[fpc-pascal] Segmentation fault gone if compiled with -glh

[Jeppe Johansen]

Den 10-01-2011 02:36, leledumbo skrev:
> Compile the attached project (really difficult to trim it down) using two
> different options. First, using -glh, then using -g. The first one raises
> nothing (program runs fine), while the second raises segmentation fault.
> When debugged deeper using gdb, the second gives this backtrace:
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x004091da in SYSTEM_REMOVE_FREED_FIXED_CHUNKS$POSCHUNK ()
> (gdb) bt
> #0 0x004091da in SYSTEM_REMOVE_FREED_FIXED_CHUNKS$POSCHUNK ()
> 0000001 0x00000010 in ?? ()
> 0000002 0x000651c4 in ?? ()
> 0000003 0x00408898 in SYSTEM_FINALIZEUNITS ()
> 0000004 0x00065a38 in ?? ()
> 0000005 0x0040c0e1 in SYSTEM_EXE_ENTRY$TENTRYINFORMATION ()
>
> Jonas told me to discuss it here due to unclearness whether this is a bug in
> my program or in fgl or wherever else.
>
> The source code:
> http://free-pascal-general.1045716.n5.nabble.com/file/n3334353/src.zip
> src.zip
For me the program results in an endless list of unhandled exceptions 
somewhere in the rtl
In the program I could narrow the problem down to line 117 in parser.pp. 
If that one was removed it ran fine

Doesn't the problem lie in that TFPGObjectList uses @ on the incoming 
parameters?

function TFPGObjectList.Add(const Item: T): Integer;
begin
   Result := inherited Add(@Item);
end;

Unless there's some magic going on, won't it then point to the stack, 
instead of the instance, in most cases?