kbuild: improve option checking, Kbuild.include cleanup GNU binutils, root users, tmpfiles, external modules ro builds must be fixed to do the right thing now. Cc: Roman Zippel Cc: Sam Ravnborg Cc: Horst Schirmeier Cc: Jan Beulich Cc: Daniel Drake Cc: Andi Kleen Cc: Randy Dunlap Signed-off-by: Oleg Verych --- -- all checks by shell united in one macro -- checker-shell; -- one disposable output sym. link to /dev/null per shell, thus no racing, `-Z' is removed; -- modules' build output directory is used, if supplied; -- every option checking function calls shell wrapper, acquires probe; -- `echo -e' bashizm substituted (people with sh != bash have distinct CC options!); -- some spelling and sense added to the comments; -- small shuffle of whitespace. Mostly all people, discussing this back in October are in the Cc list. Sam Ravnborg have not much time to reply. I've added Roman Zippel, as a very kind reviewer and commiter of previous fix. Comments and testing are appreciated. Thanks. scripts/Kbuild.include | 96 +++++++++++++++++++++++++++---------------------- 1 file changed, 53 insertions(+), 43 deletions(-) Index: linux-2.6.20/scripts/Kbuild.include =================================================================== --- linux-2.6.20.orig/scripts/Kbuild.include 2007-02-06 02:12:37.543828750 +0100 +++ linux-2.6.20/scripts/Kbuild.include 2007-02-06 02:14:37.575330250 +0100 @@ -2,5 +2,5 @@ # kbuild: Generic definitions -# Convinient variables +# Convenient constants comma := , squote := ' @@ -57,38 +57,44 @@ endef # See documentation in Documentation/kbuild/makefiles.txt -# output directory for tests below -TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) +# checker-shell +# Usage: option = $(call checker-shell, $(CC)...-o $$OUT, option-ok, otherwise) +# Exit code chooses option. $$OUT is safe location for needless output. +define checker-shell + $(shell set -e; \ + DIR=$(KBUILD_EXTMOD); \ + cd $${DIR:-$(objtree)}; \ + OUT=$$PWD/.$$$$.null; \ + \ + ln -s /dev/null $$OUT; \ + if $(1) >/dev/null 2>&1; \ + then echo "$(2)"; \ + else echo "$(3)"; \ + fi; \ + rm -f $$OUT) +endef # as-option # Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,) - -as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \ - -xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \ - else echo "$(2)"; fi ;) +as-option = $(call checker-shell, \ + $(CC) $(CFLAGS) $(1) -c -xassembler /dev/null -o $$OUT, $(1), $(2)) # as-instr # Usage: cflags-y += $(call as-instr, instr, option1, option2) - -as-instr = $(shell if echo -e "$(1)" | \ - $(CC) $(AFLAGS) -c -xassembler - \ - -o $(TMPOUT)astest$$$$.out > /dev/null 2>&1; \ - then rm $(TMPOUT)astest$$$$.out; echo "$(2)"; \ - else echo "$(3)"; fi) +as-instr = $(call checker-shell, \ + printf "$(1)" | $(CC) $(AFLAGS) -c -xassembler -o $$OUT -, $(2), $(3)) # cc-option # Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586) - -cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \ - > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;) +cc-option = $(call checker-shell, \ + $(CC) $(CFLAGS) $(if $(3),$(3),$(1)) -S -xc /dev/null -o $$OUT, $(1), $(2)) # cc-option-yn # Usage: flag := $(call cc-option-yn, -march=winchip-c6) -cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \ - > /dev/null 2>&1; then echo "y"; else echo "n"; fi;) +cc-option-yn = $(call cc-option, "y", "n", $(1)) # cc-option-align # Prefix align with either -falign or -malign cc-option-align = $(subst -functions=0,,\ - $(call cc-option,-falign-functions=0,-malign-functions=0)) + $(call cc-option,-falign-functions=0,-malign-functions=0)) # cc-version @@ -98,15 +104,13 @@ cc-version = $(shell $(CONFIG_SHELL) $(s # cc-ifversion # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) -cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \ - echo $(3); fi;) +cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3)) # ld-option # Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both) -ld-option = $(shell if $(CC) $(1) -nostdlib -xc /dev/null \ - -o $(TMPOUT)ldtest$$$$.out > /dev/null 2>&1; \ - then rm $(TMPOUT)ldtest$$$$.out; echo "$(1)"; \ - else echo "$(2)"; fi) +ld-option = $(call checker-shell, \ + $(CC) $(1) -nostdlib -xc /dev/null -o $$OUT, $(1), $(2)) + +###### -### # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= # Usage: @@ -114,17 +118,26 @@ ld-option = $(shell if $(CC) $(1) -nostd build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj -# Prefix -I with $(srctree) if it is not an absolute path -addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1) +# Prefix -I with $(srctree) if it is not an absolute path, +# add original to the end +addtree = $(if \ + $(filter-out -I/%, $(1)), $(patsubst -I%,-I$(srctree)/%,$(1))) $(1) + # Find all -I options and call addtree -flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) +flags = $(foreach o,$($(1)), \ + $(if $(filter -I%,$(o)), $(call addtree, $(o)), $(o))) -# If quiet is set, only print short version of command +# echo command. +# Short version is used, if $(quiet) equals `quiet_', otherwise full one. +echo-cmd = $(if $($(quiet)cmd_$(1)), \ + echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) + +# printing commands cmd = @$(echo-cmd) $(cmd_$(1)) -# Add $(obj)/ for paths that is not absolute -objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) +# Add $(obj)/ for paths that are not absolute +objectify = $(foreach o,$(1), $(if $(filter /%,$(o)), $(o), $(obj)/$(o))) ### -# if_changed - execute command if any prerequisite is newer than +# if_changed - execute command if any prerequisite is newer than # target, or command line has changed # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies @@ -134,5 +147,5 @@ objectify = $(foreach o,$(1),$(if $(filt ifneq ($(KBUILD_NOCMDDEP),1) -# Check if both arguments has same arguments. Result in empty string if equal +# Check if both arguments has same arguments. Result is empty string, if equal. # User may override this check using make KBUILD_NOCMDDEP=1 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ @@ -140,8 +153,4 @@ arg-check = $(strip $(filter-out $(cmd_$ endif -# echo command. Short version is $(quiet) equals quiet, otherwise full command -echo-cmd = $(if $($(quiet)cmd_$(1)), \ - echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) - # >'< substitution is for echo to work, # >$< substitution to preserve $ when reloading .cmd file @@ -154,5 +163,5 @@ make-cmd = $(subst \#,\\\#,$(subst $$,$$ any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) -# Execute command if command has changed or prerequisitei(s) are updated +# Execute command if command has changed or prerequisite(s) are updated. # if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ @@ -161,6 +170,6 @@ if_changed = $(if $(strip $(any-prereq) echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) -# execute the command and also postprocess generated .d dependencies -# file +# Execute the command and also postprocess generated .d dependencies file. +# if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ @set -e; \ @@ -170,7 +179,8 @@ if_changed_dep = $(if $(strip $(any-prer mv -f $(dot-target).tmp $(dot-target).cmd) +# Will check if $(cmd_foo) changed, or any of the prerequisites changed, +# and if so will execute $(rule_foo). # 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 $(any-prereq) $(arg-check) ), \ @set -e; \ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/