243,004 research outputs found
Formally verifying Ada programs which use real number types
Formal verification is applied to programs which use real number arithmetic operations (mathematical programs). Formal verification of a program P consists of creating a mathematical model of F, stating the desired properties of P in a formal logical language, and proving that the mathematical model has the desired properties using a formal proof calculus. The development and verification of the mathematical model are discussed
Computer-Assisted Program Reasoning Based on a Relational Semantics of Programs
We present an approach to program reasoning which inserts between a program
and its verification conditions an additional layer, the denotation of the
program expressed in a declarative form. The program is first translated into
its denotation from which subsequently the verification conditions are
generated. However, even before (and independently of) any verification
attempt, one may investigate the denotation itself to get insight into the
"semantic essence" of the program, in particular to see whether the denotation
indeed gives reason to believe that the program has the expected behavior.
Errors in the program and in the meta-information may thus be detected and
fixed prior to actually performing the formal verification. More concretely,
following the relational approach to program semantics, we model the effect of
a program as a binary relation on program states. A formal calculus is devised
to derive from a program a logic formula that describes this relation and is
subject for inspection and manipulation. We have implemented this idea in a
comprehensive form in the RISC ProgramExplorer, a new program reasoning
environment for educational purposes which encompasses the previously developed
RISC ProofNavigator as an interactive proving assistant.Comment: In Proceedings THedu'11, arXiv:1202.453
Towards a General Framework for Formal Reasoning about Java Bytecode Transformation
Program transformation has gained a wide interest since it is used for
several purposes: altering semantics of a program, adding features to a program
or performing optimizations. In this paper we focus on program transformations
at the bytecode level. Because these transformations may introduce errors, our
goal is to provide a formal way to verify the update and establish its
correctness. The formal framework presented includes a definition of a formal
semantics of updates which is the base of a static verification and a scheme
based on Hoare triples and weakest precondition calculus to reason about
behavioral aspects in bytecode transformationComment: In Proceedings SCSS 2012, arXiv:1307.802
Featherweight VeriFast
VeriFast is a leading research prototype tool for the sound modular
verification of safety and correctness properties of single-threaded and
multithreaded C and Java programs. It has been used as a vehicle for
exploration and validation of novel program verification techniques and for
industrial case studies; it has served well at a number of program verification
competitions; and it has been used for teaching by multiple teachers
independent of the authors. However, until now, while VeriFast's operation has
been described informally in a number of publications, and specific
verification techniques have been formalized, a clear and precise exposition of
how VeriFast works has not yet appeared. In this article we present for the
first time a formal definition and soundness proof of a core subset of the
VeriFast program verification approach. The exposition aims to be both
accessible and rigorous: the text is based on lecture notes for a graduate
course on program verification, and it is backed by an executable
machine-readable definition and machine-checked soundness proof in Coq
ntegrating Formal Program Verification with Testing
International audienceVerification activities mandated for critical software are essential to achieve the required level of confidence expected in life-critical or business-critical software. They are becoming increasingly costly as, over time, they require the development and maintenance of a large body of functional and robustness tests on larger and more complex applications. Formal program verification offers a way to reduce these costs while providing stronger guarantees than testing. Addressing verification activities with formal verification is supported by upcoming standards such as do-178c for software development in avionics. In the Hi-Lite project, we pursue the integration of formal verification with testing for projects developed in C or Ada. In this paper, we discuss the conditions under which this integration is at least as strong as testing alone. We describe associated costs and benefits, using a simple banking database application as a case study
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