assert(0) behavior

[Dicebot via Digitalmars-d]

On Monday, 3 August 2015 at 15:50:56 UTC, Steven Schveighoffer 
wrote:
> On 8/3/15 11:18 AM, Dicebot wrote:
>> On Monday, 3 August 2015 at 14:34:52 UTC, Steven Schveighoffer 
>> wrote:
>>> Why do we do this?
>>
>> Because all asserts must be completely removed in -release
>
> 1. They aren't removed, they are replaced with a nearly useless 
> segfault.
> 2. If we are going to put something in there instead of 
> "assert", why not just throw an error?
>
> Effectively:
>
> assert(0, msg)
>
> becomes a fancy way of writing (in any mode, release or 
> otherwise):
>
> throw new AssertError(msg);
>
> This is actually the way I thought it was done.
>
> -Steve

Now, they are completely removed. There is effectively no 
AssertError present in -release (it is defined but compiler is 
free to assume it never happens). I'd expect any reasonable 
compiler to not even emit stack unwinding code for functions with 
assert(0) (and no other throwables are present).

assert(0) is effectively same as gcc __builtin_unreachable with 
all consequences for optimization - with only difference that 
latter won't even insert HLT but just continue executing 
corrupted program.