Re: [PATCH] Makefile: check for cppcheck's --check-level option in cppcheck target

[Stefano Brivio <sbrivio@redhat.com>]

On Wed, 28 Feb 2024 08:24:49 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Tue, Feb 27, 2024 at 05:29:47PM +0100, Stefano Brivio wrote:
> > Don't run cppcheck to find out if the --check-level=exhaustive option
> > is available, unless we're actually going to run cppcheck later.
> > 
> > To avoid this, move this check under the cppcheck target, and
> > implement it in shell script instead of using Makefile directives,
> > because we can't easily implement conditionals in recipes.
> > 
> > Reported-by: Rahil Bhimjiani <me@rahil.website>
> > Link: https://bugs.gentoo.org/920795
> > Fixes: 8640d62af719 ("cppcheck: Use "exhaustive" level checking when available")
> > Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
> > ---
> >  Makefile | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/Makefile b/Makefile
> > index af4fa87..75d0bf3 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -287,17 +287,17 @@ clang-tidy: $(SRCS) $(HEADERS)
> >  	-config='{CheckOptions: [{key: bugprone-suspicious-string-compare.WarnOnImplicitComparison, value: "false"}]}' \
> >  	--warnings-as-errors=* $(SRCS) -- $(filter-out -pie,$(FLAGS) $(CFLAGS) $(CPPFLAGS)) -DCLANG_TIDY_58992
> >  
> > -CPPCHECK_EXHAUSTIVE :=
> > -ifeq ($(shell cppcheck --check-level=exhaustive /dev/null > /dev/null 2>&1; echo $$?),0)
> > -	CPPCHECK_EXHAUSTIVE += --check-level=exhaustive
> > -endif
> > -
> >  SYSTEM_INCLUDES := /usr/include $(wildcard /usr/include/$(TARGET))
> >  ifeq ($(shell $(CC) -v 2>&1 | grep -c "gcc version"),1)
> >  VER := $(shell $(CC) -dumpversion)
> >  SYSTEM_INCLUDES += /usr/lib/gcc/$(TARGET)/$(VER)/include
> >  endif
> >  cppcheck: $(SRCS) $(HEADERS)
> > +	if cppcheck --check-level=exhaustive /dev/null > /dev/null 2>&1; then \
> > +		CPPCHECK_EXHAUSTIVE="--check-level=exhaustive";		\
> > +	else								\
> > +		CPPCHECK_EXHAUSTIVE=;					\
> > +	fi;								\
> >  	cppcheck --std=c11 --error-exitcode=1 --enable=all --force	\
> >  	--inconclusive --library=posix --quiet				\
> >  	$(CPPCHECK_EXHAUSTIVE)						\  
> 
> IIUC, this is essentially moving CPPCHECK_EXHAUSTIVE from a make
> variable to a shell variable in the shell that make invokes.  Which is
> fine, but I believe $(CPPCHECK_EXHAUSTIVE) will only expand to a make
> variable.  To get the shell variable you'll need
> $${CPPCHECK_EXHAUSTIVE}.  I suspect as written, this will always
> expand empty.

Oops, you're right, I had only tested the negative case. Fixed in v2.

-- 
Stefano