[PATCH 31/36] tty/vt: consolemap: make conv_uni_to_pc() more readable

Jiri Slaby
2022-06-07T10:53:16Z

1) Fetch *conp->vc_uni_pagedir_loc first and do the NULL check on the local
variable.
2) Decouple the large "if" into few smaller "if"s.
3) Remove a \n from the definition line.

This makes the code more readable.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/vt/consolemap.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 8abf114b6c68..a9b497ffb346 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -849,8 +849,7 @@ int conv_uni_to_8bit(u32 uni)
return -1;
}

-int
-conv_uni_to_pc(struct vc_data *conp, long ucs)
+int conv_uni_to_pc(struct vc_data *conp, long ucs)
{
struct uni_pagedict *dict;
u16 **dir, *row, glyph;
@@ -869,17 +868,24 @@ conv_uni_to_pc(struct vc_data *conp, long ucs)
*/
else if ((ucs & ~UNI_DIRECT_MASK) == UNI_DIRECT_BASE)
return ucs & UNI_DIRECT_MASK;
-
- if (!*conp->vc_uni_pagedir_loc)
- return -3;

dict = *conp->vc_uni_pagedir_loc;
- if ((dir = dict->uni_pgdir[UNI_DIR(ucs)]) &&
- (row = dir[UNI_ROW(ucs)]) &&
- (glyph = row[UNI_GLYPH(ucs)]) < MAX_GLYPH)
- return glyph;
+ if (!dict)
+ return -3;
+
+ dir = dict->uni_pgdir[UNI_DIR(ucs)];
+ if (!dir)
+ return -4;
+
+ row = dir[UNI_ROW(ucs)];
+ if (!row)
+ return -4;
+
+ glyph = row[UNI_GLYPH(ucs)];
+ if (glyph >= MAX_GLYPH)
+ return -4;

- return -4; /* not found */
+ return glyph;
}

/*
--
2.36.1