build: use if_changed more consistently (and correctly) for prelink*.o

Switch to $(call if_changed,ld) where possible; presumably not doing so
in e321576f4047 ("xen/build: start using if_changed") right away was an
oversight, as it did for Arm in (just) one case. It failed to add
prelink.o to $(targets), though, causing - judging from the observed
behavior on x86 - undue rebuilds of the final binary (because of
prelink.o getting rebuild for $(cmd_prelink.o) being empty, in turn
because of .prelink.o.cmd not getting read) during "make install-xen".

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
master commit: dd2cfba88c3d0e144ffec07c6b5b86e54a9d98a9
master date: 2020-09-22 10:19:38 +0200

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 7e82b2178cd77e95ef7417e65395fdef888e8220..1ded44d200478a950c15eb8981f776bf9cb750e5 100644 (file)
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -95,12 +95,14 @@ prelink_lto.o: $(ALL_OBJS)
 
 # Link it with all the binary objects
 prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
-       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
+       $(call if_changed,ld)
 else
 prelink.o: $(ALL_OBJS) FORCE
        $(call if_changed,ld)
 endif
 
+targets += prelink.o
+
 $(TARGET)-syms: prelink.o xen.lds
        $(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o \
            $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0

diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index b388861679de24e03ce3a549f11d3ba94f00a458..26ff2a9a3e69981e738c148ecb2440e57309e0f1 100644 (file)
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -124,19 +124,21 @@ prelink-efi_lto.o: $(ALL_OBJS) efi/runtime.o efi/compat.o
        $(LD_LTO) -r -o $@ $(filter-out %/efi/built_in.o,$^)
 
 # Link it with all the binary objects
-prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
-       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
+prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o FORCE
+       $(call if_changed,ld)
 
-prelink-efi.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink-efi_lto.o efi/boot.init.o
-       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
+prelink-efi.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink-efi_lto.o efi/boot.init.o FORCE
+       $(call if_changed,ld)
 else
-prelink.o: $(ALL_OBJS)
-       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
+prelink.o: $(ALL_OBJS) FORCE
+       $(call if_changed,ld)
 
-prelink-efi.o: $(ALL_OBJS) efi/boot.init.o efi/runtime.o efi/compat.o
-       $(LD) $(XEN_LDFLAGS) -r -o $@ $(filter-out %/efi/built_in.o,$^)
+prelink-efi.o: $(filter-out %/efi/built_in.o,$(ALL_OBJS)) efi/boot.init.o efi/runtime.o efi/compat.o FORCE
+       $(call if_changed,ld)
 endif
 
+targets += prelink.o prelink-efi.o
+
 $(TARGET)-syms: prelink.o xen.lds
        $(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
            $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0