1# SPDX-License-Identifier: GPL-2.0 2### 3# Main build makefile. 4# 5# Lots of this code have been borrowed or heavily inspired from parts 6# of kbuild code, which is not credited, but mostly developed by: 7# 8# Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015 9# Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015 10# 11 12PHONY := __build 13__build: 14 15ifeq ($(V),1) 16 quiet = 17 Q = 18else 19 quiet=quiet_ 20 Q=@ 21endif 22 23# If the user is running make -s (silent mode), suppress echoing of commands 24# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS. 25ifeq ($(filter 3.%,$(MAKE_VERSION)),) 26short-opts := $(firstword -$(MAKEFLAGS)) 27else 28short-opts := $(filter-out --%,$(MAKEFLAGS)) 29endif 30 31ifneq ($(findstring s,$(short-opts)),) 32 quiet=silent_ 33endif 34 35build-dir := $(srctree)/tools/build 36 37# Define $(fixdep) for dep-cmd function 38ifeq ($(OUTPUT),) 39 fixdep := $(build-dir)/fixdep 40else 41 fixdep := $(OUTPUT)/fixdep 42endif 43 44# Generic definitions 45include $(build-dir)/Build.include 46 47# do not force detected configuration 48-include $(OUTPUT).config-detected 49 50# Init all relevant variables used in build files so 51# 1) they have correct type 52# 2) they do not inherit any value from the environment 53subdir-y := 54obj-y := 55subdir-y := 56subdir-obj-y := 57 58# Build definitions 59build-file := $(dir)/Build 60-include $(build-file) 61 62quiet_cmd_flex = FLEX $@ 63quiet_cmd_bison = BISON $@ 64quiet_cmd_test = TEST $@ 65 66# Create directory unless it exists 67quiet_cmd_mkdir = MKDIR $(dir $@) 68 cmd_mkdir = mkdir -p $(dir $@) 69 rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir)) 70 71# Compile command 72quiet_cmd_cc_o_c = CC $@ 73 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 74 75quiet_cmd_host_cc_o_c = HOSTCC $@ 76 cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $< 77 78quiet_cmd_cxx_o_c = CXX $@ 79 cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $< 80 81quiet_cmd_cpp_i_c = CPP $@ 82 cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $< 83 84quiet_cmd_cc_s_c = AS $@ 85 cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $< 86 87quiet_cmd_gen = GEN $@ 88 89# Link agregate command 90# If there's nothing to link, create empty $@ object. 91quiet_cmd_ld_multi = LD $@ 92 cmd_ld_multi = $(if $(strip $(obj-y)),\ 93 $(LD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@) 94 95quiet_cmd_host_ld_multi = HOSTLD $@ 96 cmd_host_ld_multi = $(if $(strip $(obj-y)),\ 97 $(HOSTLD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@) 98 99ifneq ($(filter $(obj),$(hostprogs)),) 100 host = host_ 101endif 102 103# Build rules 104$(OUTPUT)%.o: %.c FORCE 105 $(call rule_mkdir) 106 $(call if_changed_dep,$(host)cc_o_c) 107 108$(OUTPUT)%.o: %.cpp FORCE 109 $(call rule_mkdir) 110 $(call if_changed_dep,cxx_o_c) 111 112$(OUTPUT)%.o: %.S FORCE 113 $(call rule_mkdir) 114 $(call if_changed_dep,$(host)cc_o_c) 115 116$(OUTPUT)%.i: %.c FORCE 117 $(call rule_mkdir) 118 $(call if_changed_dep,cpp_i_c) 119 120$(OUTPUT)%.s: %.S FORCE 121 $(call rule_mkdir) 122 $(call if_changed_dep,cpp_i_c) 123 124$(OUTPUT)%.s: %.c FORCE 125 $(call rule_mkdir) 126 $(call if_changed_dep,cc_s_c) 127 128# bison and flex files are generated in the OUTPUT directory 129# so it needs a separate rule to depend on them properly 130$(OUTPUT)%-bison.o: $(OUTPUT)%-bison.c FORCE 131 $(call rule_mkdir) 132 $(call if_changed_dep,$(host)cc_o_c) 133 134$(OUTPUT)%-flex.o: $(OUTPUT)%-flex.c FORCE 135 $(call rule_mkdir) 136 $(call if_changed_dep,$(host)cc_o_c) 137 138# Gather build data: 139# obj-y - list of build objects 140# subdir-y - list of directories to nest 141# subdir-obj-y - list of directories objects 'dir/$(obj)-in.o' 142obj-y := $($(obj)-y) 143subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y))) 144obj-y := $(patsubst %/, %/$(obj)-in.o, $(obj-y)) 145subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y)) 146 147# '$(OUTPUT)/dir' prefix to all objects 148objprefix := $(subst ./,,$(OUTPUT)$(dir)/) 149obj-y := $(addprefix $(objprefix),$(obj-y)) 150subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y)) 151 152# Final '$(obj)-in.o' object 153in-target := $(objprefix)$(obj)-in.o 154 155PHONY += $(subdir-y) 156 157$(subdir-y): 158 $(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj) 159 160$(sort $(subdir-obj-y)): $(subdir-y) ; 161 162$(in-target): $(obj-y) FORCE 163 $(call rule_mkdir) 164 $(call if_changed,$(host)ld_multi) 165 166__build: $(in-target) 167 @: 168 169PHONY += FORCE 170FORCE: 171 172# Include all cmd files to get all the dependency rules 173# for all objects included 174targets := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS))) 175cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 176 177ifneq ($(cmd_files),) 178 include $(cmd_files) 179endif 180 181.PHONY: $(PHONY) 182