empty :=
space := $(empty) $(empty)
+###
+# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
+dot-target = $(dir $@).$(notdir $@)
+
###
# The temporary file to save gcc -MD generated dependencies must not
# contain a comma
-depfile = $(subst $(comma),_,$(@D)/.$(@F).d)
+depfile = $(subst $(comma),_,$(dot-target).d)
+
+###
+# filename of target with directory and extension stripped
+basetarget = $(basename $(notdir $@))
###
# Escape single quote for use in echo statements
fi
endef
+######
+# gcc support functions
+# See documentation in Documentation/kbuild/makefiles.txt
+
+# output directory for tests below
+TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
+
+# 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-instr
+# Usage: cflags-y += $(call as-instr, instr, option1, option2)
+
+as-instr = $(shell if echo -e "$(1)" | \
+ $(CC) $(AFLAGS) -c -xassembler - \
+ -o $(TMPOUT)astest$$$$.out > /dev/null 2>&1; \
+ then rm $(TMPOUT)astest$$$$.out; echo "$(2)"; \
+ else echo "$(3)"; fi)
+
+# cc-option
+# Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
+
+cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
+ > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
+
+# cc-option-yn
+# Usage: flag := $(call cc-option-yn, -march=winchip-c6)
+cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
+ > /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
+
+# cc-option-align
+# Prefix align with either -falign or -malign
+cc-option-align = $(subst -functions=0,,\
+ $(call cc-option,-falign-functions=0,-malign-functions=0))
+
+# cc-version
+# Usage gcc-ver := $(call cc-version, $(CC))
+cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
+
+# cc-ifversion
+# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
+cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
+ echo $(3); fi;)
+
+# ld-option
+# Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
+ld-option = $(shell if $(CC) $(1) -nostdlib -xc /dev/null \
+ -o $(TMPOUT)ldtest$$$$.out > /dev/null 2>&1; \
+ then rm $(TMPOUT)ldtest$$$$.out; echo "$(1)"; \
+ else echo "$(2)"; fi)
+
###
# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
# Usage:
# $(Q)$(MAKE) $(build)=dir
build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
+# Prefix -I with $(srctree) if it is not an absolute path
+addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
+# Find all -I options and call addtree
+flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
+
# If quiet is set, only print short version of command
-cmd = @$(if $($(quiet)cmd_$(1)),\
- echo ' $(call escsq,$($(quiet)cmd_$(1)))' &&) $(cmd_$(1))
+cmd = @$(echo-cmd) $(cmd_$(1))
# Add $(obj)/ for paths that is not absolute
objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
ifneq ($(KBUILD_NOCMDDEP),1)
# Check if both arguments has same arguments. Result in empty string if equal
# User may override this check using make KBUILD_NOCMDDEP=1
-arg-check = $(strip $(filter-out $(1), $(2)) $(filter-out $(2), $(1)) )
+arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
+ $(filter-out $(cmd_$@), $(cmd_$(1))) )
endif
# echo command. Short version is $(quiet) equals quiet, otherwise full command
echo-cmd = $(if $($(quiet)cmd_$(1)), \
- echo ' $(call escsq,$($(quiet)cmd_$(1)))';)
-
-# function to only execute the passed command if necessary
-# >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file
-# note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars
-#
-if_changed = $(if $(strip $? $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
- @set -e; \
- $(echo-cmd) \
- $(cmd_$(1)); \
- echo 'cmd_$@ := $(subst $$,$$$$,$(call escsq,$(cmd_$(1))))' > $(@D)/.$(@F).cmd)
+ echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
+
+# >'< substitution is for echo to work,
+# >$< substitution to preserve $ when reloading .cmd file
+# note: when using inline perl scripts [perl -e '...$$t=1;...']
+# in $(cmd_xxx) double $$ your perl vars
+make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
+
+# Find any prerequisites that is newer than target or that does not exist.
+# PHONY targets skipped in both cases.
+any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
+
+# Execute command if command has changed or prerequisitei(s) are updated
+#
+if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
+ @set -e; \
+ $(echo-cmd) $(cmd_$(1)); \
+ echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
# execute the command and also postprocess generated .d dependencies
# file
-if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\
- $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
- @set -e; \
- $(echo-cmd) \
- $(cmd_$(1)); \
- scripts/basic/fixdep $(depfile) $@ '$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))' > $(@D)/.$(@F).tmp; \
- rm -f $(depfile); \
- mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)
+if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
+ @set -e; \
+ $(echo-cmd) $(cmd_$(1)); \
+ scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
+ rm -f $(depfile); \
+ mv -f $(dot-target).tmp $(dot-target).cmd)
# Usage: $(call if_changed_rule,foo)
# will check if $(cmd_foo) changed, or any of the prequisites changed,
# and if so will execute $(rule_foo)
-if_changed_rule = $(if $(strip $? $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\
- @set -e; \
- $(rule_$(1)))
+if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
+ @set -e; \
+ $(rule_$(1)))
+
+###
+# why - tell why a a target got build
+# enabled by make V=2
+# Output (listed in the order they are checked):
+# (1) - due to target is PHONY
+# (2) - due to target missing
+# (3) - due to: file1.h file2.h
+# (4) - due to command line change
+# (5) - due to missing .cmd file
+# (6) - due to target not in $(targets)
+# (1) PHONY targets are always build
+# (2) No target, so we better build it
+# (3) Prerequisite is newer than target
+# (4) The command line stored in the file named dir/.target.cmd
+# differed from actual command line. This happens when compiler
+# options changes
+# (5) No dir/.target.cmd file (used to store command line)
+# (6) No dir/.target.cmd file and target not listed in $(targets)
+# This is a good hint that there is a bug in the kbuild file
+ifeq ($(KBUILD_VERBOSE),2)
+why = \
+ $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
+ $(if $(wildcard $@), \
+ $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
+ $(if $(arg-check), \
+ $(if $(cmd_$@),- due to command line change, \
+ $(if $(filter $@, $(targets)), \
+ - due to missing .cmd file, \
+ - due to $(notdir $@) not in $$(targets) \
+ ) \
+ ) \
+ ) \
+ ), \
+ - due to target missing \
+ ) \
+ )
+
+echo-why = $(call escsq, $(strip $(why)))
+endif