In case of LDFLAGS and EXTRA_CC/CXX flags there is no way to pass them correctly to build command, for instance when --sysroot is used or external libraries are used, like -lelf, wich can be absent in toolchain. This is used for samples/bpf cross-compiling allowing to get elf lib from sysroot. Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> --- samples/bpf/Makefile | 8 +++++++- tools/lib/bpf/Makefile | 11 ++++++++--- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 79c9aa41832e..4edc5232cfc1 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -186,6 +186,10 @@ ccflags-y += -I$(srctree)/tools/perf ccflags-y += $(D_OPTIONS) ccflags-y += -Wall ccflags-y += -fomit-frame-pointer + +EXTRA_CXXFLAGS := $(ccflags-y) + +# options not valid for C++ ccflags-y += -Wmissing-prototypes ccflags-y += -Wstrict-prototypes @@ -252,7 +256,9 @@ clean: $(LIBBPF): FORCE # Fix up variables inherited from Kbuild that tools/ build system won't like - $(MAKE) -C $(dir $@) RM='rm -rf' LDFLAGS= srctree=$(BPF_SAMPLES_PATH)/../../ O= + $(MAKE) -C $(dir $@) RM='rm -rf' EXTRA_CFLAGS="$(PROGS_CFLAGS)" \ + EXTRA_CXXFLAGS="$(EXTRA_CXXFLAGS)" LDFLAGS=$(PROGS_LDFLAGS) \ + srctree=$(BPF_SAMPLES_PATH)/../../ O= $(obj)/syscall_nrs.h: $(obj)/syscall_nrs.s FORCE $(call filechk,offsets,__SYSCALL_NRS_H__) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index c6f94cffe06e..bccfa556ef4e 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -94,6 +94,10 @@ else CFLAGS := -g -Wall endif +ifdef EXTRA_CXXFLAGS + CXXFLAGS := $(EXTRA_CXXFLAGS) +endif + ifeq ($(feature-libelf-mmap), 1) override CFLAGS += -DHAVE_LIBELF_MMAP_SUPPORT endif @@ -176,8 +180,9 @@ $(BPF_IN): force elfdep bpfdep $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION) $(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN) - $(QUIET_LINK)$(CC) --shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \ - -Wl,--version-script=$(VERSION_SCRIPT) $^ -lelf -o $@ + $(QUIET_LINK)$(CC) $(LDFLAGS) \ + --shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \ + -Wl,--version-script=$(VERSION_SCRIPT) $^ -lelf -o $@ @ln -sf $(@F) $(OUTPUT)libbpf.so @ln -sf $(@F) $(OUTPUT)libbpf.so.$(LIBBPF_MAJOR_VERSION) @@ -185,7 +190,7 @@ $(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 $@ + $(QUIET_LINK)$(CXX) $(CXXFLAGS) $(LDFLAGS) $(INCLUDES) $^ -lelf -o $@ $(OUTPUT)libbpf.pc: $(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|" \ -- 2.17.1
