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)); \ 78 $(dep-cmd)) 79 80# if_changed - execute command if any prerequisite is newer than 81# target, or command line has changed 82if_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 generation 90# - global $(CFLAGS) 91# - per target C flags 92# - per object C flags 93# - BUILD_STR macro to allow '-D"$(variable)"' constructs 94c_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 flags 101 102host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(KBUILD_HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj)) 103 104# output directory for tests below 105TMPOUT = .tmp_$$$$ 106 107# try-run 108# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 109# Exit code chooses option. "$$TMP" serves as a temporary file and is 110# automatically cleaned up. 111try-run = $(shell set -e; \ 112 TMP=$(TMPOUT)/tmp; \ 113 mkdir -p $(TMPOUT); \ 114 trap "rm -rf $(TMPOUT)" EXIT; \ 115 if ($(1)) >/dev/null 2>&1; \ 116 then echo "$(2)"; \ 117 else echo "$(3)"; \ 118 fi) 119 120# cc-option 121# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 122cc-option = $(call try-run, \ 123 $(CC) -Werror $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 124 125# delete partially updated (i.e. corrupted) files on error 126.DELETE_ON_ERROR: 127