I have jumped back onto the D2 band-wagon after a long absence, read Andrei's book, and am having a great time cutting heaps of D code. My increase in productivity and happiness when compared to working in C++ is enormous.

Bug thumbs up to everyone involved with D2, Phobos and the book.

One area I am having a bit of trouble with is debugging. Can anyone help me out with how to debug a D2 program in Linux? Currently I am reduced to printing out heaps of debug text.

Specifically:

Stack Trace:
------------

I can't get the D2 stack-trace to work properly. All I get is something like this, which isn't helpful:

Segmentation fault

The code I used to generate this was:
import std.stdio;
import std.file;
void foo(File file) {
    file.flush;
}
void main(string[] args) {
    File file;
    foo(file);
}
Is stack-trace support broken, or do I have to do something to enable it?

GDB:
----

What is the status of D support in GDB? The last post I saw was back in April. It is currently hard work to debug with gdb when it doesn't understand D name mangling.

Profiling:
----------

How do I profile a D2 program? When I try -profile in dmd, the resultant executable crashes with a segfault when I try to run it. When I try sysprof, I get a handful of mangled names, and no call graph.

Graham St Jack:
> How do I profile a D2 program? When I try -profile in dmd, the resultant executable crashes with a segfault when I try to run it.

Are you able to produce a small test case of this bug?

Bye,
bearophile

On Tue, 13 Jul 2010 02:26:22 -0400, Graham St Jack <Graham.StJack@internode.on.net> wrote:

> I have jumped back onto the D2 band-wagon after a long absence, read
> Andrei's book, and am having a great time cutting heaps of D code. My
> increase in productivity and happiness when compared to working in C++ is
> enormous.
>
> Bug thumbs up to everyone involved with D2, Phobos and the book.
>
> One area I am having a bit of trouble with is debugging. Can anyone help
> me out with how to debug a D2 program in Linux? Currently I am reduced to
> printing out heaps of debug text.
>
> Specifically:
>
> Stack Trace:
> ------------
>
> I can't get the D2 stack-trace to work properly. All I get is something
> like this, which isn't helpful:
>
> Segmentation fault
>
> The code I used to generate this was:
> import std.stdio;
> import std.file;
> void foo(File file) {
>     file.flush;
> }
> void main(string[] args) {
>     File file;
>     foo(file);
> }
> Is stack-trace support broken, or do I have to do something to enable it?

Seg faults do not generate stack traces in Linux/MacOS.  This is because a segmentation fault is generated by a signal, and it's unsafe to throw exceptions from signals.

I believe seg faults can generate exceptions in Windows, but I'm not sure.

Your best bet is to get a debugger working, and it will halt on the signal.  As I understand it, a lot of good work was done recently on dmd (can't remember who did it) to get it working better with gdb.

-Steve

On 07/13/2010 01:26 AM, Graham St Jack wrote:
> I have jumped back onto the D2 band-wagon after a long absence, read
> Andrei's book, and am having a great time cutting heaps of D code. My
> increase in productivity and happiness when compared to working in C++ is
> enormous.
>
> Bug thumbs up to everyone involved with D2, Phobos and the book.
[snip]

Thanks. Bug thumbs up? Clearly you had debugging on your mind :o).

Check http://www.zerobugs.org/.


Andrei

On 07/13/2010 10:34 AM, Andrei Alexandrescu wrote:
> On 07/13/2010 01:26 AM, Graham St Jack wrote:
>> I have jumped back onto the D2 band-wagon after a long absence, read
>> Andrei's book, and am having a great time cutting heaps of D code. My
>> increase in productivity and happiness when compared to working in C++ is
>> enormous.
>>
>> Bug thumbs up to everyone involved with D2, Phobos and the book.
> [snip]
>
> Thanks. Bug thumbs up? Clearly you had debugging on your mind :o).
>
> Check http://www.zerobugs.org/.
>
>
> Andrei

I guess the more recent site is at http://www.zero-bugs.com/2.0/product_intro.html

Andrei

On Tue, 13 Jul 2010 11:35:55 -0400, Andrei Alexandrescu <SeeWebsiteForEmail@erdani.org> wrote:

> On 07/13/2010 10:34 AM, Andrei Alexandrescu wrote:
>> On 07/13/2010 01:26 AM, Graham St Jack wrote:
>>> I have jumped back onto the D2 band-wagon after a long absence, read
>>> Andrei's book, and am having a great time cutting heaps of D code. My
>>> increase in productivity and happiness when compared to working in C++ is
>>> enormous.
>>>
>>> Bug thumbs up to everyone involved with D2, Phobos and the book.
>> [snip]
>>
>> Thanks. Bug thumbs up? Clearly you had debugging on your mind :o).
>>
>> Check http://www.zerobugs.org/.
>>
>>
>> Andrei
>
> I guess the more recent site is at http://www.zero-bugs.com/2.0/product_intro.html

Does that support D? The faq says:

 "I have started some preliminary work to support Walter Bright's D Programming Language, and a D demangler has been contributed by the D community. However, this work is in an experimental stage."

-Steve

Steven Schveighoffer Wrote:

> On Tue, 13 Jul 2010 11:35:55 -0400, Andrei Alexandrescu <SeeWebsiteForEmail@erdani.org> wrote:
> 
> > On 07/13/2010 10:34 AM, Andrei Alexandrescu wrote:
> >> On 07/13/2010 01:26 AM, Graham St Jack wrote:
> >>> I have jumped back onto the D2 band-wagon after a long absence, read
> >>> Andrei's book, and am having a great time cutting heaps of D code. My
> >>> increase in productivity and happiness when compared to working in C++
> >>> is
> >>> enormous.
> >>>
> >>> Bug thumbs up to everyone involved with D2, Phobos and the book.
> >> [snip]
> >>
> >> Thanks. Bug thumbs up? Clearly you had debugging on your mind :o).
> >>
> >> Check http://www.zerobugs.org/.
> >>
> >>
> >> Andrei
> >
> > I guess the more recent site is at http://www.zero-bugs.com/2.0/product_intro.html
> 
> Does that support D? The faq says:
> 
>   "I have started some preliminary work to support Walter Bright's D
> Programming Language, and a D demangler has been contributed by the D
> community. However, this work is in an experimental stage."
> 
> -Steve


I never got it to work. It's very picky about the environment setup.

Graham St Jack, el 13 de julio a las 06:26 me escribiste:
> GDB:
> ----
> 
> What is the status of D support in GDB? The last post I saw was back in April. It is currently hard work to debug with gdb when it doesn't understand D name mangling.

The patch was accepted a while ago and the next GDB version will heve them (you can try CVS's GDB if you need it now). I'm not sure if it support D2 new stuff though.

> Profiling:
> ----------
> 
> How do I profile a D2 program? When I try -profile in dmd, the resultant executable crashes with a segfault when I try to run it. When I try sysprof, I get a handful of mangled names, and no call graph.

Same here, I use valgrind's callgrind + kcachegrind, is slooooow, but very nice.

-- 
Leandro Lucarella (AKA luca)                     http://llucax.com.ar/
----------------------------------------------------------------------
GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145  104C 949E BFB6 5F5A 8D05)
----------------------------------------------------------------------
No debemos temer a la muerte, porque es la mejor recompensa de la vida.
	-- Ren & Stimpy

On Tue, 13 Jul 2010 03:55:08 -0400, bearophile wrote:

> Graham St Jack:
>> How do I profile a D2 program? When I try -profile in dmd, the resultant executable crashes with a segfault when I try to run it.
> 
> Are you able to produce a small test case of this bug?
> 
> Bye,
> bearophile

Small test cases don't crash. I will spend a bit of time experimenting with my way-too-big test case to find out why it crashes when run after being compiled with -profile, and post my results here.

One thing I noticed was that the trace.log file doesn't demangle the names properly either.

On Tue, 13 Jul 2010 10:34:41 -0500, Andrei Alexandrescu wrote:

> On 07/13/2010 01:26 AM, Graham St Jack wrote:
>> I have jumped back onto the D2 band-wagon after a long absence, read Andrei's book, and am having a great time cutting heaps of D code. My increase in productivity and happiness when compared to working in C++ is enormous.
>>
>> Bug thumbs up to everyone involved with D2, Phobos and the book.
> [snip]
> 
> Thanks. Bug thumbs up? Clearly you had debugging on your mind :o).
> 
> Check http://www.zerobugs.org/.
> 
> 
> Andrei

Freudian slip...

I love the book by the way - I couldn't put it down. D is totally awesome now, and there were heaps of cool new features that I didn't know about.

Thanks again.