On Tue, Dec 13, 2016 at 10:22:25PM +1300, Chris Packham wrote:
> $ make cppcheck
> cppcheck --force --quiet --inline-suppr .
> [compat/nedmalloc/malloc.c.h:4093]: (error) Possible null pointer
> dereference: sp
> [compat/nedmalloc/malloc.c.h:4106]: (error) Possible null pointer
> dereference: sp
> [compat/nedmalloc/nedmalloc.c:551]: (error) Expression
> '*(&p.mycache)=TlsAlloc(),TLS_OUT_OF_INDEXES==*(&p.mycache)' depends on order
> of evaluation of side effects
> [compat/regex/regcomp.c:3086]: (error) Memory leak: sbcset
> [compat/regex/regcomp.c:3634]: (error) Memory leak: sbcset
> [compat/regex/regcomp.c:3086]: (error) Memory leak: mbcset
> [compat/regex/regcomp.c:3634]: (error) Memory leak: mbcset
> [compat/regex/regcomp.c:2802]: (error) Uninitialized variable: table_size
> [compat/regex/regcomp.c:2805]: (error) Uninitialized variable: table_size
> [compat/regex/regcomp.c:532]: (error) Memory leak: fastmap
> [t/t4051/appended1.c:3]: (error) Invalid number of character '{' when these
> macros are defined: ''.
> [t/t4051/appended2.c:35]: (error) Invalid number of character '{' when these
> macros are defined: ''.
>
> The last 2 are just false positives from test data. I haven't looked
> into any of the others.
I think these last two are a good sign that we need to be feeding the
list of source files to cppcheck. I tried your patch and it also started
looking in t/perf/build, which are old versions of git built to serve
the performance-testing suite.
See the way that the "tags" target is handled for a possible approach.
My main complaint with any static checker is how we can handle false
positives. I think our use of "-Wall -Werror" is successful because it's
not too hard to keep the normal state to zero warnings. Looking at the
output of cppcheck on my system (which is different than on yours!), I
do see a few real problems, but many false positives, too.
Unfortunately, one of the false positives is:
int foo = foo;
to silence -Wuninitialized, which causes cppcheck to complain that "foo"
is uninitialized. I'm worried we will end up with two static checkers
fighting each other, and no good way to please both.
-Peff
