# -*- makefile -*-
# vim:set ts=8 sw=8 sts=8 noet:
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
#

ifndef INCLUDED_AUTOTARGETS_MK #{

# Conditional does not wrap the entire file so multiple
# includes will be able to accumulate dependencies.

###########################################################################
#      AUTO_DEPS - A list of deps/targets drived from other macros.
###########################################################################

MKDIR ?= mkdir -p
TOUCH ?= touch

# declare for local use, rules.mk may not have been loaded
space = $(NULL) $(NULL)

# Deps will be considered intermediate when used as a pre-requisite for
# wildcard targets.  Inhibit their removal, mkdir -p is a standalone op.
.PRECIOUS: %/.mkdir.done

#########################
##---]  FUNCTIONS  [---##
#########################

# Squeeze can be overzealous, restore root for abspath
getPathPrefix =$(if $(filter /%,$(1)),/)

# Squeeze '//' from the path, easily created by string functions
_slashSqueeze =$(foreach val,$(getargv),$(call getPathPrefix,$(val))$(subst $(space),/,$(strip $(subst /,$(space),$(val)))))

# Squeeze extraneous directory slashes from the path
#  o protect embedded spaces within the path
#  o replace //+ sequences with /
slash_strip = \
  $(strip \
    $(subst <--[**]-->,$(space),\
	$(call _slashSqueeze,\
    $(subst $(space),<--[**]-->,$(1))\
  )))

# Extract directory path from a dependency file.
mkdir_stem =$(foreach val,$(getargv),$(subst /.mkdir.done,$(NULL),$(val)))

# Function can be called by other functions to expand un-expanded make vars.
# := functionality in call(able) function form
expand = $(eval func-expand-$(1) := $($(1)))$(func-expand-$(1))

## Generate timestamp file for threadsafe directory creation
mkdir_deps = \
  $(strip \
  $(foreach var,$(getargv),\
  $(foreach dir,$(call expand,var),\
  $(call slash_strip,$(call expand,dir)/.mkdir.done) \
  )))

#######################
##---]  TARGETS  [---##
#######################

%/.mkdir.done: # mkdir -p -p => mkdir -p
	$(subst $(space)-p,$(null),$(MKDIR)) -p "$(dir $@)"
# Make the timestamp old enough for not being a problem with symbolic links
# targets depending on it. Use Jan 3, 1980 to accomodate any timezone where
# 198001010000 would translate to something older than FAT epoch.
	@$(TOUCH) -t 198001030000 "$@"

# A handful of makefiles are attempting "mkdir dot".
# tbpl/valgrind builds are using this target
# https://bugzilla.mozilla.org/show_bug.cgi?id=837754
.mkdir.done:
	@echo "WARNING: $(MKDIR) -dot- requested by $(MAKE) -C $(CURDIR) $(MAKECMDGOALS)"
	@$(TOUCH) -t 198001030000 "$@"

INCLUDED_AUTOTARGETS_MK = 1
endif #}


###########################################################################
## GENERATED_DIR(_\S+)? directory deps
## GENERATED_DIRS_{export,lib,tools} = foo   # target specific deps
###########################################################################
GENERATED_DIRS += $(foreach tgt,$(MAKECMDGOALS),$(value GENERATED_DIRS_$(tgt)))
GENERATED_DIRS := $(call expand,GENERATED_DIRS)
GENERATED_DIRS := $(strip $(sort $(GENERATED_DIRS)))
GARBAGE_DIRS   += $(GENERATED_DIRS)

# directory deps are timestamp based to only create when needed
AUTO_DEPS += $(if $(value GENERATED_DIRS),$(call mkdir_deps,GENERATED_DIRS))

#################################################################
# One ring/dep to rule them all:
#   config/rules.mk::all target is available by default
#   Add $(AUTO_DEPS) as an explicit target dependency when needed.
#################################################################
AUTO_DEPS := $(strip $(sort $(AUTO_DEPS)))

# Complain loudly if deps have not loaded so getargv != $(NULL)
$(call requiredfunction,getargv)