CERT C:Rec.PRE07-C

Avoid using repeated question marks

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描述

规则定义

Avoid using repeated question marks.1

Polyspace 实现

规则检查项会检查三字符序列的使用。

示例

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问题

当您在代码中使用三字符序列时，会出现此问题。

Polyspace® 分析会将三字符序列转换为等效字符，以用于缺陷分析。然而，Polyspace 也会引发 MISRA™ 违规。

标准要求在预处理期间，必须在删除注释之前转换三字符序列。因此，即使三字符序列出现在代码注释中，Polyspace 也会报告违反此规则。

风险

可以用两个问号后跟一个特定的第三个字符来表示三字符序列（例如，'??-' 表示一个 '~'（波浪号）字符，'??)' 表示一个 ']' 字符）。这些三字符序列可能会与两个问号的其他用法意外混淆。

注意

双字符序列（<: :>、<% %>、%:、%:%:）是允许使用的，因为它们是标记。

检查信息

组：Rec.01.预处理器 (PRE)

版本历史记录

在 R2019a 中推出

另请参阅

主题

外部网站

1 This software has been created by MathWorks incorporating portions of: the “SEI CERT-C Website,” © 2017 Carnegie Mellon University, the SEI CERT-C++ Web site © 2017 Carnegie Mellon University, ”SEI CERT C Coding Standard – Rules for Developing safe, Reliable and Secure systems – 2016 Edition,” © 2016 Carnegie Mellon University, and “SEI CERT C++ Coding Standard – Rules for Developing safe, Reliable and Secure systems in C++ – 2016 Edition” © 2016 Carnegie Mellon University, with special permission from its Software Engineering Institute.

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This software and associated documentation has not been reviewed nor is it endorsed by Carnegie Mellon University or its Software Engineering Institute.