[PATCH v5 bpf-next 11/15] libbpf: don't use cxx to test_libpf target

Ivan Khoronzhuk
2019-10-11T00:29:03Z

No need to use C++ for test_libbpf target when libbpf is on C and it
can be tested with C, after this change the CXXFLAGS in makefiles can
be avoided, at least in bpf samples, when sysroot is used, passing
same C/LDFLAGS as for lib.

Add "return 0" in test_libbpf to avoid warn, but also remove spaces at
start of the lines to keep same style and avoid warns while apply.

Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
tools/lib/bpf/Makefile | 18 +++++-------------
.../lib/bpf/{test_libbpf.cpp => test_libbpf.c} | 14 ++++++++------
2 files changed, 13 insertions(+), 19 deletions(-)
rename tools/lib/bpf/{test_libbpf.cpp => test_libbpf.c} (61%)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 1270955e4845..46280b5ad48d 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -52,7 +52,7 @@ ifndef VERBOSE
endif

FEATURE_USER = .libbpf
-FEATURE_TESTS = libelf libelf-mmap bpf reallocarray cxx
+FEATURE_TESTS = libelf libelf-mmap bpf reallocarray
FEATURE_DISPLAY = libelf bpf

INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi
@@ -142,15 +142,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \
VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)

-CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
-
-CXX_TEST_TARGET = $(OUTPUT)test_libbpf
-
-ifeq ($(feature-cxx), 1)
- CMD_TARGETS += $(CXX_TEST_TARGET)
-endif
-
-TARGETS = $(CMD_TARGETS)
+CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) $(OUTPUT)test_libbpf

all: fixdep
$(Q)$(MAKE) all_cmd
@@ -190,8 +182,8 @@ $(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN)
$(OUTPUT)libbpf.a: $(BPF_IN)
$(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^

-$(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
- $(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
+$(OUTPUT)test_libbpf: test_libbpf.c $(OUTPUT)libbpf.a
+ $(QUIET_LINK)$(CC) $(INCLUDES) $^ -lelf -o $@

$(OUTPUT)libbpf.pc:
$(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|" \
@@ -266,7 +258,7 @@ config-clean:
$(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null

clean:
- $(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \
+ $(call QUIET_CLEAN, libbpf) $(RM) $(CMD_TARGETS) \
*.o *~ *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) .*.d .*.cmd \
*.pc LIBBPF-CFLAGS bpf_helper_defs.h
$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
diff --git a/tools/lib/bpf/test_libbpf.cpp b/tools/lib/bpf/test_libbpf.c
similarity index 61%
rename from tools/lib/bpf/test_libbpf.cpp
rename to tools/lib/bpf/test_libbpf.c
index fc134873bb6d..f0eb2727b766 100644
--- a/tools/lib/bpf/test_libbpf.cpp
+++ b/tools/lib/bpf/test_libbpf.c
@@ -7,12 +7,14 @@

int main(int argc, char *argv[])
{
- /* libbpf.h */
- libbpf_set_print(NULL);
+ /* libbpf.h */
+ libbpf_set_print(NULL);

- /* bpf.h */
- bpf_prog_get_fd_by_id(0);
+ /* bpf.h */
+ bpf_prog_get_fd_by_id(0);

- /* btf.h */
- btf__new(NULL, 0);
+ /* btf.h */
+ btf__new(NULL, 0);
+
+ return 0;
}
--
2.17.1