An error "implicit declaration of function 'reallocarray'" can be thrown with the following steps: $ cd tools/testing/selftests/bpf $ make clean && make CC=<Path to GCC 4.8.5> $ make clean && make CC=<Path to GCC 7.x> The cause is that the feature folder generated by GCC 4.8.5 is not removed, leaving feature-reallocarray being 1, which causes reallocarray not defined when re-compliing with GCC 7.x. This diff adds feature folder to EXTRA_CLEAN to avoid this problem. v2: Rephrase the commit message. Signed-off-by: Hechao Li <hechaol@xxxxxx> Acked-by: Andrii Nakryiko <andriin@xxxxxx> --- tools/testing/selftests/bpf/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 2b426ae1cdc9..44fb61f4d502 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -279,4 +279,5 @@ $(OUTPUT)/verifier/tests.h: $(VERIFIER_TESTS_DIR) $(VERIFIER_TEST_FILES) ) > $(VERIFIER_TESTS_H)) EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(ALU32_BUILD_DIR) \ - $(VERIFIER_TESTS_H) $(PROG_TESTS_H) $(MAP_TESTS_H) + $(VERIFIER_TESTS_H) $(PROG_TESTS_H) $(MAP_TESTS_H) \ + feature -- 2.17.1
