Re: _e_info in NSException.h

[Richard Frith-Macdonald]

On 14 Jan 2008, at 07:35, Sebastian Reitenbach wrote:

> Hi,
>
> Richard Frith-Macdonald <richard@tiptree.demon.co.uk> wrote:
> > On 13 Jan 2008, at 21:20, Sebastian Reitenbach wrote:
> >
> > > Hi,
> > >
> > > after I got sope and sogo working with gnustep-make 2 and gnustep- 
> > > base
> > > 1.14.1, I tried to compile against gnustep-base1.15.2.
> > >
> > > sope compilation ended in an error:
> > > Structure has no member named: _e_info
> > > there is a line:
> > > ASSIGN(self->_e_info, _userInfo);
> > >
> > > after a bit digging I figured out that it was removed not long ago
> > > from
> > > NSException.h:
> > >
> > > http://svn.gna.org/viewcvs/gnustep?rev=25681&view=rev
> > > after adding again:
> > > NSDictionary *_e_info;
> > >
> > > sope compiled again.
> > >
> > > I wonder why was it removed? or is it an error to set it, in the  
> > > first
> > > place?
> >
> > It's an error to try to set it in the first place  ... the leading
> > underscore in the name if the instance variable tells you that this
> > is a private instance variable intended for internal use only.  In
> > 1.15.2 it has been replaced by _reserved (which is used only when
> > necessary to store additional information .... user info and/or
> > stacktrace ... in an exception).
> ah, thanks, understood.
>
> > NSException has no external instance variables ... I guess if the
> > sope code wants to store extra information in an exception it should
> > create a new exception based on the values returned by the methods of
> > the original one.
>
> In sope I find this:
>
> #if GNUSTEP_BASE_LIBRARY
> /* FIXME: TODO: move someplace better (hh: NGExtensions...) */
> @implementation NSException(setUserInfo)
>
> - (id)setUserInfo:(NSDictionary *)_userInfo {
>   ASSIGN(self->_e_info, _userInfo);
>   return self;
> }
>
> @end /* NSException(setUserInfo) */
> #endif
>
> and then later in the file, setUserInfo is used.
> I took a quick look and found setUserInfo available in  
> libFoundation, and
> there is no #if COCOOA, so I assume it is there available too, (I  
> have no
> MAC to make sure).

I checked the MacOS foundation headers ... no such method.
I then write a small test program:

        NSException *e;
        
	e = [NSException exceptionWithName: @"aaa" reason: @"bbb" userInfo:  
nil];
        [e setUserInfo: [NSDictionary dictionary]];

Running this produced

2008-01-14 08:08:05.166 TestTool[2478] *** Uncaught exception:  
<NSInvalidArgumentException> *** -[NSException setUserInfo:]:  
selector not recognized [self = 0x303000]

So the method definitely does not exist in Cocoa.

> In my eyes it would make most sense to add
> setUserInfo to NSException in gnustep-base, and then remove all the  
> #if
> GNUSTEP_BASE_LIBRARY stuff from sope, or at least replace it for  
> now with
> sth. that checks for the GNUSTEP_BASE version.
>
> Would that make sense, or is a too bad idea?

Given that the method does not exist except in libFoundation, it  
seems to me that the correct thing to do is to go through the sope  
code and remove all uses of it.  Actually if the code does not  
contain an implementation for Cocoa, maybe sope does not actually use  
it and all you need to do is remove the code which attempts to  
implement it for GNUstep.