Two consecutive question marks signify the start of a trigraph sequence. According to the C standard [ISO/IEC 9899:2011],
All occurrences in a source file of the following sequences of three characters (that is, trigraph sequences) are replaced with the corresponding single character.
??=
#
??)
]
??!
|
??(
[
??'
^
??>
}
??/
\
??<
{
??-
~
Noncompliant Code Example
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| Tool | Version | Checker | Description | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 81 S | Fully implemented. | |||||||
| GCC |
| Can detect violation of this recommendation when the | |||||||
| dtrigraf | Fully implemented. |
Related Vulnerabilities
Search for vulnerabilities resulting from the violation of this rule on the CERT website.
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