Re: Weird Code in parse.y (java_layout_seen_class_methods)

[Bryce McKinlay <mckinlay at redhat dot com>]

Hi Ranjit,

Ranjit Mathew wrote:

>  Consider the body of java_layout_seen_class_methods()
> in parse.y:
> -------------------------- 8< --------------------------
>   7577 void java_layout_seen_class_methods (void)
>   7578 {
>   7579   tree previous_list = all_class_list;
>   7580   tree end = NULL_TREE;
>   7581   tree current;
>   7582
>   7583   while (1)
>   7584     {
>   7585       for (current = previous_list;
>   7586            current != end; current = TREE_CHAIN (current))
>   7587         layout_class_methods (TREE_TYPE (TREE_VALUE (current)));
>   7588
>   7589       if (previous_list != all_class_list)
>   7590         {
>   7591           end = previous_list;
>   7592           previous_list = all_class_list;
>   7593         }
>   7594       else
>   7595         break;
>   7596     }
>   7597 }
> -------------------------- 8< --------------------------
>
> How can code between 7590-7593 ever execute?
> And why is there a while(1) around the for loop?
>
> Is this some vestigial code that should have been
> removed?
>  

I suspect that layout_class_methods can end up adding things to 
all_class_list, because new classes may be added/resolved during  method 
layout. This changes the value of all_class_list. The while(1) is 
presumably there so that the for-loop gets re-run on any new classes 
which appear in the list.

Regards

Bryce