akaros/scripts/Kbuild.include
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   1####
   2# kbuild: Generic definitions
   3
   4# Convenient variables
   5comma   := ,
   6squote  := '
   7empty   :=
   8space   := $(empty) $(empty)
   9
  10###
  11# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
  12dot-target = $(dir $@).$(notdir $@)
  13
  14###
  15# The temporary file to save gcc -MD generated dependencies must not
  16# contain a comma
  17depfile = $(subst $(comma),_,$(dot-target).d)
  18
  19###
  20# filename of target with directory and extension stripped
  21basetarget = $(basename $(notdir $@))
  22
  23###
  24# Escape single quote for use in echo statements
  25escsq = $(subst $(squote),'\$(squote)',$1)
  26
  27###
  28# Easy method for doing a status message
  29       kecho := :
  30 quiet_kecho := echo
  31silent_kecho := :
  32kecho := $($(quiet)kecho)
  33
  34###
  35# filechk is used to check if the content of a generated file is updated.
  36# Sample usage:
  37# define filechk_sample
  38#       echo $KERNELRELEASE
  39# endef
  40# version.h : Makefile
  41#       $(call filechk,sample)
  42# The rule defined shall write to stdout the content of the new file.
  43# The existing file will be compared with the new one.
  44# - If no file exist it is created
  45# - If the content differ the new file is used
  46# - If they are equal no change, and no timestamp update
  47# - stdin is piped in from the first prerequisite ($<) so one has
  48#   to specify a valid file as first prerequisite (often the kbuild file)
  49define filechk
  50        $(Q)set -e;                             \
  51        $(kecho) '  CHK     $@';                \
  52        mkdir -p $(dir $@);                     \
  53        $(filechk_$(1)) < $< > $@.tmp;          \
  54        if [ -r $@ ] && cmp -s $@ $@.tmp; then  \
  55                rm -f $@.tmp;                   \
  56        else                                    \
  57                $(kecho) '  UPD     $@';        \
  58                mv -f $@.tmp $@;                \
  59        fi
  60endef
  61
  62######
  63# gcc support functions
  64# See documentation in Documentation/kbuild/makefiles.txt
  65
  66# cc-cross-prefix
  67# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
  68# Return first prefix where a prefix$(CC) is found in PATH.
  69# If no $(CC) found in PATH with listed prefixes return nothing
  70cc-cross-prefix =  \
  71        $(word 1, $(foreach c,$(1),                                   \
  72                $(shell set -e;                                       \
  73                if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
  74                        echo $(c);                                    \
  75                fi)))
  76
  77# output directory for tests below
  78TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
  79
  80# try-run
  81# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
  82# Exit code chooses option. "$$TMP" is can be used as temporary file and
  83# is automatically cleaned up.
  84try-run = $(shell set -e;               \
  85        TMP="$(TMPOUT).$$$$.tmp";       \
  86        TMPO="$(TMPOUT).$$$$.o";        \
  87        if ($(1)) >/dev/null 2>&1;      \
  88        then echo "$(2)";               \
  89        else echo "$(3)";               \
  90        fi;                             \
  91        rm -f "$$TMP" "$$TMPO")
  92
  93# as-option
  94# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
  95
  96as-option = $(call try-run,\
  97        $(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
  98
  99# as-instr
 100# Usage: cflags-y += $(call as-instr,instr,option1,option2)
 101
 102as-instr = $(call try-run,\
 103        /bin/echo -e "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))
 104
 105# cc-option
 106# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 107
 108cc-option = $(call try-run,\
 109        $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
 110
 111# cc-option-yn
 112# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 113cc-option-yn = $(call try-run,\
 114        $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
 115
 116# cc-option-align
 117# Prefix align with either -falign or -malign
 118cc-option-align = $(subst -functions=0,,\
 119        $(call cc-option,-falign-functions=0,-malign-functions=0))
 120
 121# cc-version
 122# Usage gcc-ver := $(call cc-version)
 123cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
 124
 125# cc-fullversion
 126# Usage gcc-ver := $(call cc-fullversion)
 127cc-fullversion = $(shell $(CONFIG_SHELL) \
 128        $(srctree)/scripts/gcc-version.sh -p $(CC))
 129
 130# cc-ifversion
 131# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 132cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
 133
 134# cc-ldoption
 135# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
 136cc-ldoption = $(call try-run,\
 137        $(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))
 138
 139# ld-option
 140# Usage: LDFLAGS += $(call ld-option, -X)
 141ld-option = $(call try-run,\
 142        $(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
 143
 144######
 145
 146###
 147# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 148# Usage:
 149# $(Q)$(MAKE) $(build)=dir
 150build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
 151
 152###
 153# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
 154# Usage:
 155# $(Q)$(MAKE) $(modbuiltin)=dir
 156modbuiltin := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.modbuiltin obj
 157
 158# Prefix -I with $(srctree) if it is not an absolute path.
 159# skip if -I has no parameter
 160addtree = $(if $(patsubst -I%,%,$(1)), \
 161$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
 162
 163# Find all -I options and call addtree
 164flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
 165
 166# echo command.
 167# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 168echo-cmd = $(if $($(quiet)cmd_$(1)),\
 169        echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 170
 171# printing commands
 172cmd = @$(echo-cmd) $(cmd_$(1))
 173
 174# Add $(obj)/ for paths that are not absolute
 175objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 176
 177###
 178# if_changed      - execute command if any prerequisite is newer than
 179#                   target, or command line has changed
 180# if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 181#                   including used config symbols
 182# if_changed_rule - as if_changed but execute rule instead
 183# See Documentation/kbuild/makefiles.txt for more info
 184
 185ifneq ($(KBUILD_NOCMDDEP),1)
 186# Check if both arguments has same arguments. Result is empty string if equal.
 187# User may override this check using make KBUILD_NOCMDDEP=1
 188arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
 189                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )
 190endif
 191
 192# >'< substitution is for echo to work,
 193# >$< substitution to preserve $ when reloading .cmd file
 194# note: when using inline perl scripts [perl -e '...$$t=1;...']
 195# in $(cmd_xxx) double $$ your perl vars
 196make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
 197
 198# Find any prerequisites that is newer than target or that does not exist.
 199# PHONY targets skipped in both cases.
 200any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 201
 202# Execute command if command has changed or prerequisite(s) are updated.
 203#
 204if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 205        @set -e;                                                             \
 206        $(echo-cmd) $(cmd_$(1));                                             \
 207        echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
 208
 209# Execute the command and also postprocess generated .d dependencies file.
 210if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
 211        @set -e;                                                             \
 212        $(echo-cmd) $(cmd_$(1));                                             \
 213        scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
 214        rm -f $(depfile);                                                    \
 215        mv -f $(dot-target).tmp $(dot-target).cmd)
 216
 217# Usage: $(call if_changed_rule,foo)
 218# Will check if $(cmd_foo) or any of the prerequisites changed,
 219# and if so will execute $(rule_foo).
 220if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
 221        @set -e;                                                             \
 222        $(rule_$(1)))
 223
 224###
 225# why - tell why a a target got build
 226#       enabled by make V=2
 227#       Output (listed in the order they are checked):
 228#          (1) - due to target is PHONY
 229#          (2) - due to target missing
 230#          (3) - due to: file1.h file2.h
 231#          (4) - due to command line change
 232#          (5) - due to missing .cmd file
 233#          (6) - due to target not in $(targets)
 234# (1) PHONY targets are always build
 235# (2) No target, so we better build it
 236# (3) Prerequisite is newer than target
 237# (4) The command line stored in the file named dir/.target.cmd
 238#     differed from actual command line. This happens when compiler
 239#     options changes
 240# (5) No dir/.target.cmd file (used to store command line)
 241# (6) No dir/.target.cmd file and target not listed in $(targets)
 242#     This is a good hint that there is a bug in the kbuild file
 243ifeq ($(KBUILD_VERBOSE),2)
 244why =                                                                        \
 245    $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 246        $(if $(wildcard $@),                                                 \
 247            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
 248                $(if $(arg-check),                                           \
 249                    $(if $(cmd_$@),- due to command line change,             \
 250                        $(if $(filter $@, $(targets)),                       \
 251                            - due to missing .cmd file,                      \
 252                            - due to $(notdir $@) not in $$(targets)         \
 253                         )                                                   \
 254                     )                                                       \
 255                 )                                                           \
 256             ),                                                              \
 257             - due to target missing                                         \
 258         )                                                                   \
 259     )
 260
 261echo-why = $(call escsq, $(strip $(why)))
 262endif
 263