build-sys hack: link with whole .fa archives

In order to link the *-obj-y files into tests, we will make static
libraries of them in Meson, and then link them as whole archives
into the tests.  To separate regular static libraries from link-whole
libraries, give them a different file extension.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rules.mak

@@ -39,6 +39,13 @@ find-symbols = $(if $1, $(sort $(shell $(NM) -P -g $1 | $2)))
 defined-symbols = $(call find-symbols,$1,awk '$$2!="U"{print $$1}')
 undefined-symbols = $(call find-symbols,$1,awk '$$2=="U"{print $$1}')
 
+WL := -Wl,
+ifdef CONFIG_DARWIN
+whole-archive = $(WL)-force_load,$1
+else
+whole-archive = $(WL)--whole-archive $1 $(WL)--no-whole-archive
+endif
+
 # All the .mo objects in -m variables are also added into corresponding -y
 # variable in unnest-vars, but filtered out here, when LINK is called.
 #
@@ -54,11 +61,12 @@ undefined-symbols = $(call find-symbols,$1,awk '$$2=="U"{print $$1}')
 # This is necessary because the exectuable itself may not use the function, in
 # which case the function would not be linked in. Then the DSO loading will
 # fail because of the missing symbol.
-process-archive-undefs = $(filter-out %.a %.mo,$1) \
+process-archive-undefs = $(filter-out %.a %.fa %.mo,$1) \
                 $(addprefix $(WL_U), \
-                     $(filter $(call defined-symbols,$(filter %.a, $1)), \
+                     $(filter $(call defined-symbols,$(filter %.a %.fa, $1)), \
                               $(call undefined-symbols,$(filter %.mo,$1)))) \
-                $(filter %.a,$1)
+		$(foreach l,$(filter %.fa,$1),$(call whole-archive,$l)) \
+		$(filter %.a,$1)
 
 extract-libs = $(strip $(foreach o,$(filter-out %.mo,$1),$($o-libs)))
 expand-objs = $(strip $(sort $(filter %.o,$1)) \
@@ -122,7 +130,7 @@ LD_REL := $(CC) -nostdlib $(LD_REL_FLAGS)
 modules:
 
 %$(EXESUF): %.o
-	$(call LINK,$(filter %.o %.a %.mo, $^))
+	$(call LINK,$(filter %.o %.a %.mo %.fa, $^))
 
 %.a:
 	$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^,"AR","$(TARGET_DIR)$@")
@@ -378,7 +386,7 @@ define unnest-vars
                 $(error $o added in $v but $o-objs is not set)))
         $(shell mkdir -p ./ $(sort $(dir $($v))))
         # Include all the .d files
-        $(eval -include $(patsubst %.o,%.d,$(patsubst %.mo,%.d,$($v))))
+        $(eval -include $(patsubst %.o,%.d,$(patsubst %.mo,%.d,$(filter %.o,$($v)))))
         $(eval $v := $(filter-out %/,$($v))))
 endef