Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 ($(V),1)
16 quiet =
17 Q =
18else
19 quiet=quiet_
20 Q=@
21endif
22
23ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
24 quiet=silent_
25endif
26
27build-dir := $(srctree)/tools/build
28
29# Define $(fixdep) for dep-cmd function
30ifeq ($(OUTPUT),)
31 fixdep := $(build-dir)/fixdep
32else
33 fixdep := $(OUTPUT)/fixdep
34endif
35
36# Generic definitions
37include $(build-dir)/Build.include
38
39# do not force detected configuration
40-include $(OUTPUT).config-detected
41
42# Init all relevant variables used in build files so
43# 1) they have correct type
44# 2) they do not inherit any value from the environment
45subdir-y :=
46obj-y :=
47subdir-y :=
48subdir-obj-y :=
49
50# Build definitions
51build-file := $(dir)/Build
52-include $(build-file)
53
54quiet_cmd_flex = FLEX $@
55quiet_cmd_bison = BISON $@
56quiet_cmd_test = TEST $@
57
58# Create directory unless it exists
59quiet_cmd_mkdir = MKDIR $(dir $@)
60 cmd_mkdir = mkdir -p $(dir $@)
61 rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir))
62
63# Compile command
64quiet_cmd_cc_o_c = CC $@
65 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
66
67quiet_cmd_host_cc_o_c = HOSTCC $@
68 cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $<
69
70quiet_cmd_cxx_o_c = CXX $@
71 cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $<
72
73quiet_cmd_cpp_i_c = CPP $@
74 cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $<
75
76quiet_cmd_cc_s_c = AS $@
77 cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $<
78
79quiet_cmd_gen = GEN $@
80
81# Link agregate command
82# If there's nothing to link, create empty $@ object.
83quiet_cmd_ld_multi = LD $@
84 cmd_ld_multi = $(if $(strip $(obj-y)),\
85 $(LD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
86
87quiet_cmd_host_ld_multi = HOSTLD $@
88 cmd_host_ld_multi = $(if $(strip $(obj-y)),\
89 $(HOSTLD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
90
91ifneq ($(filter $(obj),$(hostprogs)),)
92 host = host_
93endif
94
95# Build rules
96$(OUTPUT)%.o: %.c FORCE
97 $(call rule_mkdir)
98 $(call if_changed_dep,$(host)cc_o_c)
99
100$(OUTPUT)%.o: %.cpp FORCE
101 $(call rule_mkdir)
102 $(call if_changed_dep,cxx_o_c)
103
104$(OUTPUT)%.o: %.S FORCE
105 $(call rule_mkdir)
106 $(call if_changed_dep,$(host)cc_o_c)
107
108$(OUTPUT)%.i: %.c FORCE
109 $(call rule_mkdir)
110 $(call if_changed_dep,cpp_i_c)
111
112$(OUTPUT)%.s: %.S FORCE
113 $(call rule_mkdir)
114 $(call if_changed_dep,cpp_i_c)
115
116$(OUTPUT)%.s: %.c FORCE
117 $(call rule_mkdir)
118 $(call if_changed_dep,cc_s_c)
119
120# Gather build data:
121# obj-y - list of build objects
122# subdir-y - list of directories to nest
123# subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'
124obj-y := $($(obj)-y)
125subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
126obj-y := $(patsubst %/, %/$(obj)-in.o, $(obj-y))
127subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y))
128
129# '$(OUTPUT)/dir' prefix to all objects
130objprefix := $(subst ./,,$(OUTPUT)$(dir)/)
131obj-y := $(addprefix $(objprefix),$(obj-y))
132subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y))
133
134# Final '$(obj)-in.o' object
135in-target := $(objprefix)$(obj)-in.o
136
137PHONY += $(subdir-y)
138
139$(subdir-y):
140 $(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj)
141
142$(sort $(subdir-obj-y)): $(subdir-y) ;
143
144$(in-target): $(obj-y) FORCE
145 $(call rule_mkdir)
146 $(call if_changed,$(host)ld_multi)
147
148__build: $(in-target)
149 @:
150
151PHONY += FORCE
152FORCE:
153
154# Include all cmd files to get all the dependency rules
155# for all objects included
156targets := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS)))
157cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
158
159ifneq ($(cmd_files),)
160 include $(cmd_files)
161endif
162
163.PHONY: $(PHONY)