kbuild: Get rid of -DMODVERSIONS, further cleanup

-DMODVERSIONS isn't used anymore, so it can go. Also, after cleaning
up include/linux/module.h, it's obvious that we don't need
include/linux/modversions.h at all if CONFIG_MODVERSIONS not set,
no need to generate it.

Rules.make explicitly lists files which depend on modversions.h,
since make dep cannot know about the
"-include include/linux/modversions.h" which gets added to
the command line. Now that we understand when it is needed, we can
even get that list right ;-)

Oh well, nice theory. .hdepend will touch module.h when modversions.h
changes, so we still get unnecessary recompiles. We really need to
switch to the new way of dependency generation, it gets all that
right without even thinking about these special cases.

We don't track dependencies for .ver files. In fact, we relied on that
checksum would only change if the corresponding exporting C source
changes. That's not true, of course, all of the included headers have
say as well. So we better force the hash to be checked
unconditionally every time "make dep" is run.

Makefile

@@ -279,14 +279,14 @@ depend dep: .hdepend
 	  $(if $(filter dep depend,$(MAKECMDGOALS)),FORCE)
 	scripts/mkdep -- `find $(FINDHPATH) -name SCCS -prune -o -follow -name \*.h ! -name modversions.h -print` > $@
 	@$(MAKE) $(patsubst %,_sfdep_%,$(SUBDIRS))
+ifdef CONFIG_MODVERSIONS
 	@$(MAKE) include/linux/modversions.h
+endif
 	@$(MAKE) archdep
 
 $(patsubst %,_sfdep_%,$(SUBDIRS)): FORCE
 	@$(MAKE) -C $(patsubst _sfdep_%, %, $@) fastdep
 
-ifdef CONFIG_MODVERSIONS
-
 # 	Update modversions.h, but only if it would change.
 
 include/linux/modversions.h: FORCE
@@ -307,13 +307,6 @@ include/linux/modversions.h: FORCE
 		mv -f $@.tmp $@; \
 	fi
 
-else # CONFIG_MODVERSIONS
-
-include/linux/modversions.h:
-	@echo "#include <linux/modsetver.h>" > $@
-
-endif # CONFIG_MODVERSIONS
-
 # ---------------------------------------------------------------------------
 # Modules
 
@@ -322,7 +315,7 @@ ifdef CONFIG_MODULES
 #	Build modules
 
 ifdef CONFIG_MODVERSIONS
-MODFLAGS += -DMODVERSIONS -include $(HPATH)/linux/modversions.h
+MODFLAGS += -include $(HPATH)/linux/modversions.h
 endif
 
 .PHONY: modules

Rules.make

@@ -291,9 +291,6 @@ script:
 #
 ifdef CONFIG_MODULES
 
-multi-objs	:= $(foreach m, $(obj-y) $(obj-m), $($(basename $(m))-objs))
-active-objs	:= $(sort $(multi-objs) $(obj-y) $(obj-m))
-
 ifdef CONFIG_MODVERSIONS
 ifneq "$(strip $(export-objs))" ""
 
@@ -311,32 +308,36 @@ else
 	genksyms_smp_prefix := 
 endif
 
-$(MODINCL)/$(MODPREFIX)%.ver: %.c
-	@if [ ! -r $(MODINCL)/$(MODPREFIX)$*.stamp -o $(MODINCL)/$(MODPREFIX)$*.stamp -ot $< ]; then \
-		echo '$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -E -D__GENKSYMS__ $<'; \
-		echo '| $(GENKSYMS) $(genksyms_smp_prefix) -k $(VERSION).$(PATCHLEVEL).$(SUBLEVEL) > $@.tmp'; \
-		$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -E -D__GENKSYMS__ $< \
-		| $(GENKSYMS) $(genksyms_smp_prefix) -k $(VERSION).$(PATCHLEVEL).$(SUBLEVEL) > $@.tmp; \
-		if [ -r $@ ] && cmp -s $@ $@.tmp; then echo $@ is unchanged; rm -f $@.tmp; \
-		else echo mv $@.tmp $@; mv -f $@.tmp $@; fi; \
-	fi; touch $(MODINCL)/$(MODPREFIX)$*.stamp
+# We don't track dependencies for .ver files, so we FORCE to check
+# them always (i.e. always at "make dep" time).
+
+cmd_create_ver = $(CC) $(CFLAGS) $(EXTRA_CFLAGS) -E -D__GENKSYMS__ $< | \
+		 $(GENKSYMS) $(genksyms_smp_prefix) -k $(VERSION).$(PATCHLEVEL).$(SUBLEVEL) > $@.tmp
 
-$(addprefix $(MODINCL)/$(MODPREFIX),$(export-objs:.o=.ver)): $(TOPDIR)/include/linux/autoconf.h
+$(MODINCL)/$(MODPREFIX)%.ver: %.c FORCE
+	@echo $(cmd_create_ver)
+	@$(cmd_create_ver)
+	@if [ -r $@ ] && cmp -s $@ $@.tmp; then \
+	  echo $@ is unchanged; rm -f $@.tmp; \
+	else \
+	  echo mv $@.tmp $@; mv -f $@.tmp $@; \
+	fi
 
 # updates .ver files but not modversions.h
 fastdep: $(addprefix $(MODINCL)/$(MODPREFIX),$(export-objs:.o=.ver))
 
 endif # export-objs 
 
-$(active-objs): $(TOPDIR)/include/linux/modversions.h
-
-endif # CONFIG_MODVERSIONS
-
-ifneq "$(strip $(export-objs))" ""
+# make dep cannot correctly figure out the dependency on the generated
+# modversions.h, so we list them here:
+# o files which export symbols and are compiled into the kernel include
+#   it (to generate a correct symbol table)
+# o all modules get compiled with -include modversions.h
 
-$(export-objs): $(TOPDIR)/include/linux/modversions.h
+$(filter $(export-objs),$(real-objs-y)): $(TOPDIR)/include/linux/modversions.h
+$(real-objs-m): $(TOPDIR)/include/linux/modversions.h
 
-endif
+endif # CONFIG_MODVERSIONS
 
 endif # CONFIG_MODULES