kbuild: Convert build and modversion phases

Alright, so now actually all four phases are converted to new-style,
i.e. we call make -f scripts/Makefile.<phase> which includes the
actual subdir Makefile.

The obvious drawback is some code duplication between the four
scripts/Makefile.<phase>, which could easily be overcome including
shared parts, but since I'm going for maximum performance, I did not
for now.

Rules.make is empty now ;) (Well, not quite, since if it was 0 bytes,
make mrproper would remove it...)

Makefile

@@ -106,6 +106,11 @@ endif
 
 MAKEFLAGS += --no-print-directory
 
+# For maximum performance (+ possibly random breakage, uncomment
+# the following)
+
+#MAKEFLAGS += -rR
+
 #	If the user wants quiet mode, echo short versions of the commands 
 #	only
 
@@ -146,7 +151,6 @@ NM		= $(CROSS_COMPILE)nm
 STRIP		= $(CROSS_COMPILE)strip
 OBJCOPY		= $(CROSS_COMPILE)objcopy
 OBJDUMP		= $(CROSS_COMPILE)objdump
-MAKEFILES	= .config
 GENKSYMS	= /sbin/genksyms
 DEPMOD		= /sbin/depmod
 KALLSYMS	= /sbin/kallsyms
@@ -165,7 +169,7 @@ AFLAGS		:= -D__ASSEMBLY__ $(CPPFLAGS)
 
 export	VERSION PATCHLEVEL SUBLEVEL EXTRAVERSION KERNELRELEASE ARCH \
 	CONFIG_SHELL TOPDIR HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC \
-	CPP AR NM STRIP OBJCOPY OBJDUMP MAKE MAKEFILES GENKSYMS PERL
+	CPP AR NM STRIP OBJCOPY OBJDUMP MAKE GENKSYMS PERL
 
 export CPPFLAGS NOSTDINC_FLAGS OBJCOPYFLAGS LDFLAGS
 export CFLAGS CFLAGS_KERNEL CFLAGS_MODULE 
@@ -369,7 +373,7 @@ $(sort $(vmlinux-objs)): $(SUBDIRS) ;
 
 .PHONY: $(SUBDIRS)
 $(SUBDIRS): .hdepend prepare
-	+@$(call descend,$@,)
+	+$(call descend,$@,)
 
 #	Things we need done before we descend to build or make
 #	module versions are listed in "prepare"
@@ -476,9 +480,11 @@ ifdef CONFIG_MODVERSIONS
 
 # 	Update modversions.h, but only if it would change.
 
-include/linux/modversions.h: FORCE
+.PHONY: __rm_tmp_export-objs
+__rm_tmp_export-objs: 
 	@rm -rf .tmp_export-objs
-	@$(MAKE) $(patsubst %,_sfdep_%,$(SUBDIRS))
+
+include/linux/modversions.h: $(patsubst %,_modver_%,$(SUBDIRS))
 	@echo -n '  Generating $@'
 	@( echo "#ifndef _LINUX_MODVERSIONS_H";\
 	   echo "#define _LINUX_MODVERSIONS_H"; \
@@ -491,8 +497,9 @@ include/linux/modversions.h: FORCE
 	) > $@.tmp; \
 	$(update-if-changed)
 
-$(patsubst %,_sfdep_%,$(SUBDIRS)): FORCE
-	+@$(call descend,$(patsubst _sfdep_%,%,$@),fastdep)
+.PHONY: $(patsubst %, _modver_%, $(SUBDIRS))
+$(patsubst %, _modver_%, $(SUBDIRS)): __rm_tmp_export-objs
+	$(Q)$(MAKE) -f scripts/Makefile.modver obj=$(patsubst _modver_%,%,$@)
 
 else # !CONFIG_MODVERSIONS
 
@@ -544,7 +551,7 @@ _modinst_post:
 
 .PHONY: $(patsubst %, _modinst_%, $(SUBDIRS))
 $(patsubst %, _modinst_%, $(SUBDIRS)) :
-	$(Q)$(MAKE) MAKEFILES= -rR -f scripts/Makefile.modinst obj=$(patsubst _modinst_%,%,$@)
+	$(Q)$(MAKE) -f scripts/Makefile.modinst obj=$(patsubst _modinst_%,%,$@)
 else # CONFIG_MODULES
 
 # Modules not configured
@@ -701,7 +708,7 @@ MRPROPER_DIRS += \
 clean-dirs += $(ALL_SUBDIRS) Documentation/DocBook scripts
 
 $(addprefix _clean_,$(clean-dirs)):
-	$(Q)$(MAKE) MAKEFILES= -rR -f scripts/Makefile.clean obj=$(patsubst _clean_%,%,$@)
+	$(Q)$(MAKE) -f scripts/Makefile.clean obj=$(patsubst _clean_%,%,$@)
 
 quiet_cmd_rmclean = RM  $$(CLEAN_FILES)
 cmd_rmclean	  = rm -f $(CLEAN_FILES)
@@ -890,9 +897,6 @@ endef
 #	$(call descend,<dir>,<target>)
 #	Recursively call a sub-make in <dir> with target <target> 
 
-ifeq ($(KBUILD_VERBOSE),1)
-descend = echo '$(MAKE) -f $(1)/Makefile $(2)';
-endif
-descend += $(MAKE) -f $(1)/Makefile obj=$(1) $(2)
+descend = $(Q)$(MAKE) -f scripts/Makefile.build obj=$(1) $(2)
 
 FORCE:

arch/i386/Makefile

@@ -88,6 +88,6 @@ install: vmlinux
 	+@$(call makeboot,BOOTIMAGE=$(BOOTIMAGE) install)
 
 archclean:
-	$(MAKE) -rR -f scripts/Makefile.clean obj=arch/i386/boot
+	@$(MAKE) -f scripts/Makefile.clean obj=arch/i386/boot
 
 archmrproper:

init/Makefile

@@ -11,13 +11,13 @@ include $(TOPDIR)/Rules.make
 
 # dependencies on generated files need to be listed explicitly
 
-$(obj)/version.o: $(obj)/../include/linux/compile.h
+$(obj)/version.o: include/linux/compile.h
 
 # compile.h changes depending on hostname, generation number, etc,
 # so we regenerate it always.
 # mkcompile_h will make sure to only update the
 # actual file if its content has changed.
 
-$(obj)/../include/linux/compile.h: FORCE
+include/linux/compile.h: FORCE
 	@echo -n '  Generating $@'
 	@sh $(srctree)/scripts/mkcompile_h $@ "$(ARCH)" "$(CONFIG_SMP)" "$(CC) $(CFLAGS)"

scripts/Makefile.clean

@@ -39,8 +39,8 @@ subdir-ymn	:= $(addprefix $(obj)/,$(subdir-ymn))
 
 __clean-files := $(wildcard $(EXTRA_TARGETS) $(host-progs) $(clean-files))
 
-quiet_cmd_clean = CLEAN   $(__cleanfiles)
-      cmd_clean = 	rm -f $(__clean-files);	$(clean-rule)
+quiet_cmd_clean = CLEAN   $(obj)
+      cmd_clean = rm -f $(__clean-files); $(clean-rule)
 
 __clean: $(subdir-ymn)
 ifneq ($(strip $(__clean-files) $(clean-rule)),)
@@ -58,7 +58,7 @@ endif
 
 .PHONY: $(subdir-ymn)
 $(subdir-ymn):
-	$(Q)$(MAKE) -rR -f scripts/Makefile.clean obj=$@
+	$(Q)$(MAKE) -f scripts/Makefile.clean obj=$@
 
 # If quiet is set, only print short version of command
 

scripts/Makefile.modver

@@ -2,12 +2,110 @@
 # Module versions
 # ===========================================================================
 
+src := $(obj)
+
+no-rules.make := 1
+
+.PHONY: modver
+modver:
+
+include .config
+
+include $(obj)/Makefile
+
+# Figure out what we need to build from the various variables
+# ===========================================================================
+
+# When an object is listed to be built compiled-in and modular,
+# only build the compiled-in version
+
+obj-m := $(filter-out $(obj-y),$(obj-m))
+
+# Handle objects in subdirs
+# ---------------------------------------------------------------------------
+# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o
+#   and add the directory to the list of dirs to descend into: $(subdir-y)
+# o if we encounter foo/ in $(obj-m), remove it from $(obj-m) 
+#   and add the directory to the list of dirs to descend into: $(subdir-m)
+
+__subdir-y	:= $(patsubst %/,%,$(filter %/, $(obj-y)))
+subdir-y	+= $(__subdir-y)
+__subdir-m	:= $(patsubst %/,%,$(filter %/, $(obj-m)))
+subdir-m	+= $(__subdir-m)
+__subdir-n	:= $(patsubst %/,%,$(filter %/, $(obj-n)))
+subdir-n	+= $(__subdir-n)
+__subdir-	:= $(patsubst %/,%,$(filter %/, $(obj-)))
+subdir-		+= $(__subdir-)
+obj-y		:= $(patsubst %/, %/built-in.o, $(obj-y))
+obj-m		:= $(filter-out %/, $(obj-m))
+
+# Subdirectories we need to descend into
+
+subdir-ym	:= $(sort $(subdir-y) $(subdir-m))
+subdir-ymn      := $(sort $(subdir-ym) $(subdir-n) $(subdir-))
+
+# export.o is never a composite object, since $(export-objs) has a
+# fixed meaning (== objects which EXPORT_SYMBOL())
+__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 $($(m:.o=-objs)), $(m))))
+multi-used-m := $(sort $(foreach m,$(__obj-m), $(if $($(m:.o=-objs)), $(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), $($(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))) $(EXTRA_TARGETS)
+real-objs-m := $(foreach m, $(obj-m), $(if $($(m:.o=-objs)),$($(m:.o=-objs)),$(m)))
+
+# Only build module versions for files which are selected to be built
+export-objs := $(filter $(export-objs),$(real-objs-y) $(real-objs-m))
+
+host-progs-single     := $(foreach m,$(host-progs),$(if $($(m)-objs),,$(m)))
+host-progs-multi      := $(foreach m,$(host-progs),$(if $($(m)-objs),$(m)))
+host-progs-multi-objs := $(foreach m,$(host-progs-multi),$($(m)-objs))
+
+# Add subdir path
+
+EXTRA_TARGETS	:= $(addprefix $(obj)/,$(EXTRA_TARGETS))
+obj-y		:= $(addprefix $(obj)/,$(obj-y))
+obj-m		:= $(addprefix $(obj)/,$(obj-m))
+export-objs	:= $(addprefix $(obj)/,$(export-objs))
+subdir-obj-y	:= $(addprefix $(obj)/,$(subdir-obj-y))
+real-objs-y	:= $(addprefix $(obj)/,$(real-objs-y))
+real-objs-m	:= $(addprefix $(obj)/,$(real-objs-m))
+multi-used-y	:= $(addprefix $(obj)/,$(multi-used-y))
+multi-used-m	:= $(addprefix $(obj)/,$(multi-used-m))
+multi-objs-y	:= $(addprefix $(obj)/,$(multi-objs-y))
+multi-objs-m	:= $(addprefix $(obj)/,$(multi-objs-m))
+subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))
+subdir-ymn	:= $(addprefix $(obj)/,$(subdir-ymn))
+clean-files	:= $(addprefix $(obj)/,$(clean-files))
+host-progs	:= $(addprefix $(obj)/,$(host-progs))
+host-progs-single     := $(addprefix $(obj)/,$(host-progs-single))
+host-progs-multi      := $(addprefix $(obj)/,$(host-progs-multi))
+host-progs-multi-objs := $(addprefix $(obj)/,$(host-progs-multi-objs))
+
+# The temporary file to save gcc -MD generated dependencies must not
+# contain a comma
+depfile = $(subst $(comma),_,$(@D)/.$(@F).d)
+
+# ===========================================================================
+
 ifeq ($(strip $(export-objs)),)
 
 # If we don't export any symbols in this dir, just descend
 # ---------------------------------------------------------------------------
 
-fastdep: $(subdir-ym)
+modver: $(subdir-ym)
 	@:
 
 else
@@ -55,7 +153,7 @@ cmd_cc_ver_c = $(CPP) $(c_flags) $< | $(GENKSYMS) $(genksyms_smp_prefix) \
 # o If the $(CPP) fails, we won't notice because it's output is piped
 #   to $(GENKSYMS) which does not fail. We recognize this case by
 #   looking if the generated $(depfile) exists, though.
-# o If the .ver file changed, touch modversions.h, which is our maker
+# o If the .ver file changed, touch modversions.h, which is our marker
 #   of any changed .ver files.
 # o Move command line and deps into their normal .*.cmd place.  
 
@@ -72,14 +170,63 @@ define rule_cc_ver_c
 	mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd
 endef
 
+targets := $(addprefix $(MODVERDIR)/,$(export-objs:.o=.ver))
+
 $(MODVERDIR)/%.ver: %.c FORCE
 	@$(call if_changed_rule,cc_ver_c)
 
-targets := $(addprefix $(MODVERDIR)/,$(export-objs:.o=.ver))
-
-fastdep: $(targets) $(subdir-ym)
+modver: $(targets) $(subdir-ym)
 	@mkdir -p $(dir $(addprefix .tmp_export-objs/modules/,$(export-objs:.o=.ver)))
 	@touch $(addprefix .tmp_export-objs/modules/,$(export-objs:.o=.ver))
 
 endif # export-objs 
 
+# Shipped files
+# ===========================================================================
+
+quiet_cmd_shipped = SHIPPED $@
+cmd_shipped = cat $< > $@
+
+%:: %_shipped
+	$(call cmd,shipped)
+
+# ===========================================================================
+# Generic stuff
+# ===========================================================================
+
+# Descending
+# ---------------------------------------------------------------------------
+
+.PHONY: $(subdir-ym)
+$(subdir-ym):
+	$(Q)$(MAKE) -f scripts/Makefile.modver obj=$@
+
+# Add FORCE to the prequisites of a target to force it to be always rebuilt.
+# ---------------------------------------------------------------------------
+
+.PHONY: FORCE
+
+FORCE:
+
+# Read all saved command lines and dependencies for the $(targets) we
+# may be building above, using $(if_changed{,_dep}). As an
+# optimization, we don't need to read them if the target does not
+# exist, we will rebuild anyway in that case.
+
+targets := $(wildcard $(sort $(targets)))
+cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
+
+ifneq ($(cmd_files),)
+  include $(cmd_files)
+endif
+
+# Usage: $(call if_changed_rule,foo)
+# will check if $(cmd_foo) changed, or any of the prequisites changed,
+# and if so will execute $(rule_foo)
+
+if_changed_rule = $(if $(strip $? \
+		               $(filter-out $(cmd_$(1)),$(cmd_$@))\
+			       $(filter-out $(cmd_$@),$(cmd_$(1)))),\
+			@set -e; \
+			mkdir -p $(dir $@); \
+			$(rule_$(1)))