On 11.03.25 00:33, Marek Vasut wrote:
On 3/10/25 10:49 PM, Tom Rini wrote:
On Mon, Mar 10, 2025 at 10:03:37PM +0100, Marek Vasut wrote:
On 3/10/25 12:17 PM, Quentin Schulz wrote:
Hi Marek,
Hi,
On 3/8/25 9:12 PM, Marek Vasut wrote:
Fix the following conversion overflow errors. The input field is
already
limited to 3/2/1 bits using the bitwise and, move the parenthesis
around
to avoid the bogus warning:
"
fs/exfat/utf.c: In function ‘utf8_to_wchar’:
fs/exfat/utf.c:165:23: warning: overflow in conversion from ‘int’ to
‘wchar_t’ {aka ‘short unsigned int’} changes value from ‘(int)(short
unsigned int)*input << 18 & 1835008’ to ‘0’ [-Woverflow]
165 | *wc = ((wchar_t) input[0] & 0x07) << 18;
| ^
fs/exfat/utf.c:170:23: warning: overflow in conversion from ‘int’ to
‘wchar_t’ {aka ‘short unsigned int’} changes value from ‘(int)(short
unsigned int)*input << 24 & 50331648’ to ‘0’ [-Woverflow]
170 | *wc = ((wchar_t) input[0] & 0x03) << 24;
| ^
fs/exfat/utf.c:175:23: warning: overflow in conversion from ‘int’ to
‘wchar_t’ {aka ‘short unsigned int’} changes value from ‘(int)(short
unsigned int)*input << 30 & 1073741824’ to ‘0’ [-Woverflow]
175 | *wc = ((wchar_t) input[0] & 0x01) << 30;
| ^
"
Since this doesn't seem to be U-Boot-specific, any chance to open a
Pull
Request on the project so we may be able to not carry this patch when
upgrading (yes, the last commit in the branch was two years ago, but it
seems the maintainer is still active on issues).
Considering that wchar_t is an unsigned short int and that USHRT_MAX is
0xffff (so 2B or 16b)...
In fact, this error does not even appear in upstream , because
upstream does
not use -fshort-wchar compiler flag . U-Boot does use this compiler
flags
since 4a85663ec7ed ("kbuild: Enable -fshort-wchar") .
So I wonder if this might be the right fix here instead:
diff --git a/fs/exfat/Makefile b/fs/exfat/Makefile
index 550c0683d65..8ca112cf0e9 100644
--- a/fs/exfat/Makefile
+++ b/fs/exfat/Makefile
@@ -1,6 +1,9 @@
# SPDX-License-Identifier: GPL-2.0+
#
+# The utf.o does really need 32bit wchar_t
+CFLAGS_REMOVE_utf.o := -fshort-wchar
+
obj-$(CONFIG_FS_EXFAT) += \
cluster.o \
io.o \
Your initial approach is right I think, I'm not sure it's a good idea
to mix and match that flag throughout the codebase.
The -fshort-wchar is needed only because of EFI , so I wonder if we
should somehow isolate the EFI code which needs this stuff instead, and
drop the flag throughout the codebase instead ? Heinrich ?
Or maybe EFI should switch to something else that is not wchar_t , so
other users can use wchar_t unrestricted ?
We already changed all L"" strings to u"".
But the compiler complains about printf("%ls\n", (u16 *)buf); without
-fshort-wchar.
So we cannot do without the flag.
In fs/exfat/Makefile you should be able to disable the flag with
CFLAGS_REMOVE_* and AFLAGS_REMOVE_*
Best regards
Heinrich
