cpp:S1121 false-positive with assignment explicitly enclosed in parentheses

Rules and Languages Report False-positive / False-negative...
,
1

  • What language is this for?
    C++

  • Which rule?
    cpp:S1121 (“Assignments should not be made from within conditions”)

  • Why do you believe it’s a false-positive/false-negative?
    Because the rule text says “This rule ignores assignments explicitly enclosed in parentheses.”, and the rule doesn’t ignore them.

  • SonarQube for VS 2026, v10.1.0.16642 in connected mode with SonarQube Server

static void foo(int) {}

int main() {
    int a = 0;
    foo((a = 1));
    [[maybe_unused]] int b = a;
}

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2

Hi,

The current version of SonarQube for Visual Studio (formerly SonarLint) is 10.2.3. Can you upgrade and see if this is still replicable?

 
Thx,
Ann

3

Yes, it is.

4

Hi,

Thanks for confirming. I’ve flagged this for the language experts.

 
Ann

6

Thanks. By the way, it’s unclear to me why this exact rule triggers at all, given that it considers “conditionals” which my call is not.

8

Hi @bers,

We are aware of issues with this rule… :frowning:
… and fixes should come soon! :slight_smile:

First, the rule description did not fit the implementation. The goal is to detect assignments that are sub-expressions, so not only in conditionals. So, without the double parentheses, your code would still be non-compliant.

Then, the implementation itself had several shortcoming, including incorrect detection of assignments enclosed in parentheses. This has been fixed too.

Both fixes should be available in our next release.