Re: [patch] for PR17474

[Diego Novillo <dnovillo at redhat dot com>]

On Mon, 2004-09-20 at 16:13, Zdenek Dvorak wrote:
> Hello,
> 
> > > this handles just the cases when the base variable does not have
> > > a type memory tag; in such case the variable itself acts as an
> > > operand in VUSES/VDEFS (well -- I guess; it seems to work this way...)
> > >
> > If the base variable didn't have an alias tag already, something is
> > _very_ wrong.  The base variable is dereferenced, so it must have a tag
> > (either type or name).  If that's not the case, the only graceful thing
> > you can do here is ICE.
> 
> then you are going to ICE very often.  For example in the following
> program
> 
> int arr[100];
> 
> void xxx(void)
> {
>   int i;
> 
>   for (i = 0; i < 100; i++)
>     arr[i] = i;
> }
> 
> arr does not have type memory tag (well, did not have in time I wrote
> this piece of code few months ago; perhaps this changed since then?)
> 
arr is not a pointer.  Of course it doesn't have a tag.  That function
should only try to copy aliasing information out of pointers (I had the
impression that this function only takes care of pointer dereferences).


Diego.