29 Sep
2024
29 Sep
'24
6:56 p.m.
>> malloc(0) isn't undefined behaviour but
implementation defined.
>
> In modern C there is no difference between those two concepts.
Can you explain more about your view
There certainly is a difference, but in this case the practical
implications are the same: avoid malloc(0). malloc(0) lies at the high end
of a range of severity of concerns about implementation-definedness. At the
low end are things like the size of ints, which only affects applications
that may confront very large numbers. In the middle is the default
signedness of chars, which generally may be mitigated by explicit type
declarations.
For the size of ints, C offers guardrails like INT_MAX. There is no test to
discern what an error return from malloc(0) means.
Is there any other C construct that implementation-definedness renders
useless?
Doug