@noreturn property

[Daniel Gibson]

Leandro Lucarella schrieb:
> Iain Buclaw, el 21 de octubre a las 11:54 me escribiste:
>> A few standard library functions, such as 'abort' and 'exit', cannot return.
>> However there is no way in DMD to let the compiler know about this.
>> Currently in D2, you must either have a 'return' or 'assert(0)' statement at
>> the end of a function body. It would be nice however if you can give hints to
>> the compiler to let it know that a function is never going to return.
>>
>> Example:
>>
>> @noreturn void fatal()
>> {
>>     print("Error");
>>     exit(1);
>> }
>>
>> The 'noreturn' keyword would tell the compiler that 'fatal' cannot return, and
>> can then optimise without regard to what would happen if 'fatal' ever did
>> return. This should also allow fatal to be used instead of a return or assert
>> statement.
>>
>> Example:
>>
>> int mycheck(int x)
>> {
>>     if (x > 1)
>>         return OK;
>>     fatal();
>> }
>>
>>
>> Thoughts?
> 
> You want to include in the language what you can do (or at least could)
> do in GDC using:
> 
> pragma(GNU_attribute, noreturn)) void fatal()
> {
>      print("Error");
>      exit(1);
> }
> 
> ?
> 

Obviously he wants a portable way to do this that will work on any up-to-date D2 compiler.. doesn't 
make much sense to have a gdc-only solution that makes code incompatible with dmd (and possibly 
other compilers). Of course one may use version(GDC) or something like that to ensure compatibility, 
but that's just ugly.

Cheers,
- Daniel