When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool.

While looking into the source code I found duplicate assignments in misc tools for the LLVM eco system, e.g. clang and llvm-objcopy.

Move the Clang, LLC and/or LLVM utils definitions to tools/scripts/Makefile.include file and add missing includes where needed. Honestly, I was inspired by commit c8a950d0d3b9 ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions").

I tested with bpftool and perf on Debian/testing AMD64 and LLVM/Clang v11.1.0-rc1.

Build instructions:

[ make and make-options ] MAKE="make V=1" MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1" MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"

[ clean-up ] $MAKE $MAKE_OPTS -C tools/ clean

[ bpftool ] $MAKE $MAKE_OPTS -C tools/bpf/bpftool/

[ perf ] PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/

I was careful with respecting the user's wish to override custom compiler, linker, GNU/binutils and/or LLVM utils settings.

Some personal notes: 1. I have NOT tested with cross-toolchain for other archs (cross compiler/linker etc.). 2. This patch is on top of Linux v5.11-rc4.

I hope to get some feedback from especially Linux-bpf folks.

Acked-by: Jiri Olsa jolsa@redhat.com # tools/build and tools/perf Signed-off-by: Sedat Dilek sedat.dilek@gmail.com --- Changelog RFC v1->v2: - Add Jiri's ACK - Adapt to fit Linux v5.11-rc4

tools/bpf/bpftool/Makefile | 2 -- tools/bpf/runqslower/Makefile | 3 --- tools/build/feature/Makefile | 4 ++-- tools/perf/Makefile.perf | 1 - tools/scripts/Makefile.include | 7 +++++++ tools/testing/selftests/bpf/Makefile | 3 +-- tools/testing/selftests/tc-testing/Makefile | 3 +-- 7 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index f897cb5fb12d..71c14efa6e91 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -75,8 +75,6 @@ endif

INSTALL ?= install RM ?= rm -f -CLANG ?= clang -LLVM_STRIP ?= llvm-strip

FEATURE_USER = .bpftool FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib libcap \ diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefile index 4d5ca54fcd4c..9d9fb6209be1 100644 --- a/tools/bpf/runqslower/Makefile +++ b/tools/bpf/runqslower/Makefile @@ -3,9 +3,6 @@ include ../../scripts/Makefile.include

OUTPUT ?= $(abspath .output)/

-CLANG ?= clang -LLC ?= llc -LLVM_STRIP ?= llvm-strip BPFTOOL_OUTPUT := $(OUTPUT)bpftool/ DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)bpftool BPFTOOL ?= $(DEFAULT_BPFTOOL) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 89ba522e377d..3e55edb3ea54 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -1,4 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +include ../../scripts/Makefile.include + FILES= \ test-all.bin \ test-backtrace.bin \ @@ -76,8 +78,6 @@ FILES= \ FILES := $(addprefix $(OUTPUT),$(FILES))

PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config -LLVM_CONFIG ?= llvm-config -CLANG ?= clang

all: $(FILES)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 62f3deb1d3a8..f4df7534026d 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -176,7 +176,6 @@ endef LD += $(EXTRA_LDFLAGS)

PKG_CONFIG = $(CROSS_COMPILE)pkg-config -LLVM_CONFIG ?= llvm-config

RM = rm -f LN = ln -f diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include index 1358e89cdf7d..4255e71f72b7 100644 --- a/tools/scripts/Makefile.include +++ b/tools/scripts/Makefile.include @@ -69,6 +69,13 @@ HOSTCC ?= gcc HOSTLD ?= ld endif

+# Some tools require Clang, LLC and/or LLVM utils +CLANG ?= clang +LLC ?= llc +LLVM_CONFIG ?= llvm-config +LLVM_OBJCOPY ?= llvm-objcopy +LLVM_STRIP ?= llvm-strip + ifeq ($(CC_NO_CLANG), 1) EXTRA_WARNINGS += -Wstrict-aliasing=3 endif diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index c51df6b91bef..952e2bc5f3bc 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 include ../../../../scripts/Kbuild.include include ../../../scripts/Makefile.arch +include ../../../scripts/Makefile.include

CXX ?= $(CROSS_COMPILE)g++

@@ -18,8 +19,6 @@ ifneq ($(wildcard $(GENHDR)),) GENFLAGS := -DHAVE_GENHDR endif

-CLANG ?= clang -LLVM_OBJCOPY ?= llvm-objcopy BPF_GCC ?= $(shell command -v bpf-gcc;) SAN_CFLAGS ?= CFLAGS += -g -rdynamic -Wall -O2 $(GENFLAGS) $(SAN_CFLAGS) \ diff --git a/tools/testing/selftests/tc-testing/Makefile b/tools/testing/selftests/tc-testing/Makefile index 91fee5c43274..4d639279f41e 100644 --- a/tools/testing/selftests/tc-testing/Makefile +++ b/tools/testing/selftests/tc-testing/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 +include ../../../scripts/Makefile.include

top_srcdir = $(abspath ../../../..) APIDIR := $(top_scrdir)/include/uapi @@ -7,8 +8,6 @@ TEST_GEN_FILES = action.o KSFT_KHDR_INSTALL := 1 include ../lib.mk

-CLANG ?= clang -LLC ?= llc PROBE := $(shell $(LLC) -march=bpf -mcpu=probe -filetype=null /dev/null 2>&1)

ifeq ($(PROBE),)