topic Debugger behaviour on Itanium in Operating System - OpenVMS

Debugger behaviour on Itanium

Chris Barratt — Tue, 23 Oct 2007 00:27:47 GMT

I post this merely as a curiousity....

One of our programmers was debugging a Pascal program on IA64 and noticed the following..

In the Pascal code,

Type
Episode_type : char := ‘Y’

DBG> examine episode_type

IMS_SUB_STM_INPATIENT_V2\IMS_SUB_STM_INPATIENT_V2\EPISODE_TYPE: 89

When the same thing is done on Alpha,

DBG> examine episode_type

IMS_SUB_STM_INPATIENT_V2\IMS_SUB_STM_INPATIENT_V2\EPISODE_TYPE: 'Y'

Just wondering why the different behaviour ?

(Obviously, using exam/ascii on Itanium would give the same result as Alpha).

Cheers,
Chris

Re: Debugger behaviour on Itanium

Chris Barratt — Tue, 23 Oct 2007 00:30:17 GMT

a couple of corrections...

curiosity

and

Episode_type : char := 'Y';

Re: Debugger behaviour on Itanium

Dean McGorrill — Tue, 23 Oct 2007 12:57:23 GMT

hi Chris,
Interesting. the debugger does not appear to recognize the data type for pascal. perhaps some porting oversight.
in dcl...

$ episode_type[0,8]==89
$ show symbol episode_type
EPISODE_TYPE == "Y"
$

It at least has the right value. Dean

Re: Debugger behaviour on Itanium

John Gillings — Tue, 23 Oct 2007 17:23:45 GMT

Hi Chris,

Obviously the Alpha behaviour is correct. DEBUG should know the data type and display the data correctly.

Please build a small reproducer (should be trivial) and raise a case with your friendly Customer Support Centre to be passed through to enginnering.

Re: Debugger behaviour on Itanium

John Reagan — Wed, 24 Oct 2007 10:40:00 GMT

Jeff Nelson and I have talked about this on and off for several years now. The problem is that the DWARF CHAR type is very oriented towards C's CHAR type. For those of you keeping score at home, C's CHAR type is basically an integer type.

At present, we don't have a solution.

Re: Debugger behaviour on Itanium

Chris Barratt — Wed, 24 Oct 2007 18:27:58 GMT

Thanks John....good to know it was a known problem and hadn't slipped through the cracks.

When it all comes down to it, it's not a major issue and easily worked around.

Cheers,
Chris

Re: Debugger behaviour on Itanium

John Reagan — Thu, 25 Oct 2007 08:01:09 GMT

Well, I find it rather embarassing. We're working on some other debug related bugs at the moment in the compilers. I'll see if I can fold this issue into the mix and take another shot at it.