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Message-ID: <20070412174443.GA26002@uhulinux.hu>
Date: Thu, 12 Apr 2007 19:44:43 +0200
From: Egmont Koblinger <egmont@...linux.hu>
To: "H. Peter Anvin" <hpa@...or.com>
Cc: Jan Engelhardt <jengelh@...ux01.gwdg.de>,
Alan Cox <alan@...rguk.ukuu.org.uk>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] console UTF-8 fixes
On Thu, Apr 12, 2007 at 10:35:24AM -0700, H. Peter Anvin wrote:
> Yes, I didn't realize at the time that that was dead code.
:-))))
Version 4 of the patch follows. Dead code omitted from version 3.
Signed-off-by: Egmont Koblinger <egmont@...linux.hu>
diff -Naur linux-2.6.20.orig/drivers/char/consolemap.c linux-2.6.20/drivers/char/consolemap.c
--- linux-2.6.20.orig/drivers/char/consolemap.c 2007-02-04 19:44:54.000000000 +0100
+++ linux-2.6.20/drivers/char/consolemap.c 2007-04-11 18:45:45.000000000 +0200
@@ -626,10 +626,10 @@
/* Only 16-bit codes supported at this time */
if (ucs > 0xffff)
- ucs = 0xfffd; /* U+FFFD: REPLACEMENT CHARACTER */
- else if (ucs < 0x20 || ucs >= 0xfffe)
+ return -4; /* Not found */
+ else if (ucs < 0x20)
return -1; /* Not a printable character */
- else if (ucs == 0xfeff || (ucs >= 0x200a && ucs <= 0x200f))
+ else if (ucs == 0xfeff || (ucs >= 0x200b && ucs <= 0x200f))
return -2; /* Zero-width space */
/*
* UNI_DIRECT_BASE indicates the start of the region in the User Zone
diff -Naur linux-2.6.20.orig/drivers/char/vt.c linux-2.6.20/drivers/char/vt.c
--- linux-2.6.20.orig/drivers/char/vt.c 2007-02-04 19:44:54.000000000 +0100
+++ linux-2.6.20/drivers/char/vt.c 2007-04-12 19:38:51.000000000 +0200
@@ -1934,6 +1934,46 @@
char con_buf[CON_BUF_SIZE];
DECLARE_MUTEX(con_buf_sem);
+/* is_double_width() is based on the wcwidth() implementation by
+ * Markus Kuhn -- 2003-05-20 (Unicode 4.0)
+ * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+struct interval {
+ uint32_t first;
+ uint32_t last;
+};
+
+static int bisearch(uint32_t ucs, const struct interval *table, int max)
+{
+ int min = 0;
+ int mid;
+
+ if (ucs < table[0].first || ucs > table[max].last)
+ return 0;
+ while (max >= min) {
+ mid = (min + max) / 2;
+ if (ucs > table[mid].last)
+ min = mid + 1;
+ else if (ucs < table[mid].first)
+ max = mid - 1;
+ else
+ return 1;
+ }
+ return 0;
+}
+
+static int is_double_width(uint32_t ucs)
+{
+ static const struct interval double_width[] = {
+ { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
+ { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
+ { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 }, { 0xFFE0, 0xFFE6 },
+ { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
+ };
+ return bisearch(ucs, double_width,
+ sizeof(double_width) / sizeof(*double_width) - 1);
+}
+
/* acquires console_sem */
static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
@@ -1950,6 +1990,10 @@
unsigned int currcons;
unsigned long draw_from = 0, draw_to = 0;
struct vc_data *vc;
+ unsigned char vc_attr;
+ uint8_t rescan;
+ uint8_t inverse;
+ uint8_t width;
u16 himask, charmask;
const unsigned char *orig_buf = NULL;
int orig_count;
@@ -2012,51 +2056,81 @@
buf++;
n++;
count--;
+ rescan = 0;
+ inverse = 0;
+ width = 1;
/* Do no translation at all in control states */
if (vc->vc_state != ESnormal) {
tc = c;
} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
- /* Combine UTF-8 into Unicode */
- /* Malformed sequences as sequences of replacement glyphs */
+ /* Combine UTF-8 into Unicode in vc_utf_char */
+ /* vc_utf_count is the number of continuation bytes still expected to arrive */
+ /* vc_npar is the number of continuation bytes arrived so far */
rescan_last_byte:
- if(c > 0x7f) {
+ if ((c & 0xc0) == 0x80) {
+ /* Continuation byte received */
+ static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
if (vc->vc_utf_count) {
- if ((c & 0xc0) == 0x80) {
- vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
- if (--vc->vc_utf_count) {
- vc->vc_npar++;
- continue;
- }
- tc = c = vc->vc_utf_char;
- } else
- goto replacement_glyph;
- } else {
- vc->vc_npar = 0;
- if ((c & 0xe0) == 0xc0) {
- vc->vc_utf_count = 1;
- vc->vc_utf_char = (c & 0x1f);
- } else if ((c & 0xf0) == 0xe0) {
- vc->vc_utf_count = 2;
- vc->vc_utf_char = (c & 0x0f);
- } else if ((c & 0xf8) == 0xf0) {
- vc->vc_utf_count = 3;
- vc->vc_utf_char = (c & 0x07);
- } else if ((c & 0xfc) == 0xf8) {
- vc->vc_utf_count = 4;
- vc->vc_utf_char = (c & 0x03);
- } else if ((c & 0xfe) == 0xfc) {
- vc->vc_utf_count = 5;
- vc->vc_utf_char = (c & 0x01);
- } else
- goto replacement_glyph;
+ vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
+ vc->vc_npar++;
+ if (--vc->vc_utf_count) {
+ /* Still need some bytes */
continue;
- }
+ }
+ /* Got a whole character */
+ c = vc->vc_utf_char;
+ /* Reject overlong sequences */
+ if (c <= utf8_length_changes[vc->vc_npar - 1] || c > utf8_length_changes[vc->vc_npar]) {
+ c = 0xfffd;
+ }
+ } else {
+ /* Unexpected continuation byte */
+ vc->vc_utf_count = 0;
+ c = 0xfffd;
+ }
} else {
- if (vc->vc_utf_count)
- goto replacement_glyph;
- tc = c;
+ /* Single ASCII byte or first byte of a sequence received */
+ if (vc->vc_utf_count) {
+ /* Continuation byte expected */
+ rescan = 1;
+ vc->vc_utf_count = 0;
+ c = 0xfffd;
+ } else if (c > 0x7f) {
+ /* First byte of a multibyte sequence received */
+ vc->vc_npar = 0;
+ if ((c & 0xe0) == 0xc0) {
+ vc->vc_utf_count = 1;
+ vc->vc_utf_char = (c & 0x1f);
+ } else if ((c & 0xf0) == 0xe0) {
+ vc->vc_utf_count = 2;
+ vc->vc_utf_char = (c & 0x0f);
+ } else if ((c & 0xf8) == 0xf0) {
+ vc->vc_utf_count = 3;
+ vc->vc_utf_char = (c & 0x07);
+ } else if ((c & 0xfc) == 0xf8) {
+ vc->vc_utf_count = 4;
+ vc->vc_utf_char = (c & 0x03);
+ } else if ((c & 0xfe) == 0xfc) {
+ vc->vc_utf_count = 5;
+ vc->vc_utf_char = (c & 0x01);
+ } else {
+ /* 254 and 255 are invalid */
+ c = 0xfffd;
+ }
+ if (vc->vc_utf_count) {
+ /* Still need some bytes */
+ continue;
+ }
+ }
+ /* Nothing to do if an ASCII byte was received */
}
+ /* End of UTF-8 decoding. */
+ /* c is the received character, or U+FFFD for invalid sequences. */
+ /* Replace invalid Unicode code points with U+FFFD too */
+ if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
+ c = 0xfffd;
+ tc = c;
} else { /* no utf or alternate charset mode */
tc = vc->vc_translate[vc->vc_toggle_meta ? (c | 0x80) : c];
}
@@ -2078,56 +2152,81 @@
&& (c != 128+27);
if (vc->vc_state == ESnormal && ok) {
+ if (vc->vc_utf && !vc->vc_disp_ctrl) {
+ if (is_double_width(c)) {
+ width = 2;
+ }
+ }
/* Now try to find out how to display it */
tc = conv_uni_to_pc(vc, tc);
if (tc & ~charmask) {
- if ( tc == -4 ) {
- /* If we got -4 (not found) then see if we have
- defined a replacement character (U+FFFD) */
-replacement_glyph:
- tc = conv_uni_to_pc(vc, 0xfffd);
- if (!(tc & ~charmask))
- goto display_glyph;
- } else if ( tc != -3 )
- continue; /* nothing to display */
- /* no hash table or no replacement --
- * hope for the best */
- if ( c & ~charmask )
- tc = '?';
- else
- tc = c;
+ if (tc == -1 || tc == -2) {
+ continue; /* nothing to display */
+ }
+ /* Glyph not found */
+ if (!(vc->vc_utf && !vc->vc_disp_ctrl) && !(c & ~charmask)) {
+ /* In legacy mode use the glyph we get by a 1:1 mapping.
+ This would make absolutely no sense with Unicode in mind. */
+ tc = c;
+ } else {
+ /* Display U+FFFD. If it's not found, display an inverse question mark. */
+ tc = conv_uni_to_pc(vc, 0xfffd);
+ if (tc < 0) {
+ inverse = 1;
+ tc = conv_uni_to_pc(vc, '?');
+ if (tc < 0) tc = '?';
+ }
+ }
}
-display_glyph:
- if (vc->vc_need_wrap || vc->vc_decim)
- FLUSH
- if (vc->vc_need_wrap) {
- cr(vc);
- lf(vc);
- }
- if (vc->vc_decim)
- insert_char(vc, 1);
- scr_writew(himask ?
- ((vc->vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
- (vc->vc_attr << 8) + tc,
- (u16 *) vc->vc_pos);
- if (DO_UPDATE(vc) && draw_x < 0) {
- draw_x = vc->vc_x;
- draw_from = vc->vc_pos;
- }
- if (vc->vc_x == vc->vc_cols - 1) {
- vc->vc_need_wrap = vc->vc_decawm;
- draw_to = vc->vc_pos + 2;
+ if (!inverse) {
+ vc_attr = vc->vc_attr;
} else {
- vc->vc_x++;
- draw_to = (vc->vc_pos += 2);
+ /* invert vc_attr */
+ if (!vc->vc_can_do_color) {
+ vc_attr = (vc->vc_attr) ^ 0x08;
+ } else if (vc->vc_hi_font_mask == 0x100) {
+ vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
+ } else {
+ vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
+ }
}
- if (vc->vc_utf_count) {
- if (vc->vc_npar) {
- vc->vc_npar--;
- goto display_glyph;
+
+ while (1) {
+ if (vc->vc_need_wrap || vc->vc_decim)
+ FLUSH
+ if (vc->vc_need_wrap) {
+ cr(vc);
+ lf(vc);
+ }
+ if (vc->vc_decim)
+ insert_char(vc, 1);
+ scr_writew(himask ?
+ ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
+ (vc_attr << 8) + tc,
+ (u16 *) vc->vc_pos);
+ if (DO_UPDATE(vc) && draw_x < 0) {
+ draw_x = vc->vc_x;
+ draw_from = vc->vc_pos;
+ }
+ if (vc->vc_x == vc->vc_cols - 1) {
+ vc->vc_need_wrap = vc->vc_decawm;
+ draw_to = vc->vc_pos + 2;
+ } else {
+ vc->vc_x++;
+ draw_to = (vc->vc_pos += 2);
}
- vc->vc_utf_count = 0;
+
+ if (!--width) break;
+
+ tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
+ if (tc < 0) tc = ' ';
+ }
+
+ if (rescan) {
+ rescan = 0;
+ inverse = 0;
+ width = 1;
c = orig;
goto rescan_last_byte;
}
-
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