Are there any default dmd optimizations

[Timon Gehr]

On 02/28/2013 05:55 AM, Walter Bright wrote:
> On 2/27/2013 8:01 PM, deadalnix wrote:
>> Plus, this is really hard to ensure that everything is initialized
>> properly
>> without going eager with setting to init.
>
> Yeah, the forward reference order of evaluation thingie.

It's really easy. DMD can be convinced to do a sufficient conservative 
analysis even now, but the behaviour is undocumented and seems 
unintentional.


     void main() {
         void foo()() { bar(); }
         void bar()() { i = 3; }
         int i;
         foo();
     }

It's a fine idea to disallow the use of both a shadowed and the 
shadowing symbol in the same function anyway, so we wouldn't lose a lot 
by allowing forward references from local functions.

Then the template behaviour could be fixed:

int i = 0;

void main(){
     void foo(int x){ i = x; }
     foo(1);
     int i = 0;
     foo(2);
     assert(.i==2&&i==0);
}

int i = 0;

void main(){
     void foo(int x){ i = x; }
     // foo(1);
     int i = 0;
     foo(2);
     assert(.i==0&&.i==2);
}

(Currently, presence of one call can magically influence the behaviour 
of other calls.)