[PATCH 10/14] KVM: selftests: Include lib.mk before consuming $(CC)

Sean Christopherson
2022-12-13T00:17:14Z

Include lib.mk before consuming $(CC) and document that lib.mk overwrites
$(CC) unless make was invoked with -e or $(CC) was specified after make
(which apparently makes the environment override the Makefile?!?!).
Including lib.mk after using it for probing, e.g. for -no-pie, can lead
to weirdness.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
tools/testing/selftests/kvm/Makefile | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 6594ed51eeea..2487db21b177 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -182,6 +182,11 @@ TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(ARCH_DIR))
TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(ARCH_DIR))
LIBKVM += $(LIBKVM_$(ARCH_DIR))

+# lib.mak defines $(OUTPUT), prepends $(OUTPUT)/ to $(TEST_GEN_PROGS), and most
+# importantly defines, i.e. overwrites, $(CC) (unless `make -e` or `make CC=`,
+# which causes the environment variable to override the makefile).
+include ../lib.mk
+
INSTALL_HDR_PATH = $(top_srcdir)/usr
LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
@@ -207,10 +212,6 @@ pgste-option = $(call try-run, echo 'int main(void) { return 0; }' | \
LDLIBS += -ldl
LDFLAGS += -pthread $(no-pie-option) $(pgste-option)

-# After inclusion, $(OUTPUT) is defined and
-# $(TEST_GEN_PROGS) starts with $(OUTPUT)/
-include ../lib.mk
-
LIBKVM_C := $(filter %.c,$(LIBKVM))
LIBKVM_S := $(filter %.S,$(LIBKVM))
LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C))
--
2.39.0.rc1.256.g54fd8350bd-goog