[PATCH RESEND v2] Makefile: check for cppcheck's --check-level option in cppcheck target

[PATCH RESEND v2] Makefile: check for cppcheck's --check-level option in cppcheck target

[Stefano Brivio]

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.rocks>
Link: https://bugs.gentoo.org/920795
Fixes: 8640d62af719 ("cppcheck: Use "exhaustive" level checking when available")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
Re-send to/with the right address for Rahil (Gentoo maintainer)

v2: Actually fetch the shell variable for cppcheck's command line

 Makefile | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index af4fa87..75f49dc 100644
--- a/Makefile
+++ b/Makefile
@@ -287,20 +287,20 @@ 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 $$?),0)
-	CPPCHECK_EXHAUSTIVE += --check-level=exhaustive
-endif
-
 SYSTEM_INCLUDES := /usr/include $(wildcard /usr/include/$(TARGET))
 ifeq ($(shell $(CC) -v 2>&1 | grep -c "gcc version"),1)
 VER := $(shell $(CC) -dumpversion)
 SYSTEM_INCLUDES += /usr/lib/gcc/$(TARGET)/$(VER)/include
 endif
 cppcheck: $(SRCS) $(HEADERS)
+	if cppcheck --check-level=exhaustive /dev/null > /dev/null 2>&1; then \
+		CPPCHECK_EXHAUSTIVE="--check-level=exhaustive";		\
+	else								\
+		CPPCHECK_EXHAUSTIVE=;					\
+	fi;								\
 	cppcheck --std=c11 --error-exitcode=1 --enable=all --force	\
 	--inconclusive --library=posix --quiet				\
-	$(CPPCHECK_EXHAUSTIVE)						\
+	$${CPPCHECK_EXHAUSTIVE}						\
 	$(SYSTEM_INCLUDES:%=-I%)					\
 	$(SYSTEM_INCLUDES:%=--config-exclude=%)				\
 	$(SYSTEM_INCLUDES:%=--suppress=*:%/*)				\
-- 
@@ -287,20 +287,20 @@ 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 $$?),0)
-	CPPCHECK_EXHAUSTIVE += --check-level=exhaustive
-endif
-
 SYSTEM_INCLUDES := /usr/include $(wildcard /usr/include/$(TARGET))
 ifeq ($(shell $(CC) -v 2>&1 | grep -c "gcc version"),1)
 VER := $(shell $(CC) -dumpversion)
 SYSTEM_INCLUDES += /usr/lib/gcc/$(TARGET)/$(VER)/include
 endif
 cppcheck: $(SRCS) $(HEADERS)
+	if cppcheck --check-level=exhaustive /dev/null > /dev/null 2>&1; then \
+		CPPCHECK_EXHAUSTIVE="--check-level=exhaustive";		\
+	else								\
+		CPPCHECK_EXHAUSTIVE=;					\
+	fi;								\
 	cppcheck --std=c11 --error-exitcode=1 --enable=all --force	\
 	--inconclusive --library=posix --quiet				\
-	$(CPPCHECK_EXHAUSTIVE)						\
+	$${CPPCHECK_EXHAUSTIVE}						\
 	$(SYSTEM_INCLUDES:%=-I%)					\
 	$(SYSTEM_INCLUDES:%=--config-exclude=%)				\
 	$(SYSTEM_INCLUDES:%=--suppress=*:%/*)				\
-- 
2.39.2