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| author | Joey Pabalinas <joeypabalinas@gmail.com> | 2018-04-10 12:46:24 -1000 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-04-11 20:43:37 +0200 |
| commit | 551b85c8a241bd45b267db152eca4cb01eddce39 (patch) | |
| tree | f317dfe5e9da6ec56e2d4db4b3a2a9eeceb4c026 /sparse.1 | |
| parent | 8d1fb16c9e5f1fd1b3e3b5b39daad85b28b875f7 (diff) | |
| download | sparse-dev-551b85c8a241bd45b267db152eca4cb01eddce39.tar.gz | |
sparse: add -Wpointer-arith flag to toggle sizeof(void) warnings
Recent changes to the min()/max() macros in include/linux/kernel.h
have added a lot of noise when compiling the kernel with Sparse checking
enabled. This mostly is due to the *huge* increase in the number of
sizeof(void) warnings, a larger number of which can safely be ignored.
Add the -Wpointer-arith flag to enable/disable these warnings (along
with the warning when applying sizeof to function types as well as
warning about pointer arithmetic on these types exactly like the
GCC -Wpointer-arith flag) on demand; the warning itself has been disabled
by default to reduce the large influx of noise which was inadvertently
added by commit 3c8ba0d61d04ced9f8 (kernel.h: Retain constant expression
output for max()/min()).
Update the manpage to document the new flag and add a validation case
for sizeof(void).
CC: Kees Cook <keescook@chromium.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
CC: Al Viro <viro@ZenIV.linux.org.uk>
CC: Christopher Li <sparse@chrisli.org>
CC: Joey Pabalinas <joeypabalinas@gmail.com>
CC: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'sparse.1')
| -rw-r--r-- | sparse.1 | 13 |
1 files changed, 13 insertions, 0 deletions
@@ -291,6 +291,19 @@ initializer. GCC allows this syntax as an extension. With Sparse does not issue these warnings by default. . .TP +.B \-Wpointer\-arith +Warn about anything that depends on the \fBsizeof\fR a void or function type. + +C99 does not allow the \fBsizeof\fR operator to be applied to function types +or to incomplete types such as void. GCC allows \fBsizeof\fR to be applied to +these types as an extension and assigns these types a size of \fI1\fR. With +\fB\-pointer\-arith\fR, Sparse will warn about pointer arithmetic on void +or function pointers, as well as expressions which directly apply the +\fBsizeof\fR operator to void or function types. + +Sparse does not issue these warnings by default. +. +.TP .B \-Wptr\-subtraction\-blows Warn when subtracting two pointers to a type with a non-power-of-two size. |