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Static Analysis Using Facebook Infer to Find Atomicity Violations
Harmim, Dominik ; Smrčka, Aleš (referee) ; Vojnar, Tomáš (advisor)
The goal of this thesis is to propose a static analyser that detects atomicity violations. The proposed analyser Atomer is implemented as a module of Facebook Infer, which is an open-source and extendable static analysis framework that promotes efficient modular and incremental analysis. The analyser works on the level of sequences of function calls. The proposed solution is based on the assumption that sequences executed atomically once should probably be executed always atomically. The implemented analyser has been successfully verified and evaluated on both smaller programs created for testing purposes as well as publicly available benchmarks derived from real-life low-level programs.
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Improving Precision of Program Analysis in the 2LS Framework
Smutný, Martin ; Vojnar, Tomáš (referee) ; Malík, Viktor (advisor)
Cílem této práce je navrhnout způsob vedoucí ke zvýšení přesnosti analýzy programů pomocí nástroje 2LS, založený na existujících konceptech, a to hlavně na syntézi invariant na základě šablon. 2LS je nástroj pro statickou analýzu programů napsaných v jazyce C, který využívá SMT solver a abstraktní interpretaci k automatickému odvození invariant. V případě kdy 2LS nedokáže rozhodnout zda je program správný, navrhované řešení analyzuje invarianty vypočítané v různých abstraktních doménách, a identifikuje takové části invariant, které mohou s největší pravděpodobností způsobit nejednoznačnost verifikace. Pomocí těchto získaných informací, dokáže navrhnutá metoda identifikovat proměnné původního programu, na kterých pravděpodobně závisí úspěch verifikace. Výstup tohoto řešení může posloužit jako zpětná vazba indikující proměnné, jejíchž problematické hodnoty by měly být omezeny. Také může být výstup využit vývojáři 2LS pro účely debugování při vývoji nových analýz. Řešení bylo implementováno v nástroji 2LS. Na základě různých experimentů mezinárodní soutěže ve verifikaci programů SV-COMP, dokáže řešení identifikovat proměnné způsobující nejednoznačnost verifikace ve více než polovině programů, na kterých verifikace momentálně selhává.
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Static Analysis Using Facebook Infer Focused on Performance Analysis
Pavela, Ondřej ; Lengál, Ondřej (referee) ; Rogalewicz, Adam (advisor)
Static analysis has nowadays become one of the most popular ways of catching bugs early in the modern software. However, reasonably precise static analysis tools still often struggle to scale well on large and quickly changing codebases. Efficient static analysers, such as Coverity or Code Sonar, are usually proprietary and difficult to openly evaluate or extend. On the contrary, Facebook Infer offers an open source static analysis framework with the emphasis on compositional, incremental and consequently highly scalable inter-procedural analysis. This thesis presents Looper --- a new performance oriented resource bounds analyser which extends the capabilities of Facebook Infer. We have based our implementation on an existing resource bounds analyser Loopus and evaluated it on two different test suites, showing encouraging results in comparison with the existing Cost analyser developed by the Infer team.
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Static Analyzer for List Manipulating Programs
Kotoun, Michal ; Lengál, Ondřej (referee) ; Vojnar, Tomáš (advisor)
Creating a software verification tool is a complex task -- one must implement source code parsing, instruction representation, value abstraction, user interface, ... and the analysis itself. Therefore, we decided to create a static analysis framework to prevent unnecessary wheel reinventing by an analyses implementers. We propose a general design of the framework called Angie with a primary focus on usability, and describe a prototype implementation of the framework, including a model analysis based on symbolic memory graphs. Angie is implemented in C++ and uses the LLVM toolchain as the front-end for parsing the source code of analysed programs.
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String Analysis for Code Contracts
Dort, Vlastimil ; Parízek, Pavel (advisor) ; Kofroň, Jan (referee)
Using contracts such as method preconditions, postconditions, and class invariants in code is an approach to preventing bugs in object-oriented programs. In the .NET Framework, this is possible due to the framework of Code Contracts, which includes Clousot, a tool for static program analysis based on abstract interpretation. Although string is a fundamental type in .NET programs, Clousot does not have a usable support for analysis of string values. In this thesis, we explore the specifics of string manipulation in the C# language and in the .NET Framework, and show how they can be covered by static analysis. Our approach is to use the methods of the String class and a subset of regular expressions to specify string properties in code, and to use abstract interpretation with non-relational abstract domains to reason about those properties. We chose a small number of already published abstract domains for strings, which vary in their complexity and ability to represent different properties. We adapted those domains to our setting, including definitions of abstract semantics for the supported string methods. We implemented the abstract domains in Clousot in a way that cooperates with numerical analysis and allows adding more string abstract domains in the future. Powered by TCPDF (www.tcpdf.org)
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Static Value Analysis over C Programs
Ďuričeková, Daniela ; Peringer, Petr (referee) ; Vojnar, Tomáš (advisor)
Value-range analysis is a static analysis technique based on arguing about the values that a variable may take on a given program point. It can be used to prove absence of run-time errors such as out-of-bound array accesses. Since value-range analysis collects information on each program point, data-flow analysis can be used in association with it. The main goal of this work is designing and implementing such a value-range analysis tool. The work begins with an introduction into the topic, an explanation of data-flow and value-range analyses and a description of abstract interpretation, which provides the formal basis of the analyser. The core of this work is the design, implementation, testing and evaluation of the analyser. In the conclusion, our personal experience obtained in the area of the thesis is mentioned, along with a discussion of a possible future development of the designed tool.
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