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