Linguagem de Programação C - NORMA ISO/IEC 9899TC2

Linguagem de Programação C - NORMA ISO/IEC 9899TC2

(Parte 3 de 11)

ISO/IEC 9899:TC2Committee Draft — May 6, 2005WG14/N1124

—all minimal requirements of a data-processing system that is capable of supporting a conforming implementation.

2. Normative references

1The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard.Fordated references, subsequent amendments to, or revisions of, anyofthese publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.Members of ISO and IEC maintain registers of currently valid International Standards.

2ISO 31−1:1992,Quantities and units — Part 1: Mathematical signs and symbols for use in the physical sciences and technology.

3ISO/IEC 646,Information technology —ISO7-bit coded character set for information interchange.

4ISO/IEC 2382−1:1993,Information technology — Vocabulary — Part 1: Fundamental terms.

5ISO 4217,Codes for the representation of currencies and funds.

6ISO 8601,Data elements and interchangeformats — Information interchange— Representation of dates and times.

7ISO/IEC 10646(all parts),Information technology — Universal Multiple-Octet Coded Character Set (UCS).

8IEC 60559:1989,Binary floating-point arithmetic for microprocessor systems(previously designated IEC 559:1989).

2General §2

WG14/N1124 CommitteeDraft — May 6, 2005ISO/IEC 9899:TC2

3. Terms, definitions, and symbols

1Forthe purposes of this International Standard, the following definitions apply.Other terms are defined where theyappear initalictype or on the left side of a syntax rule. Terms explicitly defined in this International Standard are not to be presumed to refer implicitly to similar terms defined elsewhere. Terms not defined in this International Standard are to be interpreted according to ISO/IEC2382−1. Mathematicalsymbols not defined in this International Standard are to be interpreted according to ISO 31−1.

2NOTE 1Where only one of these twoactions is meant, ‘‘read’’or‘‘modify’’isused. 3NOTE 2"Modify’’includes the case where the newvalue being stored is the same as the previous value. 4NOTE 3Expressions that are not evaluated do not access objects.

3.2 1 alignment requirement that objects of a particular type be located on storage boundaries with addresses that are particular multiples of a byte address

3.3 1 argument actual argument actual parameter (deprecated) expression in the comma-separated list bounded by the parentheses in a function call expression, or a sequence of preprocessing tokens in the comma-separated list bounded by the parentheses in a function-likemacro invocation

3.4 1 behavior external appearance or action

3.4.1 1 implementation-defined behavior unspecified behavior where each implementation documents howthe choice is made

2EXAMPLE Anexample of implementation-defined behavior is the propagation of the high-order bit when a signed integer is shifted right.

3.4.2 1 locale-specific behavior behavior that depends on local conventions of nationality,culture, and language that each implementation documents

§3.4.2 General3

ISO/IEC 9899:TC2Committee Draft — May 6, 2005WG14/N1124

2EXAMPLE Anexample of locale-specific behavior is whether theislowerfunction returns true for characters other than the 26 lowercase Latin letters.

3.4.3 1undefined behavior behavior,upon use of a nonportable or erroneous program construct or of erroneous data, for which this International Standard imposes no requirements

2NOTE Possibleundefined behavior ranges from ignoring the situation completely with unpredictable results, to behaving during translation or program execution in a documented manner characteristic of the environment (with or without the issuance of a diagnostic message), to terminating a translation or execution (with the issuance of a diagnostic message).

3EXAMPLE Anexample of undefined behavior is the behavior on integer overflow.

3.4.4 1 unspecified behavior use of an unspecified value, or other behavior where this International Standard provides twoormore possibilities and imposes no further requirements on which is chosen in any instance

2EXAMPLE Anexample of unspecified behavior is the order in which the arguments to a function are evaluated.

3.5 1 bit unit of data storage in the execution environment large enough to hold an object that may have one of twovalues

2NOTE Itneed not be possible to express the address of each individual bit of an object.

3.6 1 byte addressable unit of data storage large enough to hold anymember of the basic character set of the execution environment

2NOTE 1It is possible to express the address of each individual byte of an object uniquely.

3NOTE 2Abyte is composed of a contiguous sequence of bits, the number of which is implementationdefined. Theleast significant bit is called thelow-order bit;the most significant bit is called thehigh-order bit.

3.7 1 character 〈abstract〉member of a set of elements used for the organization, control, or representation of data

4General §3.7.1

WG14/N1124 CommitteeDraft — May 6, 2005ISO/IEC 9899:TC2

3.7.2 1 multibyte character sequence of one or more bytes representing a member of the extended character set of either the source or the execution environment

2NOTE Theextended character set is a superset of the basic character set.

3.7.3 1wide character bit representation that fits in an object of typewchar_t,capable of representing any character in the current locale

3.8 1 constraint restriction, either syntactic or semantic, by which the exposition of language elements is to be interpreted

3.9 1correctly rounded result representation in the result format that is nearest in value, subject to the effective rounding mode, to what the result would be givenunlimited range and precision

3.10 1diagnostic message message belonging to an implementation-defined subset of the implementation’smessage output

3.1 1forward reference reference to a later subclause of this International Standard that contains additional information relevant to this subclause

3.12 1 implementation particular set of software, running in a particular translation environment under particular control options, that performs translation of programs for,and supports execution of functions in, a particular execution environment

3.13 1 implementation limit restriction imposed upon programs by the implementation

3.14 1 object region of data storage in the execution environment, the contents of which can represent values

§3.14 General5

ISO/IEC 9899:TC2Committee Draft — May 6, 2005WG14/N1124

(Parte 3 de 11)