make cppcheck takes a long time, because it checks a large number of
different configurations.  It's assembling this very large set of
configurations not because of conditionals in the passt code itself, but
from those in the system headers.  By adding --config-exclude directives
to stop considering those configs, make cppcheck because around 60x faster.

Similarly, any problems that are found in the system headers are not our
problem, and so we can uniformly suppress them, rather than having specific
suppressions for particular problems in particular files (which might not
be correct for all different distro / version combinations either).

Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
 Makefile | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/Makefile b/Makefile
index 0598865..b6c68bd 100644
--- a/Makefile
+++ b/Makefile
@@ -268,27 +268,19 @@ clang-tidy: $(SRCS) $(HEADERS)
 	-config='{CheckOptions: [{key: bugprone-suspicious-string-compare.WarnOnImplicitComparison, value: "false"}]}' \
 	--warnings-as-errors=* $(SRCS) -- $(filter-out -pie,$(FLAGS) $(CFLAGS))
 
+SYSTEM_INCLUDES := /usr/include
 ifeq ($(shell $(CC) -v 2>&1 | grep -c "gcc version"),1)
 TARGET := $(shell ${CC} -v 2>&1 | sed -n 's/Target: \(.*\)/\1/p')
 VER := $(shell $(CC) -dumpversion)
-EXTRA_INCLUDES := /usr/lib/gcc/$(TARGET)/$(VER)/include
-EXTRA_INCLUDES_OPT := -I$(EXTRA_INCLUDES)
-else
-EXTRA_INCLUDES_OPT :=
+SYSTEM_INCLUDES += /usr/lib/gcc/$(TARGET)/$(VER)/include
 endif
 cppcheck: $(SRCS) $(HEADERS)
 	cppcheck --std=c99 --error-exitcode=1 --enable=all --force	\
 	--inconclusive --library=posix					\
-	-I/usr/include $(EXTRA_INCLUDES_OPT)				\
-									\
-	--suppress=syntaxError:/usr/include/stdlib.h			\
-	--suppress=missingIncludeSystem					\
-	--suppress="*:$(EXTRA_INCLUDES)/avx512fintrin.h"		\
-	--suppress="*:$(EXTRA_INCLUDES)/xmmintrin.h"			\
-	--suppress="*:$(EXTRA_INCLUDES)/emmintrin.h"			\
-	--suppress="*:$(EXTRA_INCLUDES)/avxintrin.h"			\
-	--suppress="*:$(EXTRA_INCLUDES)/bmiintrin.h"			\
-									\
+	$(SYSTEM_INCLUDES:%=-I%)					\
+	$(SYSTEM_INCLUDES:%=--config-exclude=%)				\
+	$(SYSTEM_INCLUDES:%=--suppress=*:%/*)				\
+	$(SYSTEM_INCLUDES:%=--suppress=unmatchedSuppression:%/*)	\
 	--suppress=objectIndex:tcp.c --suppress=objectIndex:udp.c	\
 	--suppress=va_list_usedBeforeStarted:util.c			\
 	--suppress=unusedFunction					\
-- 
2.37.3