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Cyclone (programming Language)
The Cyclone programming language is intended to be a safe dialect of the C language C (''pronounced like the letter c'') is a general-purpose computer programming language. It was created in the 1970s by Dennis Ritchie, and remains very widely used and influential. By design, C's features cleanly reflect the capabilities o .... Cyclone is designed to avoid buffer overflows and other vulnerabilities that are possible in C programs, without losing the power and convenience of C as a tool for system programming. Cyclone development was started as a joint project of AT&T Labs Research and Greg Morrisett's group at Cornell in 2001. Version 1.0 was released on May 8, 2006. Language features Cyclone attempts to avoid some of the common pitfalls of C (programming language), C, while still maintaining its look and performance. To this end, Cyclone places the following limits on programs: * Null pointer, NULL checks are inserted to prevent segmentation faults * Pointer arithmetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT&T Labs
AT&T Labs is the research & development division of AT&T, the telecommunications company. It employs some 1,800 people in various locations, including: Bedminster NJ; Middletown, NJ; Manhattan, NY; Warrenville, IL; Austin, TX; Dallas, TX; Atlanta, GA; San Francisco, CA; San Ramon, CA; and Redmond, WA. The main research division, made up of around 450 people, is based across the Bedminster, Middletown, San Francisco, and Manhattan locations. AT&T Labs traces its history from AT&T Bell Labs. Much research is in areas traditionally associated with networks and systems, ranging from the physics of optical transmission to foundational topics in computing and communications. Other research areas address the technical challenges of large operational networks and the resulting large data sets. Achievements Since its creation in 1996, AT&T Labs has been issued over 2,000 US patents. Researchers at AT&T Labs developed UWIN a package for running Unix applications on Windows; Graphviz, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bounds Checking
In computer programming, bounds checking is any method of detecting whether a variable is within some bounds before it is used. It is usually used to ensure that a number fits into a given type (range checking), or that a variable being used as an array index is within the bounds of the array (index checking). A failed bounds check usually results in the generation of some sort of exception signal. Because performing bounds checking during every usage is time-consuming, it is not always done. Bounds-checking elimination is a compiler optimization technique that eliminates unneeded bounds checking. Range checking A range check is a check to make sure a number is within a certain range; for example, to ensure that a value about to be assigned to a 16-bit integer is within the capacity of a 16-bit integer (i.e. checking against wrap-around). This is not quite the same as type checking. Other range checks may be more restrictive; for example, a variable to hold the number of a cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Compiler Collection
The GNU Compiler Collection (GCC) is an optimizing compiler produced by the GNU Project supporting various programming languages, hardware architectures and operating systems. The Free Software Foundation (FSF) distributes GCC as free software under the GNU General Public License (GNU GPL). GCC is a key component of the GNU toolchain and the standard compiler for most projects related to GNU and the Linux kernel. With roughly 15 million lines of code in 2019, GCC is one of the biggest free programs in existence. It has played an important role in the growth of free software, as both a tool and an example. When it was first released in 1987 by Richard Stallman, GCC 1.0 was named the GNU C Compiler since it only handled the C programming language. It was extended to compile C++ in December of that year. Front ends were later developed for Objective-C, Objective-C++, Fortran, Ada, D and Go, among others. The OpenMP and OpenACC specifications are also supported in the C and C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ANSI C
ANSI C, ISO C, and Standard C are successive standards for the C programming language published by the American National Standards Institute (ANSI) and ISO/IEC JTC 1/SC 22/WG 14 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Historically, the names referred specifically to the original and best-supported version of the standard (known as C89 or C90). Software developers writing in C are encouraged to conform to the standards, as doing so helps portability between compilers. History and outlook The first standard for C was published by ANSI. Although this document was subsequently adopted by ISO/IEC and subsequent revisions published by ISO/IEC have been adopted by ANSI, "ANSI C" is still used to refer to the standard. While some software developers use the term ISO C, others are standards-body neutral and use Standard C. Standardizing C In 1983, the American National Standards Institute formed a committee, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Signal
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star. Computer scientists and mathematicians often vocalize it as star (as, for example, in ''the A* search algorithm'' or '' C*-algebra''). In English, an asterisk is usually five- or six-pointed in sans-serif typefaces, six-pointed in serif typefaces, and six- or eight-pointed when handwritten. Its most common use is to call out a footnote. It is also often used to censor offensive words. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointers, repetition, or multiplication. History The asterisk has already been used as a symbol in ice age cave paintings. There is also a two thousand-year-old character used by Aristarchus of Samothrace called the , , which he used when proofreading Homeric poetry to mark lines that were duplicated. Origen i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIGSEGV
In computing, a segmentation fault (often shortened to segfault) or access violation is a fault, or failure condition, raised by hardware with memory protection, notifying an operating system (OS) the software has attempted to access a restricted area of memory (a memory access violation). On standard x86 computers, this is a form of general protection fault. The operating system kernel will, in response, usually perform some corrective action, generally passing the fault on to the offending process by sending the process a signal. Processes can in some cases install a custom signal handler, allowing them to recover on their own,''Expert C programming: deep C secrets'' By Peter Van der Linden, page 188 but otherwise the OS default signal handler is used, generally causing abnormal termination of the process (a program crash), and sometimes a core dump. Segmentation faults are a common class of error in programs written in languages like C that provide low-level memory access and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undefined Behavior
In computer programming, undefined behavior (UB) is the result of executing a program whose behavior is prescribed to be unpredictable, in the language specification to which the computer code adheres. This is different from unspecified behavior, for which the language specification does not prescribe a result, and implementation-defined behavior that defers to the documentation of another component of the platform (such as the ABI or the translator documentation). In the C community, undefined behavior may be humorously referred to as "nasal demons", after a comp.std.c post that explained undefined behavior as allowing the compiler to do anything it chooses, even "to make demons fly out of your nose". Overview Some programming languages allow a program to operate differently or even have a different control flow than the source code, as long as it exhibits the same user-visible side effects, ''if undefined behavior never happens during program execution''. Undefined behavior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fat Pointer
In computer science, dynamic dispatch is the process of selecting which implementation of a polymorphic operation (method or function) to call at run time. It is commonly employed in, and considered a prime characteristic of, object-oriented programming (OOP) languages and systems. Object-oriented systems model a problem as a set of interacting objects that enact operations referred to by name. Polymorphism is the phenomenon wherein somewhat interchangeable objects each expose an operation of the same name but possibly differing in behavior. As an example, a object and a object both have a method that can be used to write a personnel record to storage. Their implementations differ. A program holds a reference to an object which may be either a object or a object. Which it is may have been determined by a run-time setting, and at this stage, the program may not know or care which. When the program calls on the object, something needs to choose which behavior gets enacted. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pointer Arithmetic
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer ''references'' a location in memory, and obtaining the value stored at that location is known as ''dereferencing'' the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page. The actual format and content of a pointer variable is dependent on the underlying computer architecture. Using pointers significantly improves performance for repetitive operations, like traversing iterable data structures (e.g. strings, lookup tables, control tables and tree structures). In particular, it is often much cheaper in time and space to copy and dereference pointers than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pointer (computer Science)
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer ''references'' a location in memory, and obtaining the value stored at that location is known as ''dereferencing'' the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page. The actual format and content of a pointer variable is dependent on the underlying computer architecture. Using pointers significantly improves performance for repetitive operations, like traversing iterable data structures (e.g. strings, lookup tables, control tables and tree structures). In particular, it is often much cheaper in time and space to copy and dereference pointers than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exception Handling
In computing and computer programming, exception handling is the process of responding to the occurrence of ''exceptions'' – anomalous or exceptional conditions requiring special processing – during the execution of a program. In general, an exception breaks the normal flow of execution and executes a pre-registered ''exception handler''; the details of how this is done depend on whether it is a hardware or software exception and how the software exception is implemented. Exception handling, if provided, is facilitated by specialized programming language constructs, hardware mechanisms like interrupts, or operating system (OS) inter-process communication (IPC) facilities like signals. Some exceptions, especially hardware ones, may be handled so gracefully that execution can resume where it was interrupted. Definition The definition of an exception is based on the observation that each procedure has a precondition, a set of circumstances for which it will terminate "normal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Void Pointer
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer ''references'' a location in memory, and obtaining the value stored at that location is known as '' dereferencing'' the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page. The actual format and content of a pointer variable is dependent on the underlying computer architecture. Using pointers significantly improves performance for repetitive operations, like traversing iterable data structures (e.g. strings, lookup tables, control tables and tree structures). In particular, it is often much cheaper in time and space to copy and dereference pointers t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
