[fpc-devel] Wrong docs: not initialized global variables

[Sven Barth]

Ondrej Pokorny <lazarus at kluug.net> schrieb am Di., 3. Juli 2018, 22:57:

> On 03.07.2018 22:08, Florian Klämpfl wrote:
> > Am 03.07.2018 um 21:30 schrieb Ondrej Pokorny:
> >> On 03.07.2018 20:54, Florian Klämpfl wrote:
> >> program Project1;
> >> type
> >>    TMyArray = array[0..10] of Integer;
> >>    procedure Init2(var A: TMyArray);
> >>    begin
> >>      A[2] := 1;
> >>    end;
> >> var
> >>    A: TMyArray;
> >> begin
> >>    Init2(A);
> >> end.
> >>
> >> should not emit the warning because A is not being read in Init2.
> >
> > (please note it throws only a hint in this case as A *is* initialized
> > as it is a global variable).
> >
> > FPC has no global data flow analysis (and I do not plan to do so yet),
> > so this is warning is currently far out of reach.
>
> Doing it for SetLength/FillChar would be a good start.
>

As Florian already wrote: FillChar() is nothing special. It's merely an
ordinary procedure with an untyped var parameter. The compiler can't make
any assumptions about what the code inside is doing with the parameter.

Regards,
Sven

>
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