From 4f1933620f57145212cdbb1ac6ce099eeeb21c5a Mon Sep 17 00:00:00 2001 From: Paul Smith Date: Sun, 5 Mar 2006 17:14:10 -0500 Subject: 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 $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith Signed-off-by: Sam Ravnborg --- Makefile | 64 +++++++++++++++++++++++++++++++++++----------------------------- 1 file changed, 35 insertions(+), 29 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 12c8d71..a59c1e2 100644 --- a/Makefile +++ b/Makefile @@ -95,7 +95,7 @@ ifdef O endif # That's our default target when none is given on the command line -.PHONY: _all +PHONY := _all _all: ifneq ($(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_ +install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra) +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) -- cgit v1.1