Re: [xml] xmllib2-2.3.4 compiler warnings on QNX

[Daniel Veillard <veillard redhat com>]

On Fri, Mar 23, 2001 at 11:29:02AM +0100, Peter Jacobi wrote:
> Hi Daniel, All,
>
> >    if this is the use of COPY_BUF macro it seems, I don't see how
> > the compiler can detect an unreachable code in
> >
> > #define COPY_BUF(l,b,i,v)                                     \
> >     if (l == 1) b[i++] = (xmlChar) v;                                   \
> >     else i += xmlCopyChar(l,&b[i],v)
> >
> > int val = xmlParseStringCharRef(ctxt, &str);
> > if (val != 0) {
> >     COPY_BUF(0,buffer,nbchars,val);
> > }
> >
> >   And I would appreciate insight on who's wrong there...
>
> Calling COPY_BUF with first parameter (l) equal 0 will never process the 
> b[i++] = (xmlChar) v part.

  Dohh, right ..
Question is, would calling xmlCopyChar() directly be any better ?
Maybe ...

> I'm looking at a old sources (2.2.11), but I assume the documentation for 
> xmlCopyChar is out of sync, as the first parameter is referred to as 
> @len:  pointer to the length of the char read (or zero)

  hum, not really. In this case there was nothing read or at least
not as a char. Having len == 0 indicates we don't know what's the size
of the UTF8 serialization of this character.

> On a related topic, the len parameter is hardly used in xmlCopyChar and 
> can probably be eliminated, along with the code branch computing len 
> when the parameter is zero:

  there is 2 things:
    - xmlCopyChar is public, it is exported from parserInternals.h
      so we can't change its signature now
    - I tend to agree that the len > 1 case don't make an useful
      use of the information. Would your patch still improve things
      considering we still pass the len parameter ? I.e. is it
      faster or cleaner ?

 Seems I have troubles making decisions today ...

Daniel

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