[libvirt] [PATCH] Improved error messages in XM conf module

[Daniel Veillard]

On Mon, Sep 15, 2008 at 04:12:58PM +0100, Daniel P. Berrange wrote:
> On Mon, Sep 15, 2008 at 04:06:46PM +0100, Richard W.M. Jones wrote:
> > The attached patch improves error handling in the XM config file
> > parser (src/conf.c).
> > 
> > Currently it has a custom error function called virConfError which has
> > three problems.  Firstly the conf argument is ignored and therefore
> > pointless to even pass.  Secondly the function takes a line number
> > parameter (for reporting the line number where parsing failed), but
> > this is swallowed and not printed in error messages.  Thirdly, and
> > most importantly, the name of the file where the error occurs is not
> > printed by default unless the caller happens to print it.
> > 
> > If there is an _empty_ file in /etc/xen we get this error:
> > 
> >   # virsh list --all
> >   libvir: error : failed to read configuration file /etc/xen/foobar
> > 
> > but if the spurious file under /etc/xen is non-empty, like a script,
> > you get completely anonymous errors such as:
> > 
> >   libvir: error : configuration file syntax error: expecting an assignment
> > 
> > or:
> > 
> >   libvir: error : configuration file syntax error: expecting a value
> > 
> > The patch fixes this by printing out the filename and line number if
> > these are available from the parser context (and the parser context is
> > passed to virConfError instead of the unused virConfPtr).  With this
> > patch you'll get errors for the second case like this:
> > 
> >   # virsh list --inactive
> >   libvir: error : /etc/xen/foobar:1: expecting a value
> 
> ACK, this has annoyed the hell out of me for ages.

  +1, no problem,

Daniel

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