#

# Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.

# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

#

# This code is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License version 2 only, as

# published by the Free Software Foundation.  Oracle designates this

# particular file as subject to the "Classpath" exception as provided

# by Oracle in the LICENSE file that accompanied this code.

#

# This code is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

# version 2 for more details (a copy is included in the LICENSE file that

# accompanied this code).

#

# You should have received a copy of the GNU General Public License version

# 2 along with this work; if not, write to the Free Software Foundation,

# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

#

# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

# or visit www.oracle.com if you need additional information or have any

# questions.

#

################################################################

#

# Setup common utility functions.

#

################################################################

ifndef _MAKEBASE_GMK

_MAKEBASE_GMK := 1

################################################################################

# This macro translates $ into \$ to protect the $ from expansion in the shell.

# To make this macro resilient against already escaped strings, first remove

# any present escapes before escaping so that no double escapes are added.

EscapeDollar = $(subst $$,\$$,$(subst \$$,$$,$(strip $1)))

################################################################################

# This macro translates $ into $$ to protect the string from make itself.

DoubleDollar = $(subst $$,$$$$,$(strip $1))

################################################################################

# If the variable that you want to send to stdout for piping into a file or otherwise,

# is potentially long, for example the a list of file paths, eg a list of all package directories.

# Then you need to use ListPathsSafely, which optimistically splits the output into several shell

# calls as well as use compression on recurrent file paths segments, to get around the potential

# command line length problem that exists in cygwin and other shells.

compress_pre:=$(strip $(shell $(CAT) $(SRC_ROOT)/make/common/support/ListPathsSafely-pre-compress.incl))

compress_post:=$(strip $(shell $(CAT) $(SRC_ROOT)/make/common/support/ListPathsSafely-post-compress.incl))

compress_paths=$(compress_pre)\

$(subst $(SRC_ROOT),X97,\

$(subst $(OUTPUT_ROOT),X98,\

$(subst X,X00,\

$(subst $(SPACE),\n,$(strip $1)))))\

$(compress_post)

decompress_paths=$(SED) -f $(SRC_ROOT)/make/common/support/ListPathsSafely-uncompress.sed -e 's|X99|\\n|g' \

    -e 's|X98|$(OUTPUT_ROOT)|g' -e 's|X97|$(SRC_ROOT)|g' \

    -e 's|X00|X|g' | tr '\n' '$2'

define ListPathsSafely_If

	$(if $(word $3,$($1)),$(eval $1_LPS$3:=$(call compress_paths,$(wordlist $3,$4,$($1)))))

endef

define ListPathsSafely_Printf

	$(if $(strip $($1_LPS$4)),$(if $(findstring $(LOG_LEVEL),trace),,@)printf \

	    -- "$(strip $(call EscapeDollar, $($1_LPS$4)))\n" | $(decompress_paths) $3)

endef

# Receipt example:

#   rm -f thepaths

#   $(call ListPathsSafely,THEPATHS,\n, >> thepaths)

# The \n argument means translate spaces into \n

# if instead , , (a space) is supplied, then spaces remain spaces.

define ListPathsSafely

	$(if $(word 16001,$($1)),$(error Cannot list safely more than 16000 paths. $1 has $(words $($1)) paths!))

	$(ECHO) $(LOG_DEBUG) Writing $(words $($1)) paths to '$3'

	$(call ListPathsSafely_If,$1,$2,1,250)

	$(call ListPathsSafely_If,$1,$2,251,500)

	$(call ListPathsSafely_If,$1,$2,501,750)

	$(call ListPathsSafely_If,$1,$2,751,1000)

	$(call ListPathsSafely_If,$1,$2,1001,1250)

	$(call ListPathsSafely_If,$1,$2,1251,1500)

	$(call ListPathsSafely_If,$1,$2,1501,1750)

	$(call ListPathsSafely_If,$1,$2,1751,2000)

	$(call ListPathsSafely_If,$1,$2,2001,2250)

	$(call ListPathsSafely_If,$1,$2,2251,2500)

	$(call ListPathsSafely_If,$1,$2,2501,2750)

	$(call ListPathsSafely_If,$1,$2,2751,3000)

	$(call ListPathsSafely_If,$1,$2,3001,3250)

	$(call ListPathsSafely_If,$1,$2,3251,3500)

	$(call ListPathsSafely_If,$1,$2,3501,3750)

	$(call ListPathsSafely_If,$1,$2,3751,4000)

	$(call ListPathsSafely_If,$1,$2,4001,4250)

	$(call ListPathsSafely_If,$1,$2,4251,4500)

	$(call ListPathsSafely_If,$1,$2,4501,4750)

	$(call ListPathsSafely_If,$1,$2,4751,5000)

	$(call ListPathsSafely_If,$1,$2,5001,5250)

	$(call ListPathsSafely_If,$1,$2,5251,5500)

	$(call ListPathsSafely_If,$1,$2,5501,5750)

	$(call ListPathsSafely_If,$1,$2,5751,6000)

	$(call ListPathsSafely_If,$1,$2,6001,6250)

	$(call ListPathsSafely_If,$1,$2,6251,6500)

	$(call ListPathsSafely_If,$1,$2,6501,6750)

	$(call ListPathsSafely_If,$1,$2,6751,7000)

	$(call ListPathsSafely_If,$1,$2,7001,7250)

	$(call ListPathsSafely_If,$1,$2,7251,7500)

	$(call ListPathsSafely_If,$1,$2,7501,7750)

	$(call ListPathsSafely_If,$1,$2,7751,8000)

	$(call ListPathsSafely_If,$1,$2,8001,8250)

	$(call ListPathsSafely_If,$1,$2,8251,8500)

	$(call ListPathsSafely_If,$1,$2,8501,8750)

	$(call ListPathsSafely_If,$1,$2,8751,9000)

	$(call ListPathsSafely_If,$1,$2,9001,9250)

	$(call ListPathsSafely_If,$1,$2,9251,9500)

	$(call ListPathsSafely_If,$1,$2,9501,9750)

	$(call ListPathsSafely_If,$1,$2,9751,10000)

	$(call ListPathsSafely_If,$1,$2,10001,10250)

	$(call ListPathsSafely_If,$1,$2,10251,10500)

	$(call ListPathsSafely_If,$1,$2,10501,10750)

	$(call ListPathsSafely_If,$1,$2,10751,11000)

	$(call ListPathsSafely_If,$1,$2,11001,11250)

	$(call ListPathsSafely_If,$1,$2,11251,11500)

	$(call ListPathsSafely_If,$1,$2,11501,11750)

	$(call ListPathsSafely_If,$1,$2,11751,12000)

	$(call ListPathsSafely_If,$1,$2,12001,12250)

	$(call ListPathsSafely_If,$1,$2,12251,12500)

	$(call ListPathsSafely_If,$1,$2,12501,12750)

	$(call ListPathsSafely_If,$1,$2,12751,13000)

	$(call ListPathsSafely_If,$1,$2,13001,13250)

	$(call ListPathsSafely_If,$1,$2,13251,13500)

	$(call ListPathsSafely_If,$1,$2,13501,13750)

	$(call ListPathsSafely_If,$1,$2,13751,14000)

	$(call ListPathsSafely_If,$1,$2,14001,14250)

	$(call ListPathsSafely_If,$1,$2,14251,14500)

	$(call ListPathsSafely_If,$1,$2,14501,14750)

	$(call ListPathsSafely_If,$1,$2,14751,15000)

	$(call ListPathsSafely_If,$1,$2,15001,15250)

	$(call ListPathsSafely_If,$1,$2,15251,15500)

	$(call ListPathsSafely_If,$1,$2,15501,15750)

	$(call ListPathsSafely_If,$1,$2,15751,16000)

	$(call ListPathsSafely_Printf,$1,$2,$3,1)

	$(call ListPathsSafely_Printf,$1,$2,$3,251)

	$(call ListPathsSafely_Printf,$1,$2,$3,501)

	$(call ListPathsSafely_Printf,$1,$2,$3,751)

	$(call ListPathsSafely_Printf,$1,$2,$3,1001)

	$(call ListPathsSafely_Printf,$1,$2,$3,1251)

	$(call ListPathsSafely_Printf,$1,$2,$3,1501)

	$(call ListPathsSafely_Printf,$1,$2,$3,1751)

	$(call ListPathsSafely_Printf,$1,$2,$3,2001)

	$(call ListPathsSafely_Printf,$1,$2,$3,2251)

	$(call ListPathsSafely_Printf,$1,$2,$3,2501)

	$(call ListPathsSafely_Printf,$1,$2,$3,2751)

	$(call ListPathsSafely_Printf,$1,$2,$3,3001)

	$(call ListPathsSafely_Printf,$1,$2,$3,3251)

	$(call ListPathsSafely_Printf,$1,$2,$3,3501)

	$(call ListPathsSafely_Printf,$1,$2,$3,3751)

	$(call ListPathsSafely_Printf,$1,$2,$3,4001)

	$(call ListPathsSafely_Printf,$1,$2,$3,4251)

	$(call ListPathsSafely_Printf,$1,$2,$3,4501)

	$(call ListPathsSafely_Printf,$1,$2,$3,4751)

	$(call ListPathsSafely_Printf,$1,$2,$3,5001)

	$(call ListPathsSafely_Printf,$1,$2,$3,5251)

	$(call ListPathsSafely_Printf,$1,$2,$3,5501)

	$(call ListPathsSafely_Printf,$1,$2,$3,5751)

	$(call ListPathsSafely_Printf,$1,$2,$3,6001)

	$(call ListPathsSafely_Printf,$1,$2,$3,6251)

	$(call ListPathsSafely_Printf,$1,$2,$3,6501)

	$(call ListPathsSafely_Printf,$1,$2,$3,6751)

	$(call ListPathsSafely_Printf,$1,$2,$3,7001)

	$(call ListPathsSafely_Printf,$1,$2,$3,7251)

	$(call ListPathsSafely_Printf,$1,$2,$3,7501)

	$(call ListPathsSafely_Printf,$1,$2,$3,7751)

	$(call ListPathsSafely_Printf,$1,$2,$3,8001)

	$(call ListPathsSafely_Printf,$1,$2,$3,8251)

	$(call ListPathsSafely_Printf,$1,$2,$3,8501)

	$(call ListPathsSafely_Printf,$1,$2,$3,8751)

	$(call ListPathsSafely_Printf,$1,$2,$3,9001)

	$(call ListPathsSafely_Printf,$1,$2,$3,9251)

	$(call ListPathsSafely_Printf,$1,$2,$3,9501)

	$(call ListPathsSafely_Printf,$1,$2,$3,9751)

	$(call ListPathsSafely_Printf,$1,$2,$3,10001)

	$(call ListPathsSafely_Printf,$1,$2,$3,10251)

	$(call ListPathsSafely_Printf,$1,$2,$3,10501)

	$(call ListPathsSafely_Printf,$1,$2,$3,10751)

	$(call ListPathsSafely_Printf,$1,$2,$3,11001)

	$(call ListPathsSafely_Printf,$1,$2,$3,11251)

	$(call ListPathsSafely_Printf,$1,$2,$3,11501)

	$(call ListPathsSafely_Printf,$1,$2,$3,11751)

	$(call ListPathsSafely_Printf,$1,$2,$3,12001)

	$(call ListPathsSafely_Printf,$1,$2,$3,12251)

	$(call ListPathsSafely_Printf,$1,$2,$3,12501)

	$(call ListPathsSafely_Printf,$1,$2,$3,12751)

	$(call ListPathsSafely_Printf,$1,$2,$3,13001)

	$(call ListPathsSafely_Printf,$1,$2,$3,13251)

	$(call ListPathsSafely_Printf,$1,$2,$3,13501)

	$(call ListPathsSafely_Printf,$1,$2,$3,13751)

	$(call ListPathsSafely_Printf,$1,$2,$3,14001)

	$(call ListPathsSafely_Printf,$1,$2,$3,14251)

	$(call ListPathsSafely_Printf,$1,$2,$3,14501)

	$(call ListPathsSafely_Printf,$1,$2,$3,14751)

	$(call ListPathsSafely_Printf,$1,$2,$3,15001)

	$(call ListPathsSafely_Printf,$1,$2,$3,15251)

	$(call ListPathsSafely_Printf,$1,$2,$3,15501)

	$(call ListPathsSafely_Printf,$1,$2,$3,15751)

endef

define ListPathsSafelyNow_IfPrintf

  ifneq (,$$(word $4,$$($1)))

    $$(eval $1_LPS$4:=$$(call compress_paths,$$(wordlist $4,$5,$$($1))))

    $$(shell printf -- "$$(strip $$($1_LPS$4))\n" | $(decompress_paths) $3)

  endif

endef

# And an non-receipt version:

define ListPathsSafelyNow

  ifneq (,$$(word 10001,$$($1)))

    $$(error Cannot list safely more than 10000 paths. $1 has $$(words $$($1)) paths!)

  endif

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,1,250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,251,500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,501,750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,751,1000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,1001,1250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,1251,1500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,1501,1750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,1751,2000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,2001,2250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,2251,2500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,2501,2750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,2751,3000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,3001,3250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,3251,3500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,3501,3750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,3751,4000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,4001,4250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,4251,4500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,4501,4750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,4751,5000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,5001,5250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,5251,5500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,5501,5750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,5751,6000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,6001,6250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,6251,6500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,6501,6750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,6751,7000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,7001,7250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,7251,7500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,7501,7750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,7751,8000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,8001,8250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,8251,8500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,8501,8750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,8751,9000)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,9001,9250)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,9251,9500)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,9501,9750)

  $(call ListPathsSafelyNow_IfPrintf,$1,$2,$3,9751,10000)

endef

# The source tips can come from the Mercurial repository, or in the files

# $(HGTIP_FILENAME) which contains the tip but is also positioned in the same

# directory as the original $(HGDIR) directory.

# These should not be := assignments, only used from the root Makefile.

HG_VERSION = $(shell $(HG) version 2> /dev/null)

HG_DIRECTORY=.hg

HGTIP_FILENAME=.hgtip

HG_SEARCH = ./REPO ./*/REPO ./*/*/REPO ./*/*/*/REPO

REPO_LIST = $(patsubst ./%,%,$(patsubst %/,%,$(sort $(dir \

    $(shell $(CD) $(SRC_ROOT) ; ( $(LS) -d $(HG_SEARCH:%/REPO=%/$(HG_DIRECTORY)) ; \

        $(LS) $(HG_SEARCH:%/REPO=%/$(HGTIP_FILENAME)) ) \

        2> /dev/null)))))

# Emit the repo:tip pairs to $@

define GetSourceTips

	$(CD) $(SRC_ROOT) ; \

	for i in $(REPO_LIST) IGNORE ; do \

	  if [ "$${i}" = "IGNORE" ] ; then \

	    continue; \

	  elif [ -d $${i}/$(HG_DIRECTORY) -a "$(HG_VERSION)" != "" ] ; then \

	    $(PRINTF) " %s:%s" \

	        "$${i}" `$(HG) tip --repository $${i} --template '{node|short}\n'` ; \

	  elif [ -f $${i}/$(HGTIP_FILENAME) ] ; then \

	    $(PRINTF) " %s:%s" \

	        "$${i}" `$(CAT) $${i}/$(HGTIP_FILENAME)` ; \

	  fi; \

	done >> $@

	$(PRINTF) "\n" >> $@

endef

# Create the HGTIP_FILENAME file. Called from jdk/make/closed/bundles.gmk

define CreateHgTip

	$(HG) tip --repository $1 --template '{node|short}\n' > $1/$(HGTIP_FILENAME); \

	$(ECHO) $1/$(HGTIP_FILENAME)

endef

define SetupLogging

  ifeq ($$(LOG_LEVEL),trace)

    # Shell redefinition trick inspired by http://www.cmcrossroads.com/ask-mr-make/6535-tracing-rule-execution-in-gnu-make

    # For each target executed, will print

    # Building <TARGET> (from <FIRST PREREQUISITE>) (<ALL NEWER PREREQUISITES> newer)

    # but with a limit of 20 on <ALL NEWER PREREQUISITES>, to avoid cluttering logs too much

    # (and causing a crash on Cygwin).

    # Default shell seems to always be /bin/sh. Must override with bash to get this to work on Solaris.

    # Only use time if it's GNU time which supports format and output file.

    WRAPPER_SHELL:=$$(BASH) $$(SRC_ROOT)/common/bin/shell-tracer.sh $$(if $$(findstring yes,$$(IS_GNU_TIME)),$$(TIME),-) $$(OUTPUT_ROOT)/build-trace-time.log $$(SHELL)

    SHELL=$$(warning $$(if $$@,Building $$@,Running shell command) $$(if $$<, (from $$<))$$(if $$?, ($$(wordlist 1, 20, $$?) $$(if $$(wordlist 21, 22, $$?), ... [in total $$(words $$?) files]) newer)))$$(WRAPPER_SHELL)

  endif

  # Never remove warning messages; this is just for completeness

  LOG_WARN=

  ifneq ($$(findstring $$(LOG_LEVEL),info debug trace),)

    LOG_INFO=

  else

    LOG_INFO=> /dev/null

  endif

  ifneq ($$(findstring $$(LOG_LEVEL),debug trace),)

    LOG_DEBUG=

  else

    LOG_DEBUG=> /dev/null

  endif

  ifneq ($$(findstring $$(LOG_LEVEL),trace),)

    LOG_TRACE=

  else

    LOG_TRACE=> /dev/null

  endif

endef

# Make sure logging is setup for everyone that includes MakeBase.gmk.

$(eval $(call SetupLogging))

# This is to be called by all SetupFoo macros

define LogSetupMacroEntry

  $(if $(27),$(error Internal makefile error: Too many arguments to LogSetupMacroEntry, please update MakeBase.gmk))

  $(if $(findstring $(LOG_LEVEL),debug trace), $(info $1 $(foreach i,2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26,$(if $($i),$(NEWLINE) $(strip [$i] $($i))))))

endef

# Support macro for all SetupFoo macros.

define EvalDebugWrapper

  $(if $(DEBUG_$1),

    $(info -------- <<< Begin expansion of $1)

    $(info $2)

    $(info -------- >>> End expansion of $1)

  )

  $2

endef

# Make directory without forking mkdir if not needed

MakeDir = \

    $(strip $(if $(subst $(wildcard $1 $2 $3 $4 $5 $6 $7 $8 $9),,$(strip $1 $2 $3 $4 $5 $6 $7 $8 $9)),\

      $(shell $(MKDIR) -p $1 $2 $3 $4 $5 $6 $7 $8 $9)))

ifeq ($(OPENJDK_TARGET_OS),solaris)

  # On Solaris, if the target is a symlink and exists, cp won't overwrite.

  # Cp has to operate in recursive mode to allow for -P flag, to preserve soft links. If the

  # name of the target file differs from the source file, rename after copy.

  # If the source and target parent directories are the same, recursive copy doesn't work

  # so we fall back on regular copy, which isn't preserving symlinks.

  define install-file

	$(MKDIR) -p '$(@D)'

	$(RM) '$@'

	if [ "$(@D)" != "$(<D)" ]; then \

	  $(CP) -f -r -P '$<' '$(@D)'; \

	  if [ "$(@F)" != "$(<F)" ]; then \

	    $(MV) '$(@D)/$(<F)' '$@'; \

	  fi; \

	else \

	  if [ -L '$<' ]; then \

	    $(ECHO) "Source file is a symlink and target is in the same directory: $< $@" ; \

	    exit 1; \

	  fi; \

	  $(CP) -f '$<' '$@'; \

	fi

  endef

else ifeq ($(OPENJDK_TARGET_OS),macosx)

  # On mac, extended attributes sometimes creep into the source files, which may later

  # cause the creation of ._* files which confuses testing. Clear these with xattr if

  # set. Some files get their write permissions removed after being copied to the

  # output dir. When these are copied again to images, xattr would fail. By only clearing

  # attributes when they are present, failing on this is avoided.

  define install-file

	$(MKDIR) -p '$(@D)'

	$(CP) -fRP '$<' '$@'

	if [ -n "`$(XATTR) -l '$@'`" ]; then $(XATTR) -c '$@'; fi

  endef

else

  # Running mkdir and cp in the same shell speeds up copy intensive tasks in Cygwin

  # significantly.

  define install-file

	$(MKDIR) -p '$(@D)' && $(CP) -fP '$<' '$@'

  endef

endif

# Convenience functions for working around make's limitations with $(filter ).

containing = $(strip $(foreach v,$(strip $2),$(if $(findstring $(strip $1),$v),$v)))

not-containing = $(strip $(foreach v,$(strip $2),$(if $(findstring $(strip $1),$v),,$v)))

# Filter out duplicate sub strings while preserving order. Keeps the first occurance.

uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))

# String equals

equals = $(and $(findstring $(1),$(2)),$(findstring $(2),$(1)))

ifneq ($(DISABLE_CACHE_FIND), true)

  ################################################################################

  # In Cygwin, finds are very costly, both because of expensive forks and because

  # of bad file system caching. Find is used extensively in $(shell) commands to

  # find source files. This makes rerunning make with no or few changes rather

  # expensive. To speed this up, these two macros are used to cache the results

  # of simple find commands for reuse.

  #

  # Runs a find and stores both the directories where it was run and the results.

  # This macro can be called multiple times to add to the cache. Only finds files

  # with no filters.

  #

  # Needs to be called with $(eval )

  #

  # Even if the performance benifit is negligible on other platforms, keep the

  # functionality active unless explicitly disabled to exercise it more.

  #

  # Initialize FIND_CACHE_DIRS with := to make it a non recursively-expanded variable

  FIND_CACHE_DIRS :=

  # Param 1 - Dirs to find in

  # Param 2 - (optional) specialization. Normally "-a \( ... \)" expression.

  define FillCacheFind

    # Filter out already cached dirs. The - is needed when FIND_CACHE_DIRS is empty

    # since filter out will then return empty.

    FIND_CACHE_NEW_DIRS := $$(filter-out $$(addsuffix /%,\

        - $(FIND_CACHE_DIRS)) $(FIND_CACHE_DIRS), $1)

    ifneq ($$(FIND_CACHE_NEW_DIRS), )

      # Remove any trailing slash from dirs in the cache dir list

      FIND_CACHE_DIRS += $$(patsubst %/,%, $$(FIND_CACHE_NEW_DIRS))

      FIND_CACHE := $$(sort $$(FIND_CACHE) $$(shell $(FIND) $$(FIND_CACHE_NEW_DIRS) \( -type f -o -type l \) $2))

    endif

  endef

  # Mimics find by looking in the cache if all of the directories have been cached.

  # Otherwise reverts to shell find. This is safe to call on all platforms, even if

  # cache is deactivated.

  #

  # $1 can be either a directory or a file. If it's a directory, make

  # sure we have exactly one trailing slash before the wildcard.

  # The extra - is needed when FIND_CACHE_DIRS is empty but should be harmless.

  #

  # Param 1 - Dirs to find in