• Amex (20/20) May 24 2019 I'm having serious issues with this. I moved some code to a
• Amex (15/15) May 25 2019 First-chance exception: 0xc0000096: Privileged instruction
• Rainer Schuetze (12/17) May 26 2019 No. The D runtime disables catching the (custom) exception for the stack

Amex <Amex gmail.com> writes:

I'm having serious issues with this. I moved some code to a 
different directory and it's broke all over the place(even though 
I updated every occurrence of the paths). Somewhere something is 
not being loaded and it's producing a null reference somewhere 
which is propagating through the app in a very strange way(I 
think it has to do with the Orange SerDes.

The problem is that for any crash such as a range error or a null 
pointer reference, the debugger throws a 'Privileged 
instruction'. and then exists the program.

Hence I can't see the stack or anything and can't debug the 
program. I have to run it in the command prompt and have it crash 
then launch a new instance of VS and then it will show the line, 
but still say 'Privileged instruction' error. I can see the stack 
and eventually locate the error.  [There are lot's of windows/VS 
dialog boxes that slow the process down]

It's very slow doing it this way. Surely something can be done? 
Unfortunately I'm using x64 binaries with x64 GTK and others so 
it's a lot of trouble to switch to x86.

Could you look in to this when you get a chance?

Thanks.

Amex <Amex gmail.com> writes:

First-chance exception: 0xc0000096: Privileged instruction
Unhandled exception: 0xc0000096: Privileged instruction

Since this error only occurs in VS and not when running the app 
from the command line, surely these is a VS/VD issue?

"A privileged instruction is a processor op-code (assembler 
instruction) which can only be executed in "supervisor" (or 
Ring-0) mode. These types of instructions tend to be used to 
access I/O devices and protected data structures from the windows 
kernel.

Regular programs execute in "user mode" (Ring-3) which disallows 
direct access to I/O devices, etc...

As others mentioned, the cause is probably a corrupted stack or a 
messed up function pointer call."

I'm wondering if there is a bug in some VD code that causes this 
when handling exceptions in x64?

Rainer Schuetze <r.sagitario gmx.de> writes:

On 25/05/2019 21:28, Amex wrote:
 First-chance exception: 0xc0000096: Privileged instruction
 Unhandled exception: 0xc0000096: Privileged instruction
 
 Since this error only occurs in VS and not when running the app from the
 command line, surely these is a VS/VD issue?

No. The D runtime disables catching the (custom) exception for the stack
trace when running in a debugger. This allows you to analyze the call
stack of unhandled exceptions in the debugger.

Unfortunately, there is currently no way to re-enable that catch, only
to disable it for regular execution. If you have a long running process
you can attach to it after program start, that will result in the
unhandled exception being shown.

The next release of Visual D will show the exception type and message
(and the location if available) in the output window along with the
"Priviledged instruction" messages. I hope to be able to release a beta
in the next couple of days.