efi/printf: Add support for wchar_t (UTF-16) (d850a2ff) · Commits · 戴 / test

drivers/firmware/efi/libstub/vsprintf.c

+106 −5

Original line number	Diff line number	Diff line
		@@ -147,6 +147,7 @@ char number(char end, unsigned long long num, int base, char locase)
		#define LEFT 16 /* left justified */
		#define SMALL 32 /* Must be 32 == 0x20 */
		#define SPECIAL 64 /* 0x */
		#define WIDE 128 /* UTF-16 string */

		static
		int get_flags(const char **fmt)
		@@ -238,6 +239,58 @@ char get_sign(long long *num, int flags)
		return 0;
		}

		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;
		}

		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;
		}

		#define PUTC(c) \
		do { \
		if (pos < size) \
		@@ -325,18 +378,31 @@ int vsnprintf(char buf, size_t size, const char fmt, va_list ap)
		switch (*fmt) {
		case 'c':
		flags &= LEFT;
		tmp[0] = (unsigned char)va_arg(args, int);
		s = tmp;
		if (qualifier == 'l') {
		((u16 *)tmp)[0] = (u16)va_arg(args, unsigned int);
		((u16 *)tmp)[1] = L'\0';
		precision = INT_MAX;
		goto wstring;
		} else {
		tmp[0] = (unsigned char)va_arg(args, int);
		precision = len = 1;
		}
		goto output;

		case 's':
		flags &= LEFT;
		if (precision < 0)
		precision = INT_MAX;
		s = va_arg(args, char *);
		s = va_arg(args, void *);
		if (!s)
		s = precision < 6 ? "" : "(null)";
		else if (qualifier == 'l') {
		wstring:
		flags \|= WIDE;
		precision = len = utf16s_utf8nlen((const u16 *)s, precision);
		goto output;
		}
		precision = len = strnlen(s, precision);
		goto output;

		@@ -436,8 +502,43 @@ output:
		while (precision-- > len)
		PUTC('0');
		/* Actual output */
		if (flags & WIDE) {
		const u16 ws = (const u16 )s;

		while (len-- > 0) {
		u32 c32 = utf16_to_utf32(&ws);
		u8 *s8;
		size_t clen;

		if (c32 < 0x80) {
		PUTC(c32);
		continue;
		}

		/* Number of trailing octets */
		clen = 1 + (c32 >= 0x800) + (c32 >= 0x10000);

		len -= clen;
		s8 = (u8 *)&buf[pos];

		/* Avoid writing partial character */
		PUTC('\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;
		}
		} else {
		while (len-- > 0)
		PUTC(*s++);
		}
		/* Trailing padding with ' ' */
		while (field_width-- > 0)
		PUTC(' ');

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