Nonnull variable assignment violation

Overview

Use this check to detect when you assign null to a variable with the _Nonnull annotation. Available in Xcode 9 and later.

Violation of nonnull annotation with variable assignment in C

In the following example, the call to assigns_a_value breaks the _Nonnull annotation of the variable q:

void assigns_a_value(int *p) {     
    int *_Nonnull q = p; // Warning: null can be assigned
}
assigns_a_value(NULL); // Error: _Nonnull variable violation

Solution

Correct logic errors, or remove the _Nonnull annotation.

See Also

Undefined Behavior Sanitizer

• Misaligned pointer
• Invalid Boolean value
• Out-of-bounds array access
• Invalid enumeration value
• Reaching of unreachable point
• Dynamic type violation
• Invalid float cast
• Division by zero
• Nonnull argument violation
• Nonnull return value violation
• Null reference creation and null pointer dereference
• Invalid object size
• Invalid shift
• Integer overflow
• Invalid variable-length array