NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/comp/sys/hp/13049

Text File | 1992-11-18 | 1.9 KB | 50 lines

Newsgroups: comp.sys.hp
Path: sparky!uunet!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!cs.utexas.edu!torn!watserv2.uwaterloo.ca!madmax.uwaterloo.ca!gordon
From: [e-mail] (Gordon R. Strachan)
Subject: Re: xdb accessing 'opaque' data structures
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: University of Waterloo
References: <[e-mail]> <[e-mail]>
Date: Wed, 18 Nov 1992 14:21:11 GMT
Lines: 38

In article <[e-mail]> [e-mail] (Bruno Melli) writes:
>The reason xdb can't show you what a widget looks like is that it has
>no debug info about widgets. If you look at Intrinsic.h you get:
>
>typedef struct _WidgetRec *Widget;
>
>Try to find _WidgetRec in intrinsic.h. You won't find it.
>So xdb knows that a Widget is a pointer to a struct _WidgetRec but
>has no idea what the _WidgetRec struct looks like.
>
>To work around this problem you need to have a file include CoreP.h.
>You could link in a dummy object file when you build your debugable
>executable, or you could have something like this in one of your
>source file.

Are you absolutely sure about this?  I have been writing my own widget which
naturally defines its own widget structue.  Now the file includes the
private header files for both my widget and the CoreP.h files.  So my
program knows exactly what is in the structure so presumably the debugger
should as well.  However, if you try to print out the widget structure the
debugger still claims it doesn't know what it is.  Interestingly enough, if
I cast the widget prior to printing then it will work.  Ie: the xdb command

p w

were w is the widget won't work but

p *(struct _MyWidgetRec *)w

will.  So the debugger know what _MyWidgetRec structure looks like, it just
can't figure out that typedef MyWidget.  It all very strange to me.

>
>bruno.

Gordon