Re: question for gdb users...

[Richard Frith-Macdonald]

On 24 Sep 2009, at 04:40, Matt Rice wrote:

> there is some discussion here about removing the convenience mechanism
> that allows
> you to go
>
> break foo
> where foo then turns into -[class foo]
>
> this causes lots of issues which are fairly hard to fix in gdb,
> which is why the whole 'break main' with recent gdb causes issues.  
> because of
> [NSThread main].
>
> if you guys opposed to it please let me know and I will relay it into
> the gdb thread,
> I for one wasn't even aware of this feature until it started causing  
> problems
>
> http://sourceware.org/ml/gdb-patches/2009-09/msg00734.html
> here is the thread.

I use this feature tens of times a day, perhaps more ... it's actually  
almost the only way I set breakpoints (though I occasionally set  
breakpoints at particular lines or in C functions).

Now, it's not obvious, from a quick read of the thread, why there is a  
specific problem with objc ... though it seems to imply that objc is a  
special case and this feature is fine in C++  and desired in pascal  
and ada.

I don't mind using the 'break [class method]'  syntax where I know  
that the implementation of the method is in one particular class, but  
*usually* I don't know which class  I want to break in (because I'm  
not aware of all the libraries/subclasses that might be involved).

If the underlying problem is one of confusion between objc methods and  
C functions (the example of the confusion between the main() function  
and the [NSThread-main] method suggests that this may be the case)  
then perhaps it could be resolved using a modification of the square  
brackets syntax ...

at present we have:

+[class method] a factory method of a specific class
-[class method]   in instance method in a particular class
[class method]  either a factory method or an instance method, with an  
option to choose if both exist

and could add:

+[method]       a factory method of any class
-[method]   in instance method in any class
[method]  either a factory method or an instance method,

So 'break [method] would be like the current 'break method' syntax but  
'method' would be treated *only* as an ObjC method name, never as a  
function or method in another language.

If this would help resolve the issue, it would satisfy me.  Simply  
losing the ability to set a breakpoint in any class would not.