ISO/IEC JTC 1/SC 22/WG 14 - C

1 This document specifies the form and establishes the interpretation of programs written in the C programming language.1) It specifies - the representation of C programs; - the syntax and constraints of the C language; - the semantic rules for interpreting C programs; - the representation of input data to be processed by C programs; - the representation of output data produced by C programs; - the restrictions and limits imposed by a conforming implementation of C. 2 This document does not specify - the mechanism by which C programs are transformed for use by a data-processing system; - the mechanism by which C programs are invoked for use by a data-processing system; - the mechanism by which input data are transformed for use by a C program; - the mechanism by which output data are transformed after being produced by a C program; - the size or complexity of a program and its data that will exceed the capacity of any specific data-processing system or the capacity of a particular processor; - all minimal requirements of a data-processing system that is capable of supporting a conforming implementation.

ISO/IEC TS 18661-1:2014 extends programming language C to support binary floating-point arithmetic conforming to ISO/IEC/IEEE 60559:2011. It covers all requirements of IEC 60559 as they pertain to C floating types that use IEC 60559 binary formats. ISO/IEC TS 18661-1:2014 does not cover decimal floating-point arithmetic, nor does it cover most optional features of IEC 60559. ISO/IEC TS 18661-1:2014 is primarily an update to IEC 9899:2011 (C11), normative Annex F (IEC 60559 floating-point arithmetic). However, it proposes that the new interfaces that are suitable for general implementations be added in the Library clauses of C11. Also it includes a few auxiliary changes in C11 where the specification is problematic for IEC 60559 support.

ISO/IEC TR 24731 provides alternative functions for the C library that promote safer, more secure programming. ISO/IEC TR 24731-1 provides simple replacement functions for the library functions of ISO/IEC 9899:1999 that provide bounds checking. Those functions can be used as simple replacements for the original library functions in legacy code. ISO/IEC TR 24731-2:2010 presents replacements for many of these functions that use dynamically allocated memory to ensure that buffer overflow does not occur.

ISO/IEC 24747:2009 defines extensions to the C Standard Library that is defined in the International Standard for the C programming language (ISO/IEC 9899). Unless otherwise specified, the whole of the C Standard Library is included in ISO/IEC 24747:2009 by reference. ISO/IEC 24747:2009 defines library extensions to the C Standard Library to support Mathematical Special functions to be added to and .

ISO/IEC TR 24731-1:2007 provides alternative functions for the C Library (as defined in ISO/IEC 9899:1999) that promote safer, more secure programming. The functions verify that output buffers are large enough for the intended result, and return a failure indicator if they are not. Optionally, failing functions call a "runtime-constraint handler" to report the error. Data is never written past the end of an array. All string results are null terminated. In addition, the functions in ISO/IEC TR 24731-1:2007 are re-entrant: they never return pointers to static objects owned by the function. ISO/IEC TR 24731-1:2007 also contains functions that address insecurities with the C input-output facilities.

ISO/IEC 9899:2011 specifies the form and establishes the interpretation of programs written in the C programming language.It specifies the representation of C programs; the syntax and constraints of the C language; the semantic rules for interpreting C programs; the representation of input data to be processed by C programs; the representation of output data produced by C programs; the restrictions and limits imposed by a conforming implementation of C. ISO/IEC 9899:2011 does not specify the mechanism by which C programs are transformed for use by a data-processing system; the mechanism by which C programs are invoked for use by a data-processing system; the mechanism by which input data are transformed for use by a C program; the mechanism by which output data are transformed after being produced by a C program; the size or complexity of a program and its data that will exceed the capacity of any specific data-processing system or the capacity of a particular processor; all minimal requirements of a data-processing system that is capable of supporting a conforming implementation. ISO/IEC 9899:2011 is designed to promote the portability of C programs among a variety of data-processing systems. It is intended for use by implementers and programmers.

ISO/IEC TR 24732:2009 specifies an extension to the programming language C, specified by the International Standard ISO/IEC 9899:1999. The extension provides support for decimal floating-point arithmetic that is intended to be consistent with the specification in IEEE 754-2008. Any conflict between the requirements described here and that specification is unintentional. ISO/IEC TR 24732:2009 defers to IEEE 754-2008. The binary floating-point arithmetic as specified in IEEE 754-2008 is not considered in ISO/IEC TR 24732:2009.

ISO/IEC TR 19769:2004 specifies two extended character data types as an extension to the programming language C, specified by ISO/IEC 9899.