Re: [PATCH] Expand INTERNAL_SIZE_T macro.

[OndÅej BÃlka <neleai at seznam dot cz>]

On Tue, Dec 10, 2013 at 10:16:10AM +0000, Will Newton wrote:
> On 9 December 2013 18:21, OndÅej BÃlka <neleai@seznam.cz> wrote:
> > Hi,
> >
> > other malloc macro that causes bit of confusion is INTERNAL_SIZE_T.
> > We define it as size_t, only way this could be usable is user compiling
> > custom allocator.
> >
> > I am for dropping these as we then do not have to assume that change.
> >
> >
> >         * malloc/hooks.c (mem2mem_check, top_check, free_check, realloc_check):
> >         Change INTERNAL_SIZE_T to size_t.
> >         * malloc/malloc.c (__malloc_assert, static, mremap_chunk,
> >         __libc_malloc, __libc_realloc, __libc_calloc, _int_malloc, _int_free,
> >         _int_realloc, _int_memalign, __malloc_trim, int_mallinfo): Likewise.
> 
> This looks like a good cleanup to me, although I would be grateful if
> someone with more experience in this area could give their thoughts.
>
So does somebody else have comments?

> > -    Changing default word sizes:
> > -
> > -    INTERNAL_SIZE_T            size_t
> > -    MALLOC_ALIGNMENT           MAX (2 * sizeof(INTERNAL_SIZE_T),
> > -                                   __alignof__ (long double))
> > -
> 
> Should the MALLOC_ALIGNMENT comment stay?
> 
It duplicates a comment before MALLOC_ALIGNMENT definition, it is not needed here.

> >
> >  #define REQUEST_OUT_OF_RANGE(req)                                 \
> >    ((unsigned long)(req) >=                                        \
> > -   (unsigned long)(INTERNAL_SIZE_T)(-2 * MINSIZE))
> > +   (unsigned long)(size_t)(-2 * MINSIZE))
> 
> I think these casts can go if we use size_t.
> 
There are many other casts that can go away, that cleanup should be done
in separate patch.

> >
> >    /* internal size_t must be no wider than pointer type */
> > -  assert(sizeof(INTERNAL_SIZE_T) <= sizeof(char*));
> > +  assert(sizeof(size_t) <= sizeof(char*));
> 
> Should this use SIZE_SZ?
> 
Yes, but this also belongs to separate patch. Also  2 * SIZE_SZ is in
most of places size of header so we should use HEADER_SZ or such.