[Info-vax] VMS Cobol - GnuCOBOL

[Arne Vajhøj]

On 2/27/2023 5:42 PM, David Wade wrote:
> On 27/02/2023 20:58, Arne Vajhøj wrote:
>> On 2/27/2023 11:49 AM, ultr... at gmail.com wrote:
>>> On Thursday, February 23, 2023 at 5:05:50 PM UTC-5, Paul Gavin wrote:
>>>> What, DEC C cannot be debugged?
>>>> Working on some enhancements in a C based app on Alphas running 8.4.
>>>> Can get to debugger just fine, step through code, look at data, set 
>>>> break points, etc., even from within ACMS.
>>>
>>> never debugged dec c but if the compiler debugger is anything like C 
>>> it is difficult ...
>>
>> The VMS C compiler behaves pretty much like other VMS compilers.
>>
>> The same VMS debugger is used for C as for any other (DEC/CPQ/HPE/VSI) 
>> language.
> 
> I feel the issue with debugging "C" is that in order to effectively use 
> the debugger you tend to need to turn down optimisation, but turning 
> down optimization tends to make the code work as you expect. When you 
> turn it up again, undefined behaviour tends to re-emerge.

/DEB/NOOP is not required but tend to make it easier to
debug because there is a closer correlation between the
instruction stream and the lines of source code.

And as you point out then that can in fact by itself
remove symptoms of a bug.

But isn't that the case for all VMS compilers? I know
I use /DEB/NOOP for both Fortran, Pascal and C when I want
to debug.

Arne