[PATCH] _dl_exception_create_format: Support %x/%lx/%Zx

H.J. Lu hjl.tools@gmail.com
Tue Nov 27 21:34:00 GMT 2018


On Tue, Nov 27, 2018 at 7:49 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 23/11/2018 14:18, H.J. Lu wrote:
> > On Fri, Nov 23, 2018 at 2:53 AM Szabolcs Nagy <Szabolcs.Nagy@arm.com> wrote:
> >> On 22/11/18 17:38, H.J. Lu wrote:
> >>> Add support for %x, %lx and %Zx to _dl_exception_create_format and pad
> >>> to the full width with 0.
> >>>
> >>>       * elf/dl-exception.c (_dl_exception_create_format): Support
> >>>       %x, %lx and %Zx.
> >> why Z and not z?  the glibc man says
> >>
> >> " Z   A nonstandard synonym for z that predates the appearance of z.
> >>   Do not use in new code."
> > Like this?
> >
> > -- H.J.
> >
> >
> > 0001-_dl_exception_create_format-Support-x-lx-zx.patch
> >
> > From d937bf4bf3b92897b1ff60406ca065e2968bcdbe Mon Sep 17 00:00:00 2001
> > From: "H.J. Lu" <hjl.tools@gmail.com>
> > Date: Thu, 22 Nov 2018 09:02:40 -0800
> > Subject: [PATCH] _dl_exception_create_format: Support %x/%lx/%zx
> >
> > Add support for %x, %lx and %zx to _dl_exception_create_format and pad
> > to the full width with 0.
> >
> >       * elf/dl-exception.c (_dl_exception_create_format): Support
> >       %x, %lx and %zx.
>
> LGTM.
>
> > ---
> >  elf/dl-exception.c | 40 ++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 40 insertions(+)
> >
> > diff --git a/elf/dl-exception.c b/elf/dl-exception.c
> > index 1c63e4a3a6..1e41d89a7d 100644
> > --- a/elf/dl-exception.c
> > +++ b/elf/dl-exception.c
> > @@ -111,6 +111,20 @@ _dl_exception_create_format (struct dl_exception *exception, const char *objname
> >              case 's':
> >                length += strlen (va_arg (ap, const char *));
> >                break;
> > +           /* Recognize the l modifier.  It is only important on some
> > +              platforms where long and int have a different size.  We
> > +              can use the same code for size_t.  */
> > +         case 'l':
> > +         case 'z':
> > +           if (p[1] == 'x')
> > +             {
> > +               length += LONG_WIDTH / 4;
> > +               ++p;
> > +               break;
> > +             }
> > +         case 'x':
> > +           length += INT_WIDTH / 4;
> > +           break;
> >              default:
> >                /* Assumed to be '%'.  */
> >                ++length;
> > @@ -167,6 +181,32 @@ _dl_exception_create_format (struct dl_exception *exception, const char *objname
> >                *wptr = '%';
> >                ++wptr;
> >                break;
> > +         case 'x':
> > +           {
> > +             unsigned long int num = va_arg (ap, unsigned int);
> > +             char *start = wptr;
> > +             wptr += INT_WIDTH / 4;
> > +             char *cp = _itoa (num, wptr, 16, 0);
> > +             /* Pad to the full width with 0.  */
> > +             while (cp != start)
> > +               *--cp = '0';
> > +           }
> > +           break;
> > +         case 'l':
> > +         case 'z':
> > +           if (p[1] == 'x')
> > +             {
> > +               unsigned long int num = va_arg (ap, unsigned long int);
> > +               char *start = wptr;
> > +               wptr += LONG_WIDTH / 4;
> > +               char *cp = _itoa (num, wptr, 16, 0);
> > +               /* Pad to the full width with 0.  */
> > +               while (cp != start)
> > +                 *--cp = '0';
> > +               ++p;
> > +               break;
> > +             }
> > +            /* FALLTHROUGH */
> >              default:
> >                _dl_fatal_printf ("Fatal error:"
> >                                  " invalid format in exception string\n");
> > -- 2.19.1
> >
>
> What about adding a test for _dl_exception_create_format, such as:
>
> ---
> #include <ldsodefs.h>
> #include <array_length.h>
>
> #include <support/check.h>
> #include <support/xunistd.h>
> #include <support/capture_subprocess.h>
>
> #define TEST(es, objn, fmt, ...)                                        \
>   ({                                                                    \
>     struct dl_exception exception;                                      \
>     _dl_exception_create_format (&exception, objn, fmt, __VA_ARGS__);   \
>     TEST_COMPARE_STRING (exception.objname, objn == NULL ? "" : objn);  \
>     TEST_COMPARE_STRING (exception.errstring, es);                      \
>     _dl_exception_free (&exception);                                    \
>   })
>
> static void
> do_test_invalid_conversion (void *closure)
> {
>   TEST ("(null)", NULL, "%p", NULL);
> }
>
> /* Exit status after abnormal termination.  */
> static int invalid_status;
>
> static void
> init_invalid_status (void)
> {
>   pid_t pid = xfork ();
>   if (pid == 0)
>     _exit (127);
>   xwaitpid (pid, &invalid_status, 0);
> }
>
> static int
> do_test (void)
> {
>   init_invalid_status ();
>
>   TEST ("test",      NULL,   "%s",      "test");
>   TEST ("test-test", NULL,   "%s-test", "test");
>   TEST ("test",      "test", "%s",      "test");
>   TEST ("test-test", "test", "%s-test", "test");
>
>   TEST ("test%",      NULL,   "%s%%",      "test");
>   TEST ("test%-test", NULL,   "%s%%-test", "test");
>   TEST ("test%",      "test", "%s%%",      "test");
>   TEST ("test%-test", "test", "%s%%-test", "test");
>
>   TEST ("0000007b",      NULL,   "%x",      123);
>   TEST ("0000007b-test", NULL,   "%x-test", 123);
>   TEST ("0000007b",      "test", "%x",      123);
>   TEST ("0000007b-test", "test", "%x-test", 123);
>
> #define TEST_LONG(es, objn, fmt, ...)                                   \
>   ({                                                                    \
>     if (sizeof (int) == sizeof (long int))                              \
>       TEST (es, objn, fmt, __VA_ARGS__);                                \
>     else                                                                \
>       TEST ("ffffffff" es, objn, fmt, __VA_ARGS__);                     \
>   })
>
>   TEST_LONG ("fffffffd",      NULL,   "%lx",      (long int)~2ul);
>   TEST_LONG ("fffffffd-test", NULL,   "%lx-test", (long int)~2ul);
>   TEST_LONG ("fffffffd",      "test", "%lx",      (long int)~2ul);
>   TEST_LONG ("fffffffd-test", "test", "%lx-test", (long int)~2ul);
>
>   TEST_LONG ("fffffffe",      NULL,   "%zx",      (size_t)~1ul);
>   TEST_LONG ("fffffffe-test", NULL,   "%zx-test", (size_t)~1ul);
>   TEST_LONG ("fffffffe",      "test", "%zx",      (size_t)~1ul);
>   TEST_LONG ("fffffffe-test", "test", "%zx-test", (size_t)~1ul);
>
>   {
>     struct support_capture_subprocess result;
>     result = support_capture_subprocess (do_test_invalid_conversion, NULL);
>     support_capture_subprocess_check (&result, "dl-exception", invalid_status,
>                                       sc_allow_stderr);
>     TEST_COMPARE_STRING (result.err.buffer,
>                          "Fatal error: invalid format in exception string\n");
>   }
>
>   return 0;
> }
>
> #include <support/test-driver.c>
> ---

This is what I am going to check in.

Thanks.

-- 
H.J.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-_dl_exception_create_format-Support-x-lx-zx.patch
Type: text/x-patch
Size: 6899 bytes
Desc: not available
URL: <http://sourceware.org/pipermail/libc-alpha/attachments/20181127/9c80d245/attachment.bin>


More information about the Libc-alpha mailing list