Build.include

  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: