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Pointer Analysis
In computer science, pointer analysis, or points-to analysis, is a static code analysis technique that establishes which pointers, or heap references, can point to which variables, or storage locations. It is often a component of more complex analyses such as escape analysis. A closely related technique is shape analysis. This is the most common colloquial use of the term. A secondary use has ''pointer analysis'' be the collective name for both ''points-to analysis'', defined as above, and alias analysis. Points-to and alias analysis are closely related but not always equivalent problems. Example For the following example program, a points-to analysis would compute that the points-to set of p is . int x; int y; int* p = unknown() ? &x : &y; Introduction As a form of static analysis, fully precise pointer analysis can be shown to be undecidable. Most approaches are sound, but range widely in performance and precision. Many design decisions impact both the precision and perf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical disciplines (including the design and implementation of Computer architecture, hardware and Computer programming, software). Computer science is generally considered an area of research, academic research and distinct from computer programming. Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and for preventing Vulnerability (computing), security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Progr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyvariance
In program analysis, polyvariance is an analysis in which functions are analyzed multiple times—typically once at each call site In programming, a spot of a function or subroutine is the location (line of code) where the function is called (or may be called, through dynamic dispatch). A call site is where zero or more arguments are passed to the function, and zero or more r ...—to improve the precision of the analysis. References Program analysis Polymorphism (computer science) {{comp-sci-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pointer Analysis - Abstracting Memory Addresses By Their Allocation Site
Pointer may refer to: Places * Pointer, Kentucky * Pointers, New Jersey * Pointers Airport, Wasco County, Oregon, United States * The Pointers, a pair of rocks off Antarctica People with the name * Pointer (surname), a surname (including a list of people with the name) Arts, entertainment, and media * ''Pointer'' (journal), the official journal of the Singapore Armed Forces * ''The Pointer'', a 1939 American animated short film * The Pointer Sisters, an American R&B vocal group formed in 1969 Astronomy Pairs of stars popularly called "The Pointers": *Alpha Centauri and Beta Centauri, which point to the Southern Cross *Alpha Ursae Majoris (Dubhe) and Beta Ursae Majoris (Merak), which point to Polaris Brands and enterprises * Pointer (wireless phone), a short-lived mobile phone service in Finland in the 1980s * Pointer Insecticide, a brand of injected Imidacloprid for systemic insect control in trees * Pointer Telocation, an Israeli company specializing in stolen vehicle recov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract Interpretation
In computer science, abstract interpretation is a theory of sound approximation of the semantics of computer programs, based on monotonic functions over ordered sets, especially lattices. It can be viewed as a partial execution of a computer program which gains information about its semantics (e.g., control-flow, data-flow) without performing all the calculations. Its main concrete application is formal static analysis, the automatic extraction of information about the possible executions of computer programs; such analyses have two main usages: * inside compilers, to analyse programs to decide whether certain optimizations or transformations are applicable; * for debugging or even the certification of programs against classes of bugs. Abstract interpretation was formalized by the French computer scientist working couple Patrick Cousot and Radhia Cousot in the late 1970s. Intuition This section illustrates abstract interpretation by means of real-world, non-computing example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LLVM
LLVM is a set of compiler and toolchain technologies that can be used to develop a front end for any programming language and a back end for any instruction set architecture. LLVM is designed around a language-independent intermediate representation (IR) that serves as a portable, high-level assembly language that can be optimized with a variety of transformations over multiple passes. LLVM is written in C++ and is designed for compile-time, link-time, run-time, and "idle-time" optimization. Originally implemented for C and C++, the language-agnostic design of LLVM has since spawned a wide variety of front ends: languages with compilers that use LLVM (or which do not directly use LLVM but can generate compiled programs as LLVM IR) include ActionScript, Ada, C#, Common Lisp, PicoLisp, Crystal, CUDA, D, Delphi, Dylan, Forth, Fortran, Free Basic, Free Pascal, Graphical G, Halide, Haskell, Java bytecode, Julia, Kotlin, Lua, Objective-C, OpenCL, PostgreSQL's SQL and PLpg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Union-find Data Structure
In computer science, a disjoint-set data structure, also called a union–find data structure or merge–find set, is a data structure that stores a collection of disjoint (non-overlapping) sets. Equivalently, it stores a partition of a set into disjoint subsets. It provides operations for adding new sets, merging sets (replacing them by their union), and finding a representative member of a set. The last operation makes it possible to find out efficiently if any two elements are in the same or different sets. While there are several ways of implementing disjoint-set data structures, in practice they are often identified with a particular implementation called a disjoint-set forest. This is a specialized type of forest which performs unions and finds in near-constant amortized time. To perform a sequence of addition, union, or find operations on a disjoint-set forest with nodes requires total time , where is the extremely slow-growing inverse Ackermann function. Disjo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steensgaard's Algorithm
In computer science, Steensgaard's algorithm is a scalable, flow-insensitive, algorithm for pointer analysis. It is often used in compilers, due to its speed (for example, an implementation is available in the LLVM compiler framework). In its original formulation, this algorithm was field-, context-, and array-insensitive. Steensgaard's algorithm is based on ''equality constraints'', as opposed to Andersen's algorithm, which is based on ''subset constraints''. This allows points-to information to be tracked using a union-find data structure. This choice gives the algorithm its characteristic speed; when implemented using a union-find data structure it is linear space and almost linear time in the size of the input program. Bjarne Steensgaard's formulation of the algorithm was in terms of type inference and type checking In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shape Analysis (software)
In program analysis, shape analysis is a static code analysis technique that discovers and verifies properties of linked, dynamically allocated data structures in (usually imperative) computer programs. It is typically used at compile time to find software bugs or to verify high-level correctness properties of programs. In Java programs, it can be used to ensure that a sort method correctly sorts a list. For C programs, it might look for places where a block of memory is not properly freed. Applications Shape analysis has been applied to a variety of problems: * Memory safety: finding memory leaks, dereferences of dangling pointers, and discovering cases where a block of memory is freed more than once. * Finding array out-of-bounds errors * Checking type-state properties (for example, ensuring that a file is open() before it is read()) * Ensuring that a method to reverse a linked list does not introduce cycles into the list * Verifying that a sort method returns a result that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object (computer Science)
In computer science, an object can be a variable, a data structure, a function, or a method. As regions of memory, they contain value and are referenced by identifiers. In the object-oriented programming paradigm, ''object'' can be a combination of variables, functions, and data structures; in particular in class-based variations of the paradigm it refers to a particular instance of a class. In the relational model of database management, an object can be a table or column, or an association between data and a database entity (such as relating a person's age to a specific person). Object-based languages An important distinction in programming languages is the difference between an object-oriented language and an object-based language. A language is usually considered object-based if it includes the basic capabilities for an object: identity, properties, and attributes. A language is considered object-oriented if it is object-based and also has the capability of polymorphism, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Code Analysis
In computer science, static program analysis (or static analysis) is the analysis of computer programs performed without executing them, in contrast with dynamic program analysis, which is performed on programs during their execution. The term is usually applied to analysis performed by an automated tool, with human analysis typically being called "program understanding", program comprehension, or code review. In the last of these, software inspection and software walkthroughs are also used. In most cases the analysis is performed on some version of a program's source code, and, in other cases, on some form of its object code. Rationale The sophistication of the analysis performed by tools varies from those that only consider the behaviour of individual statements and declarations, to those that include the complete source code of a program in their analysis. The uses of the information obtained from the analysis vary from highlighting possible coding errors (e.g., the lint t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Record (computer Science)
In computer science, a record (also called a structure, struct, or compound data) is a basic data structure. Records in a database or spreadsheet are usually called "rows". A record is a collection of ''fields'', possibly of different data types, typically in a fixed number and sequence. The fields of a record may also be called ''members'', particularly in object-oriented programming; fields may also be called ''elements'', though this risks confusion with the elements of a collection. For example, a date could be stored as a record containing a numeric year field, a month field represented as a string, and a numeric day-of-month field. A personnel record might contain a name, a salary, and a rank. A Circle record might contain a center and a radius—in this instance, the center itself might be represented as a point record containing x and y coordinates. Records are distinguished from arrays by the fact that their number of fields is determined in the definition of the rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
