define int_vars
#Set defaults for vars which may be overridden per-package
$(1)_cc=$($($(1)_type)_CC)
$(1)_cxx=$($($(1)_type)_CXX)
$(1)_objc=$($($(1)_type)_OBJC)
$(1)_objcxx=$($($(1)_type)_OBJCXX)
$(1)_ar=$($($(1)_type)_AR)
$(1)_ranlib=$($($(1)_type)_RANLIB)
$(1)_libtool=$($($(1)_type)_LIBTOOL)
$(1)_nm=$($($(1)_type)_NM)
$(1)_cflags=$($($(1)_type)_CFLAGS)
$(1)_cxxflags=$($($(1)_type)_CXXFLAGS)
$(1)_ldflags=$($($(1)_type)_LDFLAGS) -L$($($(1)_type)_prefix)/lib
$(1)_cppflags:=-I$($($(1)_type)_prefix)/include
$(1)_recipe_hash:=
endef

define int_get_all_dependencies
$(sort $(foreach dep,$(2),$(2) $(call int_get_all_dependencies,$(1),$($(dep)_dependencies))))
endef

define fetch_file
(test -f $(SOURCES_PATH)/$(3) || \
  ( mkdir -p $$($(1)_extract_dir) && $(build_DOWNLOAD) "$$($(1)_extract_dir)/$(3).temp" "$(2)" && \
    echo "$(4)  $$($(1)_extract_dir)/$(3).temp" > $$($(1)_extract_dir)/.$(3).hash && \
    $(build_SHA256SUM) -c $$($(1)_extract_dir)/.$(3).hash && \
    mv $$($(1)_extract_dir)/$(3).temp $(SOURCES_PATH)/$(3) ))
endef

define int_get_build_recipe_hash
$(eval $(1)_all_file_checksums:=$(shell $(build_SHA256SUM) $(meta_depends) packages/$(1).mk $(addprefix $(PATCHES_PATH)/$(1)/,$($(1)_patches))))
$(eval $(1)_recipe_hash:=$(shell echo -n "$($(1)_all_file_checksums)" | $(build_SHA256SUM)))
endef

define int_get_build_id
$(eval $(1)_dependencies += $($(1)_$(host_arch)_$(host_os)_dependencies) $($(1)_$(host_os)_dependencies))
$(eval $(1)_all_dependencies:=$(call int_get_all_dependencies,$(1),$($($(1)_type)_native_toolchain) $($(1)_dependencies)))
$(foreach dep,$($(1)_all_dependencies),$(eval $(1)_build_id_deps+=$(dep)-$($(dep)_version)-$($(dep)_recipe_hash)))
$(eval $(1)_build_id_long:=$(1)-$($(1)_version)-$($(1)_recipe_hash) $($(1)_build_id_deps))
$(eval $(1)_build_id:=$(shell echo -n "$($(1)_build_id_long)" | $(build_SHA256SUM) | cut -c-$(HASH_LENGTH)))
final_build_id_long+=$($(package)_build_id_long)

#compute package-specific paths
$(1)_build_subdir?=.
$(1)_download_file?=$($(1)_file_name)
$(1)_source:=$(SOURCES_PATH)/$($(1)_file_name)
$(1)_staging_dir=$(base_staging_dir)/$(host)/$(1)/$($(1)_version)-$($(1)_build_id)
$(1)_staging_prefix_dir:=$$($(1)_staging_dir)$($($(1)_type)_prefix)
$(1)_extract_dir:=$(base_build_dir)/$(host)/$(1)/$($(1)_version)-$($(1)_build_id)
$(1)_build_dir:=$$($(1)_extract_dir)/$$($(1)_build_subdir)
$(1)_patch_dir:=$(base_build_dir)/$(host)/$(1)/$($(1)_version)-$($(1)_build_id)/.patches-$($(1)_build_id)
$(1)_prefixbin:=$($($(1)_type)_prefix)/bin/
$(1)_cached:=$(BASE_CACHE)/$(host)/$(1)/$(1)-$($(1)_version)-$($(1)_build_id).tar.gz

#stamps
$(1)_fetched=$$($(1)_extract_dir)/.stamp_fetched
$(1)_extracted=$$($(1)_extract_dir)/.stamp_extracted
$(1)_preprocessed=$$($(1)_extract_dir)/.stamp_preprocessed
$(1)_cleaned=$$($(1)_extract_dir)/.stamp_cleaned
$(1)_built=$$($(1)_build_dir)/.stamp_built
$(1)_configured=$$($(1)_build_dir)/.stamp_configured
$(1)_staged=$$($(1)_staging_dir)/.stamp_staged
$(1)_postprocessed=$$($(1)_staging_prefix_dir)/.stamp_postprocessed
$(1)_download_path_fixed=$(subst :,\:,$$($(1)_download_path))


#default commands
$(1)_fetch_cmds ?= $(call fetch_file,$(1),$(subst \:,:,$$($(1)_download_path_fixed)/$$($(1)_download_file)),$($(1)_file_name),$($(1)_sha256_hash))
$(1)_extract_cmds ?= mkdir -p $$($(1)_extract_dir) && echo "$$($(1)_sha256_hash)  $$($(1)_source)" > $$($(1)_extract_dir)/.$$($(1)_file_name).hash &&  $(build_SHA256SUM) -c $$($(1)_extract_dir)/.$$($(1)_file_name).hash && tar --strip-components=1 -xf $$($(1)_source)
$(1)_preprocess_cmds ?=
$(1)_build_cmds ?=
$(1)_config_cmds ?=
$(1)_stage_cmds ?=
$(1)_set_vars ?=


all_sources+=$$($(1)_fetched)
endef
#$(foreach dep_target,$($(1)_all_dependencies),$(eval $(1)_dependency_targets=$($(dep_target)_cached)))


define int_config_attach_build_config
$(eval $(call $(1)_set_vars,$(1)))
$(1)_cflags+=$($(1)_cflags_$(host_arch))
$(1)_cflags+=$($(1)_cflags_$(host_os))
$(1)_cflags+=$($(1)_cflags_$(host_arch)_$(host_os))

$(1)_cxxflags+=$($(1)_cxxflags_$(host_arch))
$(1)_cxxflags+=$($(1)_cxxflags_$(host_os))
$(1)_cxxflags+=$($(1)_cxxflags_$(host_arch)_$(host_os))

$(1)_cppflags+=$($(1)_cppflags_$(host_arch))
$(1)_cppflags+=$($(1)_cppflags_$(host_os))
$(1)_cppflags+=$($(1)_cppflags_$(host_arch)_$(host_os))

$(1)_ldflags+=$($(1)_ldflags_$(host_arch))
$(1)_ldflags+=$($(1)_ldflags_$(host_os))
$(1)_ldflags+=$($(1)_ldflags_$(host_arch)_$(host_os))

$(1)_build_opts+=$$($(1)_build_opts_$(host_arch))
$(1)_build_opts+=$$($(1)_build_opts_$(host_os))
$(1)_build_opts+=$$($(1)_build_opts_$(host_arch)_$(host_os))

$(1)_config_opts+=$$($(1)_config_opts_$(host_arch))
$(1)_config_opts+=$$($(1)_config_opts_$(host_os))
$(1)_config_opts+=$$($(1)_config_opts_$(host_arch)_$(host_os))

$(1)_config_env+=$($(1)_config_env_$(host_arch))
$(1)_config_env+=$($(1)_config_env_$(host_os))
$(1)_config_env+=$($(1)_config_env_$(host_arch)_$(host_os))

$(1)_config_env+=PKG_CONFIG_LIBDIR=$($($(1)_type)_prefix)/lib/pkgconfig
$(1)_config_env+=PKG_CONFIG_PATH=$($($(1)_type)_prefix)/share/pkgconfig
$(1)_config_env+=PATH=$(build_prefix)/bin:$(PATH)
$(1)_build_env+=PATH=$(build_prefix)/bin:$(PATH)
$(1)_stage_env+=PATH=$(build_prefix)/bin:$(PATH)
$(1)_autoconf=./configure --host=$($($(1)_type)_host) --disable-dependency-tracking --prefix=$($($(1)_type)_prefix) $$($(1)_config_opts) CC="$$($(1)_cc)" CXX="$$($(1)_cxx)"

ifneq ($($(1)_nm),)
$(1)_autoconf += NM="$$($(1)_nm)"
endif
ifneq ($($(1)_ranlib),)
$(1)_autoconf += RANLIB="$$($(1)_ranlib)"
endif
ifneq ($($(1)_ar),)
$(1)_autoconf += AR="$$($(1)_ar)"
endif
ifneq ($($(1)_cflags),)
$(1)_autoconf += CFLAGS="$$($(1)_cflags)"
endif
ifneq ($($(1)_cxxflags),)
$(1)_autoconf += CXXFLAGS="$$($(1)_cxxflags)"
endif
ifneq ($($(1)_cppflags),)
$(1)_autoconf += CPPFLAGS="$$($(1)_cppflags)"
endif
ifneq ($($(1)_ldflags),)
$(1)_autoconf += LDFLAGS="$$($(1)_ldflags)"
endif
endef

define int_add_cmds
$($(1)_fetched):
	$(AT)echo Fetching $(1)...
	$(AT)mkdir -p $$(@D) $(SOURCES_PATH)
	$(AT)cd $$(@D); $(call $(1)_fetch_cmds,$(1))
	$(AT)touch $$@
$($(1)_extracted): | $($(1)_fetched)
	$(AT)echo Extracting $(1)...
	$(AT)mkdir -p $$(@D)
	$(AT)cd $$(@D); $(call $(1)_extract_cmds,$(1))
	$(AT)touch $$@
$($(1)_preprocessed): | $($(1)_dependencies) $($(1)_extracted)
	$(AT)echo Preprocessing $(1)...
	$(AT)mkdir -p $$(@D) $($(1)_patch_dir)
	$(AT)$(foreach patch,$($(1)_patches),cd $(PATCHES_PATH)/$(1); cp $(patch) $($(1)_patch_dir) ;)
	$(AT)cd $$(@D); $(call $(1)_preprocess_cmds, $(1))
	$(AT)touch $$@
$($(1)_configured): | $($(1)_preprocessed)
	$(AT)echo Configuring $(1)...
	$(AT)rm -rf $(host_prefix); mkdir -p $(host_prefix)/lib; cd $(host_prefix); $(foreach package,$($(1)_all_dependencies), tar xf $($(package)_cached); )
	$(AT)mkdir -p $$(@D)
	$(AT)+cd $$(@D); $($(1)_config_env) $(call $(1)_config_cmds, $(1))
	$(AT)touch $$@
$($(1)_built): | $($(1)_configured)
	$(AT)echo Building $(1)...
	$(AT)mkdir -p $$(@D)
	$(AT)+cd $$(@D); $($(1)_build_env) $(call $(1)_build_cmds, $(1))
	$(AT)touch $$@
$($(1)_staged): | $($(1)_built)
	$(AT)echo Staging $(1)...
	$(AT)mkdir -p $($(1)_staging_dir)/$(host_prefix)
	$(AT)cd $($(1)_build_dir); $($(1)_stage_env) $(call $(1)_stage_cmds, $(1))
	$(AT)rm -rf $($(1)_extract_dir)
	$(AT)touch $$@
$($(1)_postprocessed): | $($(1)_staged)
	$(AT)echo Postprocessing $(1)...
	$(AT)cd $($(1)_staging_prefix_dir); $(call $(1)_postprocess_cmds)
	$(AT)touch $$@
$($(1)_cached): | $($(1)_dependencies) $($(1)_postprocessed)
	$(AT)echo Caching $(1)...
	$(AT)cd $$($(1)_staging_dir)/$(host_prefix); find . | sort | tar --no-recursion -czf $$($(1)_staging_dir)/$$(@F) -T -
	$(AT)mkdir -p $$(@D)
	$(AT)rm -rf $$(@D) && mkdir -p $$(@D)
	$(AT)mv $$($(1)_staging_dir)/$$(@F) $$(@)
	$(AT)rm -rf $($(1)_staging_dir)

.PHONY: $(1)
$(1): | $($(1)_cached)
.SECONDARY: $($(1)_postprocessed) $($(1)_staged) $($(1)_built) $($(1)_configured) $($(1)_preprocessed) $($(1)_extracted) $($(1)_fetched)

endef

# These functions create the build targets for each package. They must be
# broken down into small steps so that each part is done for all packages
# before moving on to the next step. Otherwise, a package's info
# (build-id for example) would only be avilable to another package if it
# happened to be computed already.

#set the type for host/build packages.
$(foreach native_package,$(native_packages),$(eval $(native_package)_type=build))
$(foreach package,$(packages),$(eval $(package)_type=$(host_arch)_$(host_os)))

#set overridable defaults
$(foreach package,$(all_packages),$(eval $(call int_vars,$(package))))

#include package files
$(foreach package,$(all_packages),$(eval include packages/$(package).mk))

#compute a hash of all files that comprise this package's build recipe
$(foreach package,$(all_packages),$(eval $(call int_get_build_recipe_hash,$(package))))

#generate a unique id for this package, incorporating its dependencies as well
$(foreach package,$(all_packages),$(eval $(call int_get_build_id,$(package))))

#compute final vars after reading package vars
$(foreach package,$(all_packages),$(eval $(call int_config_attach_build_config,$(package))))

#create build targets
$(foreach package,$(all_packages),$(eval $(call int_add_cmds,$(package))))

#special exception: if a toolchain package exists, all non-native packages depend on it
$(foreach package,$(packages),$(eval $($(package)_unpacked): |$($($(host_arch)_$(host_os)_native_toolchain)_cached) ))