Integration of static and dynamic analysis for understanding legacy source code
Download as pptx, pdf0 likes173 views
The document describes an approach to integrating static and dynamic analysis to generate documentation for understanding legacy source code. It aims to capture dependencies between inputs and outputs of computational models. The approach was applied to a real-world process model from the steel industry. Static analysis extracted mathematical formulas and execution paths, while dynamic analysis provided concrete values from a model run. The results were merged to generate step-by-step documentation of how each output is computed from the inputs in a compact and understandable format. The analysis revealed a significant reduction in complexity compared to source code alone. The approach provides a characterization of computational models in process control software through integrated static and dynamic program analysis.
More Related Content
What's hot (17)
Similar to Integration of static and dynamic analysis for understanding legacy source code (20)
Recently uploaded (20)
Integration of static and dynamic analysis for understanding legacy source code
- 1. SCCH is an initiative of SCCH is located in Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Michael Moser +43 7236 3343 814 [email protected] www.scch.at ICSME’16, Industry Track, 06.10.2016
- 2. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code An Industry Collaboration 2© Software Competence Center Hagenberg GmbH Michael Moser [email protected] Pichler Josef [email protected] Wilhelm Kirchmayr [email protected] Ludwig Nocke [email protected] Rudolf Tober [email protected]
- 3. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 3© Software Competence Center Hagenberg GmbH Background: Mr. Kaufmann’s Process Models Mr. Kaufmann (Process Engineer)
- 4. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 4© Software Competence Center Hagenberg GmbH Background: Mr. Kaufmann’s Process Models Mr. Kaufmann (Process Engineer)
- 5. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 5© Software Competence Center Hagenberg GmbH Background: Mr. Kaufmann’s Process Models Mr. Kaufmann (Process Engineer) controlled by
- 6. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 6© Software Competence Center Hagenberg GmbH Background: Mr. Kaufmann’s Process Models Mr. Kaufmann (Process Engineer) controlled by feedback from
- 7. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 7© Software Competence Center Hagenberg GmbH Integration of Static and Dynamic Analysis for Understanding Legacy Source Code C++, 5600 LoC Core Model created by 3rd party company 20 model outputs from 22 inputs Evolved in a multi-shell model Background: Mr. Kaufmann’s Process Models DeMo - Process model for desulphurization Influence of input values not documented Mr. Kaufmann
- 8. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 8© Software Competence Center Hagenberg GmbH Mr. Kaufmann (retired) Background: Mr. Kaufmann’s Process Models Mr. Bauer / Mr. Huber (Process Engineers)
- 9. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 9© Software Competence Center Hagenberg GmbH Background: Mr. Kaufmann’s Process Models Questions ??? What is the formula for a model result? Which input values affect which result? What are all results of a process model? Mr. Kaufmann (retired) Mr. Bauer / Mr. Huber (Process Engineers)
- 10. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Starting Point: Requirements and Goals 10© Software Competence Center Hagenberg GmbH Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Documentation requested! Simplify maintenance and optimization Grant quick overview of the system Capture dependencies between inputs and outputs Flexible clipping of model source code Reflect the hierarchical structure Offline documentation
- 11. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code use of dynamic analysis Examine program execution Do not fully capture behavior Needed: Model Interpretation Include values from model execution Merge with results from static analysis Starting Point: Overall Approach 11 use of static analysis Analyze entire program sources Extract abstract representations Application of RbG* to extract Mathematical formulae Decision tables / path conditions Essential program structures Needed: Stepwise Computation from a model input to its outputs Out1 Var1 In1 Var2 In2 Out1 Var1 In1 Var2 In2 input values *M. Moser and J. Pichler: RbG: A Documentation Generator for Scientific and Engineering Software, (SANER 2015)
- 12. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Example: A process model 12© Software Competence Center Hagenberg GmbH Calling Context typedef struct { double snow_density; } output; typedef struct { double snow_height; double gamma_rho_S; bool useFudgeFactor; } input;
- 13. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Example: A process model 13© Software Competence Center Hagenberg GmbH Pre processing of input in outer shell
- 14. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Example: A process model 14© Software Competence Center Hagenberg GmbH Execution of core computational model
- 15. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Example: A process model 15© Software Competence Center Hagenberg GmbH Post processing of result data
- 16. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results for Example: Stepwise Computation Symbol Formula Path Condition Input
- 17. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results for Example: Stepwise Computation Symbol Formula Path Condition Input One table for each result One row for each computation that may influence result Variables used within definitions are repeatedly resolved Variable names may be replaced with symbol info
- 18. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 18© Software Competence Center Hagenberg GmbH Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results for Example: Model Execution Symbol Formula Value Path Condition Input
- 19. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 19© Software Competence Center Hagenberg GmbH Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results for Example: Model Execution Symbol Formula Value Path Condition Input Results from model execution merged with static tables Model execution with concrete input values Unexecuted rows are hidden
- 20. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 20© Software Competence Center Hagenberg GmbH Results for Example: Model Execution Symbol Formula Value Path Condition Input Results from model execution merged with static tables Model execution with concrete input values Unexecuted rows can be displayed
- 21. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results for Example: Big Picture 21© Software Competence Center Hagenberg GmbH
- 22. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results for Example: Big Picture 22© Software Competence Center Hagenberg GmbH Fits on a sheet of paper C++ methods and functions Ordered call relations Sub model clustering Database access Side-by-side with code Packaged with documentation
- 23. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code dynamic analysis model execution program interpretation flow-sensitive analysis inter-procedural control-flow-graph Specification of concrete values Merge with stepwise computation Analysis: A little more details 23© Software Competence Center Hagenberg GmbH static analysis stepwise computation Construction of use-definition chains Inter-procedural control-flow-graph Forward propagation of definitions Use-Definition chains per model output “Entry-Point” Aware big picture Call-graph analysis Pattern-matching Out1 Var1 In1 Var2 In2 Out1 Var1 In1 Var2 In2 input values
- 24. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results: Tool Support for Documentation Generation 24© Software Competence Center Hagenberg GmbH
- 25. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results: Lessons Learned from DeMo Process Model 25© Software Competence Center Hagenberg GmbH
- 26. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Results: Lessons Learned from DeMo Process Model 26© Software Competence Center Hagenberg GmbH domain experts provided model outputs and model inputs 2 entry point definitions (F1, F2) 3 sets of input values core entry point (F2) 21 outputs, 22 inputs significant drop of rows reduction 78% - 98%
- 27. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Limitations: For the General Case 27© Software Competence Center Hagenberg GmbH Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Implementation limited in several ways Bindings are only statically resolved No 100% language coverage for C++ Pointer arithmetic not supported Missing input values yield incomplete results Interpreted model execution vs. real program execution Extraction of formulae is limited (partly on purpose) Scalability of big picture representation Limited
- 28. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code 28© Software Competence Center Hagenberg GmbH Take Aways / Summary Characterization of computational models in process control software Integration of static and dynamic program analysis Documentation generation for a real world process model Dynamic analysis creates more compact and understandable documentation
- 29. Integration of Static and Dynamic Analysis for Understanding Legacy Source Code Thanks and Discussion Michael Moser Software Analytics and Evolution Software Competence Center Hagenberg, Austria [email protected] 29© Software Competence Center Hagenberg GmbH