[PATCH 16/45] tty: vt: define an enum for ascii characters

Jiri Slaby (SUSE)
2024-01-18T07:58:32Z

I didn't find definitions for ascii in the kernel yet, so define it for
non-printable characters used here.

Note we use ' ' instead of 32 on one line too.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
drivers/tty/vt/vt.c | 62 ++++++++++++++++++++++++++++++++-------------
1 file changed, 44 insertions(+), 18 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 4b514187ef15..7006889c920d 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2157,6 +2157,28 @@ static bool ansi_control_string(unsigned int state)
return false;
}

+enum {
+ ASCII_NULL = 0,
+ ASCII_BELL = 7,
+ ASCII_BACKSPACE = 8,
+ ASCII_IGNORE_FIRST = ASCII_BACKSPACE,
+ ASCII_HTAB = 9,
+ ASCII_LINEFEED = 10,
+ ASCII_VTAB = 11,
+ ASCII_FORMFEED = 12,
+ ASCII_CAR_RET = 13,
+ ASCII_IGNORE_LAST = ASCII_CAR_RET,
+ ASCII_SHIFTOUT = 14,
+ ASCII_SHIFTIN = 15,
+ ASCII_CANCEL = 24,
+ ASCII_SUBSTITUTE = 26,
+ ASCII_ESCAPE = 27,
+ ASCII_CSI_IGNORE_FIRST = ' ', /* 0x2x, 0x3a and 0x3c - 0x3f */
+ ASCII_CSI_IGNORE_LAST = '?',
+ ASCII_DEL = 127,
+ ASCII_EXT_CSI = 128 + ASCII_ESCAPE,
+};
+
/* console_lock is held */
static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
{
@@ -2164,21 +2186,22 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
* Control characters can be used in the _middle_
* of an escape sequence, aside from ANSI control strings.
*/
- if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
+ if (ansi_control_string(vc->vc_state) && c >= ASCII_IGNORE_FIRST &&
+ c <= ASCII_IGNORE_LAST)
return;
switch (c) {
- case 0:
+ case ASCII_NULL:
return;
- case 7:
+ case ASCII_BELL:
if (ansi_control_string(vc->vc_state))
vc->vc_state = ESnormal;
else if (vc->vc_bell_duration)
kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
return;
- case 8:
+ case ASCII_BACKSPACE:
bs(vc);
return;
- case 9:
+ case ASCII_HTAB:
vc->vc_pos -= (vc->state.x << 1);

vc->state.x = find_next_bit(vc->vc_tab_stop,
@@ -2190,34 +2213,37 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
vc->vc_pos += (vc->state.x << 1);
notify_write(vc, '\t');
return;
- case 10: case 11: case 12:
+ case ASCII_LINEFEED:
+ case ASCII_VTAB:
+ case ASCII_FORMFEED:
lf(vc);
if (!is_kbd(vc, lnm))
return;
fallthrough;
- case 13:
+ case ASCII_CAR_RET:
cr(vc);
return;
- case 14:
+ case ASCII_SHIFTOUT:
vc->state.charset = 1;
vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
vc->vc_disp_ctrl = 1;
return;
- case 15:
+ case ASCII_SHIFTIN:
vc->state.charset = 0;
vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
vc->vc_disp_ctrl = 0;
return;
- case 24: case 26:
+ case ASCII_CANCEL:
+ case ASCII_SUBSTITUTE:
vc->vc_state = ESnormal;
return;
- case 27:
+ case ASCII_ESCAPE:
vc->vc_state = ESesc;
return;
- case 127:
+ case ASCII_DEL:
del(vc);
return;
- case 128+27:
+ case ASCII_EXT_CSI:
vc->vc_state = ESsquare;
return;
}
@@ -2352,7 +2378,7 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
vc->vc_par[vc->vc_npar] += c - '0';
return;
}
- if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
+ if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST) {
vc->vc_state = EScsiignore;
return;
}
@@ -2514,7 +2540,7 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
}
return;
case EScsiignore:
- if (c >= 0x20 && c <= 0x3f)
+ if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST)
return;
vc->vc_state = ESnormal;
return;
@@ -2775,17 +2801,17 @@ static bool vc_is_control(struct vc_data *vc, int tc, int c)
* useless without them; to display an arbitrary font position use the
* direct-to-font zone in UTF-8 mode.
*/
- if (c < 32) {
+ if (c < ' ') {
if (vc->vc_disp_ctrl)
return CTRL_ALWAYS & BIT(c);
else
return vc->vc_utf || (CTRL_ACTION & BIT(c));
}

- if (c == 127 && !vc->vc_disp_ctrl)
+ if (c == ASCII_DEL && !vc->vc_disp_ctrl)
return true;

- if (c == 128 + 27)
+ if (c == ASCII_EXT_CSI)
return true;

return false;
--
2.43.0