[fpc-devel] Windows 64bit SEH exception handling

michael.vancanneyt at wisa.be michael.vancanneyt at wisa.be
Wed Jun 20 08:48:36 CEST 2012

On Wed, 20 Jun 2012, Sergei Gorelkin wrote:

> 19.06.2012 23:43, tomek пишет:
>> Hello,
>> with reference to http://bugs.freepascal.org/view.php?id=12742 about random 
>> crash with Windows
>> OpenDialog Box only on Win7 64bit.
>> Today I compile trunk-fpc with TEST_WIN64_SEH support and it seems that 
>> this bug is resolved with SEH.
>> I checked a few times to make sure that this is due to SEH support.
>> My question is, why? how is it possible that support for SEH exceptions 
>> handling fix OpenDialog issue ?
>> or perhaps an exception is hidden ? as described in 
>> http://support.microsoft.com/kb/976038
>> do have you any suggestions ?
> Non-SEH exception handling on Win64 is known to handle exceptions too early, 
> bypassing frame-based handlers and therefore disrupting the intended control 
> flow. Most probably the exception under question was meant to be handled 
> within OS libraries and not passed to the application.

It makes you wonder why they created 2 systems in the first place...


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