1### 2# build: Generic definitions 3# 4# Lots of this code have been borrowed or heavily inspired from parts 5# of kbuild code, which is not credited, but mostly developed by: 6# 7# Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015 8# Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015 9# 10 11### 12# Convenient variables 13comma := , 14squote := ' 15pound := \# 16 17### 18# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 19dot-target = $(dir $@).$(notdir $@) 20 21### 22# filename of target with directory and extension stripped 23basetarget = $(basename $(notdir $@)) 24 25### 26# The temporary file to save gcc -MD generated dependencies must not 27# contain a comma 28depfile = $(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 statements 37escsq = $(subst $(squote),'\$(squote)',$1) 38 39# Echo command 40# 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 >$$< to preserve $ when reloading the .cmd file 46# (needed for make) 47# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 48# (needed for make) 49# Replace >'< with >'\''< to be able to enclose the whole string in '...' 50# (needed for the shell) 51make-cmd = $(call escsq,$(subst $(pound),$$(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 file 60# - gcc -M dependency info 61# - 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 than 73# target, or command line has changed and update 74# dependencies in the cmd file 75if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)), \ 76 @set -e; \ 77 $(echo-cmd) $(cmd_$(1)) && $(dep-cmd)) 78 79# if_changed - execute command if any prerequisite is newer than 80# target, or command line has changed 81if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 82 @set -e; \ 83 $(echo-cmd) $(cmd_$(1)); \ 84 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) 85 86### 87# C flags to be used in rule definitions, includes: 88# - depfile generation 89# - global $(CFLAGS) 90# - per target C flags 91# - per object C flags 92# - BUILD_STR macro to allow '-D"$(variable)"' constructs 93c_flags_1 = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj)) 94c_flags_2 = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(c_flags_1)) 95c_flags = $(filter-out $(CFLAGS_REMOVE_$(obj)), $(c_flags_2)) 96cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj)) 97 98### 99## HOSTCC C flags 100 101host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(KBUILD_HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj)) 102