefloor

Reputation: 600

C++ include issue

I am writing a plugin for Autodesk Maya using C++ and have a linker error.

My main class is Maya_Search_Plugin.cpp

#include <Utilities.h>

DeclareSimpleCommand( search_face, PLUGIN_COMPANY, "4.5");

//doIt method is entry point for plugin
MStatus search_face::doIt( const MArgList& )
{
    //calls to Maya types/functions and Utilities functions
}

Then I have a Utilities class containing some static methods with header looking like this

#ifndef __Maya_CPP_Plugin__Utilities__
#define __Maya_CPP_Plugin__Utilities__
//#pragma once

//standard libs
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <iostream>
#include <math.h>

//maya libs
#include <maya/MDagPath.h>
#include <maya/MFn.h>
#include <maya/MFileIO.h>
#include <maya/MIOStream.h>
#include <maya/MFnMesh.h>
#include <maya/MFnTransform.h>
#include <maya/MGlobal.h>
#include <maya/MSelectionList.h>
#include <maya/MSimple.h>
#include <maya/MTypes.h>
#include <maya/MPointArray.h>
#include <maya/MObjectArray.h>


class Utilities{
    public: static const int max_mov = 50;
public:
    static double get_mesh_error(MPointArray, MPointArray, int);
    static MStatus translateManipulator(double amount, MObject *path);
    static void GetSelected(MObjectArray* objects, MFn::Type type);
};

#endif /* defined(__Maya_CPP_Plugin__Utilities__) */

with the implementation like this

#include <Utilities.h>

double Utilities::get_mesh_error(MPointArray a, MPointArray b, int vertexCount){
   ...
}


MStatus Utilities::translateManipulator(double amount, MObject *path){
   ...
}


void Utilities::GetSelected(MObjectArray* objects, MFn::Type type) {
   ...
}

However I am getting the following error

duplicate symbol _MApiVersion in:
    /Users/tmg06qyu/Library/Developer/Xcode/DerivedData/Maya_CPP_Plugin-hjrwvybwlvqyyscbmixdkcpdzjqr/Build/Intermediates/Maya_CPP_Plugin.build/Debug/Maya_CPP_Plugin.build/Objects-normal/x86_64/Maya_Search_Plugin.o
    /Users/tmg06qyu/Library/Developer/Xcode/DerivedData/Maya_CPP_Plugin-hjrwvybwlvqyyscbmixdkcpdzjqr/Build/Intermediates/Maya_CPP_Plugin.build/Debug/Maya_CPP_Plugin.build/Objects-normal/x86_64/Utilities.o
ld: 1 duplicate symbol for architecture x86_64
Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld failed with exit code 1

Which I presume is a linking error and there is some circular reference somewhere, but I can't work out where it is.

Any help appreciated.

Thanks.

Upvotes: 4

Views: 795

Answers (2)

Laurent Crivello
Laurent Crivello

Reputation: 3931

The issue may happen if you have multiple files which include MFnPlugin.h

Upvotes: 0

Pascal
Pascal

Reputation: 851

I know this is a year old. But I stumbled on this again a couple minutes ago...

Add 

#define MNoVersionString
#define MNoPluginEntry
#include <maya/MFnPlugin.h>

to your header or cpp files where you wrote your plugin code. Include 

#include <maya/MFnPlugin.h>

directly in your main.cpp that initializes the plugin.

Most of the examples in maya have the following string:

// This is added to prevent multiple definitions of the MApiVersion string.
#define _MApiVersion

before including anything. For example here.

Upvotes: 5

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