objc:S1854 false positive, used variable labelled as unused since recent update

[colmcd (Colin)]

Make sure to read this post before raising a thread here:

How to Report a False-positive / False-negative

Hey SonarSource Community! False-positives happen, as do false-negatives, and we’re eager to fix them. We are thrilled when our users report problems, so we can make our products better. What is a false-positive (FP)? A false-positive is when an issue is raised unexpectedly on code that should not trigger an issue, or where the suggested action doesn’t make any sense for the code. What is a false-negative (FN)? A false-negative is when an issue should be raised on a piece of code, but isn’t. …

Then tell us:

• What language is this for? - Objective C
• Which rule? S1854 Value stored during it’s initialization is never read.
• Why do you believe it’s a false-positive/false-negative? Because we are using/reading it in the next 2 lines.
• Are you using
  • SonarQube Server / Community Build - which version? 9.9.2
• How can we reproduce the problem? Give us a self-contained snippet of code (formatted text, no screenshots)

-(NSArray*)fooData
{
    NSArray* fud = [self fieldProperties];
*Value stored to 'fud' during its initialization is never read*
    NSMutableArray* foo = [[NSMutableArray alloc]init];
    [fp addObject: @"foo"];
    [fp addObject:fud];
    return foo;
}

[balazs.benics (Balázs Benics)]

Hi @colmcd! Long time no see.

Objective C is not my strongest language. Could you please send us a reproducer file to investigate this whenever we have some time?

To generate the reproducer file:

• Search in the analysis log for the full path of the source file for which you want to create a reproducer (for instance, a file that contains a false-positive). You will have to use exactly this name (same case, / or \…)
• Add the reproducer option to the scanner configuration:
  sonar.cfamily.reproducer=“Full path to the .source file”
• Re-run the scanner to generate a file named sonar-cfamily-reproducer.zip in the project folder.
• Please share this file. If you think this file contains private information, let us know, and we’ll send you a private message that will allow you to send it privately.

Thank you for your report, we could look into the case once we have the reproducer.