Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1###
2# build: Generic definitions
3#
4# Lots of this code have been borrowed or heavily inspired from parts
5# of kbuild code, which is not credited, but mostly developed by:
6#
7# Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015
8# Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015
9#
10
11###
12# Convenient variables
13comma := ,
14squote := '
15pound := \#
16empty :=
17space := $(empty) $(empty)
18
19###
20# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
21dot-target = $(dir $@).$(notdir $@)
22
23###
24# filename of target with directory and extension stripped
25basetarget = $(basename $(notdir $@))
26
27###
28# The temporary file to save gcc -MD generated dependencies must not
29# contain a comma
30depfile = $(subst $(comma),_,$(dot-target).d)
31
32###
33# Check if both arguments has same arguments. Result is empty string if equal.
34arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
35 $(filter-out $(cmd_$@), $(cmd_$(1))) )
36
37###
38# Escape single quote for use in echo statements
39escsq = $(subst $(squote),'\$(squote)',$1)
40
41# Echo command
42# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
43echo-cmd = $(if $($(quiet)cmd_$(1)),\
44 echo ' $(call escsq,$($(quiet)cmd_$(1)))';)
45
46###
47# Replace >$< with >$$< to preserve $ when reloading the .cmd file
48# (needed for make)
49# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
50# (needed for make)
51# Replace >'< with >'\''< to be able to enclose the whole string in '...'
52# (needed for the shell)
53make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
54
55###
56# Find any prerequisites that is newer than target or that does not exist.
57# PHONY targets skipped in both cases.
58any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
59
60###
61# Copy dependency data into .cmd file
62# - gcc -M dependency info
63# - command line to create object 'cmd_object :='
64dep-cmd = $(if $(wildcard $(fixdep)), \
65 $(fixdep) $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp; \
66 rm -f $(depfile); \
67 mv -f $(dot-target).tmp $(dot-target).cmd, \
68 printf '$(pound) cannot find fixdep (%s)\n' $(fixdep) > $(dot-target).cmd; \
69 printf '$(pound) using basic dep data\n\n' >> $(dot-target).cmd; \
70 cat $(depfile) >> $(dot-target).cmd; \
71 printf '\n%s\n' 'cmd_$@ := $(make-cmd)' >> $(dot-target).cmd)
72
73###
74# if_changed_dep - execute command if any prerequisite is newer than
75# target, or command line has changed and update
76# dependencies in the cmd file
77if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)), \
78 @set -e; \
79 $(echo-cmd) $(cmd_$(1)); \
80 $(dep-cmd))
81
82# if_changed - execute command if any prerequisite is newer than
83# target, or command line has changed
84if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
85 @set -e; \
86 $(echo-cmd) $(cmd_$(1)); \
87 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
88
89###
90# C flags to be used in rule definitions, includes:
91# - depfile generation
92# - global $(CFLAGS)
93# - per target C flags
94# - per object C flags
95# - BUILD_STR macro to allow '-D"$(variable)"' constructs
96c_flags_1 = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj))
97c_flags_2 = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(c_flags_1))
98c_flags = $(filter-out $(CFLAGS_REMOVE_$(obj)), $(c_flags_2))
99cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj))
100
101###
102## HOSTCC C flags
103
104host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj))
105
106# output directory for tests below
107TMPOUT = .tmp_$$$$
108
109# try-run
110# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
111# Exit code chooses option. "$$TMP" serves as a temporary file and is
112# automatically cleaned up.
113try-run = $(shell set -e; \
114 TMP=$(TMPOUT)/tmp; \
115 mkdir -p $(TMPOUT); \
116 trap "rm -rf $(TMPOUT)" EXIT; \
117 if ($(1)) >/dev/null 2>&1; \
118 then echo "$(2)"; \
119 else echo "$(3)"; \
120 fi)
121
122# cc-option
123# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
124cc-option = $(call try-run, \
125 $(CC) -Werror $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
126
127# delete partially updated (i.e. corrupted) files on error
128.DELETE_ON_ERROR: