[TUHS] Minimum Array Sizes in 16 bit C (was Maximum)

[Rob Pike]

Gradually the writers of optimizing compilers have leaned so hard on the
implementation-defined and undefined behaviors that, while far from
useless, C and C++ have become non-portable and dangerously insecure, as
well as often very surprising to the point that the US government arguing
against using them.

-rob


On Mon, Sep 30, 2024 at 2:56 AM Douglas McIlroy <
douglas.mcilroy at dartmouth.edu> wrote:

> >>> 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
>
>
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