Building BPF selftests with custom HOSTCFLAGS yields an error:
# make HOSTCFLAGS="-O2"
[...]
HOSTCC ./tools/testing/selftests/bpf/tools/build/resolve_btfids/main.o
main.c:73:10: fatal error: linux/rbtree.h: No such file or directory
73 | #include <linux/rbtree.h>
| ^~~~~~~~~~~~~~~~
The reason is that tools/bpf/resolve_btfids/Makefile passes header
include paths by extending HOSTCFLAGS which is overridden by setting
HOSTCFLAGS in the make command (because of Makefile rules [1]).
This patch fixes the above problem by passing the include paths via
`HOSTCFLAGS_resolve_btfids` which is used by tools/build/Build.include
and can be combined with overridding HOSTCFLAGS.
[1] https://www.gnu.org/software/make/manual/html_node/Overriding.html
Fixes: 56a2df7615fa ("tools/resolve_btfids: Compile resolve_btfids as host program")
Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx>
---
tools/bpf/resolve_btfids/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
index ac548a7baa73..4b8079f294f6 100644
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -67,7 +67,7 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OU
LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
-HOSTCFLAGS += -g \
+HOSTCFLAGS_resolve_btfids += -g \
-I$(srctree)/tools/include \
-I$(srctree)/tools/include/uapi \
-I$(LIBBPF_INCLUDE) \
@@ -76,7 +76,7 @@ HOSTCFLAGS += -g \
LIBS = $(LIBELF_LIBS) -lz
-export srctree OUTPUT HOSTCFLAGS Q HOSTCC HOSTLD HOSTAR
+export srctree OUTPUT HOSTCFLAGS_resolve_btfids Q HOSTCC HOSTLD HOSTAR
include $(srctree)/tools/build/Makefile.include
$(BINARY_IN): fixdep FORCE prepare | $(OUTPUT)
--
2.40.1
