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Re: Ada: fix wrong code generated for small strings passed by reference


> > The compiler generated wrong code for
> >   Blank_8_Str : aliased constant String := (1 .. 8 => <space>);
> >   S : aliased String := Blank_8_Str;
> >   subtype Small_String is String (1 .. 8);
> > when S is passed by reference as an (in-)out parameter of type
> > Small_String. Objects like S are a bit special: they are formally
> > constrained, yet gigi builds a template type for them because they are
> > aliased.  When the function call is built, the argument must be converted
> > back to the constrained form of the type before its address can be taken,
> > as prescribed by the signature of the function.
>
>  Do you have a complete test case for this?

Not really, the original testcase would need to be sanitized.  However the bug 
is very easy to trigger on the SPARC for example: passing S as an in-out 
parameter and modifying it in the called function is sufficient to seriously 
damage it.

-- 
Eric Botcazou


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