[Lazarus] Is this a bug?

[Joost van der Sluis]

On 06/16/2017 11:43 AM, Wolf via Lazarus wrote:
> If I understand you correctly, because
> 2. since ParamStr() is handled by the system unit, a call to halt will
> result in a memory leak because Heaptrc is not aware of this allocation.

Only the initialization of the system-unit is done before the 
heap-manager is in place. So this is no issue.

The memory being allocated for the commandline and it's parameters 
itself is system-specific. If there is any memory allocated at all.

> If this is correct, then the conclusion has to be that Heaptrc cannot be
> trusted as a debugging tool because it is ill-informed about what the
> system unit is up to.

Heaptrace is a great debugging-tool. Debugging-tools give you more 
information to help you find problems. But they can never be trusted. 
The same holds for any debugger, btw.

The part about the system-unit is incorrect. (See above)

Calling Halt(), is, well... dangerous. On the other hand you should not 
care about memory-leaks on application exit. But I can imagine that it 
obfuscates things when you are searching for real memory-leaks.

Try to place your code in a 'try .. finally' block, and call Halt() 
thereafter. Of even better, in a procedure, and halt after the 
procedure-call. You have probably problems with implicit try-finally 
sections, as Mattias pointed out. You can also investigate this by 
looking at the created assembly. (fpc -an)

Regards,

Joost.

> wolf (rather disillusioned)
>
> On 16/06/17 20:47, Mattias Gaertner via Lazarus wrote:
>> On Fri, 16 Jun 2017 20:36:54 +1200
>> Wolf via Lazarus <lazarus at lists.lazarus-ide.org> wrote:
>>
>>> Now I am nicely confused: If halt does call finalization sections, isn't
>>> then all heap space requested by the system unit supposed to be freed as
>>> well?
>> The system unit is special. It is loaded even before the heap manager
>> is initialized. Heaptrc does not report memory of the system unit.
>>
>> Heaptrc reports allocations after its initialization, which is
>> usually right after the system unit.
>>
>>
>> Mattias
>