[Piglit] [Patch RFC] Piglit Segmentation Handler

[Ken Phillis Jr]

On Mon, Feb 18, 2013 at 10:40 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
> I think this is a great idea.
>
> Concerning Windows, I don't have time to test myself now, but FWIW, feel free to lift inspiration/code from apitrace's exception handler: https://github.com/apitrace/apitrace/blob/master/common/os_win32.cpp#L248 I know it works very well.
>

I did find some of that useful. I also see that I probably *should*
add a function to remove the handlers for the cases when a particular
host system does not support automatically reverting things to default
state. However, From what I can see, Windows automatically uses
default handlers.

> However this is not enough to make piglit on windows 100% handsfree -- because assertion failures / errors on windows often create an interactive dialog box, the only way to be 100% sure the test won't hang is to have the piglit python framework periodically search for dialog boxes...
>
> Jose
>

SetErrorMode is what you use to simply enable/disable error
Functionality. SEM_NOGPFAULTERRORBOX is the exact flag that needs to
be used to disable the crash dialog.


As for other things, the best way to capture crash backtraces that I
can find is to use the AddVectoredExceptionHandler ( and
RemoveVectoredExceptionHandler ) functions over the other functions (
SetUnhandledExceptionFilter, Signal, and _set_se_translator ). That
said, Currently I only have backtraces generated for the following
exceptions...

EXCEPTION_FLT_DIVIDE_BY_ZERO
EXCEPTION_INT_DIVIDE_BY_ZERO
EXCEPTION_ACCESS_VIOLATION

That said, Here's some of the documentation I'm using to figure out
what exceptions to handle/use...

MSDN - EXCEPTION_RECORD Structure
http://msdn.microsoft.com/en-us/library/windows/desktop/aa363082%28v=vs.85%29.aspx


MSDN - SetErrorMode documentation
http://msdn.microsoft.com/en-us/library/windows/desktop/ms680621%28v=vs.85%29.aspx

MSDN - AddVectoredExceptionHandler
http://msdn.microsoft.com/en-us/library/windows/desktop/ms679274%28v=vs.85%29.aspx
MSDN - RemoveVectoredExceptionHandler
http://msdn.microsoft.com/en-us/library/windows/desktop/ms680571%28v=vs.85%29.aspx

As for backtracing, I am using SymFromAddr, SymGetLineFromAddr64, and
SymInitialize from dbghelp (
http://msdn.microsoft.com/en-us/library/windows/desktop/ms679309%28v=vs.85%29.aspx
), and CaptureStackBackTrace (
http://msdn.microsoft.com/en-us/library/windows/desktop/bb204633%28v=vs.85%29.aspx
)


NOTE: I have not yet tested the backtrace capture on a real driver
with windows, but with an in-program crash the capture works well
enough to guarantee that piglit will get a "Crash" result and
backtrace before the program closes out.