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1###2# build: Generic definitions3#4# Lots of this code have been borrowed or heavily inspired from parts5# of kbuild code, which is not credited, but mostly developed by:6#7# Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 20158# Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 20159#10 11###12# Convenient variables13comma := ,14squote := '15pound := \#16 17###18# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o19dot-target = $(dir $@).$(notdir $@)20 21###22# filename of target with directory and extension stripped23basetarget = $(basename $(notdir $@))24 25###26# The temporary file to save gcc -MD generated dependencies must not27# contain a comma28depfile = $(subst $(comma),_,$(dot-target).d)29 30###31# Check if both arguments has same arguments. Result is empty string if equal.32arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \33 $(filter-out $(cmd_$@), $(cmd_$(1))) )34 35###36# Escape single quote for use in echo statements37escsq = $(subst $(squote),'\$(squote)',$1)38 39# Echo command40# Short version is used, if $(quiet) equals `quiet_', otherwise full one.41echo-cmd = $(if $($(quiet)cmd_$(1)),\42 echo ' $(call escsq,$($(quiet)cmd_$(1)))';)43 44###45# Replace >$< with >$$< to preserve $ when reloading the .cmd file46# (needed for make)47# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file48# (needed for make)49# Replace >'< with >'\''< to be able to enclose the whole string in '...'50# (needed for the shell)51make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))52 53###54# Find any prerequisites that is newer than target or that does not exist.55# PHONY targets skipped in both cases.56any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)57 58###59# Copy dependency data into .cmd file60# - gcc -M dependency info61# - command line to create object 'cmd_object :='62dep-cmd = $(if $(wildcard $(fixdep)), \63 $(fixdep) $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp; \64 rm -f $(depfile); \65 mv -f $(dot-target).tmp $(dot-target).cmd, \66 printf '$(pound) cannot find fixdep (%s)\n' $(fixdep) > $(dot-target).cmd; \67 printf '$(pound) using basic dep data\n\n' >> $(dot-target).cmd; \68 cat $(depfile) >> $(dot-target).cmd; \69 printf '\n%s\n' 'cmd_$@ := $(make-cmd)' >> $(dot-target).cmd)70 71###72# if_changed_dep - execute command if any prerequisite is newer than73# target, or command line has changed and update74# dependencies in the cmd file75if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)), \76 @set -e; \77 $(echo-cmd) $(cmd_$(1)); \78 $(dep-cmd))79 80# if_changed - execute command if any prerequisite is newer than81# target, or command line has changed82if_changed = $(if $(strip $(any-prereq) $(arg-check)), \83 @set -e; \84 $(echo-cmd) $(cmd_$(1)); \85 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)86 87###88# C flags to be used in rule definitions, includes:89# - depfile generation90# - global $(CFLAGS)91# - per target C flags92# - per object C flags93# - BUILD_STR macro to allow '-D"$(variable)"' constructs94c_flags_1 = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj))95c_flags_2 = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(c_flags_1))96c_flags = $(filter-out $(CFLAGS_REMOVE_$(obj)), $(c_flags_2))97cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj))98 99###100## HOSTCC C flags101 102host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj))103 104# output directory for tests below105TMPOUT = .tmp_$$$$106 107# try-run108# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)109# Exit code chooses option. "$$TMP" serves as a temporary file and is110# automatically cleaned up.111try-run = $(shell set -e; \112 TMP=$(TMPOUT)/tmp; \113 mkdir -p $(TMPOUT); \114 trap "rm -rf $(TMPOUT)" EXIT; \115 if ($(1)) >/dev/null 2>&1; \116 then echo "$(2)"; \117 else echo "$(3)"; \118 fi)119 120# cc-option121# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)122cc-option = $(call try-run, \123 $(CC) -Werror $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))124 125# delete partially updated (i.e. corrupted) files on error126.DELETE_ON_ERROR:127