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Subject: Re: Visibility
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Date: 2003-06-08T16:18:23+00:00
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Frank J. Lhota wrote:

> Yes, only at startup. By the time that the main procedure starts execution,
> everything it uses is elaborated.

It is highly unlikely that anyone will accidently create a program which 
fails an Elaboration_Check after the main program begins execution.  But 
there is a lot of elaboration that happens after the main program has 
started.  Consider for example a task type.  Its declaration is 
elaborated when the declarative part it appears in is elaborated, 
usually before the execution of the main program begins.  But 
elaboration of the object of the task type occurs after it is created, 
which could occur as the result of an allocator:

     Bar: Task_Access;
...
     Bar := new Some_Task;

If this is the first creation of an object of type Some_Task, and the 
elaboration of Some_Task fails an elaboaration check, the allocation 
will fail.