bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS

Prepare for future changes where EXTRA_CFLAGS may include flags not
applicable to the host compiler.

Move the HOST_CFLAGS assignment before appending EXTRA_CFLAGS to
CFLAGS so that HOST_CFLAGS does not inherit flags from EXTRA_CFLAGS.

Acked-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Link: https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-2-c76e5250ea1c@arm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index c070111df22d198c8b631179f907fb5aba3bea32..49bae0359144f7fd736c3040da682bc38d9ff1d1 100644 (file)
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -82,6 +82,12 @@ CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
 ifneq ($(BPFTOOL_VERSION),)
 CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"'
 endif
+
+# This must be done before appending EXTRA_CFLAGS to CFLAGS to avoid
+# including flags that are not applicable to the host compiler.
+HOST_CFLAGS := $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),\
+               $(subst $(CLANG_CROSS_FLAGS),,$(CFLAGS)))
+
 ifneq ($(EXTRA_CFLAGS),)
 CFLAGS += $(EXTRA_CFLAGS)
 endif
@@ -89,8 +95,6 @@ ifneq ($(EXTRA_LDFLAGS),)
 LDFLAGS += $(EXTRA_LDFLAGS)
 endif
 
-HOST_CFLAGS := $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),\
-               $(subst $(CLANG_CROSS_FLAGS),,$(CFLAGS)))
 HOST_LDFLAGS := $(LDFLAGS)
 
 # Remove warnings for libbpf bootstrap build