Suppress OCLint Warnings

There are two scenarios you might want to suppress an warning:

  • the standard for certain code measurement is controversial
  • it is a false positive

There are several methods you could consider to suppress OCLint rule violations:

  • If the warning you need to suppress also appeals to other OCLint users, e.g. a false positive
    • Patch test cases, amend the rule to make tests pass, and submit a pull request. Your help would be greatly appreciated by everyone
    • Open an issue with your code snippet on github or discuss with us in the mailing list
  • If the standard of your project is slightly different from OCLint default settings
  • If certain rules are really annoying for your projects
  • If it is a case-by-case thing, and only particular places need to be suppressed


By adding annotations to the source code, you can communicate with OCLint and order it to discard certain types of rule violations within a context-based range.

Annotation Syntax

You can suppress one rule like this:

__attribute__((annotate("oclint:suppress[unused method parameter]")))

Or, you can suppress multiple rules at the same time, like this:

__attribute__((annotate("oclint:suppress[high cyclomatic complexity]"), annotate("oclint:suppress[high npath complexity]"), annotate("oclint:suppress[high ncss method]")))

OCLint also allows you to suppress all rules with a shortcut:


Effective Range

Annotations are added to a particular declaration of the source code, and each suppress has the impact on the same scope of the declaration, usually this scope covers the current declaration itself and all its children.

For example, if an annotation is added to a method declaration, then the suppress effects the method, its entire content, including all its parameters, statements, expression, local variables, and so on.


bool __attribute__((annotate("oclint:suppress"))) aMethod(int aParameter)
    // warnings within this method are suppressed at all
    // like unused aParameter variable and empty if statement
    if (1) {}

    return true;

- (IBAction)turnoverValueChanged:
    (id) __attribute__((annotate("oclint:suppress[unused method parameter]"))) sender
    // suppress sender variable
    int i; // won't suppress this one
    [self calculateTurnover];

- (void)dismissAllViews:(id)currentView parentView:(id)parentView
   // again, suppress the warnings for entire method
    [self dismissTurnoverView];
    // plus 30+ lines of code of dismissing other views

!OCLint Comment

Alternatively, the warnings of a specific line can be suppressed by appending //!OCLint comment, for example:

void a() {
    int unusedLocalVariable; //!OCLINT

As a good practice, it’s highly recommend to add the reasoning for the comment, like:

int Results::numberOfWarnings()
    std::lock_guard<std::mutex> lock(_mutex); //!OCLint(FP - meant to be unused)
    //Everything after the letter 't' is ignored, but just for better readability
    return _compilerWarningSet->numberOfViolations();

Note that comment-based suppress doesn’t care the violation type nor number of violations, it simply ignore every warnings on that specific line. So the comment is expected to be on the same line as the violation. For example, when empty if statement is supposed to be suppressed, //!OCLint needs to be put on the line containing if statement, e.g.:

if (true) //!OCLint goes here
    // it is empty