| Message ID | 20200226113355.2532224-24-anthony.perard@citrix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen: Build system improvements | expand |
On 26.02.2020 12:33, Anthony PERARD wrote: > --- a/xen/Rules.mk > +++ b/xen/Rules.mk > @@ -115,6 +115,9 @@ endif > # FIXME LTO broken, but we would need a different way to filter -flto out > # $(obj-bin-y): CFLAGS := $(filter-out -flto,$(CFLAGS)) > > +# target with its suffix stripped > +target-stem = $(basename $@) I'd appreciate if the word "stem" was used in a makefile only for what make doc uses it for - the part of the target of a pattern rule that % matches. I.e. here perhaps name the variable target-basename? (But see below, maybe this isn't needed.) > --- a/xen/arch/x86/mm/Makefile > +++ b/xen/arch/x86/mm/Makefile > @@ -11,11 +11,14 @@ obj-y += p2m.o p2m-pt.o > obj-$(CONFIG_HVM) += p2m-ept.o p2m-pod.o > obj-y += paging.o > > -guest_walk_%.o: guest_walk.c Makefile > - $(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ > +$(foreach gw,$(filter guest_walk_%.o,$(obj-y)),\ > + $(eval CFLAGS_$(gw) = -DGUEST_PAGING_LEVELS=$$*)) So the $$* here matches ... > -guest_walk_%.i: guest_walk.c Makefile > - $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ > +guest_walk_%.o: guest_walk.c FORCE > + $(call if_changed_rule,cc_o_c) ... the stem of the target of this rule. This is not good. Can't you have something like guest_walk_%.o guest_walk_%.i guest_walk_%.s: CFLAGS_$(target-stem).o = -DGUEST_PAGING_LEVELS=$* on a line immediately ahead of the rule, so that them having to match up will be very obvious, and breakage of the connection very noticable? (Of course this also demonstrates that tying the CFLAGS modifier to the object file name may be slightly confusing. But I don't have a better suggestion. Question is whether here use of an object [or whatever else] file specific variable is helpful at all, when make already offers per-target variable customization. Is there a specific reason the above couldn't e.g. be guest_walk_%.o guest_walk_%.i guest_walk_%.s: CFLAGS-y += -DGUEST_PAGING_LEVELS=$* ?) If this alternative worked, there'd be the positive side effect of us avoiding the use of $(eval ) here - ISTR it not working very reliably in make 3.80, which we still document as acceptable for building. Jan
diff --git a/xen/Rules.mk b/xen/Rules.mk index 02cd37d04054..1ffb02f42914 100644 --- a/xen/Rules.mk +++ b/xen/Rules.mk @@ -115,6 +115,9 @@ endif # FIXME LTO broken, but we would need a different way to filter -flto out # $(obj-bin-y): CFLAGS := $(filter-out -flto,$(CFLAGS)) +# target with its suffix stripped +target-stem = $(basename $@) + # Calculation of flags, first the generic flags, then the arch specific flags, # and last the flags modified for a target or a directory. @@ -123,7 +126,7 @@ a_flags = -MMD -MF $(@D)/.$(@F).d $(XEN_AFLAGS) include $(BASEDIR)/arch/$(TARGET_ARCH)/Rules.mk -c_flags += $(CFLAGS-y) +c_flags += $(CFLAGS-y) $(CFLAGS_$(target-stem).o) a_flags += $(CFLAGS-y) $(AFLAGS-y) quiet_cmd_ld_builtin = LD $@ diff --git a/xen/arch/x86/mm/Makefile b/xen/arch/x86/mm/Makefile index a2431fde6bb4..4750bfa0ff91 100644 --- a/xen/arch/x86/mm/Makefile +++ b/xen/arch/x86/mm/Makefile @@ -11,11 +11,14 @@ obj-y += p2m.o p2m-pt.o obj-$(CONFIG_HVM) += p2m-ept.o p2m-pod.o obj-y += paging.o -guest_walk_%.o: guest_walk.c Makefile - $(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ +$(foreach gw,$(filter guest_walk_%.o,$(obj-y)),\ + $(eval CFLAGS_$(gw) = -DGUEST_PAGING_LEVELS=$$*)) -guest_walk_%.i: guest_walk.c Makefile - $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ +guest_walk_%.o: guest_walk.c FORCE + $(call if_changed_rule,cc_o_c) -guest_walk_%.s: guest_walk.c Makefile - $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -S $< -o $@ +guest_walk_%.i: guest_walk.c FORCE + $(call if_changed,cpp_i_c) + +guest_walk_%.s: guest_walk.c FORCE + $(call if_changed,cc_s_c) diff --git a/xen/arch/x86/mm/hap/Makefile b/xen/arch/x86/mm/hap/Makefile index 22e7ad54bd33..8cd31e9cdc5e 100644 --- a/xen/arch/x86/mm/hap/Makefile +++ b/xen/arch/x86/mm/hap/Makefile @@ -5,11 +5,14 @@ obj-y += guest_walk_4level.o obj-y += nested_hap.o obj-y += nested_ept.o -guest_walk_%level.o: guest_walk.c Makefile - $(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ +$(foreach gw,$(filter guest_walk_%level.o,$(obj-y)),\ + $(eval CFLAGS_$(gw) = -DGUEST_PAGING_LEVELS=$$*)) -guest_walk_%level.i: guest_walk.c Makefile - $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ +guest_walk_%level.o: guest_walk.c FORCE + $(call if_changed_rule,cc_o_c) -guest_walk_%level.s: guest_walk.c Makefile - $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -S $< -o $@ +guest_walk_%level.i: guest_walk.c FORCE + $(call if_changed,cpp_i_c) + +guest_walk_%level.s: guest_walk.c FORCE + $(call if_changed,cc_s_c) diff --git a/xen/arch/x86/mm/shadow/Makefile b/xen/arch/x86/mm/shadow/Makefile index 23d3ff10802c..d11e9e2fac08 100644 --- a/xen/arch/x86/mm/shadow/Makefile +++ b/xen/arch/x86/mm/shadow/Makefile @@ -6,11 +6,14 @@ else obj-y += none.o endif -guest_%.o: multi.c Makefile - $(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ +$(foreach gw,$(filter guest_%.o,$(obj-y)),\ + $(eval CFLAGS_$(gw) = -DGUEST_PAGING_LEVELS=$$*)) -guest_%.i: multi.c Makefile - $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ +guest_%.o: multi.c FORCE + $(call if_changed_rule,cc_o_c) -guest_%.s: multi.c Makefile - $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -S $< -o $@ +guest_%.i: multi.c FORCE + $(call if_changed,cpp_i_c) + +guest_%.s: multi.c FORCE + $(call if_changed,cc_s_c)
Use if_changed for building all guest_%.o objects, and make use of command that already exist. This patch also introduces CFLAGS_$@, it is used so that flags are applied to all .o .i and .s targets. This patch make a change to the way guest_%.o files are built, and now run the same commands that enforce unique symbols. But with patch "xen,symbols: rework file symbols selection", symbols should still select the file symbols directive intended to be used for guest_%.o objects. Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> --- xen/Rules.mk | 5 ++++- xen/arch/x86/mm/Makefile | 15 +++++++++------ xen/arch/x86/mm/hap/Makefile | 15 +++++++++------ xen/arch/x86/mm/shadow/Makefile | 15 +++++++++------ 4 files changed, 31 insertions(+), 19 deletions(-)