7 research outputs found

    Cyclic abduction of inductively defined safety and termination preconditions

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    We introduce cyclic abduction: a new method for automatically inferring safety and termination preconditions of heap manipulating while programs, expressed as inductive definitions in separation logic. Cyclic abduction essentially works by searching for a cyclic proof of the desired property, abducing definitional clauses of the precondition as necessary in order to advance the proof search process. We provide an implementation, Caber, of our cyclic abduction method, based on a suite of heuristically guided tactics. It is often able to automatically infer preconditions describing lists, trees, cyclic and composite structures which, in other tools, previously had to be supplied by hand

    Cyclic abduction of inductively defined safety and termination preconditions

    Get PDF
    We introduce cyclic abduction: a new method for automatically inferring safety and termination preconditions of heap manipulating while programs, expressed as inductive definitions in separation logic. Cyclic abduction essentially works by searching for a cyclic proof of the desired property, abducing definitional clauses of the precondition as necessary in order to advance the proof search process. We provide an implementation, Caber, of our cyclic abduction method, based on a suite of heuristically guided tactics. It is often able to automatically infer preconditions describing lists, trees, cyclic and composite structures which, in other tools, previously had to be supplied by hand

    Automatically verifying temporal properties of pointer programs with cyclic proof

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    We propose a deductive reasoning approach to the automatic verification of temporal properties of pointer programs, based on cyclic proof. We present a proof system whose judgements express that a program has a certain temporal property over memory state assertions in separation logic, and whose rules operate directly on the temporal modal-ities as well as symbolically executing programs. Cyclic proofs in our system are, as usual, finite proof graphs subject to a natural, decidable soundness condition, encoding a form of proof by infinite descent. We present a proof system tailored to proving CTL properties of non-deterministic pointer programs, and then adapt this system to handle fair execution conditions. We show both systems to be sound, and provide an implementation of each in the Cyclist theorem prover, yielding an automated tool that is capable of automatically discovering proofs of (fair) temporal properties of heap-aware programs. Experimental evaluation of our tool indicates that our approach is viable, and offers an interesting alternative to traditional model checking techniques

    Learning to Verify the Heap

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    Abstract. We present a data-driven verification framework to automatically prove memory safety and functional correctness of heap programs. For this, we introduce a novel statistical machine learning technique that maps observed program states to (possibly disjunctive) separation logic formulas describing the invariant shape of (possibly nested) data structures at relevant program locations. We then attempt to verify these predictions using a theorem prover, where counterexamples to a predicted invariant are used as additional input to the shape predictor in a refinement loop. After obtaining valid shape invariants, we use a second learning algorithm to strengthen them with data invariants, again employing a refinement loop using the underlying theorem prover. We have implemented our techniques in Cricket, an extension of the GRASShopper verification tool. Cricket is able to automatically prove memory safety and correctness of implementations of a variety of classical heap-manipulating programs such as insertionsort, quicksort and traversals of nested data structures

    Automated Specification Inference in a Combined Domain via User-Defined Predicates

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    Discovering program specifications automatically for heap-manipulating programs is a challenging task due\ud to the complexity of aliasing and mutability of data structures. This task is further complicated by an\ud expressive domain that combines shape, numerical and bag information. In this paper, we propose a compositional analysis framework that would derive the summary for each method in the expressive abstract\ud domain, independently from its callers. We propose a novel abstraction method with a bi-abduction technique in the combined domain to discover pre-/post-conditions that could not be automatically inferred\ud before. The analysis does not only infer memory safety properties, but also finds relationships between pure\ud and shape domains towards full functional correctness of programs. A prototype of the framework has been\ud implemented and initial experiments have shown that our approach can discover interesting properties for\ud non-trivial programs

    Separation Logic

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    Separation logic is a key development in formal reasoning about programs, opening up new lines of attack on longstanding problems
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