ACRyL is a data-driven tool for detecting compatibility issues in Android apps. ACRyL requires dex2jar in order to be executed.

To build ACRyL, just run mvn package. The JAR file will be available in the target directory.

ACRyL requires a ruleset file containing all the rules that it will check in the target Android app. If you have such a ruleset, simply skip this step. Otherwise, you can build one following the next steps.

To build the ruleset it is necessary to extract CAUs (Conditional API Usages) from the training APKs. To do this, run this command on each APK:

java -cp acryl.jar it.unimol.acryl.runnable.APIVersionExtractor /path/to/android-tools/ /path/to/android-sdk/ /path/to/dex2jar /path/to/target-apk.apk /path/to/output-filename.csv

The class output a CSV file (/path/to/output-filename.csv) containing all the CAUs of the chosen APK (/path/to/target-apk.apk). Please, put all the extracted CSV files in a folder (e.g, /path/to/caus/, from now on)

Another piece of information needed to build the ruleset is represented by the API usages. To extract API usages, run

java -cp acryl.jar it.unimol.acryl.runnable.AndroidApiExtractor /path/to/android-tools/ /path/to/android-sdk/ /path/to/dex2jar /path/to/target-apk.apk /path/to/output-filename.csv

Please, put all the API usages CSV file in a folder (e.g., path/to/api-usages/, from now on)

To build the ruleset, you can just run a Ruby script from the ruleset-builder folder:

ruby workflow_build_ruleset.rb /path/to/caus/ /path/to/ruleset.csv /path/to/api-usages/

A CSV file containing the ruleset will be created at /path/to/ruleset.csv.

ACRyL detector can be run on the target Android app (APK) to find compatibility issues using the following command:

java -cp acryl.jar it.unimol.acryl.runnable.Detector /path/to/android-tools/ /path/to/android-sdk/ /path/to/dex2jar /path/to/target-apk.apk /path/to/output-filename.csv /path/to/ruleset.csv /path/to/api_lifetime.txt {min-confidence} 0 {api-level} 

Where:

• /path/to/android-tools/, /path/to/android-sdk/, /path/to/dex2jar are the same previously described;
• /path/to/target-apk.apk is the path to the APK of the app on which ACRyL should find compatibility issues;
• /path/to/output-filename.csv is the path to the output file containing the warnings found by ACRyL;
• /path/to/ruleset.csv is the path to the ruleset;
• /path/to/api_lifetime.txt is the path to a file (API lifetime) which specifies, for each method signatures, its lifetime; it was built using CiD (e.g.: https://raw.githubusercontent.com/lilicoding/CiD/master/res/android_api_lifetime.txt)
• {min-confidence} is the minimum confidence level for the rules (suggested: 5). The higher this number, the lower the number of warnings.
• 0: this argument is there for legacy reasons and it will be ignored, but you need to keep it if you want to specify the other argument;
• {api-level}: optional parameter indicating the target Android API level. Use a numeric value (e.g., 27).