[PATCH v2 1/4] tests: fixup domid make fragment

[dmukhin@xxxxxxx]

From: Denis Mukhin <dmukhin@xxxxxxxx> 

There can be multiple test harnesses per one test target (e.g. harness.h
and harness2.h). Account for that by further parametrizing existing
emit-harness-nested-rule().

Add guard against HOSTCC != CC (similarly to how its done in PDX unit test).

Account for multiple test targets in install and uninstall make targets.

Introduce CFLAGS dedicated for find-next-bit.c only to avoid contaminating
global CFLAGS.

Honor mocked hypervisor header over tools/include/xen symlinks.

Finally, add some clarifications for the functions.

Amends: 2d5065060710 ("xen/domain: unify domain ID allocation")
Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
---
Changes since v1:
- updated commentaries
- added ability to select the harness header filename
- fixup for picking up mocked header files
---
 tools/tests/domid/Makefile | 63 ++++++++++++++++++++++++++------------
 1 file changed, 44 insertions(+), 19 deletions(-)

diff --git a/tools/tests/domid/Makefile b/tools/tests/domid/Makefile
index 753129029ed9..dd22a25b038a 100644
--- a/tools/tests/domid/Makefile
+++ b/tools/tests/domid/Makefile
@@ -4,36 +4,55 @@
 #
 # Copyright 2025 Ford Motor Company
 
-XEN_ROOT=$(CURDIR)/../../..
-include $(XEN_ROOT)/tools/Rules.mk
-
 TESTS := test-domid
 
+XEN_ROOT = $(CURDIR)/../../..
+include $(XEN_ROOT)/tools/Rules.mk
+
 define list-c-headers
 $(shell sed -n \
     's/^[ \t]*# *include[ \t]*[<"]\([^">]*\)[">].*/\1/p' $(1) 2>/dev/null)
 endef
 
-# NB: $1 cannot be a list
+# Generate mock environment by replicating header file hierarchy;
+# each header file will point to a harness header.
+#
+# $1 target
+# $2 list of test harnesses
 define emit-harness-nested-rule
-$(1): $(CURDIR)/harness.h
-       mkdir -p $$(@D);
-       ln -sf $$< $$@;
+$(1): $(2)
+       set -e; \
+       mkdir -p $$(@D); \
+       for i in $(2); do [ -e $$@ ] || ln -s $$$$i $$@; done
 
 endef
 
+# Helper function to emit mocked hypervisor code dependencies.
+#
+# $1 Harness file name.
+# $2 Mocked hypervisor file name.
+# $3 List of dependencies to mock.
 define emit-harness-rules
-$(foreach x,$(2),$(call emit-harness-nested-rule,$(CURDIR)/generated/$(x)))
-$(1:.c=.o): $(addprefix $(CURDIR)/generated/,$(2))
+$(foreach x,$(3),$(call emit-harness-nested-rule,\
+                        $(CURDIR)/generated/$(x),\
+                        $(addprefix $(CURDIR)/,$(1))))
+$(2:.c=.o): $(addprefix $(CURDIR)/generated/,$(3))
 endef
 
 define emit-harness-deps
-$(if $(strip $(2)),$(call emit-harness-rules,$1,$2),)
+$(if $(strip $(3)),$(call emit-harness-rules,$1,$2,$3),)
 endef
 
+# Emit dependencies for mocked hypervisor code.
+#
+# $1 Hypervisor file name.
+# $2 Hypervisor source path.
+# $3 Harness header file name (optional).
 define vpath-with-harness-deps
 vpath $(1) $(2)
-$(call emit-harness-deps,$(1),$(call list-c-headers,$(2)$(1)))
+$(call emit-harness-deps,$(or $(strip $(3)),harness.h),\
+                         $(1),\
+                         $(call list-c-headers,$(2)$(1)))
 endef
 
 .PHONY: all
@@ -41,7 +60,11 @@ all: $(TESTS)
 
 .PHONY: run
 run: $(TESTS)
+ifeq ($(CC),$(HOSTCC))
        set -e; $(foreach t,$(TESTS),./$(t);)
+else
+       $(warning HOSTCC != CC, will not run test)
+endif
 
 .PHONY: clean
 clean:
@@ -55,25 +78,27 @@ distclean: clean
 .PHONY: install
 install: all
        $(INSTALL_DIR) $(DESTDIR)$(LIBEXEC)/tests
-       $(INSTALL_PROG) test-domid $(DESTDIR)$(LIBEXEC)/tests
+       set -e; $(foreach t,$(TESTS),$(INSTALL_PROG) $t 
$(DESTDIR)$(LIBEXEC)/tests;)
 
 .PHONY: uninstall
 uninstall:
-       $(RM) -- $(DESTDIR)$(LIBEXEC)/tests/test-domid
+       set -e; $(foreach t,$(TESTS),$(RM) -- $(DESTDIR)$(LIBEXEC)/tests/$t;)
 
 CFLAGS += -D__XEN_TOOLS__
+
 # find-next-bit.c
-CFLAGS += '-DEXPORT_SYMBOL(x)=' \
+CFLAGS-find-next-bit.c += '-DEXPORT_SYMBOL(x)=' \
           -Dfind_first_bit \
           -Dfind_first_zero_bit \
           -Dfind_next_bit \
           -Dfind_next_bit_le \
           -Dfind_next_zero_bit_le
-CFLAGS += $(APPEND_CFLAGS)
-CFLAGS += $(CFLAGS_xeninclude)
-CFLAGS += -I./generated/
 
-LDFLAGS += $(APPEND_LDFLAGS)
+find-next-bit.o: CFLAGS += $(CFLAGS-find-next-bit.c)
+
+# Honor mocked hypervisor header over tools/include/xen symlinks
+CFLAGS += -I$(CURDIR)/generated/
+CFLAGS += $(CFLAGS_xeninclude)
 
 vpath find-next-bit.c $(XEN_ROOT)/xen/lib/
 
@@ -83,6 +108,6 @@ vpath find-next-bit.c $(XEN_ROOT)/xen/lib/
 $(eval $(call vpath-with-harness-deps,domid.c,$(XEN_ROOT)/xen/common/))
 
 test-domid: domid.o find-next-bit.o test-domid.o
-       $(CC) $^ -o $@ $(LDFLAGS)
+       $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
 
 -include $(DEPS_INCLUDE)
-- 
2.52.0