[cfe-dev] RFC: Nullability qualifiers

[Daniel Marjamäki]

Hello!

Basically a good idea.

> It is obvious to a programmer who knows the semantics of strchr that
> it's important to check for a returned null, because null is used as the
> sentinel for "not found". 

In most cases that is very true.

However strchr is not a good example imho where this could be used.

The strchr return value is well defined, therefore you don't always need to check if it returns null. For instance:

    strcat(s,"abcd");
    char *c = strchr(s,'c');

I would personally say a warning after this code about missing null pointer check is a FP.

Is there some better function that could have such an attribute? I guess if its return value is unpredictable and can be null at any time then it's a good candidate.

Personally I would not say malloc/realloc are good candidates neither. Since they only return null if there is oom. if there is oom then a null pointer dereference that crash the program may not be a problem.

Best regards,
Daniel Marjamäki


..................................................................................................................
Daniel Marjamäki
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Evidente ES East AB 
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