> Like I said, it's not nice. Making nocode_wanted work seems
> preferable. But if it turns out to be too difficult then there are
> perhaps alternatives
Is it possible to implement "undo" like in editors, i.e. save current
generated code state (output position) when nocode_wanted=1 and then
restore it when nocode_wanted=0?
PS: The problem with the ({}) is exposed only with while()/for() inside it
2016-04-03 22:39 GMT+03:00 Edmund Grimley Evans <
[email protected]>:
> Michael:
>
> > Of course, because the whole parsing of the ({block}) still
> > generates code. The nocode_wanted hack currently doesn't work for
> > statement expressions, and as Edmund says deserves a little thought
> > if it's applied at the right level currently (well I think it's
> > clear that it isn't, but the question what the right level is
> > remains).
>
> Yes.
>
> I've just been thinking about whether there might be any viable
> alternatives to making nocode_wanted work properly, and perhaps there
> are, but they're not nice...
>
> For example, when you encounter a statement expression you could
> distinguish three cases:
>
> 1. If you're in a place where it's impossible to generate code, such
> as inside the declaration of a global variable, then stop with an
> error. This might imply the limitation (which I think people could
> live with) of not being able to handle a global declaration such as:
>
> int a[sizeof(({ for (;;) ; }), 1)];
>
> (On the other hand, are there any places where it's totally impossible
> to generate code? Would it matter if you generated unreachable garbage
> code between two functions?)
>
> 2. If you're somethere where it's possible to generate code, but you
> didn't want there to be any code, then generate an unconditional
> branch forwards so it doesn't matter if any garbage code gets
> generated while the statement expression is being parsed.
>
> 3. If you're inside case 2, or anywhere else where you know that
> you're generating unreachable code, then just carry on: if any garbage
> code gets generated it won't do any harm.
>
> Like I said, it's not nice. Making nocode_wanted work seems
> preferable. But if it turns out to be too difficult then there are
> perhaps alternatives.
>
> Edmund
>
> _______________________________________________
> Tinycc-devel mailing list
> [email protected]
> https://lists.nongnu.org/mailman/listinfo/tinycc-devel
>
_______________________________________________
Tinycc-devel mailing list
[email protected]
https://lists.nongnu.org/mailman/listinfo/tinycc-devel
