Re: [PATCH 10/18] Use a ui_file in print_wchar

[Andrew Burgess <aburgess@redhat.com>]

* Tom Tromey <tom@tromey.com> [2022-02-16 06:55:10 -0700]:

> This introduces a new ui_file subclass, that turns a host string into
> a wide string and appends it to an obstack.  print_wchar is rewritten
> to use this new ui_file.  This will be more useful in a later patch.

LGTM.

Thanks,
Andrew

> ---
>  gdb/valprint.c | 49 +++++++++++++++++++++++++++----------------------
>  1 file changed, 27 insertions(+), 22 deletions(-)
> 
> diff --git a/gdb/valprint.c b/gdb/valprint.c
> index dec1dce9d3c..00c0cd2c72a 100644
> --- a/gdb/valprint.c
> +++ b/gdb/valprint.c
> @@ -2163,19 +2163,29 @@ wchar_printable (gdb_wchar_t w)
>  	  || w == LCST ('\v') || w == LCST ('\0'));
>  }
>  
> -/* A helper function that converts the contents of STRING to wide
> -   characters and then appends them to OUTPUT.  */
> -
> -static void
> -append_string_as_wide (const char *string,
> -		       struct obstack *output)
> -{
> -  for (; *string; ++string)
> -    {
> -      gdb_wchar_t w = gdb_btowc (*string);
> -      obstack_grow (output, &w, sizeof (gdb_wchar_t));
> -    }
> -}
> +/* A ui_file that writes wide characters to an obstack.  */
> +class obstack_wide_file : public ui_file
> +{
> +public:
> +  explicit obstack_wide_file (struct obstack *output)
> +    : m_output (output)
> +  {
> +  }
> +
> +  ~obstack_wide_file () = default;
> +
> +  void write (const char *buf, long length_buf) override
> +  {
> +    for (long i = 0; i < length_buf; ++i)
> +      {
> +	gdb_wchar_t w = gdb_btowc (buf[i]);
> +	obstack_grow (m_output, &w, sizeof (gdb_wchar_t));
> +      }
> +  }
> +
> +private:
> +  struct obstack *m_output;
> +};
>  
>  /* Print a wide character W to OUTPUT.  ORIG is a pointer to the
>     original (target) bytes representing the character, ORIG_LEN is the
> @@ -2236,10 +2246,10 @@ print_wchar (gdb_wint_t w, const gdb_byte *orig,
>  	  else
>  	    {
>  	      int i;
> +	      obstack_wide_file file (output);
>  
>  	      for (i = 0; i + width <= orig_len; i += width)
>  		{
> -		  char octal[30];
>  		  ULONGEST value;
>  
>  		  value = extract_unsigned_integer (&orig[i], width,
> @@ -2247,19 +2257,14 @@ print_wchar (gdb_wint_t w, const gdb_byte *orig,
>  		  /* If the value fits in 3 octal digits, print it that
>  		     way.  Otherwise, print it as a hex escape.  */
>  		  if (value <= 0777)
> -		    xsnprintf (octal, sizeof (octal), "\\%.3o",
> -			       (int) (value & 0777));
> +		    fprintf_filtered (&file, "\\%.3o", (int) (value & 0777));
>  		  else
> -		    xsnprintf (octal, sizeof (octal), "\\x%lx", (long) value);
> -		  append_string_as_wide (octal, output);
> +		    fprintf_filtered (&file, "\\x%lx", (long) value);
>  		}
>  	      /* If we somehow have extra bytes, print them now.  */
>  	      while (i < orig_len)
>  		{
> -		  char octal[5];
> -
> -		  xsnprintf (octal, sizeof (octal), "\\%.3o", orig[i] & 0xff);
> -		  append_string_as_wide (octal, output);
> +		  fprintf_filtered (&file, "\\%.3o", orig[i] & 0xff);
>  		  ++i;
>  		}
>  
> -- 
> 2.31.1
>