On Thu, 3 Aug 2017, Jakub Jelinek wrote:
> Hi!
>
> This patch attempts to fix some overflows during computation of the size
> and then effectively uses MIN (SSIZE_MAX, user_specified_value) as the
> bound.
>
> Not really sure what exact behavior we want, whether that, or default
> to SSIZE_MAX (note the documentation mistakenly talks about SIZE_MAX / 2
> instead) and use MIN (SIZE_MAX, user_specified_value) for user specified
> value, or error out if user_specified_value is larger than
> SSIZE_MAX or larger than SIZE_MAX. Also the else unit = 0; case
> probably should get diagnostics. Another issue is if we want to diagnose,
> that right now it will be diagnosed only if some allocation routine is seen,
> diagnosing stuff during option processing is unfortunately too early because
> we don't have sizetype/ssizetype built yet.
>
> Anyway, the following has been bootstrapped/regtested on x86_64-linux and
> i686-linux.
Ok.
Richard.
> 2017-08-03 Jakub Jelinek <ja...@redhat.com>
>
> PR driver/81650
> * calls.c (alloc_max_size): Use HOST_WIDE_INT_UC (10??)
> instead of 10??LU, perform unit multiplication in wide_int,
> don't change alloc_object_size_limit if the limit is larger
> than SSIZE_MAX.
>
> * gcc.dg/pr81650.c: New test.
>
> --- gcc/calls.c.jj 2017-06-12 12:42:01.000000000 +0200
> +++ gcc/calls.c 2017-08-02 13:41:00.887324420 +0200
> @@ -1222,32 +1222,38 @@ alloc_max_size (void)
> else if (!strcasecmp (end, "KiB") || strcmp (end, "KB"))
> unit = 1024;
> else if (!strcmp (end, "MB"))
> - unit = 1000LU * 1000;
> + unit = HOST_WIDE_INT_UC (1000) * 1000;
> else if (!strcasecmp (end, "MiB"))
> - unit = 1024LU * 1024;
> + unit = HOST_WIDE_INT_UC (1024) * 1024;
> else if (!strcasecmp (end, "GB"))
> - unit = 1000LU * 1000 * 1000;
> + unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000;
> else if (!strcasecmp (end, "GiB"))
> - unit = 1024LU * 1024 * 1024;
> + unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024;
> else if (!strcasecmp (end, "TB"))
> - unit = 1000LU * 1000 * 1000 * 1000;
> + unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000;
> else if (!strcasecmp (end, "TiB"))
> - unit = 1024LU * 1024 * 1024 * 1024;
> + unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024;
> else if (!strcasecmp (end, "PB"))
> - unit = 1000LU * 1000 * 1000 * 1000 * 1000;
> + unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000 * 1000;
> else if (!strcasecmp (end, "PiB"))
> - unit = 1024LU * 1024 * 1024 * 1024 * 1024;
> + unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024 * 1024;
> else if (!strcasecmp (end, "EB"))
> - unit = 1000LU * 1000 * 1000 * 1000 * 1000 * 1000;
> + unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000 * 1000
> + * 1000;
> else if (!strcasecmp (end, "EiB"))
> - unit = 1024LU * 1024 * 1024 * 1024 * 1024 * 1024;
> + unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024 * 1024
> + * 1024;
> else
> unit = 0;
> }
>
> if (unit)
> - alloc_object_size_limit
> - = build_int_cst (ssizetype, limit * unit);
> + {
> + wide_int w = wi::uhwi (limit, HOST_BITS_PER_WIDE_INT + 64);
> + w *= unit;
> + if (wi::ltu_p (w, alloc_object_size_limit))
> + alloc_object_size_limit = wide_int_to_tree (ssizetype, w);
> + }
> }
> }
> }
> --- gcc/testsuite/gcc.dg/pr81650.c.jj 2017-08-02 14:52:22.864787221 +0200
> +++ gcc/testsuite/gcc.dg/pr81650.c 2017-08-02 14:21:11.000000000 +0200
> @@ -0,0 +1,9 @@
> +/* PR driver/81650 */
> +/* { dg-do compile } */
> +/* { dg-options "-Walloc-size-larger-than=9223372036854775807" } */
> +
> +void *
> +foo (void)
> +{
> + return __builtin_malloc (5);
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
