ISO IEC 8652 CORR 1-2016 Information technology - Programming languages - Ada Technical Corrigendum 1《信息技术 编程语言 Ada 技术勘误表1》.pdf

1、 INTERNATIONAL STANDARD ISO/IEC 8652:2012 TECHNICAL CORRIGENDUM 1 Published 2016-02-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION LECTROTECHNIQUE INTERNATIONALEProgramming languages Ada TECHNICAL CO

2、RRIGENDUM 1 Langages de programmation Ada RECTIFICATIF TECHNIQUE 1 Technical Corrigendum 1 to ISO/IEC 8652:2012 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 22, Programming languages, their environments and system software interfaces. ICS 35.060 Re

3、f. No. ISO/IEC 8652:2012/Cor.1:2016(E) ISO/IEC 2016 All rights reserved Published in Switzerland ISO/IEC 8652:2012/Cor.1:2016 ii ISO/IEC 2016 All rights reserved Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the special

4、ized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical comm

5、ittees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. The procedu

6、res used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of document should be noted. This document was drafted in accordance with the editorial rules

7、 of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details of any patent rights

8、 identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an expla

9、nation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this docu

10、ment is ISO/IEC JTC 1, Information technology, SC22, Programming languages, their environments and system software interfaces. Technical Corrigendum 1 cancels and replaces those portions of International Standard ISO/IEC 8652:2012 as specified by the body of this corrigendum. Those portions of the I

11、nternational Standard not modified by this corrigendum remain in force. ISO/IEC 8652:2012/Cor.1:2016 ISO/IEC 2016 All rights reserved iii Introduction This corrigendum contains corrections to the Ada 2012 standard ISO/IEC 8652:2012. The corrigendum is organized by clauses corresponding to those in t

12、he Ada 2012 standard. These clauses include wording changes to the Ada 2012 standard. Subclause headings are given for each subclause that contains a wording change. Other subclauses are omitted. For each change, a reference to the defect report(s) that prompted the wording change is included in the

13、 form 8652/0000. The defect reports have been developed by the ISO/IEC JTC 1/SC 22/WG 9 Ada Rapporteur Group to address specific questions about the Ada standard. Refer to the defect reports for details on the issues. For each change, an anchor paragraph from the original Ada 2012 standard is given.

14、 New or revised text and instructions are given with each change. The anchor paragraph can be replaced or deleted, or text can be inserted before or after it. When a heading immediately precedes the anchor paragraph, any text inserted before the paragraph is intended to appear under the heading. Typ

15、ographical conventions: Instructions about the text changes are in this font. The actual text changes are in the same fonts as the Ada 2012 standard - this font for text, this font for syntax, and this font for Ada source code. Introduction Of International Standard ISO/IEC 8652:2012. Modifications

16、of this section of that standard are found here. Replace paragraph 57.15: 8652/0117 The concept of assertions introduced in the 2005 edition is extended with the ability to specify preconditions and postconditions for subprograms, and invariants for private types. The concept of constraints in defin

17、ing subtypes is supplemented with subtype predicates that enable subsets to be specified other than as simple ranges. These properties are all indicated using aspect specifications. See subclauses 3.2.4, 6.1.1, and 7.3.2. by: The concept of assertions introduced in the 2005 edition is extended with

18、the ability to specify preconditions and postconditions for subprograms, and invariants for private types and interfaces. The concept of constraints in defining subtypes is supplemented with subtype predicates that enable subsets to be specified other than as simple ranges. These properties are all

19、indicated using aspect specifications. See subclauses 3.2.4, 6.1.1, and 7.3.2. Replace paragraph 57.16: 8652/0117 New forms of expressions are introduced. These are if expressions, case expressions, quantified expressions, and expression functions. As well as being useful for programming in general

20、by avoiding the introduction of unnecessary assignments, they are especially valuable in conditions and invariants since they avoid the need to introduce auxiliary functions. See subclauses 4.5.7, 4.5.8, and 6.8. Membership tests are also made more flexible. See subclauses 4.4 and 4.5.2. by: New for

21、ms of expressions are introduced. These are if expressions, case expressions, quantified expressions, expression functions, and raise expressions. As well as being useful for programming in general by avoiding the introduction of unnecessary assignments, they are especially valuable in conditions an

22、d invariants since they avoid the need to introduce auxiliary functions. See subclauses 4.5.7, 4.5.8, 6.8, and 11.3. Membership tests are also made more flexible. See subclauses 4.4 and 4.5.2. ISO/IEC 2016 All rights reserved 1 ISO/IEC 8652:2012/Cor.1:2016 ISO/IEC 8652:2012/Cor.1:2016 2 ISO/IEC 2016

23、 All rights reserved Section 1: General 1.1 Scope Replace paragraph 3: 8652/0118 The language provides rich support for real-time, concurrent programming, and includes facilities for multicore and multiprocessor programming. Errors can be signaled as exceptions and handled explicitly. The language a

24、lso covers systems programming; this requires precise control over the representation of data and access to system-dependent properties. Finally, a predefined environment of standard packages is provided, including facilities for, among others, input-output, string manipulation, numeric elementary f

25、unctions, and random number generation, and definition and use of containers. by: The language provides rich support for real-time, concurrent programming, and includes facilities for multicore and multiprocessor programming. Errors can be signaled as exceptions and handled explicitly. The language

26、also covers systems programming; this requires precise control over the representation of data and access to system-dependent properties. Finally, a predefined environment of standard packages is provided, including facilities for, among others, input-output, string manipulation, numeric elementary

27、functions, random number generation, and definition and use of containers. 1.1.2 Structure Replace paragraph 24: 8652/0118 Each section is divided into subclauses that have a common structure. Each clause and subclause first introduces its subject. After the introductory text, text is labeled with t

28、he following headings: by: Each clause is divided into subclauses that have a common structure. Each clause and subclause first introduces its subject. After the introductory text, text is labeled with the following headings: ISO/IEC 8652:2012/Cor.1:2016 ISO/IEC 2016 All rights reserved 3 Section 2:

29、 Lexical Elements No changes in this clause. ISO/IEC 8652:2012/Cor.1:2016 4 ISO/IEC 2016 All rights reserved Section 3: Declarations and Types 3.2.4 Subtype Predicates Replace paragraph 4: 8652/0119; 8 652/0120 For a (first) subtype defined by a derived type declaration, the predicates of the parent

30、 subtype and the progenitor subtypes apply. by: For a (first) subtype defined by a type declaration, any predicates of parent or progenitor subtypes apply. Delete paragraph 6: 8652/0119 The predicate of a subtype consists of all predicate specifications that apply, and-ed together; if no predicate s

31、pecifications apply, the predicate is True (in particular, the predicate of a base subtype is True). Replace paragraph 12: 8652/0120 If a subtype is defined by a derived type declaration that does not include a predicate specification, then predicate checks are enabled for the subtype if and only if

32、 predicate checks are enabled for at least one of the parent subtype and the progenitor subtypes; by: If a subtype is defined by a type declaration that does not include a predicate specification, then predicate checks are enabled for the subtype if and only if any predicate checks are enabled for p

33、arent or progenitor subtypes; Insert after paragraph 14: 8652/0121 Otherwise, predicate checks are disabled for the given subtype. the new paragraphs: For a subtype with a directly-specified predicate aspect, the following additional language-defined aspect may be specified with an aspect_specificat

34、ion (see 13.1.1): Predicate_Failure This aspect shall be specified by an expression, which determines the action to be performed when a predicate check fails because a directly-specified predicate aspect of the subtype evaluates to False, as explained below. Name Resolution Rules The expected type f

35、or the Predicate_Failure expression is String. Replace paragraph 17: 8652/0122 a membership test whose simple_expression is the current instance, and whose membership_choice_list meets the requirements for a static membership test (see 4.9); by: a membership test whose tested_simple_expression is th

36、e current instance, and whose membership_choice_list meets the requirements for a static membership test (see 4.9); Replace paragraph 20: 8652/0120 a call to a predefined boolean logical operator, where each operand is predicate-static; by: a call to a predefined boolean operator and, or, xor, or no

37、t, where each operand is predicate-static; Insert before paragraph 30: 8652/0119 If predicate checks are enabled for a given subtype, then: the new paragraphs: If any of the above Legality Rules is violated in an instance of a generic unit, Program_Error is raised at the point of the violation. ISO/

38、IEC 8652:2012/Cor.1:2016 ISO/IEC 2016 All rights reserved 5 To determine whether a value satisfies the predicates of a subtype S, the following tests are performed in the following order, until one of the tests fails, in which case the predicates are not satisfied and no further tests are performed,

39、 or all of the tests succeed, in which case the predicates are satisfied: the value is first tested to determine whether it satisfies any constraints or any null exclusion of S; then: if S is a first subtype, the value is tested to determine whether it satisfies the predicates of the parent and prog

40、enitor subtypes (if any) of S (in an arbitrary order); if S is defined by a subtype_indication, the value is tested to determine whether it satisfies the predicates of the subtype denoted by the subtype_mark of the subtype_indication; finally, if S is defined by a declaration to which one or more pr

41、edicate specifications apply, the predicates are evaluated (in an arbitrary order) to test that all of them yield True for the given value. Replace paragraph 31: 8652/0121; 8 652/0119 On every subtype conversion, the predicate of the target subtype is evaluated, and a check is performed that the pre

42、dicate is True. This includes all parameter passing, except for certain parameters passed by reference, which are covered by the following rule: After normal completion and leaving of a subprogram, for each in out or out parameter that is passed by reference, the predicate of the subtype of the actu

43、al is evaluated, and a check is performed that the predicate is True. For an object created by an object_declaration with no explicit initialization expression, or by an uninitialized allocator, if any subcomponents have default_expressions, the predicate of the nominal subtype of the created object

44、 is evaluated, and a check is performed that the predicate is True. Assertions.Assertion_Error is raised if any of these checks fail. by: On every subtype conversion, a check is performed that the operand satisfies the predicates of the target subtype. This includes all parameter passing, except for

45、 certain parameters passed by reference, which are covered by the following rule: After normal completion and leaving of a subprogram, for each in out or out parameter that is passed by reference, a check is performed that the value of the parameter satisfies the predicates of the subtype of the act

46、ual. For an object created by an object_declaration with no explicit initialization expression, or by an uninitialized allocator, if any subcomponents have default_expressions, a check is performed that the value of the created object satisfies the predicates of the nominal subtype. If any of the pr

47、edicate checks fail, Assertion_Error is raised, unless the subtype whose directly-specified predicate aspect evaluated to False also has a directly-specified Predicate_Failure aspect. In that case, the specified Predicate_Failure expression is evaluated; if the evaluation of the Predicate_Failure ex

48、pression propagates an exception occurrence, then this occurrence is propagated for the failure of the predicate check; otherwise, Assertion_Error is raised, with an associated message string defined by the value of the Predicate_Failure expression. In the absence of such a Predicate_Failure aspect, an implementation-defined message string is associated with the Assertion_Error exception. Delete paragraph 32: 8652/0119 A value satisfies a predicate if the predicate is True for that value. Delete paragraph 33: 8652/0119 If any of the ab