xref: /linux/tools/build/Makefile.build (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78) 
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   $@
56
57# Create directory unless it exists
58quiet_cmd_mkdir = MKDIR   $(dir $@)
59      cmd_mkdir = mkdir -p $(dir $@)
60     rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir))
61
62# Compile command
63quiet_cmd_cc_o_c = CC      $@
64      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
65
66quiet_cmd_host_cc_o_c = HOSTCC  $@
67      cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $<
68
69quiet_cmd_cxx_o_c = CXX     $@
70      cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $<
71
72quiet_cmd_cpp_i_c = CPP     $@
73      cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $<
74
75quiet_cmd_cc_s_c = AS      $@
76      cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $<
77
78quiet_cmd_gen = GEN     $@
79
80# Link agregate command
81# If there's nothing to link, create empty $@ object.
82quiet_cmd_ld_multi = LD      $@
83      cmd_ld_multi = $(if $(strip $(obj-y)),\
84                     $(LD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
85
86quiet_cmd_host_ld_multi = HOSTLD  $@
87      cmd_host_ld_multi = $(if $(strip $(obj-y)),\
88                          $(HOSTLD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
89
90ifneq ($(filter $(obj),$(hostprogs)),)
91  host = host_
92endif
93
94# Build rules
95$(OUTPUT)%.o: %.c FORCE
96	$(call rule_mkdir)
97	$(call if_changed_dep,$(host)cc_o_c)
98
99$(OUTPUT)%.o: %.cpp FORCE
100	$(call rule_mkdir)
101	$(call if_changed_dep,cxx_o_c)
102
103$(OUTPUT)%.o: %.S FORCE
104	$(call rule_mkdir)
105	$(call if_changed_dep,$(host)cc_o_c)
106
107$(OUTPUT)%.i: %.c FORCE
108	$(call rule_mkdir)
109	$(call if_changed_dep,cpp_i_c)
110
111$(OUTPUT)%.s: %.S FORCE
112	$(call rule_mkdir)
113	$(call if_changed_dep,cpp_i_c)
114
115$(OUTPUT)%.s: %.c FORCE
116	$(call rule_mkdir)
117	$(call if_changed_dep,cc_s_c)
118
119# Gather build data:
120#   obj-y        - list of build objects
121#   subdir-y     - list of directories to nest
122#   subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'
123obj-y        := $($(obj)-y)
124subdir-y     := $(patsubst %/,%,$(filter %/, $(obj-y)))
125obj-y        := $(patsubst %/, %/$(obj)-in.o, $(obj-y))
126subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y))
127
128# '$(OUTPUT)/dir' prefix to all objects
129objprefix    := $(subst ./,,$(OUTPUT)$(dir)/)
130obj-y        := $(addprefix $(objprefix),$(obj-y))
131subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y))
132
133# Final '$(obj)-in.o' object
134in-target := $(objprefix)$(obj)-in.o
135
136PHONY += $(subdir-y)
137
138$(subdir-y):
139	$(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj)
140
141$(sort $(subdir-obj-y)): $(subdir-y) ;
142
143$(in-target): $(obj-y) FORCE
144	$(call rule_mkdir)
145	$(call if_changed,$(host)ld_multi)
146
147__build: $(in-target)
148	@:
149
150PHONY += FORCE
151FORCE:
152
153# Include all cmd files to get all the dependency rules
154# for all objects included
155targets   := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS)))
156cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
157
158ifneq ($(cmd_files),)
159  include $(cmd_files)
160endif
161
162.PHONY: $(PHONY)
163