[Patch, Newlib-nano]Improve printf to support non nul-terminated string

[Bin.Cheng]

On Thu, Nov 6, 2014 at 5:01 PM, Corinna Vinschen <vinschen@redhat.com> wrote:
>
> [Please don't CC me.  I'm reading the mailing list anyway.  Thanks]
>
> On Nov  6 13:53, Terry Guo wrote:
>> Thanks. Here is updated patch. Is this one OK?
>
> It's fine from my POV.  Bin?

Hi,
We don't have write access, please help us apply it.  Thanks very much.

Thanks,
bin
>
>
> Corinna
>
>>
>> BR,
>> Terry
>
>> diff --git a/newlib/libc/stdio/nano-vfprintf_i.c b/newlib/libc/stdio/nano-vfprintf_i.c
>> index b1b0d1d..b75a142 100644
>> --- a/newlib/libc/stdio/nano-vfprintf_i.c
>> +++ b/newlib/libc/stdio/nano-vfprintf_i.c
>> @@ -211,15 +211,15 @@ number:
>>      case 's':
>>        cp = GET_ARG (N, *ap, char_ptr_t);
>>        /* Precision gives the maximum number of chars to be written from a
>> -      string, and take prec == -1 into consideration.  */
>> -      if ((u_int)(pdata->size = strlen (cp)) > (u_int)(pdata->prec))
>> -     pdata->size = pdata->prec;
>> -      /* Below code is kept for reading.  The check is redundant because
>> -      pdata->prec will be set to pdata->size if it is -1 previously.  */
>> -#if 0
>> -      if (pdata->prec > pdata->size)
>> -#endif
>> -      pdata->prec = pdata->size;
>> +      string, and take prec == -1 into consideration.
>> +      Use normal Newlib approach here to support case where cp is not
>> +      nul-terminated.  */
>> +      char *p = memchr (cp, 0, pdata->prec);
>> +
>> +      if (p != NULL)
>> +     pdata->prec = p - cp;
>> +
>> +      pdata->size = pdata->prec;
>>        goto non_number_nosign;
>>      default:
>>        /* "%?" prints ?, unless ? is NUL.  */
>> diff --git a/newlib/testsuite/newlib.stdio/nulprintf.c b/newlib/testsuite/newlib.stdio/nulprintf.c
>> new file mode 100644
>> index 0000000..5e4131b
>> --- /dev/null
>> +++ b/newlib/testsuite/newlib.stdio/nulprintf.c
>> @@ -0,0 +1,17 @@
>> +/*
>> + * Copyright (C) 2014 by ARM Ltd. All rights reserved.
>> + *
>> + * Permission to use, copy, modify, and distribute this software
>> + * is freely granted, provided that this notice is preserved.
>> + */
>> +
>> +#include <stdio.h>
>> +#include "check.h"
>> +
>> +const char m[8] = {'M','M','M','M','M','M','M','M'};
>> +
>> +int main()
>> +{
>> +  printf ("%.*s\n", 8, m);
>> +  exit (0);
>> +}
>
>
> --
> Corinna Vinschen
> Cygwin Maintainer
> Red Hat