Message ID | 20190910103830.20794-11-ivan.khoronzhuk@linaro.org |
---|---|
State | Changes Requested |
Delegated to: | BPF Maintainers |
Headers | show |
Series | samples: bpf: improve/fix cross-compilation | expand |
On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote: > 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@linaro.org> > --- > samples/bpf/Makefile | 8 +++++++- > tools/lib/bpf/Makefile | 11 ++++++++--- > 2 files changed, 15 insertions(+), 4 deletions(-) Could you separate this patch into two? One of libbpf and another for samples. The subject 'libbpf: ...' is not entirely accurate. > > 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)|" \ >
On Fri, Sep 13, 2019 at 09:43:22PM +0000, Yonghong Song wrote: > > >On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote: >> 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@linaro.org> >> --- >> samples/bpf/Makefile | 8 +++++++- >> tools/lib/bpf/Makefile | 11 ++++++++--- >> 2 files changed, 15 insertions(+), 4 deletions(-) > >Could you separate this patch into two? >One of libbpf and another for samples. > >The subject 'libbpf: ...' is not entirely accurate. Yes, ofc. But there is too many patches already, but better a lot of small changes then couple huge. > >> >> 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)|" \ >>
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)|" \
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@linaro.org> --- samples/bpf/Makefile | 8 +++++++- tools/lib/bpf/Makefile | 11 ++++++++--- 2 files changed, 15 insertions(+), 4 deletions(-)