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 15build-dir := $(srctree)/tools/build 16 17# Define $(fixdep) for dep-cmd function 18ifeq ($(OUTPUT),) 19 fixdep := $(build-dir)/fixdep 20else 21 fixdep := $(OUTPUT)/fixdep 22endif 23 24# Generic definitions 25include $(build-dir)/Build.include 26 27# do not force detected configuration 28-include $(OUTPUT).config-detected 29 30# Init all relevant variables used in build files so 31# 1) they have correct type 32# 2) they do not inherit any value from the environment 33subdir-y := 34obj-y := 35subdir-y := 36subdir-obj-y := 37 38# Build definitions 39build-file := $(dir)/Build 40-include $(build-file) 41 42quiet_cmd_flex = FLEX $@ 43quiet_cmd_bison = BISON $@ 44quiet_cmd_test = TEST $@ 45 46# Create directory unless it exists 47quiet_cmd_mkdir = MKDIR $(dir $@) 48 cmd_mkdir = mkdir -p $(dir $@) 49 rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir)) 50 51# Compile command 52quiet_cmd_cc_o_c = CC $@ 53 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 54 55quiet_cmd_host_cc_o_c = HOSTCC $@ 56 cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $< 57 58quiet_cmd_cxx_o_c = CXX $@ 59 cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $< 60 61quiet_cmd_cpp_i_c = CPP $@ 62 cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $< 63 64quiet_cmd_cc_s_c = AS $@ 65 cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $< 66 67quiet_cmd_gen = GEN $@ 68 69# Link agregate command 70# If there's nothing to link, create empty $@ object. 71quiet_cmd_ld_multi = LD $@ 72 cmd_ld_multi = $(if $(strip $(obj-y)),\ 73 printf "$(objprefix)%s " $(patsubst $(objprefix)%,%,$(filter $(obj-y),$^)) | \ 74 xargs $(LD) -r -o $@,rm -f $@; $(AR) rcs $@) 75 76quiet_cmd_host_ld_multi = HOSTLD $@ 77 cmd_host_ld_multi = $(if $(strip $(obj-y)),\ 78 printf "$(objprefix)%s " $(patsubst $(objprefix)%,%,$(filter $(obj-y),$^)) | \ 79 xargs $(HOSTLD) -r -o $@,rm -f $@; $(HOSTAR) rcs $@) 80 81rust_common_cmd = \ 82 $(RUSTC) $(rust_flags) \ 83 --crate-type staticlib -L $(objtree)/rust/ \ 84 --emit=dep-info=$(depfile),link 85 86quiet_cmd_rustc_a_rs = $(RUSTC) $(quiet_modtag) $@ 87 cmd_rustc_a_rs = $(rust_common_cmd) -o $@ -g $< $(cmd_objtool) 88 89ifneq ($(filter $(obj),$(hostprogs)),) 90 host = host_ 91endif 92 93# Build rules 94$(OUTPUT)%.o: %.c FORCE 95 $(call rule_mkdir) 96 $(call if_changed_dep,$(host)cc_o_c) 97 98$(OUTPUT)%.o: %.cpp FORCE 99 $(call rule_mkdir) 100 $(call if_changed_dep,cxx_o_c) 101 102$(OUTPUT)%.o: %.S FORCE 103 $(call rule_mkdir) 104 $(call if_changed_dep,$(host)cc_o_c) 105 106$(OUTPUT)%.i: %.c FORCE 107 $(call rule_mkdir) 108 $(call if_changed_dep,cpp_i_c) 109 110$(OUTPUT)%.s: %.S FORCE 111 $(call rule_mkdir) 112 $(call if_changed_dep,cpp_i_c) 113 114$(OUTPUT)%.s: %.c FORCE 115 $(call rule_mkdir) 116 $(call if_changed_dep,cc_s_c) 117 118# it's recommended to build a static rust library, when a foreight (to rust) 119# linker is used. 120$(OUTPUT)%.a: %.rs FORCE 121 $(call rule_mkdir) 122 $(call if_changed_dep,rustc_a_rs) 123 124# bison and flex files are generated in the OUTPUT directory 125# so it needs a separate rule to depend on them properly 126$(OUTPUT)%-bison.o: $(OUTPUT)%-bison.c FORCE 127 $(call rule_mkdir) 128 $(call if_changed_dep,$(host)cc_o_c) 129 130$(OUTPUT)%-flex.o: $(OUTPUT)%-flex.c FORCE 131 $(call rule_mkdir) 132 $(call if_changed_dep,$(host)cc_o_c) 133 134# Gather build data: 135# obj-y - list of build objects 136# subdir-y - list of directories to nest 137# subdir-obj-y - list of directories objects 'dir/$(obj)-in.o' 138obj-y := $($(obj)-y) 139subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y))) 140obj-y := $(patsubst %/, %/$(obj)-in.o, $(obj-y)) 141subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y)) 142 143# '$(OUTPUT)/dir' prefix to all objects 144objprefix := $(subst ./,,$(OUTPUT)$(dir)/) 145obj-y := $(addprefix $(objprefix),$(obj-y)) 146subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y)) 147 148# Separate out test log files from real build objects. 149test-y := $(filter %_log, $(obj-y)) 150obj-y := $(filter-out %_log, $(obj-y)) 151 152# Final '$(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) $(test-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