release/src-rt-6.x.4708/makefiles/RelPath.mk

   1 ifdef _RELPATH_MK_
   2 $(if $D,$(info =-= Avoiding redundant include ($(MAKEFILE_LIST))))
   3 else
   4 unexport _RELPATH_MK_   # in case of make -e
   5 _RELPATH_MK_ := 1
   6
   7 # Protection against process recursion when this file is
   8 # included by setting MAKEFILES.
   9 ifneq (,$(filter %$(notdir $(lastword $(MAKEFILE_LIST))),$(MAKEFILES)))
  10 MAKEFILES := $(filter-out %$(notdir $(lastword $(MAKEFILE_LIST))),$(MAKEFILES))
  11 ifndef MAKEFILES
  12 unexport MAKEFILES
  13 endif
  14 endif
  15
  16 # Usage: $(call relpath,[<from-dir>,]<to-dir>)
  17 # Returns the relative path from <from-dir> to <to-dir>; <from-dir>
  18 # may be elided in which case it defaults to $(CURDIR).
  19
  20 _rp_space :=
  21 _rp_space +=
  22 _rp_uname_s := $(shell uname -s)
  23
  24 # Utility functions.
  25 _rp_compose = $(subst ${_rp_space},$(strip $1),$(strip $2))
  26 _rp_endlist = $(wordlist $1,$(words $2),$2)
  27 _rp_canonpath = $(if $(findstring CYGWIN,$(_rp_uname_s)),$(shell cygpath -a -u $1),$(abspath $1))
  28
  29 # ----relpath(): Self-recursive function which compares the first element
  30 #                of two given paths, then calls itself with the next two
  31 #                elements, and so on, until a difference is found.  At each
  32 #                step, if the first element of both paths matches, that
  33 #                element is produced.
  34 ----relpath = $(if $(filter $(firstword $1),$(firstword $2)), \
  35                 $(firstword $1) \
  36                 $(call $0,$(call _rp_endlist,2,$1),$(call _rp_endlist,2,$2)) \
  37                )
  38 # ---relpath():  This function removes $1 from the front of both $2 and
  39 #                $3 (removes common path prefix) and generates a relative
  40 #                path between the locations given by $2 and $3, by replacing
  41 #                each remaining element of $2 (after common prefix removal)
  42 #                with '..', then appending the remainder of $3 (after common
  43 #                prefix removal) to the string of '..'s
  44 ---relpath  = $(foreach e,$(subst /, ,$(patsubst $(if $1,/)$1/%,%,$2)),..) \
  45               $(if $3,$(patsubst $(if $1,/)$1/%,%,$3))
  46 # --relpath():   This function runs the output of ----relpath() through
  47 #                ---relpath(), and turns the result into an actual relative
  48 #                path string, separated by '/'.
  49 --relpath   = $(call _rp_compose,/, \
  50                 $(call -$0,$(call _rp_compose,/,$(call --$0,$3,$4)),$1,$2) \
  51                )
  52 # -relpath():    This function makes a determination about the two given
  53 #                paths -- does one strictly prefix the other?  If so, this
  54 #                function produces a relative path between the two inputs,
  55 #                without calling --relpath() and taking the "long road".
  56 #                If $1 prefixes $2, the result is the remainder of $2 after
  57 #                removing $1.  If $2 prefixes $1, the result is the remainder
  58 #                of $1 after removing $2, but with each element in that
  59 #                remainder converted to '..'.
  60 -relpath    = $(if $(filter $1,$2),., \
  61                 $(if $(filter $1/%,$2), \
  62                  $(patsubst $1/%,%,$2), \
  63                  $(if $(filter $2/%,$1), \
  64                    $(call _rp_compose,/, \
  65                      $(foreach e,$(subst /, ,$(patsubst $2/%,%,$1)),..) \
  66                     ), \
  67                    $(call -$0,$1,$2,$(subst /, ,$1),$(subst /, ,$2)) \
  68                   ) \
  69                 ) \
  70               )
  71
  72 # relpath():     This function loops over each element in $2, calculating
  73 #                the relative path from $1 to each element of $2.
  74 relpath     = $(if $1,,$(error Error: missing first parameter to $0))$(strip \
  75                 $(if $2, \
  76                   $(foreach d,$2,$(call -$0,$(call _rp_canonpath,$1),$(call _rp_canonpath,$d))), \
  77                   $(foreach d,$1,$(call -$0,$(call _rp_canonpath,${CURDIR}),$(call _rp_canonpath,$d))) \
  78                  ) \
  79                )
  80
  81 endif #_RELPATH_MK_