[fpc-devel]Re: Another problem with fpc v1.1

Peter Vreman peter at freepascal.org
Tue Jul 2 15:32:56 CEST 2002

> On zaterdag, juni 29, 2002, at 02:02 , Sergey Korshunoff wrote:
> > My answer: fpc v1.1 use a stack of modules which must be compiled
> > (may be as a local variables in parser.pas). Sometimes
> > this dynamic variable is destoryed (  aTInputFileVar.Free is executed),
> > but it is keept in stack and fpc v1.1 go to use this already invalid
> > reference.
> >
> > Why we can not see a problem in standard configuration?
> >     there is a _big_ chance (for a standard heap.inc realization) that
> >     a freed block is used again for the same type of variable
> >
> > I think we can raise this error too by increasing a blocksize value in
> > heap.inc
> >
> > What I found with fpc v1.1 made with
> >      maxblocksize := 304 + blocksize;
> > in rtl/inc/heap.inc.
> With this change, I can also reproduce it easily. The problem is that 
> the tinputfile of a unit is both stored in the tppumodule and in the 
> tscannerfile of a unit. So in the function loadunit in fppu.pas line 
> 1109-1111 are wrong:
>                 scanner:=tscannerfile(hp.scanner);
>                 hp.reset;
>                 hp.scanner:=scanner;
> The reset destroys the tinputfile of the tppumodule (it's in the 
> sourcefiles list of tmodule, which is reset by tmodule.reset, which is 
> called by tppumodule.reset), but this same tinputfile is still assigned 
> to the inputfile field of the scanner and reused! Peter, can you have a 
> look at this?

Not soon. I just heard that i've to leave for work to Ireland tomorrow, so i've to pack
and arrange things.

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