mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Nathan Chancellor
0bfe7d3cae
Clang generates a warning when it sees a logical not followed by a
conditional operator like ==, >, or < because it thinks that the logical
not should be applied to the whole statement:
drivers/scsi/qla2xxx/qla_nx.c:3702:7: warning: logical not is only
applied to the left hand side of this comparison
[-Wlogical-not-parentheses]
if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
^
drivers/scsi/qla2xxx/qla_nx.c:3702:7: note: add parentheses after the
'!' to evaluate the comparison first
if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
^
(
drivers/scsi/qla2xxx/qla_nx.c:3702:7: note: add parentheses around left
hand side expression to silence this warning
if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
^
(
1 warning generated.
It assumes the author might have made a mistake in their logic:
if (!a == b) -> if (!(a == b))
Sometimes that is the case; other times, it's just a super convoluted
way of saying 'if (a)' when b = 0:
if (!1 == 0) -> if (0 == 0) -> if (true)
Alternatively:
if (!1 == 0) -> if (!!1) -> if (1)
Simplify this comparison so that Clang doesn't complain.
Link: https://github.com/ClangBuiltLinux/linux/issues/80
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.