What is reason of Warning "Pointer is missing a nullability type specifier"?

Question

+ (UIColor*) getColorWithHexa(NSString*)hexString;

:

This is a method definition in my class. It's causing a warning. What is cause of similar warnings and how can these be resolved?

I am returning an UIColor object, while that question relates to blocks, which is given in comments.

So, it's helpful.

Answer 1

NS_ASSUME_NONNULL_BEGIN/END:

Annotating any pointer in an Objective-C header file causes the compiler to expect annotations for the entire file, bringing on a cascade of warnings. Given that most annotations will be nonnull, a new macro can help streamline the process of annotating existing classes. Simply mark the beginning and end of a section of your header with NS_ASSUME_NONNULL_BEGIN and ..._END, then mark the exceptions.

So,you have simply do.

NS_ASSUME_NONNULL_BEGIN
+ (UIColor*) getColorWithHexaCode:(NSString*)hexString;
NS_ASSUME_NONNULL_END

This is defined in

"NSObjCRuntime.h"

#define NS_ASSUME_NONNULL_BEGIN _Pragma("clang assume_nonnull begin")
#define NS_ASSUME_NONNULL_END _Pragma("clang assume_nonnull end")

Answer 2

You got this warning when somewhere in the file you used either _Nonnull, _Nullable, _Null_unspecified, __nullable, __nonnull, nullable or nonnull. Could also happen if the specifier was added through a macro.

To fix the warning:

• you can remove all occurrences of nullability (not recommended)
• you can assume all parameters and returned values are _Nonnull using NS_ASSUME_NONNULL_BEGIN and NS_ASSUME_NONNULL_END (recommended)