Re: [Dev-C++] Segmentation Fault - Debugging

[Jamiil A. <jal...@gm...>]

Yes Adam, thanks for the help, I have not tested the code or if what I think 
the problem is actually true, but after you pointed out that before saing 
"if (str->empty()){... " 'str' must point to someting, I realize that my 
mistake is that a declared std::string pointer does not point to anything, 
yet  I am testing if it is empty() or not.
Well I am going to go check my/your understanding of the problem and its 
solution.

Thanks Adam.

>
> I haven't used Glib, but if you are getting that error, my suspicion is 
> that
> Glib my derived it's ustring from basic_string class template, and that is
> why you are getting that reference to basic_string.h.
>
>>> Glib::ustring* str;
>
> As for why you are getting the error, again my suspicion from the code
> fragment is that you make a declaration for the pointer (statement above),
> but you don't have it pointing to anything before you test it (statement
> below).
>
>>> if (str->empty()){str = new Glib::ustring("Unknown");}
>
> You need to assign it to something. What it is pointing to is undefined.
> Pointers must point to something before you can use them. Unless you have
> done that in code you have not shown us.
>
> -Adam Jones
>
> -----Original Message-----
> From: dev...@li...
> [mailto:dev...@li...] On Behalf Of Jamiil
> Abduqadir
> Sent: Saturday, July 21, 2007 11:52 PM
> To: Per Westermark
> Cc: 'Dev Cpp MailingLinst'
> Subject: Re: [Dev-C++] Segmentation Fault - Debugging
>
> Per and Adam, thank you very much for the hand.
> Using Per's suggetion I used the DOS prompt to run gdb and tb, and as
> requested by Adam, here is the slice of code that is causing all the
> problems.
> hpp file
> #include <glibmm/ustring.h>
> ....
> Glib::ustring* str;
> ...
> cpp file
> if (str->empty()){str = new Glib::ustring("Unknown");}
> ...
>
> 'gdb' reports that the error is in basic_string.h, line 261. I am 
> compiling
> using mingw32 v 3.4.4
> In a WinXP machine.
> What has me comfused is that I am not using the std library, but the Glib
> library; yet the error comes from the std library
> Can anyone help?
> ----- Original Message ----- 
> From: "Per Westermark" <pw...@ia...>
> To: "Jamiil Abduqadir" <jal...@gm...>
> Cc: "Adam Jones" <aj...@i-...>; "'Dev Cpp MailingLinst'"
> <dev...@li...>
> Sent: Saturday, July 21, 2007 11:12 AM
> Subject: Re: [Dev-C++] Segmentation Fault - Debugging
>
>
>>I never use the built-in debugger support in Dev-C++, but if you can get
>> the application to fail in the debugger - or by running directly from gdb
>> om command line, the back trace command (bt in command line version) will
>> dump the call sequence where the application died.
>>
>> /pwm
>>
>> On Sat, 21 Jul 2007, Jamiil Abduqadir wrote:
>>
>>> Well, I would like to give you more information, but my problem is that 
>>> I
>>> don't know how to utilize Dev-Cpp's debugger to locate the problem. If
>>> you
>>> know a trick to catch the problemed code, please let me know.
>>>
>>> Thanks in advance.
>>> ----- Original Message -----
>>> From: "Adam Jones" <aj...@i-...>
>>> To: "'Jamiil Abduqadir'" <jal...@gm...>; "'Dev Cpp MailingLinst'"
>>> <dev...@li...>
>>> Sent: Saturday, July 21, 2007 5:47 AM
>>> Subject: RE: [Dev-C++] Segmentation Fault - Debugging
>>>
>>>
>>> You Wrote:
>>> > I have a segmentation fault in my program
>>>
>>> This usually indicates a pointer allocation problem. Check your pointers
>>> in
>>> your program. Make sure they are allocated and initialized correctly
>>> before
>>> using them. Without out knowing more about the code or what you are
>>> doing,
>>> this is the only advice I can give at this point.
>>>
>>> -Adam Jones
>>>
>>>
>>> From: dev...@li...
>>> [mailto:dev...@li...] On Behalf Of Jamiil
>>> Abduqadir
>>> Sent: Saturday, July 21, 2007 10:37 AM
>>> To: Dev Cpp MailingLinst
>>> Subject: [Dev-C++] Segmentation Fault - Debugging
>>>
>>> Hello.
>>> I have a segmentation fault in my program, I know that I could trace, or
>>> back trace in this case, to find where the the segmentation fault
>>> occures.
>>> What I don't know, though, how to do it.
>>> Can someone please point me out where I can get this information, or 
>>> tell
>>> how to do it under Dev-Cpp?
>>>
>>> Thanks everyone.
>>>
>>>
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>>
>
>
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