DIP1028 - Rationale for accepting as is

[Atila Neves]

On Friday, 22 May 2020 at 18:11:28 UTC, ag0aep6g wrote:
> So the DIP itself wasn't good enough to convince you.

Had that been the case, I would have rejected it.

> Your reasoning is fine when you're dealing with a function that 
> has a safe interface. I.e., it can only corrupt your code when 
> it's buggy. Then it makes sense so say "I trust the authors". D 
> users do it with Phobos. Phobos authors do it with the C 
> standard library. This kind of trust is perfectly ok.
> Your reasoning is completely wrong when you're thinking about a 
> function that doesn't have a safe interface. E.g., C's `memcpy` 
> just isn't safe.

memcpy isn't a good example since it's explicitly @system:

https://dlang.org/phobos/core_stdc_string.html#.memcpy

> It doesn't matter whether you trust the authors or not. The 
> user has to make sure that the call is correct. Otherwise, 
> `memcpy` will corrupt your memory. And `memcpy` is far from the 
> only such function.

Yes. But most of them aren't like memcpy. Most D code calls other 
D code, not C.

Am I saying nothing bad can happen if we implicitly trust 
extern(C) declarations? No. I'm saying we'll be no worse off if 
they're all implicitly @system.

This compiles with no warnings right *now*:

void main() {
     import core.stdc.stdlib: free;
     free(cast(void*) 42);
     free(new int);
     free(&main);
}