[tree-ssa] Removing useless/redundant "const" calls

[Fergus Henderson]

On 13-Jun-2003, Fergus Henderson <fjh@cs.mu.OZ.AU> wrote:
> On 12-Jun-2003, Zack Weinberg <zack@codesourcery.com> wrote:
> > Fergus Henderson <fjh@cs.mu.oz.au> writes:
> > > Doing that would violate the C standard, and would potentially create
> > > security holes.  Consider, for example:
> > >
> > > 	#define ARRAY_SIZE 10
> > > 	int array[ARRAY_SIZE];
> > >
> > > 	void checkbounds(int arg) {
> > > 		if (arg < 0) abort();
> > > 		if (arg > ARRAY_SIZE) abort();
> > > 	}
> > >
> > > 	int set_array(int posn, int val) {
> > > 		checkbounds(posn);
> > > 		array[posn] = val;
> > > 	}
> > 
> > checkbounds() returns no value, so it must be used for its side
> > effects, so it isn't pure.
> 
> OK, so make the example program slightly different:
> 
>  	#define ARRAY_SIZE 10
>  	int array[ARRAY_SIZE];
> 
>  |	int checkbounds(int arg) {
>  		if (arg < 0) abort();
>  		if (arg > ARRAY_SIZE) abort();
>  |		return arg;
>  	}
> 
>  	int set_array(int posn, int val) {
>  |  		array[checkbounds(posn)] = val;
>  	}

Sorry, I screwed that up again.  The definition of set_array()
should be as in the original example.

-- 
Fergus Henderson <fjh@cs.mu.oz.au>  |  "I have always known that the pursuit
The University of Melbourne         |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.