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 := \# 16empty := 17space := $(empty) $(empty) 18 19### 20# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 21dot-target = $(dir $@).$(notdir $@) 22 23### 24# filename of target with directory and extension stripped 25basetarget = $(basename $(notdir $@)) 26 27### 28# The temporary file to save gcc -MD generated dependencies must not 29# contain a comma 30depfile = $(subst $(comma),_,$(dot-target).d) 31 32### 33# Check if both arguments has same arguments. Result is empty string if equal. 34arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ 35 $(filter-out $(cmd_$@), $(cmd_$(1))) ) 36 37### 38# Escape single quote for use in echo statements 39escsq = $(subst $(squote),'\$(squote)',$1) 40 41# Echo command 42# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 43echo-cmd = $(if $($(quiet)cmd_$(1)),\ 44 echo ' $(call escsq,$($(quiet)cmd_$(1)))';) 45 46### 47# Replace >$< with >$$< to preserve $ when reloading the .cmd file 48# (needed for make) 49# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 50# (needed for make) 51# Replace >'< with >'\''< to be able to enclose the whole string in '...' 52# (needed for the shell) 53make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 54 55### 56# Find any prerequisites that is newer than target or that does not exist. 57# PHONY targets skipped in both cases. 58any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) 59 60### 61# Copy dependency data into .cmd file 62# - gcc -M dependency info 63# - command line to create object 'cmd_object :=' 64dep-cmd = $(if $(wildcard $(fixdep)), \ 65 $(fixdep) $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp; \ 66 rm -f $(depfile); \ 67 mv -f $(dot-target).tmp $(dot-target).cmd, \ 68 printf '$(pound) cannot find fixdep (%s)\n' $(fixdep) > $(dot-target).cmd; \ 69 printf '$(pound) using basic dep data\n\n' >> $(dot-target).cmd; \ 70 cat $(depfile) >> $(dot-target).cmd; \ 71 printf '\n%s\n' 'cmd_$@ := $(make-cmd)' >> $(dot-target).cmd) 72 73### 74# if_changed_dep - execute command if any prerequisite is newer than 75# target, or command line has changed and update 76# dependencies in the cmd file 77if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)), \ 78 @set -e; \ 79 $(echo-cmd) $(cmd_$(1)); \ 80 $(dep-cmd)) 81 82# if_changed - execute command if any prerequisite is newer than 83# target, or command line has changed 84if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 85 @set -e; \ 86 $(echo-cmd) $(cmd_$(1)); \ 87 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) 88 89### 90# C flags to be used in rule definitions, includes: 91# - depfile generation 92# - global $(CFLAGS) 93# - per target C flags 94# - per object C flags 95# - BUILD_STR macro to allow '-D"$(variable)"' constructs 96c_flags_1 = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj)) 97c_flags_2 = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(c_flags_1)) 98c_flags = $(filter-out $(CFLAGS_REMOVE_$(obj)), $(c_flags_2)) 99cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj)) 100 101### 102# Rust flags to be used on rule definition, includes: 103# - global $(RUST_FLAGS) 104# - per target Rust flags 105# - per object Rust flags 106rust_flags_1 = $(RUST_FLAGS) $(RUST_FLAGS_$(basetarget).o) $(RUST_FLAGS_$(obj)) 107rust_flags_2 = $(filter-out $(RUST_FLAGS_REMOVE_$(basetarget).o), $(rust_flags_1)) 108rust_flags = $(filter-out $(RUST_FLAGS_REMOVE_$(obj)), $(rust_flags_2)) 109 110### 111## HOSTCC C flags 112 113host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj)) 114 115# output directory for tests below 116TMPOUT = .tmp_$$$$ 117 118# try-run 119# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 120# Exit code chooses option. "$$TMP" serves as a temporary file and is 121# automatically cleaned up. 122try-run = $(shell set -e; \ 123 TMP=$(TMPOUT)/tmp; \ 124 mkdir -p $(TMPOUT); \ 125 trap "rm -rf $(TMPOUT)" EXIT; \ 126 if ($(1)) >/dev/null 2>&1; \ 127 then echo "$(2)"; \ 128 else echo "$(3)"; \ 129 fi) 130 131# cc-option 132# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 133cc-option = $(call try-run, \ 134 $(CC) -Werror $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 135 136# delete partially updated (i.e. corrupted) files on error 137.DELETE_ON_ERROR: 138