[XEN PATCH v9 06/30] build: rework test/livepatch/Makefile

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

This rework the livepatch/Makefile to make it less repetitive and make
use of the facilities. All the targets to be built are now listed in
$(extra-y) which will allow Rules.mk to build them without the need of
a local target in a future patch.

There are some changes/fixes in this patch:
- when "xen-syms" is used for a target, it is added to the dependency
  list of the target, which allow to rebuild the target when xen-syms
  changes. But if "xen-syms" is missing, make simply fails.
- modinfo.o wasn't removing it's $@.bin file like the other targets,
  this is now done.
- The command to build *.livepatch targets as been fixed to use
  $(XEN_LDFLAGS) rather than just $(LDFLAGS) which is a fallout from
  2740d96efdd3 ("xen/build: have the root Makefile generates the
  CFLAGS")

make will findout the dependencies of the *.livepatch files and thus
what to built by "looking" at the objects listed in the *-objs
variables. The actual dependencies is generated by the new
"multi-depend" macro.

"$(targets)" needs to be updated with the objects listed in the
different *-objs variables to allow make to load the .*.cmd dependency
files.

This patch copies the macro "multi_depend" from Linux 5.12, and rename
it to "multi-depend".

Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---

Notes:
    v9:
    - half acked, still need "livepatch" maintainer ack.
    
    v8:
    - rename multi_depend to multi-depend
    - use $() for single-letter make variable
    - re-indent one line

 xen/scripts/Kbuild.include  |   9 ++
 xen/test/livepatch/Makefile | 213 ++++++++++++++----------------------
 2 files changed, 91 insertions(+), 131 deletions(-)

diff --git a/xen/scripts/Kbuild.include b/xen/scripts/Kbuild.include
index f75d724ed7fd..73caf238d42c 100644
--- a/xen/scripts/Kbuild.include
+++ b/xen/scripts/Kbuild.include
@@ -151,3 +151,12 @@ why =                                                      
                  \
 
 echo-why = $(call escsq, $(strip $(why)))
 endif
+
+# Useful for describing the dependency of composite objects
+# Usage:
+#   $(call multi-depend, multi-used-targets, suffix-to-remove, suffix-to-add)
+define multi-depend
+$(foreach m, $(notdir $1), \
+       $(eval $(obj)/$(m): \
+       $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
+endef
diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile
index 148dddb90473..69fadccd01ea 100644
--- a/xen/test/livepatch/Makefile
+++ b/xen/test/livepatch/Makefile
@@ -12,81 +12,29 @@ CODE_ADDR=$(shell nm --defined $(1) | grep $(2) | awk 
'{print "0x"$$1}')
 CODE_SZ=$(shell nm --defined -S $(1) | grep $(2) | awk '{ print "0x"$$2}')
 
 .PHONY: default
-
-LIVEPATCH := xen_hello_world.livepatch
-LIVEPATCH_BYE := xen_bye_world.livepatch
-LIVEPATCH_REPLACE := xen_replace_world.livepatch
-LIVEPATCH_NOP := xen_nop.livepatch
-LIVEPATCH_NO_XEN_BUILDID := xen_no_xen_buildid.livepatch
-LIVEPATCH_PREPOST_HOOKS := xen_prepost_hooks.livepatch
-LIVEPATCH_PREPOST_HOOKS_FAIL := xen_prepost_hooks_fail.livepatch
-LIVEPATCH_ACTION_HOOKS := xen_action_hooks.livepatch
-LIVEPATCH_ACTION_HOOKS_NOFUNC := xen_action_hooks_nofunc.livepatch
-LIVEPATCH_ACTION_HOOKS_MARKER:= xen_action_hooks_marker.livepatch
-LIVEPATCH_ACTION_HOOKS_NOAPPLY:= xen_action_hooks_noapply.livepatch
-LIVEPATCH_ACTION_HOOKS_NOREVERT:= xen_action_hooks_norevert.livepatch
-LIVEPATCH_EXPECTATIONS:= xen_expectations.livepatch
-LIVEPATCH_EXPECTATIONS_FAIL:= xen_expectations_fail.livepatch
-
-LIVEPATCHES += $(LIVEPATCH)
-LIVEPATCHES += $(LIVEPATCH_BYE)
-LIVEPATCHES += $(LIVEPATCH_REPLACE)
-LIVEPATCHES += $(LIVEPATCH_NOP)
-LIVEPATCHES += $(LIVEPATCH_NO_XEN_BUILDID)
-LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS)
-LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS_FAIL)
-LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS)
-LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOFUNC)
-LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_MARKER)
-LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOAPPLY)
-LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOREVERT)
-LIVEPATCHES += $(LIVEPATCH_EXPECTATIONS)
-LIVEPATCHES += $(LIVEPATCH_EXPECTATIONS_FAIL)
-
-LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch
-
 build default: livepatch
 
-install: livepatch
-       $(INSTALL_DIR) $(DESTDIR)$(LIVEPATCH_DEBUG_DIR)
-       $(INSTALL_DATA) $(LIVEPATCHES) $(DESTDIR)$(LIVEPATCH_DEBUG_DIR)
-
-uninstall:
-       cd $(DESTDIR)$(LIVEPATCH_DEBUG_DIR) && rm -f $(LIVEPATCHES)
-
-.PHONY: clean
-clean::
-       rm -f *.o .*.o.d *.livepatch config.h expect_config.h
+extra-y += xen_hello_world.livepatch
+xen_hello_world-objs := xen_hello_world_func.o xen_hello_world.o note.o 
xen_note.o modinfo.o
+$(obj)/xen_hello_world.o: $(obj)/config.h
 
 #
 # To compute these values we need the binary files: xen-syms
 # and xen_hello_world_func.o to be already compiled.
 #
-.PHONY: config.h
-config.h: OLD_CODE_SZ=$(call CODE_SZ,$(BASEDIR)/xen-syms,xen_extra_version)
-config.h: NEW_CODE_SZ=$(call CODE_SZ,$<,xen_hello_world)
-config.h: MINOR_VERSION_SZ=$(call 
CODE_SZ,$(BASEDIR)/xen-syms,xen_minor_version)
-config.h: MINOR_VERSION_ADDR=$(call 
CODE_ADDR,$(BASEDIR)/xen-syms,xen_minor_version)
-config.h: xen_hello_world_func.o
+$(obj)/config.h: $(obj)/xen_hello_world_func.o
        (set -e; \
-        echo "#define NEW_CODE_SZ $(NEW_CODE_SZ)"; \
-        echo "#define MINOR_VERSION_SZ $(MINOR_VERSION_SZ)"; \
-        echo "#define MINOR_VERSION_ADDR $(MINOR_VERSION_ADDR)"; \
-        echo "#define OLD_CODE_SZ $(OLD_CODE_SZ)") > $@
+        echo "#define NEW_CODE_SZ $(call CODE_SZ,$<,xen_hello_world)"; \
+        echo "#define MINOR_VERSION_SZ $(call 
CODE_SZ,$(BASEDIR)/xen-syms,xen_minor_version)"; \
+        echo "#define MINOR_VERSION_ADDR $(call 
CODE_ADDR,$(BASEDIR)/xen-syms,xen_minor_version)"; \
+        echo "#define OLD_CODE_SZ $(call 
CODE_SZ,$(BASEDIR)/xen-syms,xen_extra_version)") > $@
 
-xen_hello_world.o: config.h
-
-.PHONY: $(LIVEPATCH)
-$(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o xen_note.o 
modinfo.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH) $^
-
-.PHONY: modinfo.o
-modinfo.o:
+$(obj)/modinfo.o:
        (set -e; \
         printf "LIVEPATCH_RULEZ\0") > $@.bin
        $(OBJCOPY) $(OBJCOPY_MAGIC) \
                   
--rename-section=.data=.modinfo,alloc,load,readonly,data,contents -S $@.bin $@
-       #rm -f $@.bin
+       rm -f $@.bin
 
 #
 # This target is only accessible if CONFIG_LIVEPATCH is defined, which
@@ -97,9 +45,8 @@ modinfo.o:
 # not be built (it is for EFI builds), and that we do not have
 # the note.o.bin to muck with (as it gets deleted)
 #
-.PHONY: note.o
-note.o:
-       $(OBJCOPY) -O binary --only-section=.note.gnu.build-id 
$(BASEDIR)/xen-syms $@.bin
+$(obj)/note.o: $(BASEDIR)/xen-syms
+       $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $< $@.bin
        $(OBJCOPY) $(OBJCOPY_MAGIC) \
                   
--rename-section=.data=.livepatch.depends,alloc,load,readonly,data,contents -S 
$@.bin $@
        rm -f $@.bin
@@ -108,9 +55,8 @@ note.o:
 # Append .livepatch.xen_depends section
 # with Xen build-id derived from xen-syms.
 #
-.PHONY: xen_note.o
-xen_note.o:
-       $(OBJCOPY) -O binary --only-section=.note.gnu.build-id 
$(BASEDIR)/xen-syms $@.bin
+$(obj)/xen_note.o: $(BASEDIR)/xen-syms
+       $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $< $@.bin
        $(OBJCOPY) $(OBJCOPY_MAGIC) \
                   
--rename-section=.data=.livepatch.xen_depends,alloc,load,readonly,data,contents 
-S $@.bin $@
        rm -f $@.bin
@@ -119,102 +65,107 @@ xen_note.o:
 # Extract the build-id of the xen_hello_world.livepatch
 # (which xen_bye_world will depend on).
 #
-.PHONY: hello_world_note.o
-hello_world_note.o: $(LIVEPATCH)
-       $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $(LIVEPATCH) 
$@.bin
+$(obj)/hello_world_note.o: $(obj)/xen_hello_world.livepatch
+       $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $< $@.bin
        $(OBJCOPY) $(OBJCOPY_MAGIC) \
                   
--rename-section=.data=.livepatch.depends,alloc,load,readonly,data,contents -S 
$@.bin $@
        rm -f $@.bin
 
-xen_bye_world.o: config.h
 
-.PHONY: $(LIVEPATCH_BYE)
-$(LIVEPATCH_BYE): xen_bye_world_func.o xen_bye_world.o hello_world_note.o 
xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_BYE) $^
+extra-y += xen_bye_world.livepatch
+xen_bye_world-objs := xen_bye_world_func.o xen_bye_world.o hello_world_note.o 
xen_note.o
+$(obj)/xen_bye_world.o: $(obj)/config.h
 
-xen_replace_world.o: config.h
 
-.PHONY: $(LIVEPATCH_REPLACE)
-$(LIVEPATCH_REPLACE): xen_replace_world_func.o xen_replace_world.o note.o 
xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_REPLACE) $^
+extra-y += xen_replace_world.livepatch
+xen_replace_world-objs := xen_replace_world_func.o xen_replace_world.o note.o 
xen_note.o
+$(obj)/xen_replace_world.o: $(obj)/config.h
 
-xen_nop.o: config.h
 
-.PHONY: $(LIVEPATCH_NOP)
-$(LIVEPATCH_NOP): xen_nop.o note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_NOP) $^
+extra-y += xen_nop.livepatch
+xen_nop-objs := xen_nop.o note.o xen_note.o
+$(obj)/xen_nop.o: $(obj)/config.h
 
 # This one always fails upon upload, because it deliberately
 # does not have a .livepatch.xen_depends (xen_note.o) section.
-xen_no_xen_buildid.o: config.h
-
-.PHONY: $(LIVEPATCH_NO_XEN_BUILDID)
-$(LIVEPATCH_NO_XEN_BUILDID): xen_nop.o note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_NO_XEN_BUILDID) $^
+extra-y += xen_no_xen_buildid.livepatch
+xen_no_xen_buildid-objs := xen_nop.o note.o
 
-xen_prepost_hooks.o: config.h
+$(obj)/xen_prepost_hooks.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_PREPOST_HOOKS)
-$(LIVEPATCH_PREPOST_HOOKS): xen_prepost_hooks.o xen_hello_world_func.o note.o 
xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_PREPOST_HOOKS) $^
+extra-y += xen_prepost_hooks.livepatch
+xen_prepost_hooks-objs := xen_prepost_hooks.o xen_hello_world_func.o note.o 
xen_note.o
 
-xen_prepost_hooks_fail.o: config.h
+$(obj)/xen_prepost_hooks_fail.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_PREPOST_HOOKS_FAIL)
-$(LIVEPATCH_PREPOST_HOOKS_FAIL): xen_prepost_hooks_fail.o 
xen_hello_world_func.o note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o 
$(LIVEPATCH_PREPOST_HOOKS_FAIL) $^
+extra-y += xen_prepost_hooks_fail.livepatch
+xen_prepost_hooks_fail-objs := xen_prepost_hooks_fail.o xen_hello_world_func.o 
note.o xen_note.o
 
-xen_action_hooks.o: config.h
+$(obj)/xen_action_hooks.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_ACTION_HOOKS)
-$(LIVEPATCH_ACTION_HOOKS): xen_action_hooks.o xen_hello_world_func.o note.o 
xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS) $^
+extra-y += xen_action_hooks.livepatch
+xen_action_hooks-objs := xen_action_hooks.o xen_hello_world_func.o note.o 
xen_note.o
 
-xen_action_hooks_nofunc.o: config.h
+$(obj)/xen_action_hooks_nofunc.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_ACTION_HOOKS_NOFUNC)
-$(LIVEPATCH_ACTION_HOOKS_NOFUNC): xen_action_hooks_nofunc.o note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o 
$(LIVEPATCH_ACTION_HOOKS_NOFUNC) $^
+extra-y += xen_action_hooks_nofunc.livepatch
+xen_action_hooks_nofunc-objs := xen_action_hooks_nofunc.o note.o xen_note.o
 
-xen_action_hooks_marker.o: config.h
+$(obj)/xen_action_hooks_marker.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_ACTION_HOOKS_MARKER)
-$(LIVEPATCH_ACTION_HOOKS_MARKER): xen_action_hooks_marker.o 
xen_hello_world_func.o note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o 
$(LIVEPATCH_ACTION_HOOKS_MARKER) $^
+extra-y += xen_action_hooks_marker.livepatch
+xen_action_hooks_marker-objs := xen_action_hooks_marker.o 
xen_hello_world_func.o note.o xen_note.o
 
-xen_action_hooks_noapply.o: config.h
+$(obj)/xen_action_hooks_noapply.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_ACTION_HOOKS_NOAPPLY)
-$(LIVEPATCH_ACTION_HOOKS_NOAPPLY): xen_action_hooks_marker.o 
xen_hello_world_func.o note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o 
$(LIVEPATCH_ACTION_HOOKS_NOAPPLY) $^
+extra-y += xen_action_hooks_noapply.livepatch
+xen_action_hooks_noapply-objs := xen_action_hooks_marker.o 
xen_hello_world_func.o note.o xen_note.o
 
-xen_action_hooks_norevert.o: config.h
+$(obj)/xen_action_hooks_norevert.o: $(obj)/config.h
 
-.PHONY: $(LIVEPATCH_ACTION_HOOKS_NOREVERT)
-$(LIVEPATCH_ACTION_HOOKS_NOREVERT): xen_action_hooks_marker.o 
xen_hello_world_func.o note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o 
$(LIVEPATCH_ACTION_HOOKS_NOREVERT) $^
+extra-y += xen_action_hooks_norevert.livepatch
+xen_action_hooks_norevert-objs := xen_action_hooks_marker.o 
xen_hello_world_func.o note.o xen_note.o
 
 EXPECT_BYTES_COUNT := 8
 CODE_GET_EXPECT=$(shell $(OBJDUMP) -d --insn-width=1 $(1) | sed -n -e 
'/<'$(2)'>:$$/,/^$$/ p' | tail -n +2 | head -n $(EXPECT_BYTES_COUNT) | awk 
'{$$0=$$2; printf "%s", substr($$0,length-1)}' | sed 's/.\{2\}/0x&,/g' | sed 
's/^/{/;s/,$$/}/g')
-.PHONY: expect_config.h
-expect_config.h: EXPECT_BYTES=$(call 
CODE_GET_EXPECT,$(BASEDIR)/xen-syms,xen_extra_version)
-expect_config.h:
+$(obj)/expect_config.h: $(BASEDIR)/xen-syms
        (set -e; \
-        echo "#define EXPECT_BYTES $(EXPECT_BYTES)"; \
+        echo "#define EXPECT_BYTES $(call 
CODE_GET_EXPECT,$<,xen_extra_version)"; \
          echo "#define EXPECT_BYTES_COUNT $(EXPECT_BYTES_COUNT)") > $@
 
-xen_expectations.o: expect_config.h
+$(obj)/xen_expectations.o: $(obj)/expect_config.h
 
-.PHONY: $(LIVEPATCH_EXPECTATIONS)
-$(LIVEPATCH_EXPECTATIONS): xen_expectations.o xen_hello_world_func.o note.o 
xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_EXPECTATIONS) $^
+extra-y += xen_expectations.livepatch
+xen_expectations-objs := xen_expectations.o xen_hello_world_func.o note.o 
xen_note.o
 
-.PHONY: $(LIVEPATCH_EXPECTATIONS_FAIL)
-$(LIVEPATCH_EXPECTATIONS_FAIL): xen_expectations_fail.o xen_hello_world_func.o 
note.o xen_note.o
-       $(LD) $(LDFLAGS) $(build_id_linker) -r -o 
$(LIVEPATCH_EXPECTATIONS_FAIL) $^
+extra-y += xen_expectations_fail.livepatch
+xen_expectations_fail-objs := xen_expectations_fail.o xen_hello_world_func.o 
note.o xen_note.o
+
+
+quiet_cmd_livepatch = LD      $@
+cmd_livepatch = $(LD) $(XEN_LDFLAGS) $(build_id_linker) -r -o $@ 
$(real-prereqs)
+
+$(obj)/%.livepatch: FORCE
+       $(call if_changed,livepatch)
+
+$(call multi-depend, $(filter %.livepatch,$(extra-y)), .livepatch, -objs)
+targets += $(sort $(foreach m,$(basename $(notdir $(filter 
%.livepatch,$(extra-y)))), \
+                    $($(m)-objs)))
+
+LIVEPATCHES := $(filter %.livepatch,$(extra-y))
+
+LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch
 
 .PHONY: livepatch
-livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) 
$(LIVEPATCH_NO_XEN_BUILDID) \
-           $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) 
$(LIVEPATCH_ACTION_HOOKS) \
-           $(LIVEPATCH_ACTION_HOOKS_NOFUNC) $(LIVEPATCH_ACTION_HOOKS_MARKER) 
$(LIVEPATCH_ACTION_HOOKS_NOAPPLY) \
-           $(LIVEPATCH_ACTION_HOOKS_NOREVERT) $(LIVEPATCH_EXPECTATIONS) 
$(LIVEPATCH_EXPECTATIONS_FAIL)
+livepatch: $(LIVEPATCHES)
+
+install: $(addprefix $(obj)/,$(LIVEPATCHES))
+       $(INSTALL_DIR) $(DESTDIR)$(LIVEPATCH_DEBUG_DIR)
+       $(INSTALL_DATA) $(addprefix $(obj)/,$(LIVEPATCHES)) 
$(DESTDIR)$(LIVEPATCH_DEBUG_DIR)
+
+uninstall:
+       cd $(DESTDIR)$(LIVEPATCH_DEBUG_DIR) && rm -f $(LIVEPATCHES)
+
+.PHONY: clean
+clean::
+       rm -f *.o .*.o.d *.livepatch config.h expect_config.h
-- 
Anthony PERARD