[RFC] Throwing an exception with null pointers

[Derek Fawcus]

On Wednesday, 16 April 2025 at 08:49:39 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
> On 16/04/2025 8:18 PM, Atila Neves wrote:
>
>> * Use a nullable/option type.
>
> While valid to box pointers, we would then need to disallow 
> them in business logic functions.

I'm not sure what you have in mind, what I have in mind is 
something like this:

   https://discourse.llvm.org/t/rfc-nullability-qualifiers/35672
   
https://clang.llvm.org/docs/analyzer/developer-docs/nullability.html

The checks here are performed in a distinct SA tool, not in the 
main compiler.  However it catches the main erroneous cases - 
first two listed checks of second link:

> If a pointer p has a nullable annotation and no explicit null 
> check or assert, we should warn in the following cases:
>
>-    p gets implicitly converted into nonnull pointer, for 
>example, we are passing it to a function that takes a nonnull 
>parameter.
>
>-    p gets dereferenced

Given how individual variable / fields have to be annotated, it 
probably does not need complete DFA, but only function local 
analysis for loads/stores/compares.