Re: [RFC/PATCH] Makefile: add cppcheck target

[Chris Packham <judge.packham@gmail.com>]

On Tue, Dec 13, 2016 at 10:22 PM, Chris Packham <judge.packham@gmail.com> wrote:
> Add cppcheck target to Makefile. Cppcheck is a static
> analysis tool for C/C++ code. Cppcheck primarily detects
> the types of bugs that the compilers normally do not detect.
> It is an useful target for doing QA analysis.
>
> Based-on-patch-by: Elia Pinto <gitter.spiros@gmail.com>
> Signed-off-by: Chris Packham <judge.packham@gmail.com>
> ---
> I had been playing with cppcheck for some other projects and happened to
> notice [1] in the archives. This is my attempt to resolve the feedback
> that Junio made at the time.
>
> In terms of errors that are actually reported there are only a few
>
> $ 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've also provisioned for enabling extra checks by passing CPPCHECK_ADD
> in the make invocation.
>
> $ make cppcheck CPPCHECK_ADD=--enable=all
> ... lots of output
>
> [1] - http://public-inbox.org/git/1390993371-2431-1-git-send-email-gitter.spiros@gmail.com/#t
>
>  Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index f53fcc90d..8b5976d88 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -2635,3 +2635,7 @@ cover_db: coverage-report
>  cover_db_html: cover_db
>         cover -report html -outputdir cover_db_html cover_db
>
> +.PHONY: cppcheck
> +
> +cppcheck:
> +       cppcheck --force --quiet --inline-suppr $(CPPCHECK_ADD) .

If I'm permitted a little GNU make-ism the following might make
CPPCHECK_ADD a bit more usable

+       cppcheck --force --quiet --inline-suppr $(if
$(CPPCHECK_ADD),--enable=$(CPPCHECK_ADD)) .

Which would take us from

$ make cppcheck CPPCHECK_ADD=--enable=all

to

$ make cppcheck CPPCHECK_ADD=all