Re: [PATCH bpf-next v4 09/10] selftests: Remove tools/lib/bpf from include path

On Fri, Jan 17, 2020 at 5:43 AM Toke Høiland-Jørgensen toke@redhat.com wrote:

From: Toke Høiland-Jørgensen toke@redhat.com

To make sure no new files are introduced that doesn't include the bpf/ prefix in its #include, remove tools/lib/bpf from the include path entirely.

Instead, we introduce a new header files directory under the scratch tools/ dir, and add a rule to run the 'install_headers' rule from libbpf to have a full set of consistent libbpf headers in $(OUTPUT)/tools/include/bpf, and then use $(OUTPUT)/tools/include as the include path for selftests.

For consistency we also make sure we put all the scratch build files from other bpftool and libbpf into tools/build/, so everything stays within selftests/.

Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com

tools/testing/selftests/bpf/.gitignore | 2 + tools/testing/selftests/bpf/Makefile | 49 +++++++++++++++++++++----------- 2 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index 1d14e3ab70be..8c9eac626996 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -39,4 +39,4 @@ test_cpp /no_alu32 /bpf_gcc /tools -bpf_helper_defs.h

can you please also drop libbpf.pc and libbpf.so.* rules from .gitignore?

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 858d4e3369ad..ac0292a82fdc 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -20,8 +20,8 @@ CLANG ?= clang LLC ?= llc LLVM_OBJCOPY ?= llvm-objcopy BPF_GCC ?= $(shell command -v bpf-gcc;) -CFLAGS += -g -Wall -O2 $(GENFLAGS) -I$(CURDIR) -I$(APIDIR) -I$(LIBDIR) \

•     -I$(BPFDIR) -I$(GENDIR) -I$(TOOLSINCDIR)                      \
  

+CFLAGS += -g -Wall -O2 $(GENFLAGS) -I$(CURDIR) -I$(APIDIR) \

extra space here

•     -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) -I$(TOOLSINCDIR)     \
      -Dbpf_prog_load=bpf_prog_test_load                            \
      -Dbpf_load_program=bpf_test_load_program
  

LDLIBS += -lcap -lelf -lz -lrt -lpthread @@ -97,11 +97,15 @@ OVERRIDE_TARGETS := 1 override define CLEAN $(call msg,CLEAN) $(RM) -r $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES) $(EXTRA_CLEAN)

•   $(MAKE) -C $(BPFDIR) OUTPUT=$(OUTPUT)/ clean
  

endef

include ../lib.mk

+SCRATCH_DIR := $(OUTPUT)/tools +BUILD_DIR := $(SCRATCH_DIR)/build +INCLUDE_DIR := $(SCRATCH_DIR)/include +INCLUDE_BPF := $(INCLUDE_DIR)/bpf

# Define simple and short `make test_progs`, `make test_sysctl`, etc targets # to build individual tests. # NOTE: Semicolon at the end is critical to override lib.mk's default static @@ -120,7 +124,7 @@ $(OUTPUT)/urandom_read: urandom_read.c $(call msg,BINARY,,$@) $(CC) -o $@ $< -Wl,--build-id

-$(OUTPUT)/test_stub.o: test_stub.c +$(OUTPUT)/test_stub.o: test_stub.c $(INCLUDE_BPF) $(call msg,CC,,$@) $(CC) -c $(CFLAGS) -o $@ $<

@@ -133,7 +137,7 @@ $(OUTPUT)/runqslower: force $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ OUTPUT=$(OUTPUT)/tools/ VMLINUX_BTF=$(VMLINUX_BTF)

-BPFOBJ := $(OUTPUT)/libbpf.a +BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a

$(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/test_stub.o $(BPFOBJ)

@@ -159,17 +163,28 @@ force: DEFAULT_BPFTOOL := $(OUTPUT)/tools/sbin/bpftool BPFTOOL ?= $(DEFAULT_BPFTOOL)

-$(DEFAULT_BPFTOOL): force

•   $(Q)$(MAKE) $(submake_extras)  -C $(BPFTOOLDIR)                       \
  

+$(BUILD_DIR)/libbpf $(BUILD_DIR)/bpftool $(INCLUDE_DIR):

•   $(call msg,MKDIR,,$@)
  

•   mkdir -p $@
  

+$(DEFAULT_BPFTOOL): force | $(BUILD_DIR)/bpftool

•   $(Q)$(MAKE) $(submake_extras)  -C $(BPFTOOLDIR)         \
  

slash alignment

•               OUTPUT=$(BUILD_DIR)/bpftool/                        \
                prefix= DESTDIR=$(OUTPUT)/tools/ install
  
  

-$(BPFOBJ): force

•   $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(OUTPUT)/
  

+$(BPFOBJ): force | $(BUILD_DIR)/libbpf

•   $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) \
  

•           OUTPUT=$(BUILD_DIR)/libbpf/
  

+$(INCLUDE_BPF): $(BPFOBJ) | $(INCLUDE_DIR)

•   $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) install_headers \
  

•           OUTPUT=$(BUILD_DIR)/libbpf/ DESTDIR=$(SCRATCH_DIR) prefix=
  

+BPF_HELPERS := $(or $(wildcard $(INCLUDE_BPF)/bpf_*.h),$(INCLUDE_BPF)) +ifneq ($(BPF_HELPERS),$(INCLUDE_BPF)) +$(BPF_HELPERS): $(INCLUDE_BPF) +endif

-BPF_HELPERS := $(OUTPUT)/bpf_helper_defs.h $(wildcard $(BPFDIR)/bpf_*.h) -$(OUTPUT)/bpf_helper_defs.h: $(BPFOBJ)

•   $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR)                            \
  

•               OUTPUT=$(OUTPUT)/ $(OUTPUT)/bpf_helper_defs.h
  
  

I really-really didn't like this alternating dependency on directory or a set of file, depending on current state of those temporary directories. Then also this ugly check to avoid circular dependency. All that seemed wrong. So I played a bit with how to achieve the same differently, and here's what I came up with, which I like a bit better. What do you think?

$(BPFOBJ): $(wildcard $(BPFDIR)/*.c $(BPFDIR)/*.h $(BPFDIR)/Makefile) \ ../../../include/uapi/linux/bpf.h \ | $(INCLUDE_DIR) $(BUILD_DIR)/libbpf $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \ DESTDIR=$(SCRATCH_DIR) prefix= all install_headers

So, essentially, just make sure that we install local copies of headers whenever libbpf.a needs to be re-built. ../../../include/uapi/linux/bpf.h ensures we don't miss uapi header changes as well. Now anything that uses libbpf headers will need to depend on $(BPFOBJ) and will automatically get up-to-date local copies of headers.

This seems much simpler. Please give it a try, thanks!

# Get Clang's default includes on this system, as opposed to those seen by # '-target bpf'. This fixes "missing" files on some architectures/distros, @@ -189,8 +204,8 @@ MENDIAN=$(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian)

CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG)) BPF_CFLAGS = -g -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN) \

•        -I$(OUTPUT) -I$(CURDIR) -I$(CURDIR)/include/uapi           \
  

•        -I$(APIDIR) -I$(LIBDIR) -I$(BPFDIR) -I$(abspath $(OUTPUT)/../usr/include)
  

•        -I$(INCLUDE_DIR) -I$(CURDIR) -I$(CURDIR)/include/uapi      \
  

•        -I$(APIDIR) -I$(abspath $(OUTPUT)/../usr/include)
  
  

CLANG_CFLAGS = $(CLANG_SYS_INCLUDES) \ -Wno-compare-distinct-pointer-types @@ -392,7 +407,7 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ) $(call msg,CXX,,$@) $(CXX) $(CFLAGS) $^ $(LDLIBS) -o $@

-EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) \ +EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) \ prog_tests/tests.h map_tests/tests.h verifier/tests.h \ feature \

•   $(addprefix $(OUTPUT)/,*.o *.skel.h no_alu32 bpf_gcc tools)
  

•   $(addprefix $(OUTPUT)/,*.o *.skel.h no_alu32 bpf_gcc)