| Message ID | 20220506205605.359830-11-nikos.nikoleris@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | EFI and ACPI support for arm64 | expand |
On Fri, May 06, 2022 at 09:55:52PM +0100, Nikos Nikoleris wrote: > This change adds support for wide strings (u16*) to printf() > variants. This feature is used by a future change. > > Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> > --- > lib/printf.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 100 insertions(+), 1 deletion(-) > > diff --git a/lib/printf.c b/lib/printf.c > index 724befa..14a3fed 100644 > --- a/lib/printf.c > +++ b/lib/printf.c > @@ -57,6 +57,102 @@ static void print_str(pstream_t *p, const char *s, strprops_t props) > } > } > > +/* > + * Adapted from drivers/firmware/efi/libstub/vsprintf.c > + */ > +static u32 utf16_to_utf32(const u16 **s16) > +{ > + u16 c0, c1; > + > + c0 = *(*s16)++; > + /* not a surrogate */ > + if ((c0 & 0xf800) != 0xd800) > + return c0; > + /* invalid: low surrogate instead of high */ > + if (c0 & 0x0400) > + return 0xfffd; > + c1 = **s16; > + /* invalid: missing low surrogate */ > + if ((c1 & 0xfc00) != 0xdc00) > + return 0xfffd; > + /* valid surrogate pair */ > + ++(*s16); > + return (0x10000 - (0xd800 << 10) - 0xdc00) + (c0 << 10) + c1; > +} > + > +/* > + * Adapted from drivers/firmware/efi/libstub/vsprintf.c > + */ > +static size_t utf16s_utf8nlen(const u16 *s16, size_t maxlen) > +{ > + size_t len, clen; > + > + for (len = 0; len < maxlen && *s16; len += clen) { > + u16 c0 = *s16++; > + > + /* First, get the length for a BMP character */ > + clen = 1 + (c0 >= 0x80) + (c0 >= 0x800); > + if (len + clen > maxlen) > + break; > + /* > + * If this is a high surrogate, and we're already at maxlen, we > + * can't include the character if it's a valid surrogate pair. > + * Avoid accessing one extra word just to check if it's valid > + * or not. > + */ > + if ((c0 & 0xfc00) == 0xd800) { > + if (len + clen == maxlen) > + break; > + if ((*s16 & 0xfc00) == 0xdc00) { > + ++s16; > + ++clen; > + } > + } > + } > + > + return len; > +} > + > +/* > + * Adapted from drivers/firmware/efi/libstub/vsprintf.c > + */ > +static void print_wstring(pstream_t *p, const u16 *s, strprops_t props) > +{ > + const u16 *ws = (const u16 *)s; > + size_t pos = 0, size = p->remain + 1, len = utf16s_utf8nlen(ws, props.precision); > + > + while (len-- > 0) { > + u32 c32 = utf16_to_utf32(&ws); > + u8 *s8; > + size_t clen; > + > + if (c32 < 0x80) { > + addchar(p, c32); > + continue; > + } > + > + /* Number of trailing octets */ > + clen = 1 + (c32 >= 0x800) + (c32 >= 0x10000); > + > + len -= clen; > + s8 = (u8 *)(p->buffer - p->added + pos); > + > + /* Avoid writing partial character */ > + addchar(p, '\0'); > + pos += clen; > + if (pos >= size) > + continue; > + > + /* Set high bits of leading octet */ > + *s8 = (0xf00 >> 1) >> clen; > + /* Write trailing octets in reverse order */ > + for (s8 += clen; clen; --clen, c32 >>= 6) > + *s8-- = 0x80 | (c32 & 0x3f); > + /* Set low bits of leading octet */ > + *s8 |= c32; > + } > +} > + > static char digits[16] = "0123456789abcdef"; > > static void print_int(pstream_t *ps, long long n, int base, strprops_t props) > @@ -302,7 +398,10 @@ int vsnprintf(char *buf, int size, const char *fmt, va_list va) > print_unsigned(&s, (unsigned long)va_arg(args, void *), 16, props); > break; > case 's': > - print_str(&s, va_arg(args, const char *), props); > + if (nlong) > + print_wstring(&s, va_arg(args, const u16 *), props); > + else > + print_str(&s, va_arg(args, const char *), props); > break; > default: > addchar(&s, f); > -- > 2.25.1 > Reviewed-by: Ricardo Koller <ricarkol@google.com>
diff --git a/lib/printf.c b/lib/printf.c index 724befa..14a3fed 100644 --- a/lib/printf.c +++ b/lib/printf.c @@ -57,6 +57,102 @@ static void print_str(pstream_t *p, const char *s, strprops_t props) } } +/* + * Adapted from drivers/firmware/efi/libstub/vsprintf.c + */ +static u32 utf16_to_utf32(const u16 **s16) +{ + u16 c0, c1; + + c0 = *(*s16)++; + /* not a surrogate */ + if ((c0 & 0xf800) != 0xd800) + return c0; + /* invalid: low surrogate instead of high */ + if (c0 & 0x0400) + return 0xfffd; + c1 = **s16; + /* invalid: missing low surrogate */ + if ((c1 & 0xfc00) != 0xdc00) + return 0xfffd; + /* valid surrogate pair */ + ++(*s16); + return (0x10000 - (0xd800 << 10) - 0xdc00) + (c0 << 10) + c1; +} + +/* + * Adapted from drivers/firmware/efi/libstub/vsprintf.c + */ +static size_t utf16s_utf8nlen(const u16 *s16, size_t maxlen) +{ + size_t len, clen; + + for (len = 0; len < maxlen && *s16; len += clen) { + u16 c0 = *s16++; + + /* First, get the length for a BMP character */ + clen = 1 + (c0 >= 0x80) + (c0 >= 0x800); + if (len + clen > maxlen) + break; + /* + * If this is a high surrogate, and we're already at maxlen, we + * can't include the character if it's a valid surrogate pair. + * Avoid accessing one extra word just to check if it's valid + * or not. + */ + if ((c0 & 0xfc00) == 0xd800) { + if (len + clen == maxlen) + break; + if ((*s16 & 0xfc00) == 0xdc00) { + ++s16; + ++clen; + } + } + } + + return len; +} + +/* + * Adapted from drivers/firmware/efi/libstub/vsprintf.c + */ +static void print_wstring(pstream_t *p, const u16 *s, strprops_t props) +{ + const u16 *ws = (const u16 *)s; + size_t pos = 0, size = p->remain + 1, len = utf16s_utf8nlen(ws, props.precision); + + while (len-- > 0) { + u32 c32 = utf16_to_utf32(&ws); + u8 *s8; + size_t clen; + + if (c32 < 0x80) { + addchar(p, c32); + continue; + } + + /* Number of trailing octets */ + clen = 1 + (c32 >= 0x800) + (c32 >= 0x10000); + + len -= clen; + s8 = (u8 *)(p->buffer - p->added + pos); + + /* Avoid writing partial character */ + addchar(p, '\0'); + pos += clen; + if (pos >= size) + continue; + + /* Set high bits of leading octet */ + *s8 = (0xf00 >> 1) >> clen; + /* Write trailing octets in reverse order */ + for (s8 += clen; clen; --clen, c32 >>= 6) + *s8-- = 0x80 | (c32 & 0x3f); + /* Set low bits of leading octet */ + *s8 |= c32; + } +} + static char digits[16] = "0123456789abcdef"; static void print_int(pstream_t *ps, long long n, int base, strprops_t props) @@ -302,7 +398,10 @@ int vsnprintf(char *buf, int size, const char *fmt, va_list va) print_unsigned(&s, (unsigned long)va_arg(args, void *), 16, props); break; case 's': - print_str(&s, va_arg(args, const char *), props); + if (nlong) + print_wstring(&s, va_arg(args, const u16 *), props); + else + print_str(&s, va_arg(args, const char *), props); break; default: addchar(&s, f);
This change adds support for wide strings (u16*) to printf() variants. This feature is used by a future change. Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> --- lib/printf.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 100 insertions(+), 1 deletion(-)