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