[fpc-pascal] When the variable freed in Optimize compile

[Flávio Etrusco]

On Wed, Jun 8, 2011 at 6:17 AM, Jonas Maebe <jonas.maebe at elis.ugent.be> wrote:
>
> On 08 Jun 2011, at 10:57, Zaher Dirkey wrote:
>
>> Hi, I know when compile the project with optimize in Delphi the variable
>> freed/allocated after the last line used.
>> How can i make same in FPC, O3 not worked for me.
>
> FPC only reuses stack slots allocated for temporary expressions. It does not
> reuse stack slots used by variables.
>
>
> Jonas
>

While we are at it, is this a limitation or by design?

> >   What if C is string or Interface of TInterfacedObject?
> It is the same logic. It's freed only at the end.

I recently noticed that this is also true for ansistrings. I see this
can avoid lots of errors, but also makes it very ackward to
intentionally avoid copies when modifying strings in-place if they are
obtained from a function...

-Flávio