Discussion Thread: DIP 1035-- at system Variables--Community Review Round 1

[jmh530]

On Wednesday, 17 June 2020 at 15:58:01 UTC, Dennis wrote:
> [snip]
> This DIP *is* a fix for those bugs, for which there is no 
> obvious solution. The idea is to have a consistent design, 
> instead of having a list of small enhancements and hole plugs 
> that are half-baked. Notice the trend here:
> - https://issues.dlang.org/show_bug.cgi?id=18554 (does not 
> solve union/array casts, undone by 15371, spawns your issue)
> - https://issues.dlang.org/show_bug.cgi?id=19646 (incomplete 
> solution, spawns 20347)
> - https://issues.dlang.org/show_bug.cgi?id=19968 (incomplete 
> solution, spawns 20148)
>
> So let's say we fix those second round bugs like you suggest, 
> which I will call 'bug fix':
>[snip]

I think it can't hurt to emphasize in the DIP that even if issue 
20347 is fixed, then it would only mean that the global variable 
would still be @system. For instance, the DIP example for getPtr 
could be changed to below and still not generate an error. Fixing 
20347 would just mean that you cannot make the initialization of 
x @safe.

auto getPtr() @system {return cast(int*) 0x7FFE_E800_0000;}

@system int* x = getPtr();

void main() @safe {
     int y = *x; // = 3; // memory corruption
}