Re: [PATCH] genmodes: don't truncate a mode name of length >= 7

[Richard Guenther <richard dot guenther at gmail dot com>]

On Thu, Apr 19, 2012 at 10:35 PM, Jim Meyering <jim@meyering.net> wrote:
> Richard Guenther wrote:
>> Sure, my point was that the
>>
>> ? ? ? if (strlen (m->name) >= sizeof buf)
>> ? ? ? ? {
>> ? ? ? ? ? error ("%s:%d:mode name \"%s\" is too long",
>> ? ? ? ? ? ? ? ? ?m->file, m->line, m->name);
>> ? ? ? ? ? continue;
>> ? ? ? ? }
>>
>> check does not account for the (conditional) prepending of 'C' and the
>> snprintf would silently discard the last character of the name.
>
> Here's a patch for that. ?(passes make bootstrap)
> Incidentally it removes the name-length limitation of 7 and it hoists
> the xmalloc, which induces the single added free-before-continue.
> There was some clean-up along the way: "q" was easy to eliminate, and
> I pulled the two identical snprintf calls out of the "if" block and
> replaced them with the buf[0] assignment and memcpy.

Ok.

Thanks,
Richard.

>
> 2012-04-19 ?Jim Meyering ?<meyering@redhat.com>
>
> ? ? ? ?* genmodes.c (make_complex_modes): Don't truncate a mode name of
> ? ? ? ?length 7 or more when prepending a "C". ?Suggested by Richard Guenther.
>
>
> ?gcc/genmodes.c | ? 32 +++++++++++++-------------------
> ?1 file changed, 13 insertions(+), 19 deletions(-)
>
> diff --git a/gcc/genmodes.c b/gcc/genmodes.c
> index 6bbeb6f..84517b9 100644
> --- a/gcc/genmodes.c
> +++ b/gcc/genmodes.c
> @@ -427,7 +427,6 @@ make_complex_modes (enum mode_class cl,
> ?{
> ? struct mode_data *m;
> ? struct mode_data *c;
> - ?char buf[8];
> ? enum mode_class cclass = complex_class (cl);
>
> ? if (cclass == MODE_RANDOM)
> @@ -435,6 +434,7 @@ make_complex_modes (enum mode_class cl,
>
> ? for (m = modes[cl]; m; m = m->next)
> ? ? {
> + ? ? ?char *p, *buf;
> ? ? ? size_t m_len;
>
> ? ? ? /* Skip BImode. ?FIXME: BImode probably shouldn't be MODE_INT. ?*/
> @@ -442,40 +442,34 @@ make_complex_modes (enum mode_class cl,
> ? ? ? ?continue;
>
> ? ? ? m_len = strlen (m->name);
> - ? ? ?if (m_len >= sizeof buf)
> - ? ? ? {
> - ? ? ? ? error ("%s:%d:mode name \"%s\" is too long",
> - ? ? ? ? ? ? ? ?m->file, m->line, m->name);
> - ? ? ? ? continue;
> - ? ? ? }
> + ? ? ?/* The leading "1 +" is in case we prepend a "C" below. ?*/
> + ? ? ?buf = (char *) xmalloc (1 + m_len + 1);
>
> ? ? ? /* Float complex modes are named SCmode, etc.
> ? ? ? ? Int complex modes are named CSImode, etc.
> ? ? ? ? ?This inconsistency should be eliminated. ?*/
> + ? ? ?p = 0;
> ? ? ? if (cl == MODE_FLOAT)
> ? ? ? ?{
> - ? ? ? ? char *p, *q = 0;
> - ? ? ? ? /* We verified above that m->name+NUL fits in buf. ?*/
> ? ? ? ? ?memcpy (buf, m->name, m_len + 1);
> ? ? ? ? ?p = strchr (buf, 'F');
> - ? ? ? ? if (p == 0)
> - ? ? ? ? ? q = strchr (buf, 'D');
> - ? ? ? ? if (p == 0 && q == 0)
> + ? ? ? ? if (p == 0 && strchr (buf, 'D') == 0)
> ? ? ? ? ? ?{
> ? ? ? ? ? ? ?error ("%s:%d: float mode \"%s\" has no 'F' or 'D'",
> ? ? ? ? ? ? ? ? ? ? m->file, m->line, m->name);
> + ? ? ? ? ? ? free (buf);
> ? ? ? ? ? ? ?continue;
> ? ? ? ? ? ?}
> -
> - ? ? ? ? if (p != 0)
> - ? ? ? ? ? *p = 'C';
> - ? ? ? ? else
> - ? ? ? ? ? snprintf (buf, sizeof buf, "C%s", m->name);
> ? ? ? ?}
> + ? ? ?if (p != 0)
> + ? ? ? *p = 'C';
> ? ? ? else
> - ? ? ? snprintf (buf, sizeof buf, "C%s", m->name);
> + ? ? ? {
> + ? ? ? ? buf[0] = 'C';
> + ? ? ? ? memcpy (buf + 1, m->name, m_len + 1);
> + ? ? ? }
>
> - ? ? ?c = new_mode (cclass, xstrdup (buf), file, line);
> + ? ? ?c = new_mode (cclass, buf, file, line);
> ? ? ? c->component = m;
> ? ? }
> ?}
> --
> 1.7.10.208.gb4267