As per a discussion with Muhammad Usama Anjum [1], the following is how
one is supposed to build selftests:
make headers && make -C tools/testing/selftests/mm
Change the selftest build system's lib.mk to fail out with a helpful
message if that prerequisite "make headers" has not been done yet.
[1] https://lore.kernel.org/all/bf910fa5-0c96-3707-cce4-5bcc656b6274@xxxxxxxxxxxxx/
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
tools/testing/selftests/lib.mk | 36 +++++++++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 05400462c779..b8ea03b9a015 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -44,10 +44,22 @@ endif
selfdir = $(realpath $(dir $(filter %/lib.mk,$(MAKEFILE_LIST))))
top_srcdir = $(selfdir)/../../..
-ifeq ($(KHDR_INCLUDES),)
-KHDR_INCLUDES := -isystem $(top_srcdir)/usr/include
+ifneq ($(KBUILD_OUTPUT),)
+ # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
+ # expand a shell special character '~'. We use a somewhat tedious way here.
+ abs_objtree := $(shell cd $(top_srcdir) && mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
+ $(if $(abs_objtree),, \
+ $(error failed to create output directory "$(KBUILD_OUTPUT)"))
+ # $(realpath ...) resolves symlinks
+ abs_objtree := $(realpath $(abs_objtree))
+ KHDR_DIR := ${abs_objtree}/usr/include
+else
+ abs_srctree := $(shell cd $(top_srcdir) && pwd)
+ KHDR_DIR := ${abs_srctree}/usr/include
endif
+KHDR_INCLUDES := -isystem $(KHDR_DIR)
+
# The following are built by lib.mk common compile rules.
# TEST_CUSTOM_PROGS should be used by tests that require
# custom build rule and prevent common build rule use.
@@ -58,7 +70,25 @@ TEST_GEN_PROGS := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS))
TEST_GEN_PROGS_EXTENDED := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS_EXTENDED))
TEST_GEN_FILES := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_FILES))
-all: $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES)
+all: kernel_header_files $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) \
+ $(TEST_GEN_FILES)
+
+kernel_header_files:
+ @ls $(KHDR_DIR)/linux/*.h >/dev/null 2>/dev/null; \
+ if [ $$? -ne 0 ]; then \
+ RED='\033[1;31m'; \
+ NOCOLOR='\033[0m'; \
+ echo; \
+ echo -e "$${RED}error$${NOCOLOR}: missing kernel header files."; \
+ echo "Please run this and try again:"; \
+ echo; \
+ echo " cd $(top_srcdir)"; \
+ echo " make headers"; \
+ echo; \
+ exit 1; \
+ fi
+
+.PHONY: kernel_header_files
define RUN_TESTS
BASE_DIR="$(selfdir)"; \
--
2.40.1
