[U-Boot] [PATCH 05/15] lib: vsprintf: correct printing of Unicode strings

[Alexander Graf]

On 11.08.18 17:28, Heinrich Schuchardt wrote:
> The width and precision of the printf() function refer to the number of
> characters not to the number of bytes printed.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  lib/vsprintf.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index a07128ad96..b7eb9d5f5e 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -280,18 +280,22 @@ static char *string16(char *buf, char *end, u16 *s, int field_width,
>  		int precision, int flags)
>  {
>  	u16 *str = s ? s : L"<NULL>";
> -	int utf16_len = u16_strnlen(str, precision);
> -	u8 utf8[utf16_len * MAX_UTF8_PER_UTF16];
> -	int utf8_len, i;
> -
> -	utf8_len = utf16_to_utf8(utf8, str, utf16_len) - utf8;
> +	ssize_t i, len = utf16_strnlen(str, precision);
>  
>  	if (!(flags & LEFT))
> -		while (utf8_len < field_width--)
> +		for (; len < field_width; --field_width)
>  			ADDCH(buf, ' ');
> -	for (i = 0; i < utf8_len; ++i)
> -		ADDCH(buf, utf8[i]);
> -	while (utf8_len < field_width--)
> +	for (i = 0; i < len; ++i) {
> +		s32 code = utf16_get((const u16 **)&str);
> +
> +		if (code < 0) {
> +			code = '?';
> +			if (*str)
> +				++str;
> +		}
> +		utf8_put(code, &buf);

Can you introduce or reuse a strcpy() helper in charset.c for this? That
way the compiler has the chance to inline utf16_get() and utf8_put() and
make the function fast.


Alex