all OS functions should be "nothrow @trusted @nogc"

[ag0aep6g via Digitalmars-d]

On 07/27/2017 03:24 PM, Moritz Maxeiner wrote:
> --- null.d ---
> version (linux):
> 
> import core.stdc.stdio : FILE;
> import core.sys.linux.sys.mman;
> 
> extern (C) @safe int fgetc(FILE* stream);
> 
> void mmapNull()
> {
>      void* mmapNull = mmap(null, 4096, PROT_READ | PROT_WRITE, 
> MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED | MAP_POPULATE, -1, 0);
>      assert (mmapNull == null, "Do `echo 0 > /proc/sys/vm/mmap_min_addr` 
> as root");
>      *(cast (char*) null) = 'D';
> }
> 
> void nullDeref() @safe
> {
>      fgetc(null);
> }
> 
> void main(string[] args)
> {
>      mmapNull();
>      nullDeref();
> }
> ---
> 
> For some fun on Linux, try out
> # echo 0 > /proc/sys/vm/mmap_min_addr
> $ rdmd null.d

The gist of this is that Linux can be configured so that null can be a 
valid pointer. Right?

That seems pretty bad for @safe at large, not only when C functions are 
involved.