When directories are used as prerequisites in Makefiles, they can cause a lot of unnecessary rebuilds, because a directory is considered changed whenever a file in this directory is added, removed or modified. If the only thing a target is interested in is the existence of the directory it depends on, which is the case for selftests/bpf, this directory should be specified as an order-only prerequisite: it would still be created in case it does not exist, but it would not trigger a rebuild of a target in case it's considered changed. Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> --- tools/testing/selftests/bpf/Makefile | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 277d8605e340..0e003fb6641b 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -183,12 +183,12 @@ TEST_CUSTOM_PROGS += $(ALU32_BUILD_DIR)/test_progs_32 $(ALU32_BUILD_DIR): mkdir -p $@ -$(ALU32_BUILD_DIR)/urandom_read: $(OUTPUT)/urandom_read +$(ALU32_BUILD_DIR)/urandom_read: $(OUTPUT)/urandom_read | $(ALU32_BUILD_DIR) cp $< $@ $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c $(OUTPUT)/libbpf.a\ - $(ALU32_BUILD_DIR) \ - $(ALU32_BUILD_DIR)/urandom_read + $(ALU32_BUILD_DIR)/urandom_read \ + | $(ALU32_BUILD_DIR) $(CC) $(TEST_PROGS_CFLAGS) $(CFLAGS) \ -o $(ALU32_BUILD_DIR)/test_progs_32 \ test_progs.c test_stub.c trace_helpers.c prog_tests/*.c \ @@ -197,8 +197,8 @@ $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c $(OUTPUT)/libbpf.a\ $(ALU32_BUILD_DIR)/test_progs_32: $(PROG_TESTS_H) $(ALU32_BUILD_DIR)/test_progs_32: prog_tests/*.c -$(ALU32_BUILD_DIR)/%.o: progs/%.c $(ALU32_BUILD_DIR) \ - $(ALU32_BUILD_DIR)/test_progs_32 +$(ALU32_BUILD_DIR)/%.o: progs/%.c $(ALU32_BUILD_DIR)/test_progs_32 \ + | $(ALU32_BUILD_DIR) ($(CLANG) $(CLANG_FLAGS) -O2 -target bpf -emit-llvm -c $< -o - || \ echo "clang failed") | \ $(LLC) -march=bpf -mattr=+alu32 -mcpu=$(CPU) $(LLC_FLAGS) \ @@ -236,7 +236,7 @@ $(PROG_TESTS_DIR): mkdir -p $@ PROG_TESTS_FILES := $(wildcard prog_tests/*.c) -$(PROG_TESTS_H): $(PROG_TESTS_DIR) $(PROG_TESTS_FILES) +$(PROG_TESTS_H): $(PROG_TESTS_FILES) | $(PROG_TESTS_DIR) $(shell ( cd prog_tests/; \ echo '/* Generated header, do not edit */'; \ echo '#ifdef DECLARE'; \ @@ -257,7 +257,7 @@ MAP_TESTS_H := $(MAP_TESTS_DIR)/tests.h test_maps.c: $(MAP_TESTS_H) $(OUTPUT)/test_maps: CFLAGS += $(TEST_MAPS_CFLAGS) MAP_TESTS_FILES := $(wildcard map_tests/*.c) -$(MAP_TESTS_H): $(MAP_TESTS_DIR) $(MAP_TESTS_FILES) +$(MAP_TESTS_H): $(MAP_TESTS_FILES) | $(MAP_TESTS_DIR) $(shell ( cd map_tests/; \ echo '/* Generated header, do not edit */'; \ echo '#ifdef DECLARE'; \ @@ -279,7 +279,7 @@ $(VERIFIER_TESTS_DIR): mkdir -p $@ VERIFIER_TEST_FILES := $(wildcard verifier/*.c) -$(OUTPUT)/verifier/tests.h: $(VERIFIER_TESTS_DIR) $(VERIFIER_TEST_FILES) +$(OUTPUT)/verifier/tests.h: $(VERIFIER_TEST_FILES) | $(VERIFIER_TESTS_DIR) $(shell ( cd verifier/; \ echo '/* Generated header, do not edit */'; \ echo '#ifdef FILL_ARRAY'; \ -- 2.21.0
