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.khoronz...@linaro.org>
---
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
