Decompiler Comparator

The aim of this project is compare java decompilers, see The Strengths and Behavioral Quirks of Java Bytecode Decompilers (doi:10.1109/scam.2019.00019).

% conference paper
@inproceedings{scam2019,
 title = {The Strengths and Behavioral Quirks of Java Bytecode Decompilers},
 booktitle = {Proceedings of the 19th IEEE International Working Conference on
  Source Code Analysis and Manipulation (SCAM )},
 year = {2019},
 author = {Nicolas Harrand and César Soto-Valero and Martin Monperrus and Benoit Baudry},
 doi = {10.1109/scam.2019.00019},
 url = {http://arxiv.org/pdf/1908.06895},
}

% journal paper
@article{jss2020,
 title = {Java Decompiler Diversity and its Application to Meta-decompilation},
 journal = {Journal of Systems and Software},
 year = {2020},
 doi = {10.1016/j.jss.2020.110645},
 author = {Nicolas Harrand and César Soto-Valero and Martin Monperrus and Benoit Baudry},
 url = {http://arxiv.org/pdf/2005.11315},
}

Usage

# Run decomiler -> Ast diff -> compiler -> test on each class
java -cp decompilercmp.jar se.kth.DecompilerComparator -p /path/to/test/project -d DecompilerName

# Run decomiler -> Ast diff -> compiler -> test on a single class
java -cp decompilercmp.jar se.kth.DecompilerComparator -p /path/to/test/project -d DecompilerName -c org/mypackage/MyClass

Output (projectName-decompiler-report.csv):

Class,isDecompilable,distanceToOriginal,isRecompilable,passTests

• Class: Class name
• isDecompilable: has the decompiler sucessuflly produced a java file for the given class?
• distanceToOriginal: Number of edit operation needed on the original AST to obtain the decompiled AST. (Integer.MIN_VALUE if the evaluation failed)
• nbNodesOriginal: Number of AST node in the original java source file.
• isRecompilable: can the decompiled java code be recompiled?
• bytecodeDistance: Minimum number of atomic edit to go from the original bytecode to the decompiled/recompiled one. (Computed with jardiff)
• passTests: do the tests of the project still pass after decompilation/recompilation of the class.

AST comparator is shamelessly copied from gumtree-spoon-ast-diff.

Note that if the targeted project supports it, eclipse compiler can be used instead of javac with

java -cp decompilercmp.jar se.kth.DecompilerComparator -p /path/to/test/project -d DecompilerName -j eclipse

Optional: run yajta in Tie mode to collect information on which tests to run for each class. (Put the tie-report.json in the root of the targeted project).

Complete command line help

Usage: <main class> [options]
  Options:
    --debug-class, -c       Optional. Run a single class
    --decompiler-name, -d   Name of the decompiler to test. See
                            se.kth.Decompiler for more details. Default CFR-0.141
                            Default: CFR-0.141
    --help, -h              Display this message.
                            Default: false
    --java-compiler, -j     Path to output directory. Default: default
                            Default: javac
    --output-dir, -o        Path to output directory. Default: report
                            Default: report
    --project, -p           Directory containing test reports
    --with-tests, -t        Meta decompile with tests
                            Default: false

Available decompilers: 
		Dava-3.3.0
		Procyon-0.5.34
		JADX-0.9.0
		Jode-1.1.2-pre1
		Fernflower
		CFR-0.141
		Krakatau
		JD-GUI-1.4.1
		Arlecchino

Run test on Meta-Decompiler

Flag -t can be used to stop only when a decompilation that passes tests is found.

java -cp decompilercmp.jar se.kth.DecompilerComparator -p /path/to/test/project -d Meta -j eclipse [-t]