[PATCH bpf-next] perf build: Install libbpf headers locally when building

Quentin Monnet
2021-11-05T02:02:53Z

API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's adjust perf's Makefile to install those headers
locally when building libbpf.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
---
Note: Sending to bpf-next because it's directly related to libbpf, and
to similar patches merged through bpf-next, but maybe Arnaldo prefers to
take it?
---
tools/perf/Makefile.perf | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index b856afa6eb52..3a81b6c712a9 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -241,7 +241,7 @@ else # force_fixdep

LIB_DIR = $(srctree)/tools/lib/api/
TRACE_EVENT_DIR = $(srctree)/tools/lib/traceevent/
-BPF_DIR = $(srctree)/tools/lib/bpf/
+LIBBPF_DIR = $(srctree)/tools/lib/bpf/
SUBCMD_DIR = $(srctree)/tools/lib/subcmd/
LIBPERF_DIR = $(srctree)/tools/lib/perf/
DOC_DIR = $(srctree)/tools/perf/Documentation/
@@ -293,7 +293,6 @@ strip-libs = $(filter-out -l%,$(1))
ifneq ($(OUTPUT),)
TE_PATH=$(OUTPUT)
PLUGINS_PATH=$(OUTPUT)
- BPF_PATH=$(OUTPUT)
SUBCMD_PATH=$(OUTPUT)
LIBPERF_PATH=$(OUTPUT)
ifneq ($(subdir),)
@@ -305,7 +304,6 @@ else
TE_PATH=$(TRACE_EVENT_DIR)
PLUGINS_PATH=$(TRACE_EVENT_DIR)plugins/
API_PATH=$(LIB_DIR)
- BPF_PATH=$(BPF_DIR)
SUBCMD_PATH=$(SUBCMD_DIR)
LIBPERF_PATH=$(LIBPERF_DIR)
endif
@@ -324,7 +322,10 @@ LIBTRACEEVENT_DYNAMIC_LIST_LDFLAGS = $(if $(findstring -static,$(LDFLAGS)),,$(DY
LIBAPI = $(API_PATH)libapi.a
export LIBAPI

-LIBBPF = $(BPF_PATH)libbpf.a
+LIBBPF_OUTPUT = $(OUTPUT)libbpf
+LIBBPF_DESTDIR = $(LIBBPF_OUTPUT)
+LIBBPF_INCLUDE = $(LIBBPF_DESTDIR)/include
+LIBBPF = $(LIBBPF_OUTPUT)/libbpf.a

LIBSUBCMD = $(SUBCMD_PATH)libsubcmd.a

@@ -829,12 +830,14 @@ $(LIBAPI)-clean:
$(call QUIET_CLEAN, libapi)
$(Q)$(MAKE) -C $(LIB_DIR) O=$(OUTPUT) clean >/dev/null

-$(LIBBPF): FORCE
- $(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(FEATURE_DUMP_EXPORT)
+$(LIBBPF): FORCE | $(LIBBPF_OUTPUT)
+ $(Q)$(MAKE) -C $(LIBBPF_DIR) FEATURES_DUMP=$(FEATURE_DUMP_EXPORT) \
+ O= OUTPUT=$(LIBBPF_OUTPUT)/ DESTDIR=$(LIBBPF_DESTDIR) prefix= \
+ $@ install_headers

$(LIBBPF)-clean:
$(call QUIET_CLEAN, libbpf)
- $(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) clean >/dev/null
+ $(Q)$(RM) -r -- $(LIBBPF_OUTPUT)

$(LIBPERF): FORCE
$(Q)$(MAKE) -C $(LIBPERF_DIR) EXTRA_CFLAGS="$(LIBPERF_CFLAGS)" O=$(OUTPUT) $(OUTPUT)libperf.a
@@ -1036,14 +1039,13 @@ SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h

ifdef BUILD_BPF_SKEL
BPFTOOL := $(SKEL_TMP_OUT)/bootstrap/bpftool
-LIBBPF_SRC := $(abspath ../lib/bpf)
-BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(BPF_PATH) -I$(LIBBPF_SRC)/..
+BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(LIBBPF_INCLUDE)

-$(SKEL_TMP_OUT):
+$(SKEL_TMP_OUT) $(LIBBPF_OUTPUT):
$(Q)$(MKDIR) -p $@

$(BPFTOOL): | $(SKEL_TMP_OUT)
- CFLAGS= $(MAKE) -C ../bpf/bpftool \
+ $(Q)CFLAGS= $(MAKE) -C ../bpf/bpftool \
OUTPUT=$(SKEL_TMP_OUT)/ bootstrap

VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
--
2.32.0