- Static code analysis
**Static code analysis**is the analysis of computersoftware that is performed without actually executing programs built from that software (analysis performed on executing programs is known as dynamic analysis). In most cases the analysis is performed on some version of thesource code and in the other cases some form of theobject code . The term is usually applied to the analysis performed by an automated tool, with human analysis being called program understanding orprogram comprehension .The sophistication of the analysis performed by tools varies from those that only consider the behavior of individual statements and declarations, to those that include the complete source code of a program in their analysis. Uses of the information obtained from the analysis vary from highlighting possible coding errors (e.g., the lint tool) to

formal methods that mathematically prove properties about a given program (e.g., its behavior matches that of its specification).Some peopleFact|date=January 2008 consider

software metric s andreverse engineering to be forms of static analysis.A growing commercial use of static analysis is in the verification of properties of software used in

safety-critical computer systems andlocating potentially vulnerable code.**Formal methods**Formal methods is the term applied to the analysis of

software (andhardware ) whose results are obtained purely through the use of rigorous mathematical methods. The mathematical techniques used includedenotational semantics ,axiomatic semantics ,operational semantics , andabstract interpretation .It has been proven that, barring some hypothesis that the state space of programs is finite and small, finding possible run-time errors, or more generally any kind of violation of a specification on the final result of a program, is undecidable: there is no mechanical method that can always answer truthfully whether a given program may or may not exhibit runtime errors. This result dates from the works of Church, Gödel and Turing in the 1930s (see the

halting problem andRice's theorem ). As with most undecidable questions, one can still attempt to give useful approximate solutions.Some of the implementation techniques of formal static analysis include:

*Model checking considers systems that havefinite state or may be reduced to finite state by abstraction;

*Data-flow analysis is a lattice-based technique for gathering information about the possible set of values;

*Abstract interpretation models the effect that every statement has on the state of an abstract machine (i.e., it 'executes' the software based on the mathematical properties of each statement and declaration). This abstract machine overapproximates the behaviours of the system: the abstract system is thus made simpler to analyze, at the expense of "incompleteness" (not every property true of the original system is true of the abstract system). If properly done, though, abstract interpretation is "sound" (every property true of the abstract system can be mapped to a true property of the original system).

*Use of assertions in program code as first suggested byHoare logic . There is tool support for some programming languages (e.g., theSPARK programming language (a subset of Ada) and theJava Modeling Language — JML — usingESC/Java andESC/Java2 ).**ee also***

Shape analysis (software)

*Formal semantics of programming languages

*Formal verification

*Software testing

*List of tools for static code analysis

*Documentation generator **External links*** [

*http://samate.nist.gov The SAMATE Project*] , a good resource for Automated Static Analysis tools

* [*http://www.ddj.com/dept/debug/189401916 Code Quality Improvement - Coding standards conformance checking (DDJ)*]

* [*http://www.se-radio.net/index.php?post_id=220531 Episode 59: Static Code Analysis*] Interview (Podcast ) at "Software Engineering Radio"

* [*http://www.parasoft.com/jsp/redirector.jsp/WWH_CodeAnalysis_W Why, When, How: Code Analysis*] white paper

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2010.*