####
# kbuild: Generic definitions
-# Convinient variables
+# Convenient variables
comma := ,
squote := '
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
escsq = $(subst $(squote),'\$(squote)',$1)
###
+# Easy method for doing a status message
+ kecho := :
+ quiet_kecho := echo
+silent_kecho := :
+kecho := $($(quiet)kecho)
+
+###
# filechk is used to check if the content of a generated file is updated.
# Sample usage:
# define filechk_sample
# to specify a valid file as first prerequisite (often the kbuild file)
define filechk
$(Q)set -e; \
- echo ' CHK $@'; \
+ $(kecho) ' CHK $@'; \
mkdir -p $(dir $@); \
$(filechk_$(1)) < $< > $@.tmp; \
if [ -r $@ ] && cmp -s $@ $@.tmp; then \
rm -f $@.tmp; \
else \
- echo ' UPD $@'; \
+ $(kecho) ' UPD $@'; \
mv -f $@.tmp $@; \
fi
endef
# gcc support functions
# See documentation in Documentation/kbuild/makefiles.txt
+# cc-cross-prefix
+# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
+# Return first prefix where a prefix$(CC) is found in PATH.
+# If no $(CC) found in PATH with listed prefixes return nothing
+cc-cross-prefix = \
+ $(word 1, $(foreach c,$(1), \
+ $(shell set -e; \
+ if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
+ echo $(c); \
+ fi)))
+
+# output directory for tests below
+TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
+
+# try-run
+# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
+# Exit code chooses option. "$$TMP" is can be used as temporary file and
+# is automatically cleaned up.
+try-run = $(shell set -e; \
+ TMP="$(TMPOUT).$$$$.tmp"; \
+ if ($(1)) >/dev/null 2>&1; \
+ then echo "$(2)"; \
+ else echo "$(3)"; \
+ fi; \
+ rm -f "$$TMP")
+
# as-option
-# Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,)
+# 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 try-run,\
+ $(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
+
+# as-instr
+# Usage: cflags-y += $(call as-instr,instr,option1,option2)
+
+as-instr = $(call try-run,\
+ echo -e "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))
# cc-option
-# Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
+# 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 try-run,\
+ $(CC) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
# cc-option-yn
-# Usage: flag := $(call cc-option-yn, -march=winchip-c6)
-cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
- > /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
+# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
+cc-option-yn = $(call try-run,\
+ $(CC) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
# cc-option-align
# Prefix align with either -falign or -malign
$(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 \
- $(if $(1), $(1), $(CC)))
+# Usage gcc-ver := $(call cc-version)
+cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
+
+# cc-fullversion
+# Usage gcc-ver := $(call cc-fullversion)
+cc-fullversion = $(shell $(CONFIG_SHELL) \
+ $(srctree)/scripts/gcc-version.sh -p $(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 -o ldtest$$$$.out -xc /dev/null \
- > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi; \
- rm -f ldtest$$$$.out)
+ld-option = $(call try-run,\
+ $(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))
+
+######
###
# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
# $(Q)$(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.
+# skip if -I has no parameter
+addtree = $(if $(patsubst -I%,%,$(1)), \
+$(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
+# 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)/$(o)))
###
-# if_changed - execute command if any prerequisite is newer than
+# if_changed - execute command if any prerequisite is newer than
# target, or command line has changed
# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
# including used config symbols
# See Documentation/kbuild/makefiles.txt for more info
ifneq ($(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 $(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)))';)
-
+# >'< 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 $$,$$$$,$(call escsq,$(cmd_$(1)))))
-# function to only execute the passed command if necessary
-# >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file
-# note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars
+# 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 prerequisite(s) are updated.
#
-if_changed = $(if $(strip $(filter-out $(PHONY),$?) \
- $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
- @set -e; \
- $(echo-cmd) $(cmd_$(1)); \
- echo 'cmd_$@ := $(make-cmd)' > $(@D)/.$(@F).cmd)
-
-# execute the command and also postprocess generated .d dependencies
-# file
-if_changed_dep = $(if $(strip $(filter-out $(PHONY),$?) \
- $(filter-out FORCE $(wildcard $^),$^) \
- $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
- @set -e; \
- $(echo-cmd) $(cmd_$(1)); \
- scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(@D)/.$(@F).tmp; \
- rm -f $(depfile); \
- mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)
+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 $(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 $(filter-out $(PHONY),$?) \
- $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\
- @set -e; \
- $(rule_$(1)))
+# Will check if $(cmd_foo) or any of the prerequisites changed,
+# and if so will execute $(rule_foo).
+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