Re: Destructor attribute inheritance, yea or nay?

[Stanislav Blinov via Digitalmars-d]

On Monday, 22 May 2017 at 17:05:06 UTC, Stanislav Blinov wrote:

Considering that the core runtime component - the GC - is the one that usually handles finalization, it follows that *GC collection can never be @safe*. And since collection only happens during allocation, it follows that allocation cannot be @safe either. Nor can they be @trusted, because destructors are effectively not restricted in any way.

This program, executed on my machine:

import std.stdio;

class Innocious
{
   ~this() @safe {}
}

class Malicious : Innocious
{
   int[] data;

   this() @safe
   {
       data = new int[1000000];
   }

   ~this()
   {
       writeln("    Sure, here you go:");
       writeln("      import std.random;");
       writeln("      auto n = uniform(1, uint.max);");
       writeln("      *(cast(int*)n) = 0xbadf00d;");
   }
}

void important() @safe
{

writeln("I am working here, i'm not doing anything dangerous..."); scope(exit) writeln("I'm good, no, I'm awesome. You can trust me!"); writeln(" Good GC, would you kindly give me some room to maneuver?");

   int[] storage = new int[1000000];
   /* do some calculations... */
}

void oblivious() @safe
{
   Innocious i = new Malicious();
   /* do something with i and then leave it for GC. */
}

void main()
{
   oblivious();
   important();
}

prints this:

I am working here, i'm not doing anything dangerous...
  Good GC, would you kindly give me some room to maneuver?
    Sure, here you go:
      import std.random;
      auto n = uniform(1, uint.max);
      *(cast(int*)n) = 0xbadf00d;
I'm good, no, I'm awesome. You can trust me!