CROSSmeeting UM, Fev T5: Slicing Techniques Applied to OSS Pedro Rangel Henriques Daniela da Cruz Dep. de Informática/CCTC, Universidade do Minho, Braga-Portugal UM Fevereiro de 2010

CROSSmeeting UM, Fev Context CROSS (an infrastructure for Certification and Re-engineering of Open-Source Sw) ; Code Analysis for software comprehension (quality assessment, re-use, re-engineering, transformation)

CROSSmeeting UM, Fev Motivation To contribute to the portfolio of analysis tools – that will be made available through the OSS Certification Portal (task T7) improving Code Analysis via Slicing Techniques

CROSSmeeting UM, Fev Code Analysis Code Analysis is concerned with the extraction of data from Programs the storage of information, and the visualization of knowledge SWSystem, aiming at its comprehension.

CROSSmeeting UM, Fev Code Analysis To face the growing complexity of software systems, a promising approach for CA is the restriction of the analysis to a program slice.

CROSSmeeting UM, Fev Our main Proposal Semantic slicing applied intra and inter program components increases component understanding/reusing Semantic slicing is based on contracts (pre, post-conditions and invariants)

CROSSmeeting UM, Fev Objectives We planned 5 subtasks 1. Test-bed. 2. Semantic Slicing 3. Labeled Control Graph 4. Slicing Specific Software Facets 5. Dynamic slicing techniques

CROSSmeeting UM, Fev Objectives – substask1 Test-bed. Development of a platform (web environment) to support the pragmatic validation of the semantic slicing variants under study.

CROSSmeeting UM, Fev Objectives – substask2 Development of new slicing techniques for annotated programs ( programs whose code is commented with constraints, typically logical expressions capturing pre/post conditions and invariants ). Different perspectives can be considered: ……..

CROSSmeeting UM, Fev Objectives – substask2 a) Given a traditional slicing criterion, perform backward slicing in order to identify all the pre/post conditions involving that variable; b) Given a pre/post condition of a method, perform forward slicing in order to identify all the program statements that depends on that condition;

CROSSmeeting UM, Fev Objectives – substask2 c) Given an annotated procedure, identify all its statements that do not contribute to the verification of the post- condition; d) Given an annotated procedure and set of procedure-calls remove from the procedure all the statements that do not contribute to calling needs;

CROSSmeeting UM, Fev Objectives – substask2 e) Given an annotated procedure, extract and display the annotation in order to aid in its reuse; f) Given an annotated procedure verify the precondition satisfiability at each calling point; g) Given a procedure, infer its annotation

CROSSmeeting UM, Fev Objectives – substask3 Development of new instrument for visualization and manipulation of annotated procedures : Labeled Control Flow Graph Labeled System Dependency Graph

CROSSmeeting UM, Fev Objectives – substask4 Application of slicing techniques to reverse engineering of specific software facets --business logic, user interfaces, architectural issue, etc.-- to assess a given SwSystem. ( verify its compliance with the problem requirements )

CROSSmeeting UM, Fev Objectives – substask4 To attain this objective, it is required to change the traditional definition of slicing criterion in order to deal with the vocabulary of each specific facet.

CROSSmeeting UM, Fev Objectives – substask5 Dynamic slicing techniques to extract specific behavior, dealing with strong dynamic characteristics.

CROSSmeeting UM, Fev Conclusion Present Status: Tasks 1, 2, 3 under-development (Ph.D. work + BI / M.Sc.) Future: 2nd BI