V2 [PATCH] Add "%d" support to _dl_debug_vdprintf

H.J. Lu hjl.tools@gmail.com
Tue Jun 9 14:38:41 GMT 2020


On Tue, Jun 9, 2020 at 7:18 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 05/06/2020 12:03, H.J. Lu via Libc-alpha wrote:
> > "%d" will be used to print out signed value.
>
> LGTM with some smalls nits below.
>
> > ---
> >  elf/dl-misc.c | 31 +++++++++++++++++++++++++++++--
> >  1 file changed, 29 insertions(+), 2 deletions(-)
> >
> > diff --git a/elf/dl-misc.c b/elf/dl-misc.c
> > index ab70481fda..c82c8ae6fa 100644
> > --- a/elf/dl-misc.c
> > +++ b/elf/dl-misc.c
> > @@ -167,6 +167,7 @@ _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg)
> >         switch (*fmt)
> >           {
> >             /* Integer formatting.  */
> > +         case 'd':
> >           case 'u':
> >           case 'x':
> >             {
>
> Ok.
>
> > @@ -179,11 +180,34 @@ _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg)
> >  #else
> >               unsigned long int num = va_arg (arg, unsigned int);
> >  #endif
> > +             bool negative = false;
> > +             if (*fmt == 'd')
> > +               {
> > +#if LONG_MAX != INT_MAX
> > +                 if (long_mod)
> > +                   {
> > +                     if ((long) num < 0)
>
> Full type specify on cast.

Fixed.

> > +                       negative = true;
> > +                   }
> > +                 else
> > +                   {
> > +                     if ((int) num < 0)> +                     {
> > +                         num = (unsigned int) num;
> > +                         negative = true;
> > +                       }
> > +                   }
> > +#else
> > +                 if ((int) num < 0)
> > +                   negative = true;
> > +#endif
> > +               }
> > +
> >               /* We use alloca() to allocate the buffer with the most
> >                  pessimistic guess for the size.  Using alloca() allows
> >                  having more than one integer formatting in a call.  */
> > -             char *buf = (char *) alloca (3 * sizeof (unsigned long int));
> > -             char *endp = &buf[3 * sizeof (unsigned long int)];
> > +             char *buf = (char *) alloca (1 + 3 * sizeof (unsigned long int));
> > +             char *endp = &buf[1 + 3 * sizeof (unsigned long int)];
>
> I think we can remove alloca here and use INT_STRLEN_BOUND (since the
> string is not '\0' bounded due the writev usage).  Something like:
>
>   char buf[INT_STRLEN_BOUND (unsigned long int)];
>   char *endp = &buf[INT_STRLEN_BOUND (unsigned long int)];

Fixed.

> >               char *cp = _itoa (num, endp, *fmt == 'x' ? 16 : 10, 0);
> >
> >               /* Pad to the width the user specified.  */
> > @@ -191,6 +215,9 @@ _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg)
> >                 while (endp - cp < width)
> >                   *--cp = fill;
> >
> > +             if (negative)
> > +               *--cp = '-';
> > +
> >               iov[niov].iov_base = cp;
> >               iov[niov].iov_len = endp - cp;
> >               ++niov;
> >
>
> Ok.

Here is the updated patch I am checking in.

Thanks.

-- 
H.J.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Add-d-support-to-_dl_debug_vdprintf.patch
Type: text/x-patch
Size: 2210 bytes
Desc: not available
URL: <https://sourceware.org/pipermail/libc-alpha/attachments/20200609/15c883b6/attachment-0001.bin>


More information about the Libc-alpha mailing list