C/C++/Java Duplicate Source Code Block Finder

(http://duplo.sourceforge.net/)

A more up to date version is at:

https://github.com/TrevorDArcyEvans/duplo.git

This project is a line by line port of the above project to .NET Core 6

Duplo (C/C++/Java Duplicate Source Code Block Finder)

Version 0.1.3 Readme File, May 2005

1. General Information
2. System Requirements
3. Download
4. Performance Measurements
5. Background
6. Prerequisites
7. Getting started
8. Porting to .NET Core 6
9. License

Duplicated source code blocks can harm maintainability of software systems. Duplo is a tool to find duplicated code blocks within multiple C/C++/Java source files.

src\engine\geometry\simple\TorusGeometry.cpp(56)
src\engine\geometry\simple\SphereGeometry.cpp(54)
	pBuffer[currentIndex*size+3]=(i+1)/(float)subdsU;
	pBuffer[currentIndex*size+4]=j/(float)subdsV;
	currentIndex++;
	pPrimitiveBuffer->unlock();

src\engine\geometry\subds\SubDsGeometry.cpp(37)
src\engine\geometry\SkinnedMeshGeometry.cpp(45)
    pBuffer[i*size+0]=m_ct[0]->m_pColors[i*3];
    pBuffer[i*size+1]=m_ct[0]->m_pColors[i*3+1];
    pBuffer[i*size+2]=m_ct[0]->m_pColors[i*3+2];

NAME
        Duplo 0.3.0 - duplicate source code block finder


SYNOPSIS
        duplo [OPTIONS] [INTPUT_FILELIST_FILE] [OUTPUT_FILE]

DESCRIPTION
        Duplo is a tool to find duplicated code blocks in large
        C/C++/Java/C#/VB.Net software systems.

        -ml minimal block size in lines (default is 4)
        -mc minimal characters in line (default is 3)
            lines with less characters are ignored
        -ip ignore preprocessor directives
        -d  ignore file pairs with same name
        -xml output file in XML
        INTPUT_FILELIST_FILE file with list of source files
        OUTPUT_FILE output file

VERSION
       0.3.0

AUTHORS
       Christian M. Ammann (cammann@giants.ch)
       Trevor D'Arcy-Evans (tdarcyevans@hotmail.com)

Please send Feedback and Bug Reports to:

cammann@giants.ch

tdarcyevans@hotmail.com

Generate a list of all files of a directory with:

Windows

dir /s /b /a-d *.cpp *.h > myFiles.lst
dir /s /b /a-d *.cs > myFiles.lst

UNIX

 find -name "*.cpp" > cppList.lst
 find -name "*.h" > includeList.lst
 cat cppList.lst includeList.lst > all.lst

Duplo needs about two times the memory of the total source code size. So if your Source code is about 120MB it requires 240MB.

Download Duplo here.

Duplo uses the techniques described in the paper A Language Independent Approach for Detecting Duplicated Code from Stéphane Ducasse, Matthias Rieger and Serge Demeyer to detect duplicated code blocks.

• .NET Core 6

$ git clone https://github.com/TrevorDArcyEvans/Duplo.Net.git
$ cd Duplo.Net
$ dotnet restore
$ dotnet build

As indicated at the start, this was a line by line conversion from C++ to C# In general, this was relatively straightforward due to the high degree of similarity between the languages.

Initial runtime performance was incredibly poor and profiling quickly revealed some bottlenecks:

1. matrix was reset by iterating over whole array and individually resetting each element

• C++ version used memset which writes directly to memory
• .NET version was changed to allocate a fresh matrix

2. object comparison went through several layers of indirection

• C++ version uses vtable directly
• .NET version probably uses reflection or something simlarly slow
• fix is to directly compare Hash values

Current runtime performance is still very slow, about 2 orders of magnitude slower than the C++ version.

Duplo is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Foobar is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Foobar; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

                               2005, Christian M. Ammann (cammann@giants.ch)