flac dev - Sep 2004 - const issue in FLAC__lpc_compute_residual_from_qlp_coefficients (libFLAC/lpc.c:233)

Hello,


I just tried to compile libFLAC (using Borland C++ Builder 6 on Windows).

The compilers yells at me on line 233 of libFLAC/lpc.c

*(residual++) = *(data++) - (sum >> lp_quantization);
--> data is const and cannot be modified

Funny thing is, if data is declared:
   const FLAC__int32 *data
instead of
   const FLAC__int32 data[]

everything is ok.

Is this a bug in my compiler, or a personnal lack of understanding of 
the difference in C between *data and data[] ?

Will changing const FLAC__int32 data[] to const FLAC__int32 *data will 
ruine everything ?


Denis

On Tue, Jan 13, 2004 at 02:04:48PM -0800, Josh Coalson wrote:
> --- Denis Chatelain <listes@octopodus.com> wrote:
> > Hello,
> > 
> > 
> > I just tried to compile libFLAC (using Borland C++ Builder 6 on
> > Windows).
> > 
> > The compilers yells at me on line 233 of libFLAC/lpc.c
> > 
> > *(residual++) = *(data++) - (sum >> lp_quantization);
> > --> data is const and cannot be modified
> > 
> > Funny thing is, if data is declared:
> >    const FLAC__int32 *data
> > instead of
> >    const FLAC__int32 data[]
> > 
> > everything is ok.
> > 
> > Is this a bug in my compiler, or a personnal lack of understanding of
> > the difference in C between *data and data[] ?
> 
> hmmm, not sure what the standard says on this.  but it's
> OK to change it to
> 
> const FLAC__int32 *data
> 
> in order to get it to compile.
I haven't checked, and I don't recall whether it covers the case of
const
arrays, but this article has helped me in the past:

http://www.parashift.com/c++-faq-lite/const-correctness.html

-- 
 - mdz

--- Denis Chatelain <listes@octopodus.com> wrote:
> Hello,
> 
> 
> I just tried to compile libFLAC (using Borland C++ Builder 6 on
> Windows).
> 
> The compilers yells at me on line 233 of libFLAC/lpc.c
> 
> *(residual++) = *(data++) - (sum >> lp_quantization);
> --> data is const and cannot be modified
> 
> Funny thing is, if data is declared:
>    const FLAC__int32 *data
> instead of
>    const FLAC__int32 data[]
> 
> everything is ok.
> 
> Is this a bug in my compiler, or a personnal lack of understanding of
> the difference in C between *data and data[] ?
hmmm, not sure what the standard says on this.  but it's
OK to change it to

const FLAC__int32 *data

in order to get it to compile.

Josh


__________________________________
Do you Yahoo!?
Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes
http://hotjobs.sweepstakes.yahoo.com/signingbonus

--- Josh Coalson <xflac@yahoo.com> wrote:
> --- Denis Chatelain <listes@octopodus.com> wrote:
> > Hello,
> > 
> > 
> > I just tried to compile libFLAC (using Borland C++ Builder 6 on
> > Windows).
> > 
> > The compilers yells at me on line 233 of libFLAC/lpc.c
> > 
> > *(residual++) = *(data++) - (sum >> lp_quantization);
> > --> data is const and cannot be modified
> > 
> > Funny thing is, if data is declared:
> >    const FLAC__int32 *data
> > instead of
> >    const FLAC__int32 data[]
> > 
> > everything is ok.
> > 
> > Is this a bug in my compiler, or a personnal lack of understanding
> of
> > the difference in C between *data and data[] ?
> 
> hmmm, not sure what the standard says on this.  but it's
> OK to change it to
> 
> const FLAC__int32 *data
> 
> in order to get it to compile.
finally fixed in CVS.

Josh



		
__________________________________ 
Do you Yahoo!? 
Meet the all-new My Yahoo! - Try it today! 
http://my.yahoo.com