LXR linux/tools/build/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   := \#
  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