DrDup2 is a novel clone detector based on the index of abstract syntax trees. Please, see the following paper for details:

Zdenek Tronicek, Indexing source code and clone detection, Information and Software Technology, Volume 144, 2022, 106805, ISSN 0950-5849.

To compile the code, you need to install maven and run the following command (see also compile.bat):

mvn clean compile assembly:single

The run and output of DrDup2 are controlled by a configuration file, which can contain the following configuration parameters:

• level specifies the granularity of the index; accepted values are "method" and "statement".
• compressed specifies whether the index is compressed or not; accepted values are "true" and "false".
• persistent specifies whether the index is built in main memory or on secondary storage; accepted values are "true" and "false".
• minSize specifies the minimum number of lines; for example, if minSize is 5, the code fragment must have at least 5 lines to be reported.
• ignoreUnaryAtLiterals specifies how the unary plus and minus are treated; accepted values are "true" and "false".
• ignoreAnnotations specifies whether annotations in code are taken into account; accepted values are "true" and "false".
• treatNullAsLiteral specifies how "null" is treated; accepted values are "true" and "false".
• treatSuperThisAsIdentifier specifies whether "super" and "this" are treated as identifiers; accepted values are "true" and "false".
• treatVoidAsType specifies how "void" is treated; accepted values are "true" and "false".
• batchFileSize specifies how many files are processed before the index in memory is merged with the persistent index.

Example:

• index = simplified
• level = method
• rename = blind
• compressed = true
• persistent = false
• sourceDir = /research/BigCloneBench
• minSize = 20
• outputFile = bigclonebench.xml

To run the clone detector with test.properties configuration file, use the following command:

java -jar target/DrDup2-1.0-jar-with-dependencies.jar test.properties

See also examples in the evaluation folder.