Commit 5de043f4 authored by Oleg Verych's avatar Oleg Verych Committed by Linus Torvalds
Browse files

[PATCH] 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 <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Horst Schirmeier <horst@schirmeier.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Daniel Drake <dsd@gentoo.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarOleg Verych <olecom@flower.upol.cz>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f6112ec2

scripts/Kbuild.include

+53 −43
Original line number Diff line number Diff line 
####

# kbuild: Generic definitions



# Convinient variables

# Convenient constants

comma   := ,

squote  := '

empty   :=
@@ -56,35 +56,41 @@ endef 
# gcc support functions

# 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
@@ -97,31 +103,38 @@ cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) 


# 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:

# $(Q)$(MAKE) $(build)=dir

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

# Add $(obj)/ for paths that are not absolute

objectify = $(foreach o,$(1), $(if $(filter /%,$(o)), $(o), $(obj)/$(o)))



###
@@ -133,16 +146,12 @@ objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) 
# See Documentation/kbuild/makefiles.txt for more info



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)), $(cmd_$@)) \

                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )

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

# note: when using inline perl scripts [perl -e '...$$t=1;...']
@@ -153,15 +162,15 @@ make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))) 
# PHONY targets skipped in both cases.

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)),                       \

	@set -e;                                                             \

	$(echo-cmd) $(cmd_$(1));                                             \

	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;                                                             \

	$(echo-cmd) $(cmd_$(1));                                             \
@@ -169,9 +178,10 @@ if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ 
	rm -f $(depfile);                                                    \

	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;                                                             \

	$(rule_$(1)))

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