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A function that specifies [[noreturn]] can prohibit returning by throwing an exception, entering an infinite loop, or calling another function designated with the [[noreturn]] attribute.

Noncompliant Code Example

In this noncompliant code example, if the value 0 is passed, control will flow off the end of the function, resulting in an implicit return and undefined behavior:

Code Block
bgColor#FFcccc
langcpp
#include <cstdlib>
 
[[noreturn]] void f(int i) {
  if (i > 0)
    throw "Received positive input";
  else if (i < 0)
    std::exit(0);
}

Compliant Solution

In this compliant solution, the function does not return on any code path:

Code Block
bgColor#ccccff
langcpp
#include <cstdlib>
 
[[noreturn]] void f(int i) {
  if (i > 0)
    throw "Received positive input";
  std::exit(0);
}

Risk Assessment

Returning from a function marked [[noreturn]] results in undefined behavior that might be exploited to cause data integrity violations.

Rule

Severity

Likelihood

Remediation Cost

Priority

Level

MSC37-CPP

Medium

Unlikely

Low

P2

L3

Automated Detection

Tool

Version

Checker

Description

Clang
Include Page
Clang_V
Clang_V
-Winvalid-noreturn 

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

Related Guidelines

  

Bibliography

[ISO/IEC 14882-2014]

7.6.3, "Noreturn Attribute"

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