kbuild: Small cleanups

o Use a shorter expression to transform 'foo.o' -> 'foo-objs'
o Define EXPORT_FLAGS (as -DEXPORT_SYMTAB) in the main Makefile
o Small rearrangement of code in Rules.make

Makefile

@@ -37,17 +37,22 @@ OBJDUMP		= $(CROSS_COMPILE)objdump
 MAKEFILES	= $(TOPDIR)/.config
 GENKSYMS	= /sbin/genksyms
 DEPMOD		= /sbin/depmod
+PERL		= perl
 MODFLAGS	= -DMODULE
 CFLAGS_MODULE   = $(MODFLAGS)
 AFLAGS_MODULE   =
 CFLAGS_KERNEL	=
 AFLAGS_KERNEL	=
-PERL		= perl
+EXPORT_FLAGS    =
 
 export	VERSION PATCHLEVEL SUBLEVEL EXTRAVERSION KERNELRELEASE ARCH \
 	CONFIG_SHELL TOPDIR HPATH HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC \
 	CPP AR NM STRIP OBJCOPY OBJDUMP MAKE MAKEFILES GENKSYMS PERL
 
+export CPPFLAGS EXPORT_FLAGS
+export CFLAGS CFLAGS_KERNEL CFLAGS_MODULE 
+export AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
+
 all:	do-it-all
 
 #
@@ -94,6 +99,10 @@ CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes -Wno-trigraphs -O2 \
 	  -fomit-frame-pointer -fno-strict-aliasing -fno-common
 AFLAGS := -D__ASSEMBLY__ $(CPPFLAGS)
 
+ifdef CONFIG_MODULES
+EXPORT_FLAGS := -DEXPORT_SYMTAB
+endif
+
 INIT		=init/init.o
 CORE_FILES	=kernel/kernel.o mm/mm.o fs/fs.o ipc/ipc.o
 NETWORKS	=net/network.o
@@ -157,10 +166,6 @@ DRIVERS := $(DRIVERS-y)
 
 include arch/$(ARCH)/Makefile
 
-export CPPFLAGS
-export CFLAGS CFLAGS_KERNEL CFLAGS_MODULE 
-export AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
-
 export	NETWORKS DRIVERS LIBS HEAD LDFLAGS LINKFLAGS MAKEBOOT ASFLAGS
 
 # boot target

Rules.make

@@ -73,8 +73,8 @@ __obj-y = $(filter-out export.o,$(obj-y))
 __obj-m = $(filter-out export.o,$(obj-m))
 
 # if $(foo-objs) exists, foo.o is a composite object 
-__multi-used-y := $(sort $(foreach m,$(__obj-y), $(if $($(basename $(m))-objs), $(m))))
-__multi-used-m := $(sort $(foreach m,$(__obj-m), $(if $($(basename $(m))-objs), $(m))))
+__multi-used-y := $(sort $(foreach m,$(__obj-y), $(if $($(m:.o=-objs)), $(m))))
+__multi-used-m := $(sort $(foreach m,$(__obj-m), $(if $($(m:.o=-objs)), $(m))))
 
 # FIXME: Rip this out later
 # Backwards compatibility: if a composite object is listed in
@@ -86,9 +86,16 @@ multi-used-m := $(filter-out $(list-multi),$(__multi-used-m))
 
 # Build list of the parts of our composite objects, our composite
 # objects depend on those (obviously)
-multi-objs-y := $(foreach m, $(multi-used-y), $($(basename $(m))-objs))
-multi-objs-m := $(foreach m, $(multi-used-m), $($(basename $(m))-objs))
+multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)))
+multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)))
 
+# $(subdir-obj-y) is the list of objects in $(obj-y) which do not live
+# in the local directory
+subdir-obj-y := $(foreach o,$(obj-y),$(if $(filter-out $(o),$(notdir $(o))),$(o)))
+
+# Replace multi-part objects by their individual parts, look at local dir only
+real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $($(m:.o=-objs)),$($(m:.o=-objs)),$(m)))
+real-objs-m := $(foreach m, $(obj-m), $(if $($(m:.o=-objs)),$($(m:.o=-objs)),$(m)))
 
 # ==========================================================================
 #
@@ -103,7 +110,7 @@ first_rule: all_targets
 # Compile C sources (.c)
 # ---------------------------------------------------------------------------
 
-# export_flags will be set to -DEXPORT_SYMBOL for objects in $(export-objs)
+$(export-objs): export_flags := $(EXPORT_FLAGS)
 
 c_flags = $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F))) $(export_flags)
 
@@ -122,7 +129,6 @@ cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
 %.o: %.c dummy
 	$(call if_changed,cmd_cc_o_c)
 
-
 # Compile assembler sources (.S)
 # ---------------------------------------------------------------------------
 
@@ -148,10 +154,7 @@ cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
 #
 all_targets: $(O_TARGET) $(L_TARGET) sub_dirs
 
-# $(subdir-obj-y) is the list of objects in $(obj-y) which do not live
-# in the local directory
-subdir-obj-y := $(foreach o,$(obj-y),$(if $(filter-out $(o),$(notdir $(o))),$(o)))
-# Do build these objects, we need to descend into the directories
+# To build objects in subdirs, we need to descend into the directories
 $(subdir-obj-y): sub_dirs
 
 #
@@ -344,7 +347,6 @@ endif # CONFIG_MODVERSIONS
 ifneq "$(strip $(export-objs))" ""
 
 $(export-objs): $(TOPDIR)/include/linux/modversions.h
-$(export-objs): export_flags := -DEXPORT_SYMTAB
 
 endif