scripts/Kbuild.include

   1 ####
   2 # kbuild: Generic definitions
   3
   4 # Convenient variables
   5 comma   := ,
   6 squote  := '
   7 empty   :=
   8 space   := $(empty) $(empty)
   9
  10 ###
  11 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
  12 dot-target = $(dir $@).$(notdir $@)
  13
  14 ###
  15 # The temporary file to save gcc -MD generated dependencies must not
  16 # contain a comma
  17 depfile = $(subst $(comma),_,$(dot-target).d)
  18
  19 ###
  20 # filename of target with directory and extension stripped
  21 basetarget = $(basename $(notdir $@))
  22
  23 ###
  24 # filename of first prerequisite with directory and extension stripped
  25 baseprereq = $(basename $(notdir $<))
  26
  27 ###
  28 # Escape single quote for use in echo statements
  29 escsq = $(subst $(squote),'\$(squote)',$1)
  30
  31 ###
  32 # Easy method for doing a status message
  33        kecho := :
  34  quiet_kecho := echo
  35 silent_kecho := :
  36 kecho := $($(quiet)kecho)
  37
  38 ###
  39 # filechk is used to check if the content of a generated file is updated.
  40 # Sample usage:
  41 # define filechk_sample
  42 #       echo $KERNELRELEASE
  43 # endef
  44 # version.h : Makefile
  45 #       $(call filechk,sample)
  46 # The rule defined shall write to stdout the content of the new file.
  47 # The existing file will be compared with the new one.
  48 # - If no file exist it is created
  49 # - If the content differ the new file is used
  50 # - If they are equal no change, and no timestamp update
  51 # - stdin is piped in from the first prerequisite ($<) so one has
  52 #   to specify a valid file as first prerequisite (often the kbuild file)
  53 define filechk
  54         $(Q)set -e;                             \
  55         $(kecho) '  CHK     $@';                \
  56         mkdir -p $(dir $@);                     \
  57         $(filechk_$(1)) < $< > $@.tmp;          \
  58         if [ -r $@ ] && cmp -s $@ $@.tmp; then  \
  59                 rm -f $@.tmp;                   \
  60         else                                    \
  61                 $(kecho) '  UPD     $@';        \
  62                 mv -f $@.tmp $@;                \
  63         fi
  64 endef
  65
  66 ######
  67 # gcc support functions
  68 # See documentation in Documentation/kbuild/makefiles.txt
  69
  70 # cc-cross-prefix
  71 # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
  72 # Return first prefix where a prefix$(CC) is found in PATH.
  73 # If no $(CC) found in PATH with listed prefixes return nothing
  74 cc-cross-prefix =  \
  75         $(word 1, $(foreach c,$(1),                                   \
  76                 $(shell set -e;                                       \
  77                 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
  78                         echo $(c);                                    \
  79                 fi)))
  80
  81 # output directory for tests below
  82 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
  83
  84 # try-run
  85 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
  86 # Exit code chooses option. "$$TMP" is can be used as temporary file and
  87 # is automatically cleaned up.
  88 try-run = $(shell set -e;               \
  89         TMP="$(TMPOUT).$$$$.tmp";       \
  90         TMPO="$(TMPOUT).$$$$.o";        \
  91         if ($(1)) >/dev/null 2>&1;      \
  92         then echo "$(2)";               \
  93         else echo "$(3)";               \
  94         fi;                             \
  95         rm -f "$$TMP" "$$TMPO")
  96
  97 # as-option
  98 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
  99
 100 as-option = $(call try-run,\
 101         $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
 102
 103 # as-instr
 104 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
 105
 106 as-instr = $(call try-run,\
 107         printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
 108
 109 # cc-option
 110 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 111
 112 cc-option = $(call try-run,\
 113         $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 114
 115 # cc-option-yn
 116 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 117 cc-option-yn = $(call try-run,\
 118         $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 119
 120 # cc-option-align
 121 # Prefix align with either -falign or -malign
 122 cc-option-align = $(subst -functions=0,,\
 123         $(call cc-option,-falign-functions=0,-malign-functions=0))
 124
 125 # cc-disable-warning
 126 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 127 cc-disable-warning = $(call try-run,\
 128         $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 129
 130 # cc-version
 131 # Usage gcc-ver := $(call cc-version)
 132 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
 133
 134 # cc-fullversion
 135 # Usage gcc-ver := $(call cc-fullversion)
 136 cc-fullversion = $(shell $(CONFIG_SHELL) \
 137         $(srctree)/scripts/gcc-version.sh -p $(CC))
 138
 139 # cc-ifversion
 140 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 141 cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
 142
 143 # cc-ldoption
 144 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
 145 cc-ldoption = $(call try-run,\
 146         $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
 147
 148 # ld-option
 149 # Usage: LDFLAGS += $(call ld-option, -X)
 150 ld-option = $(call try-run,\
 151         $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
 152
 153 # ar-option
 154 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
 155 # Important: no spaces around options
 156 ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
 157
 158 ######
 159
 160 ###
 161 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 162 # Usage:
 163 # $(Q)$(MAKE) $(build)=dir
 164 build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
 165
 166 ###
 167 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
 168 # Usage:
 169 # $(Q)$(MAKE) $(modbuiltin)=dir
 170 modbuiltin := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.modbuiltin obj
 171
 172 # Prefix -I with $(srctree) if it is not an absolute path.
 173 # skip if -I has no parameter
 174 addtree = $(if $(patsubst -I%,%,$(1)), \
 175 $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
 176
 177 # Find all -I options and call addtree
 178 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
 179
 180 # echo command.
 181 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 182 echo-cmd = $(if $($(quiet)cmd_$(1)),\
 183         echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 184
 185 # printing commands
 186 cmd = @$(echo-cmd) $(cmd_$(1))
 187
 188 # Add $(obj)/ for paths that are not absolute
 189 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 190
 191 ###
 192 # if_changed      - execute command if any prerequisite is newer than
 193 #                   target, or command line has changed
 194 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 195 #                   including used config symbols
 196 # if_changed_rule - as if_changed but execute rule instead
 197 # See Documentation/kbuild/makefiles.txt for more info
 198
 199 ifneq ($(KBUILD_NOCMDDEP),1)
 200 # Check if both arguments has same arguments. Result is empty string if equal.
 201 # User may override this check using make KBUILD_NOCMDDEP=1
 202 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
 203                     $(filter-out $(cmd_$@),   $(cmd_$(1))) )
 204 else
 205 arg-check = $(if $(strip $(cmd_$@)),,1)
 206 endif
 207
 208 # >'< substitution is for echo to work,
 209 # >$< substitution to preserve $ when reloading .cmd file
 210 # note: when using inline perl scripts [perl -e '...$$t=1;...']
 211 # in $(cmd_xxx) double $$ your perl vars
 212 make-cmd = $(subst \\,\\\\,$(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))))
 213
 214 # Find any prerequisites that is newer than target or that does not exist.
 215 # PHONY targets skipped in both cases.
 216 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 217
 218 # Execute command if command has changed or prerequisite(s) are updated.
 219 #
 220 if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 221         @set -e;                                                             \
 222         $(echo-cmd) $(cmd_$(1));                                             \
 223         echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
 224
 225 # Execute the command and also postprocess generated .d dependencies file.
 226 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
 227         @set -e;                                                             \
 228         $(echo-cmd) $(cmd_$(1));                                             \
 229         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
 230         rm -f $(depfile);                                                    \
 231         mv -f $(dot-target).tmp $(dot-target).cmd)
 232
 233 # Usage: $(call if_changed_rule,foo)
 234 # Will check if $(cmd_foo) or any of the prerequisites changed,
 235 # and if so will execute $(rule_foo).
 236 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
 237         @set -e;                                                             \
 238         $(rule_$(1)))
 239
 240 ###
 241 # why - tell why a a target got build
 242 #       enabled by make V=2
 243 #       Output (listed in the order they are checked):
 244 #          (1) - due to target is PHONY
 245 #          (2) - due to target missing
 246 #          (3) - due to: file1.h file2.h
 247 #          (4) - due to command line change
 248 #          (5) - due to missing .cmd file
 249 #          (6) - due to target not in $(targets)
 250 # (1) PHONY targets are always build
 251 # (2) No target, so we better build it
 252 # (3) Prerequisite is newer than target
 253 # (4) The command line stored in the file named dir/.target.cmd
 254 #     differed from actual command line. This happens when compiler
 255 #     options changes
 256 # (5) No dir/.target.cmd file (used to store command line)
 257 # (6) No dir/.target.cmd file and target not listed in $(targets)
 258 #     This is a good hint that there is a bug in the kbuild file
 259 ifeq ($(KBUILD_VERBOSE),2)
 260 why =                                                                        \
 261     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 262         $(if $(wildcard $@),                                                 \
 263             $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
 264                 $(if $(arg-check),                                           \
 265                     $(if $(cmd_$@),- due to command line change,             \
 266                         $(if $(filter $@, $(targets)),                       \
 267                             - due to missing .cmd file,                      \
 268                             - due to $(notdir $@) not in $$(targets)         \
 269                          )                                                   \
 270                      )                                                       \
 271                  )                                                           \
 272              ),                                                              \
 273              - due to target missing                                         \
 274          )                                                                   \
 275      )
 276
 277 echo-why = $(call escsq, $(strip $(why)))
 278 endif