Commit 4f193362 authored by Paul Smith's avatar Paul Smith Committed by Sam Ravnborg
Browse files

kbuild: change kbuild to not rely on incorrect GNU make behavior 

The kbuild system takes advantage of an incorrect behavior in GNU make.
Once this behavior is fixed, all files in the kernel rebuild every time,
even if nothing has changed.  This patch ensures kbuild works with both
the incorrect and correct behaviors of GNU make.

For more details on the incorrect behavior, see:

http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html



Changes in this patch:
  - Keep all targets that are to be marked .PHONY in a variable, PHONY.
  - Add .PHONY: $(PHONY) to mark them properly.
  - Remove any $(PHONY) files from the $? list when determining whether
    targets are up-to-date or not.

Signed-off-by: default avatarPaul Smith <psmith@gnu.org>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent 7b75b13c

Documentation/DocBook/Makefile

+7 −1
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ PS_METHOD = $(prefer-db2x) 


###

# The targets that may be used.

.PHONY:	xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs

PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs



BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))

xmldocs: $(BOOKS)
@@ -211,3 +211,9 @@ clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) 


#man put files in man subdir - traverse down

subdir- := man/





# Declare the contents of the .PHONY variable as phony.  We keep that

# information in a variable se we can use it in if_changed and friends.



.PHONY: $(PHONY)

Makefile

+35 −29
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ ifdef O 
endif



# That's our default target when none is given on the command line

.PHONY: _all

PHONY := _all

_all:



ifneq ($(KBUILD_OUTPUT),)
@@ -106,7 +106,7 @@ KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd) 
$(if $(KBUILD_OUTPUT),, \

     $(error output directory "$(saved-output)" does not exist))



.PHONY: $(MAKECMDGOALS)

PHONY += $(MAKECMDGOALS)



$(filter-out _all,$(MAKECMDGOALS)) _all:

	$(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) \
@@ -123,7 +123,7 @@ ifeq ($(skip-makefile),) 


# If building an external module we do not care about the all: rule

# but instead _all depend on modules

.PHONY: all

PHONY += all

ifeq ($(KBUILD_EXTMOD),)

_all: all

else
@@ -337,14 +337,14 @@ export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn --exc 
# Rules shared between *config targets and build targets



# Basic helpers built in scripts/

.PHONY: scripts_basic

PHONY += scripts_basic

scripts_basic:

	$(Q)$(MAKE) $(build)=scripts/basic



# To avoid any implicit rule to kick in, define an empty command.

scripts/basic/%: scripts_basic ;



.PHONY: outputmakefile

PHONY += outputmakefile

# outputmakefile generate a Makefile to be placed in output directory, if

# using a seperate output directory. This allows convinient use

# of make in output directory
@@ -420,7 +420,7 @@ ifeq ($(KBUILD_EXTMOD),) 
# Additional helpers built in scripts/

# Carefully list dependencies so we do not try to build scripts twice

# in parrallel

.PHONY: scripts

PHONY += scripts

scripts: scripts_basic include/config/MARKER

	$(Q)$(MAKE) $(build)=$(@)
@@ -720,7 +720,7 @@ $(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ; 
# make menuconfig etc.

# Error messages still appears in the original language



.PHONY: $(vmlinux-dirs)

PHONY += $(vmlinux-dirs)

$(vmlinux-dirs): prepare scripts

	$(Q)$(MAKE) $(build)=$@
@@ -773,10 +773,10 @@ kernelrelease = $(KERNELVERSION)$(localver-full) 
# version.h and scripts_basic is processed / created.



# Listed in dependency order

.PHONY: prepare archprepare prepare0 prepare1 prepare2 prepare3

PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3



# prepare-all is deprecated, use prepare as valid replacement

.PHONY: prepare-all

PHONY += prepare-all



# prepare3 is used to check if we are building in a separate output directory,

# and if so do:
@@ -857,7 +857,7 @@ include/linux/version.h: $(srctree)/Makefile .config .kernelrelease FORCE 


# ---------------------------------------------------------------------------



.PHONY: depend dep

PHONY += depend dep

depend dep:

	@echo '*** Warning: make $@ is unnecessary now.'
@@ -872,21 +872,21 @@ all: modules 


#	Build modules



.PHONY: modules

PHONY += modules

modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux)

	@echo '  Building modules, stage 2.';

	$(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost





# Target to prepare building external modules

.PHONY: modules_prepare

PHONY += modules_prepare

modules_prepare: prepare scripts



# Target to install modules

.PHONY: modules_install

PHONY += modules_install

modules_install: _modinst_ _modinst_post



.PHONY: _modinst_

PHONY += _modinst_

_modinst_:

	@if [ -z "`$(DEPMOD) -V 2>/dev/null | grep module-init-tools`" ]; then \

		echo "Warning: you may need to install module-init-tools"; \
@@ -913,7 +913,7 @@ depmod_opts := 
else

depmod_opts	:= -b $(INSTALL_MOD_PATH) -r

endif

.PHONY: _modinst_post

PHONY += _modinst_post

_modinst_post: _modinst_

	if [ -r System.map -a -x $(DEPMOD) ]; then $(DEPMOD) -ae -F System.map $(depmod_opts) $(KERNELRELEASE); fi
@@ -956,7 +956,7 @@ clean: rm-dirs := $(CLEAN_DIRS) 
clean: rm-files := $(CLEAN_FILES)

clean-dirs      := $(addprefix _clean_,$(srctree) $(vmlinux-alldirs))



.PHONY: $(clean-dirs) clean archclean

PHONY += $(clean-dirs) clean archclean

$(clean-dirs):

	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
@@ -974,7 +974,7 @@ mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS)) 
mrproper: rm-files := $(wildcard $(MRPROPER_FILES))

mrproper-dirs      := $(addprefix _mrproper_,Documentation/DocBook scripts)



.PHONY: $(mrproper-dirs) mrproper archmrproper

PHONY += $(mrproper-dirs) mrproper archmrproper

$(mrproper-dirs):

	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
@@ -984,7 +984,7 @@ mrproper: clean archmrproper $(mrproper-dirs) 


# distclean

#

.PHONY: distclean

PHONY += distclean



distclean: mrproper

	@find $(srctree) $(RCS_FIND_IGNORE) \
@@ -1000,7 +1000,7 @@ distclean: mrproper 
# rpm target kept for backward compatibility

package-dir	:= $(srctree)/scripts/package



.PHONY: %-pkg rpm

PHONY += %-pkg rpm



%pkg: FORCE

	$(Q)$(MAKE) -f $(package-dir)/Makefile $@
@@ -1092,12 +1092,12 @@ else # KBUILD_EXTMOD 


# We are always building modules

KBUILD_MODULES := 1

.PHONY: crmodverdir

PHONY += crmodverdir

crmodverdir:

	$(Q)rm -rf $(MODVERDIR)

	$(Q)mkdir -p $(MODVERDIR)



.PHONY: $(objtree)/Module.symvers

PHONY += $(objtree)/Module.symvers

$(objtree)/Module.symvers:

	@test -e $(objtree)/Module.symvers || ( \

	echo; \
@@ -1106,7 +1106,7 @@ $(objtree)/Module.symvers: 
	echo )



module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))

.PHONY: $(module-dirs) modules

PHONY += $(module-dirs) modules

$(module-dirs): crmodverdir $(objtree)/Module.symvers

	$(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
@@ -1114,11 +1114,11 @@ modules: $(module-dirs) 
	@echo '  Building modules, stage 2.';

	$(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost



.PHONY: modules_install

PHONY += modules_install

modules_install: _emodinst_ _emodinst_post



install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)

.PHONY: _emodinst_

PHONY += _emodinst_

_emodinst_:

	$(Q)rm -rf $(MODLIB)/$(install-dir)

	$(Q)mkdir -p $(MODLIB)/$(install-dir)
@@ -1133,13 +1133,13 @@ quiet_cmd_depmod = DEPMOD $(KERNELRELEASE) 
		      $(KERNELRELEASE);                       \

                   fi



.PHONY: _emodinst_post

PHONY += _emodinst_post

_emodinst_post: _emodinst_

	$(call cmd,depmod)



clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))



.PHONY: $(clean-dirs) clean

PHONY += $(clean-dirs) clean

$(clean-dirs):

	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
@@ -1161,7 +1161,7 @@ help: 
	@echo  ''



# Dummies...

.PHONY: prepare scripts

PHONY += prepare scripts

prepare: ;

scripts: ;

endif # KBUILD_EXTMOD
@@ -1274,7 +1274,7 @@ namespacecheck: 
endif #ifeq ($(config-targets),1)

endif #ifeq ($(mixed-targets),1)



.PHONY: checkstack

PHONY += checkstack

checkstack:

	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \

	$(PERL) $(src)/scripts/checkstack.pl $(ARCH)
@@ -1357,4 +1357,10 @@ clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj 


endif	# skip-makefile



PHONY += FORCE

FORCE:





# Declare the contents of the .PHONY variable as phony.  We keep that

# information in a variable se we can use it in if_changed and friends.

.PHONY: $(PHONY)

arch/arm/Makefile

+4 −1
Original line number Diff line number Diff line 
#

# arch/arm/Makefile

#

# This file is included by the global makefile so that you can add your own

# architecture-specific flags and dependencies.

#

# This file is subject to the terms and conditions of the GNU General Public

# License.  See the file "COPYING" in the main directory of this archive

# for more details.
@@ -176,7 +179,7 @@ endif 


archprepare: maketools



.PHONY: maketools FORCE

PHONY += maketools FORCE

maketools: include/linux/version.h include/asm-arm/.arch FORCE

	$(Q)$(MAKE) $(build)=arch/arm/tools include/asm-arm/mach-types.h

arch/arm/boot/Makefile

+4 −1
Original line number Diff line number Diff line 
#

# arch/arm/boot/Makefile

#

# This file is included by the global makefile so that you can add your own

# architecture-specific flags and dependencies.

#

# This file is subject to the terms and conditions of the GNU General Public

# License.  See the file "COPYING" in the main directory of this archive

# for more details.
@@ -73,7 +76,7 @@ $(obj)/bootpImage: $(obj)/bootp/bootp FORCE 
	$(call if_changed,objcopy)

	@echo '  Kernel: $@ is ready'



.PHONY: initrd FORCE

PHONY += initrd FORCE

initrd:

	@test "$(INITRD_PHYS)" != "" || \

	(echo This machine does not support INITRD; exit -1)

arch/arm/boot/bootp/Makefile

+4 −1
Original line number Diff line number Diff line 
#

# linux/arch/arm/boot/bootp/Makefile

#

# This file is included by the global makefile so that you can add your own

# architecture-specific flags and dependencies.

#



LDFLAGS_bootp	:=-p --no-undefined -X \

		 --defsym initrd_phys=$(INITRD_PHYS) \
@@ -21,4 +24,4 @@ $(obj)/kernel.o: arch/arm/boot/zImage FORCE 


$(obj)/initrd.o: $(INITRD) FORCE



.PHONY:	$(INITRD) FORCE
 
PHONY += $(INITRD) FORCE

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