JML in Feature-Oriented Programming

Transcription

1 JML in Feature-Oriented Programming Fabian Benduhn, Supervisor:Thomas Thüm March 23rd, 2012 University of Magdeburg, Germany

2 Java Modeling Language (JML) Specification language for Java Specification as Java comments Design by Contract Method Contract Precondition Postcondition Class invariants class BankAccount{ balance >= 0; amount >= 0; balance == \old(balance) amount; void debit(int amount) {... } Fabian Benduhn JML in Feature-Oriented Programming 2

3 Why JML? Many tools/applications: Static analysis Runtime assertions Test case generation Documentation generation Specification generation FOP specific: Feature interaction detection (Scholz et al. [2011]) Easy to learn/use (Java style syntax) Fabian Benduhn JML in Feature-Oriented Programming 3

4 Contract Composition JML is suitable to specify Java programs How can JML be used for Feature Oriented Programming? Introduction of classes/methods as usual. Refinement of classes/methods How to refine Contracts? Fabian Benduhn JML in Feature-Oriented Programming 4

5 Contract Composition How to refine Contracts? (Thüm et al. [2011]) Plain contracting: Contracts can only be introduced but not refined Contract overriding: Contracts can be overridden Consecutive contract refinement: Specification inheritance for features - contracts of previous features hold implicitly Explicit contract refinement: Contracts can be refined by referencing previous contracts Pure method refinement: Contracts are refined by refining pure methods Fabian Benduhn JML in Feature-Oriented Programming 5

6 Explicit contract refinement class Sorting { requires data!= ensures (\forall int i; 0 < i && i < data[i 1].key <= / void sort(item[] data) { / heap sort algorithm / } } refines class Sorting { requires ensures original &&...sorting is / void sort(item[] data) { / merge sort algorithm / } } class Sorting { requires data!= ensures (\forall int i; 0 < i && i < data[i 1].key <= &&..sorting is / void sort(item[] data) { / merge sort algorithm / } } Fabian Benduhn JML in Feature-Oriented Programming 6

7 Goals/Tasks We want tool support for FOP with JML support Implementation of one or more contract composition mechanisms Extend existing tool for Feature Oriented Programming: FeatureHouse Already supports Java Generic composition approach allows JML extension Evaluation of contract composition with a case study Expressiveness Specification clones... Fabian Benduhn JML in Feature-Oriented Programming 7

8 Feature Structure Tree package util; Class Calc{ int a,b,c; init(){... } stop(){... } } Fabian Benduhn JML in Feature-Oriented Programming 8

9 Composition Process Fabian Benduhn JML in Feature-Oriented Programming 9

10 Composition Process (JML Extension) Fabian Benduhn JML in Feature-Oriented Programming 10

11 Feature Structure Tree (JML Extension) Fabian Benduhn JML in Feature-Oriented Programming 11

12 Feature Structure Tree (JML Extension) Fabian Benduhn JML in Feature-Oriented Programming 12

13 Summary Implementation: Existing JML parser or own Implementation? Which composition mechanisms should be implemented? Case study/evaluation? Fabian Benduhn JML in Feature-Oriented Programming 13

14 References I Wolfgang Scholz, Thomas Thüm, Sven Apel, and Christian Lengauer. Automatic Detection of Feature Interactions using the Java Modeling Language: An Experience Report. In Proc. Int l Workshop Feature-Oriented Software Development (FOSD), pages 7:1 7:8, New York, NY, USA, ACM. ISBN doi: Thomas Thüm, Ina Schaefer, Martin Kuhlemann, and Sven Apel. Proof Composition for Deductive Verification of Software Product Lines. In Proc. Int l Workshop Variability-intensive Systems Testing, Validation and Verification (VAST), pages , Washington, DC, USA, IEEE. doi: /ICSTW Fabian Benduhn JML in Feature-Oriented Programming 14