Re: [PATCH v5 04/11] stdio-common: Add __translated_number_width

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 12/12/22 12:23, Florian Weimer via Libc-alpha wrote:
> This function will be used to compute the width of a number
> after i18n digit translation.


LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  include/printf.h                       | 13 +++++++-
>  stdio-common/Makefile                  |  1 +
>  stdio-common/translated_number_width.c | 42 ++++++++++++++++++++++++++
>  3 files changed, 55 insertions(+), 1 deletion(-)
>  create mode 100644 stdio-common/translated_number_width.c
> 
> diff --git a/include/printf.h b/include/printf.h
> index 8f064149d3..5127a45f9b 100644
> --- a/include/printf.h
> +++ b/include/printf.h
> @@ -53,7 +53,18 @@ int __wprintf_function_invoke (void *, printf_function callback,
>  
>  #include <bits/types/locale_t.h>
>  
> -/* Now define the internal interfaces.  */
> +/* Returns the width (as for printf, in bytes) of the converted ASCII
> +   number in the characters in the range [FIRST, LAST).  The range
> +   must only contain ASCII digits.  The caller is responsible for
> +   avoiding overflow.
> +
> +   This function is used during non-wide digit translation.  Wide
> +   digit translate produces one wide character per ASCII digit,
> +   so the width is simply LAST - FIRST.  */
> +int __translated_number_width (locale_t loc,
> +			       const char *first, const char *last)
> +  attribute_hidden;
> +
>  extern int __printf_fphex (FILE *, const struct printf_info *,
>  			   const void *const *) attribute_hidden;
>  extern int __printf_fp (FILE *, const struct printf_info *,

Ok.

> diff --git a/stdio-common/Makefile b/stdio-common/Makefile
> index 6e6da091b1..3e0c574ca5 100644
> --- a/stdio-common/Makefile
> +++ b/stdio-common/Makefile
> @@ -85,6 +85,7 @@ routines := \
>    tmpfile64 \
>    tmpnam \
>    tmpnam_r \
> +  translated_number_width \
>    vfprintf \
>    vfprintf-internal \
>    vfscanf \

Ok.

> diff --git a/stdio-common/translated_number_width.c b/stdio-common/translated_number_width.c
> new file mode 100644
> index 0000000000..f42d5968a1
> --- /dev/null
> +++ b/stdio-common/translated_number_width.c
> @@ -0,0 +1,42 @@
> +/* Compute the printf width of a sequence of ASCII digits.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <assert.h>
> +#include <limits.h>
> +#include <locale/localeinfo.h>
> +#include <printf.h>
> +
> +int
> +__translated_number_width (locale_t loc, const char *first, const char *last)
> +{
> +  struct lc_ctype_data *ctype = loc->__locales[LC_CTYPE]->private;
> +
> +  if (ctype->outdigit_bytes_all_equal > 0)
> +    return (last - first) * ctype->outdigit_bytes_all_equal;
> +  else
> +    {
> +      /* Digits have varying length, so the fast path cannot be used.  */
> +      int digits = 0;
> +      for (const char *p = first; p < last; ++p)
> +        {
> +          assert ('0' <= *p && *p <= '9');
> +          digits += ctype->outdigit_bytes[*p - '0'];
> +        }
> +      return digits;
> +    }
> +}

Ok.